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Über dieses Buch

On the basis of instrument electrical and automatic control system, the 5th International Conference on Electrical Engineering and Automatic Control (CEEAC) was established at the crossroads of information technology and control technology, and seeks to effectively apply information technology to a sweeping trend that views control as the core of intelligent manufacturing and life. This book takes a look forward into advanced manufacturing development, an area shaped by intelligent manufacturing. It highlights the application and promotion of process control represented by traditional industries, such as the steel industry and petrochemical industry; the technical equipment and system cooperative control represented by robot technology and multi-axis CNC; and the control and support of emerging process technologies represented by laser melting and stacking, as well as the emerging industry represented by sustainable and intelligent life. The book places particular emphasis on the micro-segments field, such as intelligent micro-grids, new energy vehicles, and the Internet of Things.



Individual Pitch Control Based on Radial Basis Function Neural Network

As the increasing of structure in wind turbine (WT), the flapping vibration force of blade is more and more serious, and the output power will be unstable in operation of the merged power networks. In this paper, to improve the WT dynamic performance in running processes, by analyzing the WT aerodynamics, wind shear, and tower shadow effect, we have designed based on radial basis function neural network (RBFNN) control strategy for individual pitch control (IPC), using RBFNN approach pitch control system unknown nonlinear functions, and introduced into the adaptive law online adjustment the system error, to improve the dynamic performance of pitch control system and alleviate structure of fatigue loads. Finally, the results show that based on RBFNN for IPC produces adaptability dynamic performance. It can effectively improve power quality to reduce fatigue load in key components of WT.

Bing Han, Lawu Zhou, Zhiwen Zhang, Meng Tian, Ningfeng Deng

Study on the Distribution Automation System Terminal Automatic Test Method

With the widespread use of DAS, higher requirements for distribution automation terminal on-site testing have been put forward on account of limitations of field working conditions. Based on the requirement of relevant standards, this paper discusses automatic testing exploratory research, by analyzing the principal experimental objects and information transmission mode of the distribution automation terminal, which adopts IEC-60870-5-104 protocol. On this basis, this paper brings forward a set of feasible distribution automation terminal test method based on automatic information acquisition and predefined rules, by scheme design, process design, and building test environment. Finally, based on the test environment which divides into online and offline modes, the relevant automatic testing system has been studied and applied, achieves a fully automated power distribution terminal test process, and improves the efficiency of this test to ensure safe and stable running of power distribution automation terminal.

Peng Li, Yimin Qian, Wei Li

Identification for Acoustic Emission Signal of Crack Based on EMD Approximate Entropy and SVM

When cracks appear, material of the pipeline will deform, which is leading to the phenomenon of acoustic emission (AE). It is a kind of nonlinear, nonstationary complex signal. Based on this feature, an effective method of the signal identification based on empirical mode decomposition (EMD) approximate entropy (ApEn) and support vector machine (SVM) is applied in this paper. First, the signals are decomposed into some intrinsic mode function (IMF) signals using EMD algorithm; secondly, with simple processing of IMF, ApEn is used to calculate feature information; and lastly, the results are used as feature vector. The experimental results show that the method is an effective and convenient way to identify the signals.

Zhen-hua Zeng, Shou-ming Zhang, Li Si

Capacitors Optimization of Novel Series-Connected Capacitor-Run Three-Phase Induction Motor Fed by Single-Phase Supply

The phase-shift capacitors played the important role in the three-phase induction motor operation with single-phase power supply. This paper provided the capacitors optimization of three-windings in series connection motor. First, the capacitors are optimized with the golden section method by selecting the smallest negative-sequence current coefficient as objective function. Then capacitances are further optimized with simulated annealing method by taking the highest efficiency under rated loads as objective function. The combined optimization method enabled the proposed motor to operate with high efficiency and provided the method for capacitors determination. The calculation and test efficiency of the motor with the optimized capacitors were compared to valid the optimization. The effect of capacitance on the motor performance was investigated with simulation, which provided the evidence of the optimization.

Hui Zhong, Xiuhe Wang, Dongwei Qiao

Distributed Cooperative Secondary Control of Microgrids with Bounded Control Input

This paper proposes a distributed cooperative secondary control of microgrids (MG) operated in islanded mode with bounded control input. Although the primary control can maintain the voltage and frequency stable when the microgrid switches to islanded mode, it leads to the voltage and frequency of each DG deviations. The secondary control is applied to restore the voltage and frequency to their references and achieve power sharing. The MG can be considered as multi-agent systems since each DG is an agent and the communication network is modelled by a digraph. Considering the limitation of control input, a tracking strategy with bounded control input is adopted. The stability of the closed-loop system is proved in theory, and the simulation on an islanded microgrid verifies the effectiveness of the proposed control strategy.

Xinsheng Wang, Tianyi Xiong

Distributed Robust Control of Uncertain Multi-agent Systems with Directed Networks

This paper investigates the distributed robust control problem of a class of uncertain linear time invariant multi-agent systems with directed networks. It is assumed that the agents have identical nominal dynamics while subject to different norm-bounded parameter uncertainties. Based on relative states information of the neighbor agents and a subset of absolute states of the agents, distributed robust controllers are constructed. Sufficient conditions are proposed based on bounded real lemma and algebraic graph theory. The effectiveness of the theoretical results is illustrated via a numerical simulation.

Wei Liu, Qingpo Wu, Shaolei Zhou

Resonant Analysis and Depression in Multi-inverter Grid-Connection System

Interaction between multiple grid-connected inverters has a negative impact on the stable operation and power quality of the power grid. Interrelated influences of each inverter LCL filter make multiple inverters constitute a high order power network and excite more complex resonances at various frequencies. This paper first establishes a microgrid admittance matrix in which inverter uses hysteresis control. Multiple resonances can then be evaluated by modal analysis. Experimental results have confirmed that the modal analysis and the active damping are effective for resonance in multiple-inverters grid-connected system.

Jian Wu, Caihong Zhang, Rui Wang, Dianguo Xu

The Application of Power Electronic Switch in the Regulated Capacity Transformer

The seasonal loads of rural, industrial, and mining enterprises vary sharply and their average load rate is at a low level. The replacement of the normal transformers by the ones able to regulate the power capacity and voltage can significantly reduce the no-load loss and the waste of electric energy. First, this paper analyzed the theory of the capacity and voltage regulating transformer (CVRT). Secondly, a simulation model is established by Simulink toolbox in Matlab to investigate the reduction of the impact of the current and voltage after the application of delay conduction.

Hongxing Chen, Zhizhen Liu, Tong Hei, Xiaodong Qu, Guozheng Qi

DC Fault Analysis and Protection Design in Shunt Modular Multilevel-Based MTDC System

Modular multilevel converters (MMC) are ideal next-generation multilevel converters well-suited for the high-voltage direct current (HVDC) transmission for multiterminal DC systems. However, the accidental DC faults in the cable or overhead lines, could give rise to safety concerns on transmission lines and converter stations. A protection design based on three-terminal voltage margin control method is proposed incorporating bypass thyristor and IGBT circuit breakers (IGBT-CBs) at DC side. In addition, IGBT-CBs isolate the DC line in case of a permanent fault utilizing the principle of handshaking method, making normal operation of the remaining system possible. This protection scheme is validated by the simulation studies on PSCAD/EMTDC, thereby demonstrating an improved DC fault reverse blocking capability of MMC-MTDC system.

Jian Wu, Yue Qi, Yanfei You, Dianguo Xu

The Simulation of Zero-Sequence Blocking Transformer (ZSBT)

The problem of zero-sequence current in a three-phase four-wire distribution system is more and more serious. ZSBT is new zero-sequence current filter equipment. The existing literature is only a brief description about the structure and principle of ZSBT, there is no perfect design method. This paper proposes a design method of ZSBT. We build the 3D simulation model of ZSBT by Ansoft to analyze the parameters such as inductance, coupling factor, and flux density. The simulation results proved that the design method of ZSBT is feasible.

Kai Xu, Zhi-zhen Liu, Xiao-dong Qu, Guo-zheng Qi

Design and Simulation of a Vivaldi Antenna Fed by Coplanar Waveguide

This paper designed a Vivaldi antenna fed by coplanar waveguide (CPW) with band width. The designed antenna had simple structure, which was easy to fabricate. The discussed Vivaldi antenna in this paper was simulated by using the full-wave electromagnetic simulation software, and the specific simulation results were provided. The average voltage standing wave ratio (VSWR) was 2 within the frequency range of 2 to 6 GHz. The simulated axial ratio (AR) at the boresight direction within the working frequency range was higher than 20 dB. The wide beams and steady gains were also observed in accordance with the simulation results. The design and simulation results of Vivaldi antenna fed by CPW in this paper can provide a reference for the practical engineering application.

Lizhong Song, Weiwei Yin, Jia Li

The PID Parameters Optimization Method Based on GA for NC Power Supply

In the design of numerical control voltage source, the PID control parameters are usually determined by theoretical arithmetic or engineering setting method, which have some problems such as complex calculation, high demand experience, and low accuracy. This paper offers an intelligent optimization method with PID parameters k p based on genetic algorithm. In terms of this optimization method, we design a PID parameter optimization system which consists of a microcontroller module, a host computer, and a LM2596 module. The microcontroller samples the output voltage, and receives the k p parameters to set the LM2596 module. The host computer processes the real-time voltage value and evaluates the PID parameter based on ITAE. Meanwhile, optimal k p parameters are generated by the genetic algorithm. The experimental results show that the mean value of ITAE reduces in the process of genetic algorithm, reflecting the fact that PID control effect is improved obviously and the parameters are becoming optimal. According to the test of full range k p and ITAE table, we can conclude that k p set by the genetic algorithm is superior to k p set by Ziegler–Nichols (Z–N) method which is the optimal solution in the full scale. This paper is of instructive value in the field of setting parameters of PID control system.

Chenjia Wei, Zehao Liu, Peizheng Li, Jianfei Chen, Sheng Zhang

Different Feature Combination Rules in CNNs for Face Detection

Convolutional neural network (CNN) is a very popular deep learning structure. It has kinds of merits in the feature learning, such as local reception region, sharing weights, subsampling, etc. CNN can learn the image by pixel without previous feature extraction, and then discover some more characteristics of the input by the feature combination. In this paper, we study the effect of different combination rules in the CNN training. The simulation tests exhibit the different kinds of combination rules in the CNN learning.

Qingyang Xu, Li Zhang

The Contact Behavior Analysis Between Microcomponents on a Low-Frequency Reciprocating–Fretting Ball-on-Flat Tribometer

Fatigue failure between the reciprocating sliding microcomponents is the key factor that affects the performance and reliability of microelectromechanical system (MEMS) under alternative load. Sliding friction pairs on the smooth surface are at very slow scan rates and friction-induced vibration is caused by stick-slip phenomenon that is generated from nanometer clearance between the friction pairs. In this paper, a developed tribometer is applied to simulate the fretting friction with low-frequency reciprocation. Dynamic friction coefficient is measured with the normal load of 0–60 mN from a series of tribological tests of a small steel ball sliding on various flat surfaces such as PTFE, silicon wafer, and glass in a straight-line, oscillating motion configuration. The contact stress, contact force, and surface deformation with or without friction in these three configurations are calculated by the variation of friction coefficient according to the Hertz contact theory. Experimental results show that the friction force is not nearly dependent of the normal load and contact deformation is at nanoscale sizes in steel ball-on-silicon wafer configuration. Friction coefficient measured by the developed tribometer is combined with the contact stress calculation for the structural design of microcomponents before manufacturing MEMS devices.

Zhongnan Wang, Wuyi Wang, Guangyu Zhang, Hejuan Chen

Single-Phase AC Voltage Control Circuit for Flow-Induced Acoustic-Vibration Piezoelectric Generator

Energy harvesting from ambient excitation has attracted numerous interests with the purpose of implementing self-powered devices. The technology of piezoelectric energy harvesting from vibrations induced by airflow is innovative research in the field of energy harvesting. A new flow-induced acoustic-vibration piezoelectric generator (FAPG) without any mechanical moving parts using this technology is developed. It converts the vibration induced by acoustic wave of external airflow inside the pipe into electrical energy via a piezoelectric transducer. Based on the scheme of FAPG using short pipe at the inlet of airflow, an effective output power conditioning circuit is designed. Simulation and experiments show that with the new designed interface circuit, which can expand the conduction angle of the Alternating Current (AC) output by FAPG, the efficiency of energy harvesting is improved significantly. In the circumstance of high-speed inflow and impedance matching, the FAPG can get high output power at consistent impedance matching points under various inflow velocities with strong practicability and flexibility.

Bo Chen, Jiacun Sun, Hejuan Chen, Jian Yang, Wei Qu

Medium and Long-Term Electric Power Planning Load Forecasting Based on Variable Weights Gray Model

Based on the gray forecasting theory, the paper studies the influence of the buffer operator on the gray forecasting results, and solves the problems of the traditional gray model in the medium and long-term electric load forecasting. By constructing the buffer operator, the dynamic preprocessing of the raw load data is realized. Based on particle swarm optimization (PSO) algorithm, taking the maximum gray correlation degree between fitted value and actual values as the goal, to choose the optimal buffer operator and buffer system, which can reasonably weak the historical load data, improve precision of the model and make a prediction results more reasonable real.

Da Song, Xiaobo Liu

Combination and Optimization Load Forecasting Based on Credibility

Load forecasting is based on the known history of electricity demands, and it considers political, economic, and climate factors to make forecasting for the future electricity demands. This article first analysis the trends of history power load, and then choose load forecasting methods according to the trends. Through the analysis and comparison of the load forecasting methods’ credibility, assess the adaptability between forecasting methods and power load integrated. Higher credibility load forecasting methods are got through credibility sorting and then weights for each method are solved by optimization. The sorted load forecasting methods are combined together to forecast load power. Then to make the forecasting result more accuracy, after-test residue checking method is used to test the forecasting results. Forecasting electricity consumption of local actual operation power load and getting high credibility forecasting results can ensure the construction of local power grid develop with correct direction.

Jia-liang Chen, Shu-bo Hu, Wei Zhou, Lin Zhao, Jian-ming Yu, Guo-hui Shen, Jing-jie Sun

Actuated Signal Control System for Pedestrian Street Crosswalk at Midblock Crossings

In order to enhance the midblock crossing safety of pedestrians at special locations, such as entrance of schools, hospitals, and supermarkets, the actuated signal control system is proposed to provide the special signal for vulnerable pedestrians’ crossing behavior, especially for the peak hours. Pressure sensors and inductive loops are applied to detect the number of pedestrians and the volume of approaching vehicles, and system function principle is designed to improve the efficiency and accuracy of signal control with a signal timing model. A roadway segment near Cuihua Road School is chosen as an example and the corresponding signal timing model is calibrated according to the geometrics of Cuihua Road. The layouts of detectors and facilities are allocated to protect pedestrians’ crossing at midblock crossings. The analysis result shows the efficiency of this method.

Longjian Wang, Yonggang Wang, Mengyang Xin

Study of a Unidirectional Hybrid Three-Phase Voltage Source Rectifier

This paper studies a unidirectional hybrid three-phase voltage source rectifier (UHTPVSR), improves the topology, and the power distribution method of UHTPVSR. The Euler–Lagrange mathematical models of the boost converter and VIENNA rectifier are set up. A hybrid control strategy based on passive control is proposed. The hybrid control strategy makes UHTPVSR having good current tracking ability, strong robustness, and is easy to implement. The simulation results show that UHTPVSR can realize voltage control at DC side and achieve sinusoidal current and unit power factor at AC side, and are able to distribute power at predetermined rate.

She Dongjin, Wang Jiuhe, Zhai Dandan

The Heading Control of POD-Driven Ship Using Adaptive Integrator Backstepping

This paper proposes a controller for pod-driven surface ships based on adaptive backstepping with integrator. The pod propulsion has the advantages of higher efficiency and better maneuvrability compared with the conventional propulsion, and large steering-induced heeling angle with the possibly large steering forces. The adaptive backstepping is normally used in the systems including uncertainty information or unknown parameters and the integrator can be added to eliminate the constant static error. Simulation results show that compared with the PID controller, the adaptive backstepping with integrator is much better in overshoot, adjusting time, and static error without disturbance and in chattering with disturbance.

Yacong Zhao, Haibin Huang, Yufei Zhuang

Dynamic Modeling of RR-RRR Spherical Parallel Manipulator for Vector Thruster

Thrust vectoring technology with single manipulator and multidimensional attitude is a novel thrust vectoring method in underwater vehicle. In order to complete both the rotational transmission and attitude adjustment, a two degree of freedom (DOF) spherical thrust vectoring parallel manipulator are proposed. Its forward and inverse kinematic solutions are formulated. And the dynamic model is established by Lagrange’s formulation and the principle of energy equivalence. Finally, numerical simulation results validate the efficiency of kinematic and dynamic models.

Han Xu, Yuan Chen, Jun Gao

Synchronous Generator-Based Design of Damping Emulation Controller for DFIG

The present work is based on developing the effect from doubly fed induction generator (DFIG) connected to the grid. The dynamic model, small signal stability analysis, and damping characteristic are conducted. By comparison with synchronous generator, there is insufficient damping performance from DFIG. The paper proposes the idea of designing a damping controller emulating synchronous generator by pole placement technique in order to improve damping. Furthermore, a mirror pole assignment solution is particularly put forward in view of instability system. The theoretical analysis and controller effectiveness are confirmed via simulation results for a size 9 MW DFIG operating under varied converter conditions, and the damping improvement observed in time domain support the result obtained from eigenvalue analysis.

Zhang Yan, Yang Chunhua, Sun Hui

Study on Control Strategy of Harmonic Suppression in a Wide Power Range Based on V2G Bidirectional Onboard Charger

With the development and widespread use of electric vehicle (EV), the vehicle-to-grid technology (V2G) has become increasingly attractive. Considering the case of V2G bidirectional onboard charger has involved in power grid frequency regulation service and the characteristics of frequency regulation signal, this paper propose a control strategy for wide power range bidirectional current harmonic suppression by combining with the quasi proportional resonant (QPR) control and the weighted feedback current (WFC) control and introducing a peak restrained LCL filter. Simulation and experimental results are provided to validate the feasibility and correctness of the proposed control strategy.

Fuhong Xie, Weifeng Gao, Xiaofei Liu, Shumei Cui

Snow Removal of Video Image Based on FPGA

With the development of science and technology, outdoor surveillance systems are applied in many fields widely. However, due to the bad weather (such as snow, fog, rain, dust), it degrades the quality of video image and the function of surveillance system. The traditional methods of snow removal are largely realized with software and cannot meet the real-time processing requirements. They are difficult to get a wide range of applications. The cause of the noise generated by the snow is analyzed. According to the improved frame difference algorithm, we propose a snow removal technology of video image based on FPGA. Compared to the traditional methods, it can process the snow video image with minimum resolution 640 × 480 in real time. At last, the results show that the snow removal technology of video image based on FPGA can remove the snow effect efficiently. Furthermore, it can improve the contrast and enhance the image details.

H. H. Li, S. Liu, Y. Piao

A New Concept: Azimuth Dilution of Precision for Monocular Observational Tracking System

The single satellite missile warning system is a monocular observational tracking system which is an inevitable transition state for the satellite missile warning network. Inspired by the idea of geometry dilution of precision (GDOP) in GPS system, a new concept named azimuth dilution of precision (ADOP) which specifies the amplification effect of the geometry between satellite and trajectory on the accuracy of the launch azimuth estimation is defined. A rapid global ADOP analysis method based on the geometry symmetry is proposed. This technique can be applied for the performance analysis and allocation optimization of monocular observational tracking observation.

Bing Liu, Dong Wang, Zhen Shen, Taihe Yi, Dongyun Yi

Study on Self-adaptive Packet Scheduling Algorithm of TD-LTE System’s Downward Frequency Domain

Round robin (RR) algorithm has best user fairness, but the system throughput is low, Max C/I algorithm has highest throughput, but poor fairness, Proportional fairness (PF) algorithm makes a compromise between throughput and fairness, but focuses on the average throughput fairness. This paper proposes a frequency domain scheduling algorithm for TD-LTE under different loads (light, medium, and heavy loads), which is called M-RR algorithm. Simulation results show that the algorithm emphasizes on fairness in terms of resource usage, and ensure the system throughput.

Jia-liang Ling, Jian-zhong Cao, Tian-fa Liao

The Research and Simulation of Three-Level NPC Inverter

Compared with the commonly used sine-wave pulse width modulation (SPWM) method, the space vector pulse width modulation (SVPWM) method has higher utilization rate of DC voltage and smaller output waveform distortion. This paper describes the basic principle and control algorithm of three-level SVPWM. The topology of the system is a diode-clamped parallel (NPC) inverter, which is built on the PSCAD software platform. The simulation waveforms are obtained through the self-built model, which verifies the correctness of the system and provides reference for the further research.

Yuan Deng, Guangyao Jin

Research and Application of 350 MW Unit Water Wall Crack Failure

A vast number of cracks have appeared at the exit of the boiler vertical water wall, which causes the boiler outage during the 350 MW supercritical unit. To solve this problem, we analyze the characteristics of cracks and boiler-related operating curve is in operation. The study found that the main factor leading to the cracks at the exit of the boiler vertical water wall is thermal stress resulted from large-scale temperature deviations between pipes and rapid changes in pipe temperature. The thermal stress generally emerged under the low-load condition after the boiler turns to dry state. In addition, there is a correspondence between vertical water wall tube temperature fluctuations and changes in boiler feed water. We made the three following recommendations for the causes and characteristics of cracks at the exit of boiler vertical water wall. First, it is to minimize this type of boiler long-term low-load operation in the dry state. Second, the operating personnel shall monitor the vertical water wall outlet temperature under the low-load after the boiler turns to dry state. Finally, we increase the adjustment ability of automatic water supply and automatic coal supply to coal–water ratio.

Rui Zhang, Chunying Wu

Optimal Design of a Linear Induction Motor for Traction Application

In traction application, the electric motor design methodology is not trivial. This paper presents a design approach using rated point. Based on a 2D finite element model, design optimization of a double-sided linear induction motor is achieved using an efficient global optimization algorithm.

J. Gong, F. Gillon, H. Zhong

Simulation on the Boost-Buck Current Compensation Device of PV Grid Connection and Active Power Filter All-in-One Machine

This paper first analyzed the alternating current AC/DC power decoupling working mechanism of photovoltaic (PV) grid connection and active power filter all-in-one machine, then put forward Boost-Buck parallel current compensation circuit and analyzed its working principle. Simultaneously, the thin-film capacitor Cdc in DC side was calculated, and finally the simulation model of current compensation device based on the Boost-Buck was established. The simulation results show that the thin-film capacitor with a small capacity (100–200 μF) can reduce the voltage fluctuation and stabilize MPPT working point as well as solve the dilemma that the life of grid-connected system is limited by power decoupling electrolytic capacitor, which provides a reliable hardware foundation for realizing the PV grid-connected and active power filter all-in-one machine.

Tian-fa Liao, Zhao-quan Cai, Jia-xiang Xue, Hong-wei Zhang

An Improved DV-Hop Node Localization Algorithm Combined with RSSI Ranging Technology

DV-Hop algorithm is a typical rang-free localization algorithm in wireless sensor network (WSN). On the basis of the localization principle and localization process of DV-Hop algorithm, this paper proposes an improved DV-Hop algorithm. The improved DV-Hop algorithm uses cluster strategy to reduce communication overhead and probability of group conflict in the first stage of DV-Hop algorithm; the Received Signal Strength Indicator (RSSI) ranging technique is employed to replace the distance measurement of one hop away from the anchor node in DV-Hop algorithm; then, estimate the node positions with quasi-Newton optimization method instead of Least square method. MATLAB7.0 simulation results indicated that this improved DV-Hop algorithm can significantly reduce the localization error without increasing computing complexity.

Hongyu Shi, Ling Peng

Processing to the Commutation Failure in Multi-infeed Direct Current System

The commutation failure in multi-infeed DC system will result in serious consequences. Influence factors are analyzed in this paper including the principle of inverter and influence failure factors for single-feed system. The countermeasures for the failure are introduced. The response for commutation failure includes precaution before failure and recovery strategy after failure. The influence to transmission power by electrical distances is studied. Engineering practice shows that STATCOM can effectively improve steady-state and transient operation characteristics of multi-infeed DC system. It will reduce the probability of commutation failure.

Xuan Wang, Hui Yan, Yuhong Wang, Junfeng Gui, Mingchao Xia, Xiaogang Hu, Pingzhu Liu

Research on Friction and Thermal Load Performance of Hydro-viscous Clutch

In this paper, the theory of friction coefficient and thermal loads in slip state of a new hydro-viscous clutch has been studied and the influencing factors are determined. Furthermore, the friction characteristics test is designed. The test results show the variation tendency of friction coefficient when the hydro-viscous clutch operates at the difference temperature, difference normal pressure and difference rotating speed. The formula of different rotating speed on the impact of the coefficient of friction is fitted. The thermal load theory calculation reflects the temperature rising trend under different thermal loads of hydro-viscous clutch. Comparing the theoretical calculation and experimental results and analyzing the heat dissipation way of hydro-viscous clutch, it shows that the equation to calculating the thermal load that described the frictional state of frictional disk of hydro-viscous needs to be developed.

Li-gang Ma, Chang-le Xiang, Ming-gang Du, Liu-yang Guo

A Comprehensive Evaluation Model for Switchgear Based on the Normal Cloud Model and D–S Evidence Theory

A hierarchical evaluation method based on normal cloud model and D–S evidential theory is proposed. By hierarchical clustering the indicator of switchgear, normal cloud model is used to determine the correlation degree of indicator and evaluation level, and improved fuzzy algorithm is applied to evaluate the first layer. On this basis, D–S evidential theory is used to assess the overall state of the switchgear. As an example, one group of data of the KYN28A-12 model switchgear is analyzed. The simulation result demonstrates the effectiveness of the assessment algorithm. The assessment model is clear and does not need a lot of historical data, which offers a new thinking to assess the operating state of high voltage switchgear.

Y. Jia, D. Liu, H. Sui

Target Tracking Based on Audio and Video Information Fusion

Particle filter is an effective technique to deal with the state estimation of nonlinear and non Gauss dynamic systems. Aiming at the problem of moving target tracking under the condition of illumination and occlusion, a particle filter algorithm based on audio and video information fusion is studied. This algorithm overcomes the deficiency of the algorithms based on a single signal source by using the time—space relativity and the complementarity of the audio and video. Pedestrian tracking experiment based on audio and video information fusion shows that the fusion algorithm is more stable and accurate than the single video tracking algorithm.

H. Wang

Experimental Research on Fatigue Damage of Composite Solid Propellant with Constant Constrain

In order to study the effect of fatigue load on composite solid propellant with constant strain, three set of experiments on propellant with different constant strains (20, 16.4, 10.9, 5.5, and 2.7 %) and different fatigue frequencies (10, 15, and 20 Hz) were conducted. Based on the uniaxial tension test, the mechanical properties’ changing law were obtained. It was shown by the results that the maximum tensile strength and the initial modulus of propellant decreased with fatigue load and constant strain, and the damage behavior under fatigue load with constant strain can be divided into three stages, stage one is that the initial modulus was decreased quickly (the fatigue times less than 600), stage two is that the initial modulus was diminished slowly, and stage three is that the modulus was cut down seriously again(the fatigue time is more than 72,000). The connection between the initial modulus and fatigue factors is confirmed at the second damage stage.

Jinfei Li, Weidong Huang, Kai Qu, Wenshuang Wang, Ming Yang

Impacts and Analysis of Electric Vehicles and Photovoltaic Integration into Power Systems

Electric vehicle (EV), photovoltaic (PV) load will affect the power grid in a certain extent when is connected to grid, such as the change of load characteristics, increase the peak valley difference. At the same time the application of inverter will bring about reverse power threat to the operation and maintenance of power grid. To weaken the influence, V2H (Vehicle to Home) technology is used to EV and grid interaction, which can control EV charging load to a specific value as well as control the EV discharge to grid. In order to actively respond to the impact of EV and distributed PV application access to the power grid, based on the actual home users, the data of household electricity load and the user level transformer are collected and analyzed. At the same time, with the peak and valley price, based on the quantitative analysis of the influence of electric cars, solar access to the grid, the interactive applications are put forward. Calculation and interactive analysis results show that the implementation of V2H can not only bring economic benefits to users but also reduce the peak valley ratio and the risk of peak on peak which result on the electric vehicle charging in disorder.

Cheng Gong, Zhongjun Chi, Baoqun Zhang, Longfei Ma, Rui Shi, Ran Jiao

A Wireless Multipoint Parameter Monitoring System for Greenhouse Environment

A system of real-time monitoring and wireless transmission of illuminance, temperature and humidity parameters for a greenhouse environment is achieved in the framework of ZigBee protocol stack. It mainly includes two kinds of minimum systems with the cores of Texas Instruments CC2530 chip and ARM STM32F103 chip. CC2530 minimum system completes network nodes function of multipoint parameter monitoring. BPW34S sensors are used to construct the illuminance collection module and SHT10 sensors are used to construct the temperature and humidity collection module. Multipoint parameter data are sampled by CC2530 nodes. A node chip transmits measured data wirelessly to another node based on ZigBee technology. The STM32 minimum system contains a CC2530 which is used to receive data from other sensor node modules through serial port. After the system processes the data, the result is displayed on LCD12864 screen. Experiment shows that data loss rate of this system are zero within 15 m communication distance. This system is suitable for a greenhouse of about 20 m × 25 m area and it has several advantages of low cost, easy installation, and high efficiency.

Xiaoqing Zhang, Yudong Jia

A Survey of Fault Location for Distribution Systems

Accurate distribution network fault location technology is the key to achieving a smart grid. Due to its complex network topology, multi-branch, load-time variant and characteristics of the different features, existing distribution network fault location methods are not applicable. In this paper, fault location methods are summarized from three perspectives: fault line selection, fault section location and fault ranging, and the developmental trends in fault location for distribution networks are considered.

Yongjun Liu, Min Liu, Cheng Lin, Kefeng Ou-yang

Numerical Simulation of Flow Field of a Centrifugal Compressor with a High Pressure Ratio

In order to study the characteristics of a type of centrifugal compressor with a high pressure ratio and the distribution of the flow field parameters in the design points, CFX software was used to simulate its flow field. According to the results, the pressure ratio and the efficiency of the compressor are high at high RPMS, and the range of mass flow rate is wide at lower RPMS. So the capacity to adapt different working conditions of this compressor is good. At the aspect of the flow field in the design points, the distribution of the overall flow field parameters is homogeneous, but the shock waves exit in the first stator entrance, making the passage narrower and bring much energy loss, which is the one of the reasons to decline the compressor efficiency.

Zhipeng Xu, Wei Shen, Yong Zhang, Longbo Gao

Render Synthetic Objects with Background Image According to Image-Based Lighting

Image-based lighting (IBL) technique helps people integrate synthetic object into real-world environment. The general IBL method renders object using the captured omnidirectional high dynamic range (HDR) image as lighting condition. This paper extends the general IBL technique to employing single-view background image in HDR format to produce environment light. This idea is different from the general IBL technique which limits the input in omnidirectional light probe image. Besides, the proposed method can modify the background image slightly for special purpose based on texture transplanting. The created texture is saved in database; when people wish to modify the background image, they call texture from database and transfer it to the target surface. The method provided in this paper can produce visual effect just as real objects would.

Binling Luo, Shuting Cai, Shaojia Wen, Daolin Hu

Reliability Evaluation of Distribution Systems Incorporating Distributed Generators Using Monte Carlo Simulation

To evaluate the reliability of distribution network containing distributed generations (DGs), at first the stochastic characteristics of power output of wind power generation and microturbine (MT) are researched, and a reliability model of hybrid generation consisting of DG is built. The Monte Carlo simulation (MCS) algorithm is applied to a modified main feeder of RBTS Bus 6 distribution network. The wind turbine (WT) generator is an example to establish the reliability of distributed power intermittent assessment model. Finally, the reliability of RBTS Bus 6 is evaluated by the built model and the proposed algorithm. This evaluation results show that the penetration of DG can improve the reliability indices of the distribution network.

Zhenpeng Wu, Aoying Ji

Circular Synthetic Aperture Sonar Imaging Using Isometric Angle Characteristic

Circular synthetic aperture sonar (CSAS) can provide fine image of interest region in three dimensions through the sonar movement along a circle at a fixed height. The severe computation complexity of the state-of-the-art imaging algorithms is of great trouble during the usage process of CSAS. According to the relationship between the azimuth and the peak-valued curve of the returns of CSAS, the isometric angle characteristic is revealed in the paper. A fast inverse algorithm of CSAS imaging employing the isometric angle characteristic is proposed combined with CLEAN algorithm. The numerical experiments show the effectiveness and the low computational complexity of the proposed algorithm.

Guo-hui Di, Jun Wang, Fu-lin Su

Analysis of the Choice of a Serial Reactor in a Parallel Capacitor Device

When there are harmonic sources in a system, a parallel capacitor will enlarge the harmonics, producing harmonic resonance. Since it is an effective strategy to install a suitable reactance rate of reactor into the capacitor to restrain the harmonics, further analysis is necessary on the choice of reactance rate. This article analyzes the relationship between the effective capacity, the ability to suppress the harmonic, the insulation of the parallel capacitor and the series the reactor in capacitor. On this basis, the article studies the deficiency of the existing reactance rate in capacitor and provides more detailed options. Generally it is a very good remedy for harmonic suppression to string a reactor in the capacitor. So, analyzing the reactance rate of the parallel capacitor is very important.

Xianzhong Long, Xiaobo Liu, Da Song

Decision Fusion Moving Target Detection of Radar Video Based on D-S Evidence Theory

In dense clutter and complex multi-objective situation, radar automatic detection and tracking will produce many false tracks. In order to solve this problem, first, using iterative threshold segmentation method to rapidly detect the suspected targets from a single frame radar video image, and gaining the continuous multiframe detection results by accumulation. Then, synthesize single frame detection results and multiple frames accumulation results to extract the area change ratio and energy density of targets, and build their basic probability assignment (BPA) functions, respectively. In addition, D-S evidence theory is adopted to carry out decision fusion, to obtain the optimal decisions in order to realize the automatic detection of moving targets. Finally, the effectiveness of the algorithm is verified by experimental results.

Xiaohan Yu, Wei Zhou, Jian Guan, Wenchao Hu

Effect of Co-doping on the Electronic Structure and Absorption Spectrum of Wurtzite ZnO Under Pressure

The effect of Co content and hydrostatic pressure on the electronic structure and absorption properties of wurtzite ZnO has been investigated by first principles calculations. The results reveal that the splitting between the energy levels of Co 3d states increased with pressures, which indicate the enhanced action of the crystalline field. In comparison to pure ZnO, a new peak appears in the low-energy region of the optical absorption spectrum in the system doped with Co and hydrostatic pressure is found to have great influence on the electronic transition of d–d orbital of Co atom in this system.

Jing Leng, De-jun Wang, Zheng-hao Sun, Wei-jie Liu, Run-ru Liu

Fitting Formula of Sheath Currents and Arrangement Optimization of Cables

There will be circulating currents in metal sheaths of cross bonding cables when length or arrangements of three segments are different. The phasor sums of sheath-induced voltages in sheath cross bonding cables are first analyzed. Then, the circulating currents are calculated by EMTP with varied lengths of three segments to get the sample data, which are in turn used to fit out the empirical formula for evaluating sheath circulating currents. Finally, the principle of mixed arrangements is proposed to reduce sheath circulating currents in sheath cross bonding cables when the lengths of cable segments are not equal.

Yong-zhi Wang, Wei Cao, Hai-sheng Liang, Fan Li

Analysis and Simulation of Electric Vehicle Power Battery

Energy and the environment have become the most current concerns in the world, and many countries have considered developing electric vehicles as an important means to solve the problem of energy and the environment. So, it is very necessary to research the effect on grid by electric vehicle charge and discharge but it must build a suitable model of batteries of electric vehicle. This paper built a PNGL and Thevenin simulation model, and compared the simulation curve with the actual measure curve. The results prove that the two methods on two occasions applications are more appropriate.

Longfei Ma, Baoqun Zhang, Cheng Gong, Ran Jiao, Rui Shi, Zhongjun Chi

Vibration Suppression of a 3-DOF Parallel Manipulator Based on Single-Mode Input Shaping Combined with PD

The residual vibration of flexible systems limits accuracy of motion trajectory and motion response speed. This paper presents the methodology of input shaping combined with PD control strategy to suppress the residual vibration of a 3-DOF parallel manipulator. First, the manipulator is introduced, and natural frequency and damping ratio of the 3-DOF parallel manipulator are obtained by experimental modal tests. Then, the theories of input shaping, PD and input shaping combined with PD are presented. Finally, the response curves of manipulator of the PD and Zero-Vibration input shaper combined with PD approaches are expressed by numerical simulation. At last, a comparison of response curves with different kp is carried out.

Bing Li, Yulan Wei

Hybrid Dual-Loop Control for a Three-Phase PWM Rectifier

This paper investigates a novel control strategy for a three-phase voltage source PWM rectifier (VSR) system with sliding mode control (SMC) and repetitive control (RP). To achieve the aim of well-controlled output DC-bus voltage, sinusoidal input currents, controlled power factor and bidirectional power flow, double closed loops control strategy are realized: i.e., outer voltage loop control with SMC and inner current loop control with the combination method of RP with PI control. The entire simulation results and experiment results are provided to demonstrate the effectiveness of the proposed control method and shows that it is in good agreement with the desired performances. In addition, the proposed method is convenient to realize and thus has a wide range of industrial applications.

Jing Cao, Chaonan Tong, Hongtao Li

A Voltage Regulating Electronic Transformer with High Power Factor and Wide Working Voltage

An electronic transformer using IR2155 has the advantages of simple structure, high output power, large current conduction angle and stable work, but it has no regulating function. When the alternating voltage range is from 180 to 250 V, output voltage also changes, so its use is limited. This paper presents the integration of APFC rectifying mode into an electronic transformer. This electronic transformer can work over a wide voltage range from 180 to 250 V; it can stabilize output voltage and has a high power factor, high output voltage, and requires only simple maintenance as well.

Hui Su, Yonggao Jin, Xiaodong Qu

The Quantitative Assessment Study on the ‘First-Class’ of the Key Indices of Grid Evaluation

Carrying out international benchmarking on the operating management of the grid can clear goal orientation, which has targeted to enhance the performances of the power grid. How to do the quantitative assessment on the key indices of grid evaluation and determine the ‘first-class’ of the international power grid has become an important issue which is worthy of study. Under this background, this paper selects eight key indices which are internationally accepted and can comprehensively reflect the overall development and operation of the grid. Furthermore, this paper does the quantitative assessment on each key index by quintile method, optimal segmentation method, and K-means clustering method in order to draw the appropriate “first-class” interval. On this basis, this paper analyzes the advantages and disadvantages of assessing different types of indices by different methods and determines the top level of each key index to a reference for the grid assessment with the combination of the actual situation.

Zheng Wu, Ming Zeng, Junhui Huang, Jan Tan, Jun Han, Wenqi Gu, Han Xu

A Novel Polarimetric Marine Radar

Considering the poor anti-interference performance of the current marine radar, a novel marine radar based on polarization technology is proposed in this paper. Aiming at the structural characteristics of the floating targets on the sea, this paper analyses the polarization scattering characteristics of the marine radar targets, and based on the fact that marine radar targets are mainly slow-moving ones, and puts forward a general design of marine radar based on the timesharing polarization technology and also a mentality of design for the antenna in dual-polarimetric marine radar. The simulation result proves that the novel polarimetric marine radar is highly improved, compared to the current marine radar, both on its detection performance and anti-interference capability.

Tao Jin, Huihui Xian, Xuebin Wang, Xiaohui Qi

Monitoring of the Performance of Excitation System Based on Measured PMU Data

Traditional evaluation methods of performance of excitation system are often carried on offline or need special conditions. To realize monitoring and evaluation of performance of the excitation system in operation, this paper proposes practical arithmetic of monitoring the unit operation status based on PMU measured data. After data preprocessing, using valid data to identify field flashing, de-excitation, load rejection and terminal voltage drop. Then corresponding performance evaluation indexes of the excitation system, respectively under different conditions is calculated . The quantitative evaluation result of the performance of excitation can be obtained and it can provide some reference for the evaluation of the practical operation performance of excitation system.

Sai Wang, Xueping Gu, Wei Tang, Zhen Li, Yuanchao Huang

Comprehensive Evaluation on the Primary Frequency Regulation Performance of Generator Units Based on Data from a Wide Area Measurement System

On-line monitoring of the unit’s primary frequency regulation performance can be realized on the basis of measured data from WAMS (Wide Area Measurement System). Based on measured data and according to the index importance, this paper establishes the unit primary frequency regulation performance evaluation index system, including the percentage of pass of the primary frequency regulation response lag time and stabilization time, the effect of primary frequency regulation, and percentage of pass of maximum regulation amplitude of load. Then, it employs close value methods to achieve the comprehensive performance evaluation of the primary frequency. The proposed method can provide some reference for comprehensive evaluations of the actual performance of a unit’s primary frequency regulation.

Yan Zhang, Xuan Pan, Xinqiao Fan, Sai Wang, Zhen Li, Yuanchao Huang

A Novel PQ Control Strategy of Microgrid with Single-Phase Connected to Grid

Based on the power hypothesis of feed-forward decoupling, PQ control is typical of the micro network control strategy, through the SPLL and d–q transformation module power and power factor control module and current control module to establish PQ control model, and in the original basis of ordinary phase lock loop to instantaneous reactive power phase lock loop. Finally using two half-bridge inverter dc micro-source to simulate practice single-phase parallel in MATLAB/Simulink simulation, it is concluded that using the control strategy of the micro-source in connection with power grid after a relatively short period of time, keeps the current in parallel and power grid voltage synchronization, output active power constant.

Baoqun Zhang, Longfei Ma, Cheng Gong, Ran Jiao, Rui Shi, Zhongjun Chi

Assessment of Civilian Demand Response Behavior Supporting Wind Power Digestion

According to the time process characteristic and the economic efficiency characteristic of civilian active load system’s interaction demand response behavior, this paper establishes the behavior analysis model of active load’s interaction response. And we decouple the response behaviors between users’ energy consuming load and electric load, and we extract out the target variables which can represent and identify the physical features of interactive response behavior from users’ energy and electricity demand and the cooperation between distributed renewable energy and grid. Considering a power grid with wind and heavy air conditioning load, this paper designs a wind and cold storage air conditioner combined system, and through a case study of response behavior analysis on residential and commercial active load system, we verify the effectiveness of the behavior analysis model and the target variables.

Ran Jiao, Baoqun Zhang, Cheng Gong, Longfei Ma, Rui Shi, Zhongjun Chi, Bing Yang, Huizhen Liu

Research on CO2 Laser Frequency Stabilization by Adjusting Grating Angle

A new frequency stabilization for CO2 laser with frequency selection by grating is presented in this paper. A closed-loop control system was designed to stabilize the laser frequency at the gain curve center by measuring the changing laser power continuously and fine adjusting the grating angle of the laser cavity. In the experiment, the long-term laser power and frequency shift of the CO2 laser 9P (10) line were measured to be less than ±0.035 W and ±7 MHz, respectively, when the frequency stabilization is in closed-loop operation. The CO2 laser frequency stability is up to 4.6 × 10−8. The frequency stabilization control system owns advantages of small volume, compact structure. It can be also used for other type of lasers.

Yanchao Zhang, Zhaoshuo Tian, Guang Dai, Chunlei Jin, Zhenghe Sun

Study on Shipborne Video Electro-optical Tracking System Based on FPGA

Shipborne video electro-optical tracking system can be used for ocean target detection and recognition, marine rescue, etc. In this paper, an FPGA is selected as the core processor to realize the target detection and servo tracking. We propose a colour matching centroid tracking algorithm to solve the impact of complex water surface changes. Test results show that the system works normally and stably. In the 640 × 480 video image resolution, the tracking accuracy of the azimuth motor is 80 pixels, and the maximum tracking angular velocity is 30°/s. The tracking accuracy of the pitch motor is 50 pixels, and the maximum tracking angular velocity is 10°/s. The minimum size of target recognition is 16 × 16 pixels matrix.

Zongjie Bi, Zhaoshuo Tian, Tao Luo, Shiyou Fu

A Timing Synchronization Method with Peak Plateau for OFDM Systems

Traditional timing synchronization methods require the identification of the peak value of the timing metric to realize the synchronization estimation. The proposed method in this paper requires only finding the peak plateau of the time metric and the terminal edge of the peak plateau. Consequently, the time metric of the novel method proposed in this paper could have no sharp peak value. A threshold to process the symbol timing metric in the proposed method must be established, after which it is easy to find the terminal end edge of the peak plateau, thus making the proposed method less complex.

Yanping Li

GRNN Model for Fault Diagnosis of Unmanned Helicopter Rotor’s Unbalance

In order to diagnose the unmanned helicopter rotor’s unbalance fault accurately, a method based on particle swarm optimization algorithm and generalized regression neural network (PSO-GRNN) is proposed. The average mean square error got from cross-validation is used as the fitness function of particle swarm, then the optimal GRNN smooth factor is attained by using particle swarm optimization algorithm, and an optimal model for fault diagnosis is achieved finally. It can be concluded that, based on the PSO-GRNN model, the type and the grade of the helicopter rotor’s unbalance can be diagnosed effectively, the diagnosis accurate rate of fault type is up to 94.29 % and the maximum error of fault grade is only 6.54 %, which is perfectly satisfied for the requirement of project.

Xi-hua Xie, Lei Xu, Liang Zhou, Yao Tan

A Double-Stage Strategy Based on DNA Computing to Search the Optimal Section of Active Splitting

Splitting section searching is a non-polynomial problem (NP problem). However, DNA computing, a new type of computing model based on DNA molecules with its amazing parallel computing ability, powerful storage capacity, and the characteristics of low energy consumption can traverse through all the feasible solutions to solve the NP problem well. For the need of active splitting when the power grid goes instable after disturbance, this paper presents a double-stage strategy based on DNA computing to search the optimal section of active splitting successfully.

Xiaoli Ye, Fei Tang, Jian Yang, Junru Xu, Yongle Zheng, Qiang Zhao

The Design and Realization of Motion Controller for Truss Robot

Truss robot has been widely used in the field of industry. In consideration of the features of truss mechanism, and after deep analysis the characteristics of TMS320F28335 DSP chip of TI EP4CE10E22C8 FPGA chip of Altera, the paper presents a design and realization of motion control solution based on DSP and FPGA. This controller can meet the real-time response and precision as the system needs. The paper introduces the hardware structure of the control system, and also illustrates the functions of different modules. The control algorithm of DSP and FPGA is explained, respectively, including the flow chart and block diagram of the software system. The fine interpolation module, PI controller, encoder acquisition module which are implemented in FPGA are also introduced in the paper. Eventually, the simulation results and the hardware platform are presented.

Peng Zheng, Wusheng Chou, Huaidong Zhou

Dynamic Characteristics of Wind Turbine Gearbox with the Chipping Fault

Studying on modulation characteristics of the transmission system to extract side frequency signals caused by the fault has important implications for planetary gearbox fault diagnosis. A torsion dynamics model of gearbox transmission system is established by lumped mass method with simulated planetary gear chipping fault through periodic pulse function. Using the Runge-Kutta method solved the equations to study the dynamic fault characteristics under the planetary chipping fault. Experimental results show: the planetary gear chipping fault can cause a large number side frequency around planetary mesh frequency, which also appears around first, second stage mesh frequency and its harmonic frequencies. The results of experimental signal analysis are the same with the theoretical analysis, so we can diagnose planetary chipping fault applying spectral analysis method.

Xin Wang, Yuxiu Xu, Taotao Li

Demonstration for Low Cost Wireless Smart Sensor Networks Based on ARM for Structural Health Monitoring

As a potential replacement of the traditional tethered system, wireless smart sensor networks (WSSNs) attract a lot of interests and have many applications, especially in civil engineering for structural health monitoring (SHM). However, many wireless sensor networks are based on some commercial wireless communication board and other sensor boards which need to be connected on it are expensive. Based on our previous research, this paper gives and demonstrates a proposal to make a low cost and low power wireless smart sensor using ARM Cortex™-M3 and some low cost and low power components. A new simple protocol is developed to realize reliable wireless communication between the gate way node (GWN) and the leaf node (LN) and an user interface on the PC client is also developed for displaying the measured results in real time.

Jian Xu, Wenhao Wan, Yuying Wu, Zhaoyu Sun

Risk Study on Long-Distance Oil and Gas Pipelines Engineering

Accidents such as leakage, fire, and explosion have happened occasionally in the long-distance oil and gas pipelines engineering in these years. Those accidents have caused large casualties, wealth loss, and environment pollution. So it is necessary to study the risk of the pipeline engineering in order to better avoid accidents and minimize losses of the long-distance oil and gas pipelines engineering. Based on the system safety theory, experts’ advices, and survey data, a comprehensive risk analysis and assessment of oil and gas pipeline engineering was carried out in this paper. From humans, materials, environment, and management four aspects, 32 risk factors were identified and assessed by combining the possibility with the severity of those identified risks. The risk level of the oil and gas pipelines was divided into five degrades from low to high. The proposed method was then applied to a natural gas pipeline engineering to identify and assess the risk of each pipe of the selected long-distance natural gas pipeline engineering. As a result, the earthquakes, avalanches, tunnel construction, and third party liability were the higher risk factors, and the risk of the forth pipe was the highest and should strengthen the risk management. Finally, some suggestions were proposed to the safety and risk management of the oil and gas pipelines engineering. The risk assessment method was thus proved to be a powerful tool to the risk decision-making and management of the long-distance oil and gas pipelines.

Shujiao Tong, Zongzhi Wu, Rujun Wang, Yingquan Duo

Optimization Method Based on Selection Strategy of Initial Point and Six Sigma Robust Design

Usually,there are three problems in the traditional optimization methods: (1) the local optima arising from choosing an inappropriate initial point; (2) low efficiency and accuracy in solving the complex optimization problems; (3) the robustness of optimal solution is not considered. To solve these problems, a new optimization method, the six sigma robust optimal design based on a strategy of initial point selection, is proposed. Firstly, latin hypercube design (LHD) is chosen to determine the optimal initial point and nonlinear Programming by Quadratic Lagrange (NLPQL) is used to search for the optimal solution. Then, the six sigma robustness of the optimal solutions is analyzed. Finally, robust optimizations of the responses which do not meet the six sigma reliability are performed and the global optimal solutions are obtained. The optimization of the machine tool spindle is used in this paper to validate the performance of this method. The results show that the optimal solution obtained by using the proposed method can ensure the high reliability, and also has a high convergence speed.

Aimin Ji, Mengni Zhang, Pin Lv, Xu Yin

Dynamic Flux and Torque Estimation of Single-Phase Induction Motors Based on the Vector Control Theory of Motors

A method for flux and torque estimation for the single-phase induction motors is presented in this paper. This work is based on the vector control theory of electrical machines, and has realized an estimation of flux and torque and some intermediate variables like direct and quadrature values. Accordance with the algorithm, a basic experimental model is built in the Simulink of the Matlab and tested for sinusoidal waveforms feeding the single-phase motor. Simulation experiments show that the methods are correct and the estimation is effective to access to internal parameter of the single-phase induction motors in order to obtain AC drives with high performance.

Dandan Sun, Ding Wang

Performance Evaluation of Ballistic Missile Detection for the Skywave OTHR Based on the Preliminary and the Weighted Indexes

Based on the ballistic missile detection characteristics of the skywave OTHR system, a ballistic missile detection performance method for the skywave OTHR is presented based on the preliminary index and the weighted index. The detection performance index is divided into the preliminary index and the weighted index. For the preliminary index, the performance quantization value is computed by a binary function. For the weighted index, a detection performance index system is constructed, and the performance quantization value of the index system is calculated according to the cloud gravity center theory. Based on the performance quantization values of the preliminary index and the weighted index, the ballistic missile detection performance is evaluated using the cloud remark assembly. Finally, the feasibility of this method is verified through a calculated example.

Shihua Liu, Defang Li, Bing Hu

Personnel Surface Electric Field Research of Live Working on Insulation Bucket Arm Car of 500-kV Transmission Lines

In order to improve the reliability and security of electricity supply and to increase the live working efficiency, a strong measure which improves the reliability of power supply is using insulated bucket arm car as work platform in live working of transmission line. With the purpose of assessing the security impact in which 500-kV transmission lines exert on a person who is using an insulated bucket arm car for live working, methods of electric field finite element calculation and electric field measurement are adopted to research the distribution law of person’s surface electric field in different working conditions. This article aims at the characteristics of live line work mode of 500-kV transmission line and uses the method of finite element calculation to study on the surface electric field distribution law of worker who is developing live working on an insulation bucket arm vehicle. Considering with the characteristics of insulation bucket arm vehicle and electric transmission line operation, we systemically proposed live working safety protection method about using insulation bucket arm vehicle in 500-kV transmission line.

Bing-ling Zhou, Dong-ze Xu

Failure Mode Analysis on Machining Center Based on Possibility Theory

Aiming at the uncertainty of the expert judgment in the failure mode and effect analysis of machining centers, a failure mode analysis method for the machining centers based on the possibility theory is proposed. To express the uncertainty of the expert judgment, the possibility distribution of the attribute of the judgment is established and the information fusion of the possibility distribution is implemented using the comprehensive analysis method, obtaining the possibility distribution of the influence factor; The values are assigned to the weights using the subjective-objective combination weighting approach which combines the variation coefficient method and the subjective weighting method. And then the possibility values of the RPN are calculated and ranked. A machining center is taken as the example, and the proposed method is applied to analyze the criticality of its failure modes, and the design for reliability promotion is presented according to the ranking of criticality.

Hongzhou Li, Fei Chen, Zhaojun Yang, Liding Wang, Yingnan Kan

Microstructure and Tensile Properties of Squeeze Cast AZ91D Magnesium Alloy

Microstructure and tensile properties of squeeze cast AZ91D alloy in different heat treatment conditions are studied. The effect of wall thickness of specimens on tensile properties is also discussed. The results show that the microstructure of squeeze cast AZ91D alloy consists of primary α-Mg matrix and β-Mg17Al12 phase which is mainly present in the matrix and grain boundaries. Single phase α-Mg solid solution is obtained after T4 treatment, and some granular precipitates are present in α-Mg matrix. After T6 treatment, finer β-Mg17Al12 phase precipitates within the α-Mg matrix and along the grain boundaries again. The yield strength (YS) and ultimate tensile strength (UTS) of squeeze cast AZ91D alloy decrease, but the elongation increases with the increase of wall thickness. The SEM analysis of fracture surfaces shows that the squeeze cast AZ91D alloy displays different fracture modes in different heat treatment conditions.

Xizi Xiao, Yun Chen, Juan Du

Research and Design of Merging Unit of Electronic Transducer

Merging unit (MU) which is the core of digital substation is an important component of the interface between electronic transducer and protective device. In this paper, MU of traction substation is studied and designed according to IEC60044-8 and IEC61850-9-2, and the overall realization scheme of traction substation MU is given, which is characterized by using field programmable gate array (FPGA) as the hardware core of MU and divided into data acquisition module, data processing module and data transmission module, and the desired functionality of each module were described in detail and specific analysis.

Zheng Qiao, Bujuan Li, Yikang Zu, Yanqin Sun

Overall Iteration Design of a New Concept Wing Disk Solar-Powered Aircraft

A new layout using wing disk solar aircraft concept with several wings around the disk fuselage is proposed in the research. The wings and fuselage can both provide lift during the overall rotation and forward flying. Propellers at the outer end of the wings are used to overcome the resisting moment, cyclical changes in the power forces, and deflection angle of ailerons to overcome the drag and roll torque in forward flight, which can also control the position and attitude. Aerodynamic analysis is developed based on rotor blade element theory and CFD method. The energy absorption and consumption and weight estimate of each subsystem are taken into account, and an optimization is laid out to meet the cruising flight requirement by iterative design.

Hong Da, Zhu Jihong

Research on an Automation Network for CSP Product Line

There are two developing technologies for automation networks designed by SMS Demag and applied to CSP in iron and steel plants, and currently a remote I/O topology for automation network via Internet can solve many of the problems of CSP’s installation, debugging and maintenance on site. This informs us that hierarchical control theory of large scale systems is no longer adapted to the development of network technology. Therefore, the CSP automation network of caster and mill, system management, time synchronization, reflective memory, field bus, remote access, VPN gateway, single port, and security features are analyzed in this paper. Either by adding HMI and remote access to the traditional hierarchical control theory of large scale systems or treating it as an independent part without the traditional hierarchical control theory, this problem is solved in our work. We conclude that HMI and remote access in automation networks have independent and integrated functions and cannot be divided into L0-to-L4 for the metallurgical automation system.

Tongbin Li, Bin Wang, Ning Zheng, Xin Kang

An Improved BBO Algorithm and Its Application in PID Optimization of CFB Bed Temperature System

In order to improve the performance of biogeography optimization (BBO) algorithm in PID controller parameter optimization of thermal systems and have superior convergence characteristics, the article gives an improved BBO algorithm. The improved BBO algorithm introduces the introducing convergence mechanism of particle swarm optimization on the basis of original migration strategy, so that the whole migration process has a certain direction. Also, the article uses phase-out strategy to remove poor parameters which are obtained after the migration and mutation processes. Thus, on the one hand, directional migration and elimination mechanism can ensure its fast convergence properties. On the other hand, mutational mechanisms can ensure the global characteristics of wide-area searching and avoid falling into local extrema. Using it in the PID optimization of CFB bed temperature system, the simulation results show that the improved BBO algorithm has a better performance than the standard BBO algorithm on convergence speed and precision. It is feasible and effective for PID controller parameter optimization in thermal system.

Hong Xue, Han Pu

Study on Joint Vibration Attenuation of the Satellite Attitude Control Actuator Using a Vibration Isolator and Vibration Absorbers

The vibration isolator is the major solution to suppress the disturbance caused by high-frequency vibration of the satellite, but it is difficult to resolve the conflicts between the attenuation in the resonance region and the high-frequency attenuation in design. This paper studies the vibration attenuation of attitude control actuators. Control moment gyroscopes, chosen as the attitude control actuators, are installed on a vibration attenuation platform consisted of a vibration isolator and vibration absorbers. The motion of equations of the whole satellite including the vibration attenuation platform is established. Then, the dynamic characteristics of the vibration isolator are analyzed, and the optimization of vibration absorbers is conducted. Finally, a system of parameters design method of the vibration attenuation platform is proposed, which satisfies the requirement of vibration attenuation and guarantees the stability of the attitude control system.

Peng Tian, Rui Zhong

Weight Calculation of Oil and Gas Pipelines Risk Factors Based on Improved AHP

Oil and gas pipelines have many risk factors, such as third party damage, corrosion, design, and maloperation, which possess many specific risk factors, the least buried depth, ground operations, ground equipment, public education, line status, patrol frequency, and many others. How to determine the weight of each factor accurately is a widespread concern. In this study, the improved three-scale AHP method is introduced to determine risk index weight of pipelines. This method has the advantages of being concise and practical, as well as having a small workload, strong pertinence, and easy-to-compare factor significance, all of which make it more accurate and objective to determine the indexes weights and to conform better to the actual situation. The method proceeds in three steps: first, using improved AHP to determine weight of the two-level index; then, similarly, determining the weight of the three-level index successively; and finally, calculating the weight values of all risk factors.

Tianyu Wang, Deyu Xu, Rujun Wang, Shujiao Tong

Optimization for the Structure of Front Transmission Gearbox

By applying finite element method and static analysis, the front transmission gearbox model of a tracked vehicle is simplified and the boundary conditions treatment and finite element mesh generation techniques were used to ensure the correctness of the analysis. Then, based on the analysis and computation, the displacement and stress distribution of the gearbox are calculated. Then, dynamic modal analysis is conducted for the gearbox to obtain the natural frequencies of various orders and the corresponding vibration modes in constraint mode, which provided basis for subsequent structure optimization. According to the results of finite element computation, the strength and the stiffness of each part of the gearbox are analyzed and the weak link is obtained. After extending the design space, the structure is redesigned through topology optimization to improve the strength and stiffness.

Zhenqi Yu

Study on the Hydrostatic Slide Film Temperature Field and Bearing Capacity of Precision Grinding Machine

In order to improve the machining precision of precision surface grinding machine, the static performance and thermal performance of the machine hydrostatic guide are analyzed, and the static characteristics and temperature distribution of the oil pad under an inlet oil pressure of 2.8–3.4 MPa and an oil film thickness of 38–44 μm were researched. The simulation results show that the initial temperature of the oil chamber area is 20 °C, and the temperature gradually decreases from the inlet. When the oil film thickness is 40 μm, the inlet oil pressure increases from 2.8 to 3.4 MPa; accordingly, the each pair of oil film bearing capacities increases from 7510 to 8240 N. The research results can provide the basis for the optimization design of guide.

ChuanShe Guo, Yi Cui

Study on Fuzzy Classifier Based on Genetic Algorithm Optimization

Most of the fuzzy classifiers are created by fuzzy rules based on transcendent knowledge or expert’s knowledge. In mountains of the existing data, it is difficult to obtain transcendent knowledge and then more difficult to obtain fuzzy rules. To solve this problem, a new way for creating fuzzy classifier based on GA for a classification problem of quantitative attribute is proposed in this paper, which consists of a set of fuzzy rules generated according to the attribute of the classified objects, then choosing the optimal fuzzy rules subset forming the classifier by the genetic algorithm to reduce the number of rules and improve the classification accuracy. The result of data simulation was applied to the iris with better effects.

Qian Gao, Nai-bao He

Research on Automatic Identification of Color and Classification Applied to Electric Online Monitoring

Rapid development of unattended substation requires that computer image recognition technology should be applied to power system more imminently. This paper analyzes the advantages of applying fuzzy pattern recognition technique to electric online monitoring image color identification and classification, and proposes a new method. Firstly, the algorithm acquires all kinds of identification color center based on sample learning sets given by experts; then, it introduces fuzzy c-means (FCM) clustering method and connected graph traversal technique. Based on the identification of color membership of pixel’s corresponding color pattern and color’s no-mutation rules, this paper comprehensively analyzes the whole image to form each color pattern and obtain the color identification results of each area. This method is prevalently instructional to similar color automatic identification.

Yi Zhang, Feng Zhang, Bin-quan Zhu, Lv Tang

Design of Control System for an Intelligent Closestool

In order to relieve the burden of nursing care for the patients or the elderly, a control system for intelligent closestool is designed for a wheelchair-bed. The hardware and software of the control system are implemented on atmega128. This developed control system has been applied in a class of closestool products. It has functions of autoup and down, auto flip, auto-induction for urine and stool, cleaning and drying, antifouling and ozone deodorization, silencing, and LCD display indication of the clearing process displayed and with voice prompt. Also, the temperature and water and wind pressure can be adjusted. The system is intelligent, humane, easy-to-use, and healthy and hygienic in use.

Shuyun Zhu, Yan Chen, Hanhan Wang, Fangjuan Xie

Research on Damage Assessment of Corroded Oil and Gas Pipelines Based on Fracture Mechanics

Generally, oil and gas pipeline is made of carbon steel, alloy steel and other metal materials. The biggest threat to the integrity of the oil and gas pipeline is the presence of corrosion. Corrosion will happened when the metal pipeline is affected by chemical or electrochemical attack, or microbial reaction with its environment. With the increasing of the service time, the corrosion of the oil and gas pipelines has become more and more serious. The wall thickness of the corroded pipeline will be lessened and that may lead the decrease of the strength of the pressurized pipeline. Thus, a leak may be happened at the corrosion area if the actual operation pressure of the pipeline is larger than the maximum safe pressure. So it is significant to study and assess the damage condition of the corroded oil and gas pipelines. Based on the theoretical foundations of fracture mechanics, the mathematical model for the failure pressure of corroded oil and gas pipelines was built in this paper firstly. And then, the corrosion damage level of the pipeline was divided into 3 grades according to the ability of the corroded pipeline. Furthermore, 20 corroded pipes were selected to study the damage assessment. The maximum safety operating pressure and damage level of each corroded pipe were carried out by applying the proposed mathematical model in the paper. As a result, the computational data were closed to the experimental data. The corrosion damage level and repair plan of the twenty pipes were discussed, and there were three pipes need to repair immediately. The results show that the proposed method can well assess the corrosion degree of the oil and gas pipelines with defects and can provide a scientific basis for the safe operation and emergency management of the oil and gas pipelines enterprise.

Rujun Wang, Shujiao Tong

The Research on Capacity Rise Phenomenon of the Cable Line Under AC Voltage Withstand Test

Capacity rise phenomenon is comparatively prevalent, which induces abroad attention. But under the tests with alternating voltage, especially to the long cable line tests, there has not enough recognition. The capacity rise phenomenon is dismissal, under the tests with alternating voltage to the short line. But to the long line, the condition is serious. Capacity rise reaches the times of impressed voltage in the extreme situation, which is unacceptable. The paper analyzes the equivalent circuit of distribution parameters, to draw the analog simulation conclusion of the correlative parts voltage response, in connection with ‘long’ and ‘short’ cable under different frequencies and sheath grounding modes. There are some suggestions at last.

Geqing Qi, Wenfeng Song, Dan Yuan, Zhuang Qi, Jianing Guo, Wei Zhang, Lulu Wang

Lyapunov-Based Control Strategy for Grid-Connected Inverter with Improved Transient Response

Repetitive control is commonly known as good steady-state tracking but slow transient response. This paper presents a hybrid control scheme with Lyapunov energy function embedded in conventional repetitive control for the purpose of fast transient response with system disturbance. Convergence of control is guaranteed by Lyapunov energy function. The proposed method is applied for single phase grid-connected inverters, which are commonly used in distributed generation interfacing to utility. Under load disturbance, the proposed method is compared with PI + Repetitive control scheme by computer simulation via MATLAB/Simulink. It is shown that the proposed hybrid control strategy has an improved dynamic response and good capacity of steady-state tracking.

Jinhao Wang, Chaoying Yang, Yulong Wu

The Simulation of STATCOM for Distribution Systems Using a Mathematical Model Approach

In this paper, the necessity and merits of STATCOM, as a reactive power compensator, are firstly analyzed. Secondly, the principle of STATCOM is introduced. And combining with the mathematical model of STATCOM, the direct current control method is introduced. At last, the model of STATCOM is built. Then through the figure contrast, the feasibility and effectiveness of this method is verified.

Wei Xie, Jian-Min Duan

The Design of Linear Three-Dimensional Calibration

This paper introduces the concept of calibration techniques and a kind of commonly used calibration method for three-dimensional (3D) target feature points. In the experiment, firstly, to improve the accuracy of the information corner, we selected optimizing and preprocessing method appropriately, and SUSAN algorithm is used to extract corner information. As a reference or approximation, linear model is utilized to get the linear model parameters, and then, different points are selected in the iteration method for more accuracy. The experimental results demonstrate this designed method can obtain the camera calibration parameters accurately.

Dequan Guo, Xinrui Zhang, Hui Ju, Hong Liu, Jin Chen

Design and Development of LED Dimming System Based on Wireless Remote and Bluetooth Control Technologies

LED illumination has good dimming characteristics, aiming at the application requirements of intelligent lighting and other application fields, and a novel LED lighting dimming control system based on wireless remote and Bluetooth control technologies was designed. The system can simultaneously achieve control by remote or Bluetooth wireless terminal devices (such as smartphone), and the system also has open- and closed-loop control optional modes to meet different needs. The system composition was described and presented in detail, and the system hardware and software design principles were given. Finally, the experimental results show that the system can achieve good dimming control functions, with good usability.

Yiwang Wang, Bo Zhang, Sikui Wu, Xiang Cang, Xiaoxiao Li

Open PID-Type Iterative Learning Control for Linear Time-Invariant System

Open PID-type Iterative learning control (ILC) is an effective and simple approach for the control of linear time-invariant system which performs the same task repetitively. In this paper, the open PID-type ILC is studied for linear time-invariant (LTI) systems, which uses the proportional, derivative and integral parameter of the tracking error to update the input variables iteratively. The paper analyzes the convergence of the open PID-type. According to the PID parameters, its convergence condition is got. By selecting appropriate gains parameters of the open PID-type ILC system, the output of the open PID-type iterative learning control system converges to desired output monotonically. The absolute error between the desired output and the actual output converges to zero faster. The simulation results show that the open PID-type ILC system in the paper is stable, effective and has high performance.

Xuelian Zhou, Qiang He

Development of an Integrative Pointing Gimbal Mechanism for Space Application

This paper summarizes the development of an integrative pointing gimbal mechanism (IPGM) for space application, such as the directional antenna, the space manipulator, the mobile camera, and other pointing mechanisms. Different from the traditional gimbal mechanisms, the two drive units of this pointing gimbal mechanism are integrated into a compact package, so the mass, the inertia, and the volume can be much smaller. And without the connecting part between the two axes, the stiffness of this IPGM is bigger under the same output ability, which offers better dynamic performance and control law. The key part of the IPGM is also analyzed by numerical calculation, so as to ensure the reliable running of the shafting under the space environments. To assess its capabilities, the qualification environment testing including the thermal cycling testing and the sinusoidal vibration were carried out. The testing results show that the performance of the IPGM is almost the same between the former and the end of each testing.

Bo Pan, Shuyang Zhang, Lin Li, Fanxin Sun, Yongqiang He

Multiuser Scheduling on Dual-Hop Relay Networks and Effect of Feedback Delay

In cooperative communication, the evaluation of the system performance and its degree of fairness mainly depend on the choice scheduling made on channel. However, in real system, feedback delay between channel estimation time and the real transmit information time cannot be ignored. And the delay effects on both the performance of the cooperative communication system and the scheduling of information transmission. In this paper, we focus on studying multiuser scheduling on dual-hop relay networks and the effect of feedback delay. Simulation advocates the performance of a multiuser relay network equipped with a single amplify-and-forward (AF) relay over Rayleigh fading environments. The results show that the channel capacity and the degree of fairness effected by feedback delay decrease obviously.

Jiyao Wei, Xianyi Rui

Research on System Modeling and Starting Strategy of Inverter for Medium-Frequency Induction Heating

Aiming at the puzzle of being low in starting success rate and poor in starting performance of the current source medium-frequency induction heating power supply, the paper presented a novel starting control strategy based on energy pre-charge starting system. In the paper, it made the anatomy and study comprehensively on a variety of energy pre-charge starting methods, constructed the system model of energy pre-charge starting control, and put forward to the starting strategy based on the load capacitor pre-charged. The results of the starting control strategy simulation demonstrated that the constructed system model and the presented starting strategy are reasonable and feasible. The research results provide a novel reference method for solving the starting control of medium-frequency induction heating power supply.

Sen-lin Cheng, Hu Xu, Chuan Wang, Qiang-zhi He

Optimal Configuration of Bypass Diodes for a High-Concentration Photovoltaic System

The high-concentration photovoltaic (HCPV) system uses high-magnification condenser lens to focus sunlight on the surfaces of group III–V photovoltaic (PV) cells. The PV cells can convert sunlight to electricity effectively. However, since the HCPV system includes PV cells and concentrating equipment, its components are more than those of general photovoltaic systems and are more prone to high cost and malfunctions. Bypass diodes are installed in the HCPV modules to prevent power consumption when they are shaded or damaged. The main purpose of this paper is to investigate the influence of bypass diodes on the HCPV modules and look for an optimal bypass diode configuration. In this research, the authors cooperated with Arima EcoEnergy Technologies Corp. whose HCPV products were used as references for modeling the simulation system. MATLAB/Simulink was used as the modeling tool to establish a HCPV simulation system using the built-in PV cell model. Simulations were implemented under different shaded conditions and investigated the effects of power generations under different bypass diode configurations. According to the simulation results, the configuration of 1 bypass diode per 2 PV cells is the best in general and random shaded conditions; however, the configuration of 1 bypass diode per 3 and 6 PV cells are better for some special conditions. The simulation results in this paper can be provided to HCPV companies as references, while designing products in the future, and should be helpful for improving performance and cost of the products.

Ting-Chung Yu, Yao Ti Hung, Yih-Bin Lin, Chih-Hao Chen, Yan-Cheng Liou

Optimal Design and Analysis of a 3.3-MW Wind Turbine Gear Train

In this paper, we design a type of 3.3-MW wind gear train based on genetic algorithm and finite element analysis method. We first construct the basic wind gear train by using two standards NWG structure and a pair of parallel shaft gears, respectively, as the low-, middle-, and high-speed stages. Then, genetic algorithm is applied to achieve optimal parameter for the basic wind gear train. Finally, ANSYS as finite element analysis tool is employed to verify the optimized gear train. We compare the deformation and stress of the every stage original and optimized gear chain under maximum operating conditions. The analysis results show that optimized parameters can well meet the requirements of 3.3-MW wind turbine.

Jianxin Zhang, Zhange Zhang

The Analysis of Battery Cooling Modes of EV

In this paper, the lithium battery for electric vehicles is used. The working principle and the heating principle of the battery are analyzed. Based on the battery heating principle, the performance of the existing battery cooling mode is qualitatively analyzed. Battery heating model is established on the basis of which different battery cooling models are established, including air cooling mode, indirect water cooling mode, and direct liquid cooling mode. Compared with the air cooling mode, the cooling effect of the liquid cooling mode is more obvious, and the range of temperature of the battery cell in battery packs is much smaller in the liquid cooling mode.

Yue Yang, Pengyu Wang, Guangming Lu, Hang Dong, Feng Li, Yanru Suo

The Research of Aviation Dangerous Weather Forecast for Fog and Haze Based on BP Neural Network

The fog–haze, as one of the dangerous aviation weather, influences the pilot to see the runway in the air. It is very dangerous to flight for safe landing. Because of the existence of fog–haze, the phenomenon of plane’s taking off or delaying is not uncommon. In this paper, analyze the main physical factors of fog–haze and establish model based on BP neural network; in addition, the forecasting performance of the model was tested; at last, the short-term forecasting operational system of fog–haze which can be used for aviation meteorological services is built based on software development techniques.

Yanfen Cheng, Rui Wu

Small Power Sine Wave Inverter Design

How to turn the DC power supply (24 V) into AC power (220 V, 50 Hz) and load feedback power supply based on single-phase full-bridge inverter circuit has been discussed, and it is converted to a stable frequency power supply for a number of electrical appliances such as lights and computer requirement use. SG3525 chip fixed-frequency pulse width modulation circuit and field effect transistor (N channel MOSFET) whose switch speed quick, nothing secondary break down and good hot stability have been applied sufficiently. Inverter main part has been composed of DC/DC circuit, input protection circuit, output protection circuit, overheat protection circuit, DC/AC conversion circuit, and full-bridge circuit. The overcurrent and overheat circuit as well as the normal work light have also been designed. Practice has proven that the system is stable, has good utility, low-cost, and strong practicability. It can be used as a variety of portable electrical general power supply.

Xuefeng Bai, Yongjian Ma, Hanqing Li, Pei Li

Uncertainty Quantification Using Random Set Based on IODM

This paper focuses on the mechanical model uncertainty quantification when the system parameters are in the form of probability box; for example, when the probability distribution of the system variable is specified by interval parameters, the variable is in the form of probability box. We develop an improved outer discretization method (IODM) for constructing random sets which provides a convenient mechanism for representing probability box. The method can increase the fineness of the random set’s approximation to the bounds of the probability box with a limited focal element. It is shown that the method is helpful for the uncertainty quantification when the model is computationally expensive.

Zhao Liang

Coordinated Control Method of AGC and AVC in Power Grid

With the coupling relationship between active power and reactive power in power system becoming stronger, the control mode that automatic generation control (AGC) and automatic voltage control (AVC) operate separately may influence the control effect. Considering the different control period of AGC and AVC, this paper proposes a coordinated control method of AGC and AVC with a connection on the timescale of minute level and second level. On the minute level, an optimal power flow model of active power and reactive power associated together is established, and a AGC and AVC associated optimization control method are proposed. On the second level, the paper improved the repective control strategies of AGC and AVC, also proposed a coordinated correction control method of both of them. Simulations are made to verify that the method proposed in this paper meets the respective control objective of AGC and AVC. At the same time, it can realize the economical operation of power system, restrain the mutual influence of AGC and AVC, while promote the mutual support between AGC and AVC.

Shiguang Li, Zian Wang, Xinjing Wu, Jiatong Du

Research into Key Points and Application Ideas of Reliability Assessment for Medium-Voltage Distribution Networks

Firstly, some commonly used terms of medium-voltage distribution networks’ reliability assessment are briefly introduced. Then, some normative suggestions about key points of reliability assessment, such as assessment indexes, parameters, and methods, are systematically put forward. In addition, some key issues of models, parameters, and methods for reliability evaluation are analyzed, and corresponding reasonable disposal methods are given. As for distribution network models, the establishing idea is given, where an organic connection is established between the reliability assessment and reliability statistics. Moreover, some ideas of applying reliability assessment in the phases of network planning, renovation, operation, and maintenance are proposed, improving the power supply reliability fundamentally and bringing more benefits for the power supply enterprises. The reliability assessment of 5 cases is conducted, which can test the effects of load switches, load curves, equipment capacity constraint, and load shedding on the reliability indexes, and the results indicate that the presented normative suggestions are practical.

Lingyun Wan, Tingting Wei, Jin Fu, Gaolin Wu, Qunying Yang, Wei Song

Heat Transfer-Based Fault Diagnosis for Heat Exchanger of Aircraft Environmental Control System

In this project, combined with the process of heat transfer for plate-fin heat exchangers in aircraft environmental control system, we attempt to establish mathematical model based on inputs and outputs of heat exchangers. Then, the relative observer is given to generate residuals by the comparison of the outputs between heat exchangers and observers. Furthermore, fault information is obtained from the evaluation of residuals. Finally, simulation results show that the proposed scheme for heat exchanger failure detection is effective; it can be regarded as the theoretical basis of relevant engineering technology.

H. Zhuohuan, W. Lulu, Y. Mo

Direct Torque Control of Permanent Magnet Synchronous Motor at Low Speed Using a Variable PI Feedback Flux Observer

In the study of direct torque control (DTC) of permanent magnet synchronous motor (PMSM), the stator resistance is easily affected by temperature variation and its value varies from time to time. What is more, it will lead to flux ripple. In order to solve the problem of error existing between the set value of the stator flux and the reality, an improved method based on variable parameter PI is proposed to compensate the stator resistance. By constructing the stator flux observer mathematical model of DTC of PMSM and analyzing the stator resistance variation influenced by the stator flux observation, it can be found that the stator resistance is compensated by adjusting PI parameters with time, the flux error will be reduced, and this new method will be testified by MATLAB software. The simulation result shows that the improved stator resistance compensation algorithm has effectively solved the flux ripple problem, decreased the flux error, and achieved the expected control effect.

Suying Zhang, Wenshuai Cui, Yankai Shen, Huixian Liu

Research on the Speed Synchronization Control Method of Double-HST Motor

Embedded spilled oil recovery machine is one of the important mechanical equipment of oil spill emergency response and the speed synchronization of sweep arm end (float) and oil boom reel is the key technology of that. The problem of that line-speed synchronization of float and oil boom reel of embedded spilled oil recovery machine has been studied and the joint synchronization control scheme which adopt PID and equal control been also put forward in order to realize the speed coordination control of dual motor driven by HST with the PLC as the core of controller in this paper. The scheme of hardware design for the speed synchronization control system has been given and the software of the key technologies also been design and ran. The system speed has been simulated and analysis by MATLAB simulation software and the evaluation methods of the linear velocity errors been also put forward. Study in this paper provides reference for the follow-up projects and similar technical design. The stages of research results provide a reference for design work of the follow-up and similar technologies.

Qian Ming Yang, Jian Li, Ling Qi Kong

Design and Development of an In Situ Radioactivity Measuring System in the Marine Environment

It is significant to develop the in situ radioactivity measuring system in the marine environment for the autonomous and continuous monitoring in the long term and even for the pollution early warning. The design of a set of a marine radioactivity measuring system was presented in the paper using the underwater spectrometer as the sensor. A data acquisition and control device was developed to collect and process the gamma ray spectra measured by the sensor, and also to be responsible for the monitoring system control and power supply. The bulk monitoring data were transferred to the server in the laboratory through the Beidou satellite. The gamma ray spectra measured and the analysis results of the radioactivity in the seawater were provided for the users. This research work and measured data have great importance to the more particular knowledge of the radioactivity in the marine environment and to the development of the marine radioactive monitoring and pollution early warning.

Yingying Zhang, Bingwei Wu, Ying Zhang, Guoxing Ren, Dongyan Liu, Lu Cao

The Design of Shield Posture’s Monitoring and Control System Based on Configuration Software

In municipal engineering construction, the shield construction method is usually adopted. How to effectively control shield posture in the shield construction directly relates to the construction quality. Based on the research of shield posture’s monitoring and control system, this paper presents a design scheme of shield posture’s monitoring and control system. It introduces the design of hardware structure: PLC monitoring and control network are based on field bus and the design and implementation of the monitoring computer and control software by using configuration software in detail. This research has been applied in the actual engineering project. It has important significance to improve the quality of shield construction and improve the level of the shield construction.

Yiping Shi, Yungen Wang

Application Research of SuperCapacitance on Fuel Consumption Wheel Crane

Through a series of experiments among the super capacitor, the battery and the traditional electric capacity, the preponderances of super capacitor in specific power density, specific energy and service life have carried out. The result states that the use of super capacitance as energy storage component can make great contributions to energy saving and environment protection and it has a bright future in application of hybrid system on fuel consumption wheel crane.

Chao Li, Lu Niu, Aihong Tang

Research on Elastic Characteristic of Interconnected Oil Gas Suspension

Regarding as rollover problem for multi-axis heavy vehicles when no transverse stability rod attached, lateral stiffness calculation and experiment were researched. Gas pressure, vertical stiffness formula, and lateral stiffness formula were deduced through real gas state equation. By program analysis, it was concluded that the vertical stiffness of interconnected structure was equivalent to that of independent suspension, but the lateral stiffness was multiplied when turning. Through real vehicle test, vehicle body lateral angles of two suspension forms were compared. It was verified that vehicle handling and stability performances are improved when suspension system is interconnected.

Y. J. Chen, L. Wang, Y. F. Zhang, G. H. Zheng, X. Zhang

Impact of Switching Three-Phase Breaker at Different Period on Inter-turn Protection for High-Voltage Shunt Reactor

In this paper, the simulation of inter-turn protection for high-voltage (HV) shunt reactors is studied by using Simulink. Expound that when the closing angles of the three-phase circuit breaker are different, the zero-sequence current and zero-sequence voltage will occur in the system. Demonstrated that during such time, the protection criterion of inter-turn protection will be satisfied in some cases, and thus, the false tripping will occur possibly. Finally, some suggestions are given to avoid the false tripping in the inter-turn protection.

Sheng-Hong Lin, Shu-Yan Pan, Hua-Ren Wu

The Application Software Framework About Distributed Intelligent Alarm Information in Intelligent Substation

With rapid development of the power grid construction and the new energy, power grid operating characteristic has major changes. The intelligent alarm processing function in the existing dispatching automation system cannot meet the requirements of the power grid operation. Distributed application has become a new application requirement for power grid dispatching automation system. In recent years, the distributed application research on distributed state estimation, distributed intelligent alarm, and distributed SCADA has been reported. Base on the status and application of the intelligent power network dispatch and control system, the intelligent alarm function analyzes the difference between the traditional alarm system and the distributed intelligent alarm system. And the paper studies the architecture and specification of the two-level distributed intelligent alarm system and analyzes the value and its future application prospect of distributed intelligent alarm for dispatching operation.

Xin Xu, Zhiqiang Yao, RenHui Dou, Hao Ren, Mingzhi Geng, Hui Ren

The Design and Implementation of Substation Graphic Gateway System Based on IEC61850 Technology

As the application of IEC61850, the condition monitoring systems and auxiliary systems have been used in substation, and the amount of substation data becomes more and more large. In order to solve the management problems generated by large amounts of substation data, the National Dispatching Center has proposed the Direct alarm and Remote browsing techniques based on traditional remote communication device. This paper uses an embedded platform graphic gateway and uses IEC61850 to get real-time data and graphics of substation. It sends the data to D5000 system of dispatch center via DL/476, and the real-time data transmission and monitoring data refresh have reached the requirements of engineering applications and achieved good applied effect.

Mingzhi Geng, Renhui Dou, Yanping Wu, Zhiqiang Yao, Hao Ren, Xin Xu

An Improved Particle Swarm Optimization and Application

Particle swarm optimization (PSO) is prone to fall into the premature convergence, and convergence precision is low and other shortcomings in solving complex problems. This paper presents an algorithm based on the adaptive inertia weight of the second-order oscillation particle swarm optimization (SOPSO); the algorithm combines SOPSO and adaptive inertia weight advantages, and it is good solution to the above-mentioned problem. Finally, the simulation on four test functions and the application on the key frame extraction from human motion capture data show that the algorithm not only has a strong search capability, and the convergence precision and stability have been effectively improved.

Dongsheng Zhou, Lin Wang, Jiang Wei

Quantitative Analysis of Air Injection for Compressor Active Control

Aimed at analysing compressor stability with continual air injection quantitatively, the effect of injection air flow coefficient was investigated based on the Moore–Greitzer model with air injection. By changing the jet velocity for changing the quasi-steady state of the compressor, the influence of constant flow coefficient on the stability of the compressor was analysed theoretically. The results show that the compressor characteristic variation is the stability mechanism of compression system with air injection. Increasing the jet speed makes the compressor characteristic lineup, and the critical stall point shifts to left. There exists a corresponding minimum injection velocity for different throttle coefficients and the stability margin can be determined theoretically.

Zhanheng Sun, Sanmai Su, Junjie Liu, Gao Rao

Thermocapillary Flows in Half-zone Liquid Bridges Under Axial Magnetic Fields

The physical and mathematical model of the liquid bridge in half-floating zone method which is exposed to static magnetic field is built and numerically simulated without the effects of gravity. The governing equations are N-S equations combined with the conservation equation of energy which is calculated by the SIMPLE algorithm. On a staggered grid, the level set function and the continuum surface force (CSF) model is adopted to capture the free surface. The result indicates that under certain strength of static magnetic field, different temperature differences between the two disks and different aspect ratios of the liquid bridge have influence both on the free surface deformation and inner velocity field in different degrees.

Ruquan Liang, Linyang Zhu, Limin Kong, Fuqiang Yan, Shuo Yang

A Dual-Redundancy Thermal Backup Control Method for the Two-Wheeled Self-balancing Robot

Aiming at the static instability and vehicle body reliability of the two-wheeled self-balancing robot, this paper puts forward a dual-redundancy thermal backup control method of self-balancing robot based on robot steering sensor and gyroscope robot body attitude sensor. It presents the effective dual-redundancy control scheme, its fault detection and switching method on power supply system, master control logic, driver control, power circuit, and actuator.

Yong Tao, Tianmiao Wang, Ye Wang, Jianhong Liang, Zhongyuan Chen

The Influence of Surface Roughness on the Aerodynamic Characteristics of Overhead Wire

The aerodynamic characteristic parameters are the foundation of vibration analysis of the overhead conductors. In this paper, a typical overhead conductor is studied using computational fluid dynamics (CFD) method. The smooth wire model and rough wire model are established, respectively, and the experimental analysis is carried out in the numerical wind tunnel. The aerodynamic parameters are obtained, and the influence of roughness of the wire surface is investigated.

Zhangqi Wang, Lizhong Qi

Multi-objective Optimization Algorithm in Mission Planning of On-Orbit Servicing Spacecraft

On-orbit servicing (OOS) spacecrafts can provide a variety of services, so it is necessary to make reasonable mission planning between spacecrafts to improve the efficiency of collaborative works. In this paper, a multiple spacecraft mission planning based on multi-objective optimization algorithm is proposed according to the specific characteristics of mission planning in order to complete the optimization target, such as task completion time, fuel consumption, and service priorities. In this algorithm, the model of mission planning problem is established by designing decision variables and formal constraints, and Pareto optimal sets and multiple sets of solutions of that problem are the results of the improved NSGA-II. In particular, ideal solution can be chosen as necessary. From the results of two simulation examples, we can see that our method can solve the multi-spacecrafts mission planning problem under multiple constraints efficiently. It is expressive, flexible, extensible, and feasible easily.

Qing Zhang, Jianxin Zhang, Qiang Zhang, Xiaopeng Wei

Product Conceptual Design Based on Polychromatic Sets Theory and Axiomatic Design

We propose a function–parameter model based on polychromatic sets theory in the paper. The proposed model aims to resolve the weaknesses of function–means tree which is difficult to convey the complex mechanical system and constraints among them and to deal with the disadvantages of axiomatic design in the product conceptual design process that does not provide the realization methodologies of specific mapping from the function requirements to the design parameters. The function–parameter model can present complex mechanical system and constraints among them and illustrate the realization methodologies of specific mapping, and five possible constraints between function requirements and design parameters are also presented. Exemplified by the main module design of snow-removing car, the function–parameter model based on polychromatic sets theory is further elaborated.

Jianxin Zhang, Yangjie Zhou, Qiang Zhang, Xiaopeng Wei

Study on Dynamic Balance PID Control Algorithm and Its Application on the Quadrotor

This paper aims to present a dynamic balance PID control algorithm for the quadrotor, and the control algorithm combines the dynamic balance algorithm and the regular PID control algorithm. The proposed control algorithm used an angle as the set point of the PID controller. The selected angle is oriented opposite the sampling value of the inclination angle of the quadrotor, and its absolute value is smaller than the sampling value of the inclination angle. By using Newton–Euler equation approach, the mathematical model of the quadrotor is derived. And the simulation model is built based on the mathematical model in MATLAB. A simulation control system for the quadrotor which is based on the dynamic balance PID control algorithm is built. Simulation results show that by using the dynamic balance PID control algorithm, the inclination angle of the quadrotor can be controlled to a set error range, which validate the proposed control algorithm.

Hongwei Yan, Hongbin Li, Shaohua Song

The Electronic, Magnetic, and Vibrational Properties of Ce3Co29Ge4B10

We have studied the electronic and vibrational properties of Ce3Co29Ge4B10 compounds using the first-principles GGA + U method. The calculation finds that the magnetic moment of Ce and Co atoms has a good agreement with experimental value when U = 3.8 eV. Also, the calculated lattice constants and atomic positions are corresponding to the experimental results. By using the interatomic pair potential obtained with the lattice inversion method, the phonon density of states of Ce3Co29Ge4B10 compounds is also studied.

Liu-Tao Zhao, Xiao-Xu Wang, Jin-Rong Huo, Hai-Xia Cheng, Jian-Qiao Xie, Lu Li, Ying Liu

Effects of Activation Treatment on Interfacial Bonding in A356-10 wt% B4C Composite Sheets Prepared by Rheo-Rolling

A novel semisolid stirring and rheo-rolling process for preparing aluminum–boron carbide composite sheets was proposed. The microstructure and interfacial bonding of A356-10 wt% B4C composites were investigated. The activated B4C particles had no impurities on the surface. Furthermore, no particles with an acute angle were observed, which contribute to improved wettability between the B4C particles and the aluminum matrix. The strengthening phases Al3BC and Al2O3 are formed on the interface between particles and matrix, resulting in chemical bonding. A356-10 wt% B4C composite sheets with good mechanical properties were fabricated via the combination of semisolid stirring and rheological rolling. The Vickers hardness of the composite sheet with activated B4C particles reached 109 HV, and the tensile strength reached 197 MPa.

Zhan Yong Zhao, Yang Zhang, Zhou Yang Zhao, Ren Guo Guan, Yuan Dong Li, Ben Chao Chen

LQR Optimal Control on the Positioning Accuracy and Rigidity for the Pneumatic Actuator

This paper aims to present a linear quadratic regulator optimal controller (LQR optimal controller) for a vertical hopping pneumatic actuator. In order to achieve stable hopping, both the piston positioning accuracy and positioning rigidity have to be controlled to the desired values during the flight phase. Because the duration of the flight phase is limited, the settling time of the system should be controlled as short as possible. The proposed LQR optimal control scheme is essential to control the piston position and the chamber pressure simultaneously and satisfy the real-time requirement of the pneumatic actuator. A pneumatic position servo model is developed by Simulink tools in the form of system function (S-function). In simulation, the piston positioning and chamber pressure error are within 0.2 mm and 0.001 MPa, respectively. The settling time is about 120 ms, which can meet the real-time requirement of the pneumatic actuator.

Hongwei Yan, Hongbin Li, Shengjun Zhou

A Study of Visual Servo System Based on Binocular Camera

In robot-assisted orthopedic surgery, instruments attached to end-effector may collide with patient in the process of drilling. To solve this problem, a robot visual servo control system based on binocular cameras is built. Visual information is used by improved PID algorithm to control the surgical robot to track the movement of the patient. In addition, the model of the control system is established by MATLAB. At last, a model experiment is performed to verify the feasibility of the system.

Lei Hu, Chen Shen

Exploration of the Gas–Liquid Separation Effect of Vortex Tool in Downhole

The increasing water rate of gas well has seriously threatened gas production, and it gets more and more people’s concern and attention. Therefore, vortex tool is developed for downhole gas–liquid separation to improve gas production. We used UG software to establish the vortex tool model and conduct simulation calculation by fluent software. Then, analyze the influence of the separation effect of gas flow rate, downhole gas–liquid ratio, and vortex tool structure. The analysis results show that gas flow rate, gas–liquid ratio, and vortex tool spiral angle are main factors influencing the effect of vortex tool drainage. The higher the gas flow rate and the greater the gas–liquid ratio, the effect of gas–liquid separation of vortex tool is better. When spiral angle of the vortex tool is 50°, separation effect is better.

Zhijian Wang, YanBob Jia, Kai Liu

Study on Hopping Height Control and Detection for the Pneumatic Actuator

The research objective of this paper is to study control algorithm and detection method for the pneumatic actuator’s hopping height. Mathematical model of the pneumatic actuator is developed based on the Newton equations and thermodynamic equations, and the simulation model is built in MATLAB. At the acceleration stage of the hopping process, acceleration time and opening of the proportional valves are controlled to adjust the hopping height of the pneumatic actuator. Vertical hopping test rig is built, and an ultrasonic ranging system is mounted beside the foot to detect the hopping height of the pneumatic actuator. Both simulation and experimental results show that the hopping height can be controlled effectively by changing the acceleration time and the opening of the proportional valves.

Hongwei Yan, Hongbin Li, Shengjun Zhou

An Interval-Reduced-Basis Approach for Predicting Acoustic Response of Coupled Structural-Acoustic System

To predict and improve the acoustic behavior, an interval-reduced-basis approach is presented for acoustic response of coupled structural-acoustic system. In the present approach, the acoustic response is approximated by using a linear combination of interval-basis vectors with undetermined coefficients. The reduced-order equations are derived based on Galerkin scheme to compute the undetermined coefficients. In addition, the determination of the acoustic response range is transformed into a sequence of quadratic programming problems subject to box constraints, which are computed using the DC algorithm effectively. Numerical example is presented to demonstrate the implementation of the present approach and show that the new approach has a good accuracy and efficiency.

Zheng Lv, Zhiping Qiu, Qi Li

FE Research on Influence of Pouring Temperature on Thermal Fatigue Depth for Aluminum Alloy Die Casting Die

A three-dimensional finite element model of the aluminum alloy front cover die casting die was established by PRO/E and PROCAST software. Thermal balance forming of die casting die and the influence of pouring temperature on thermal fatigue depth of die cavity surface were analyzed. The results showed that the temperature amplitude increased with the decrease of distance from die cavity surface. The higher the pouring temperature is, the bigger the thermal fatigue depth will be.

Chenggang Pan, Huqun Yang, Wenchao Ma, Qin Xiao, Qingming Chang

Analysis of the Protection of a Simplified Surge Protective Device for Low-Voltage AC Power System

Surge protective devices (SPDs) are applied in the low-voltage AC power system to limit lightning transient overvoltage so as to protect the low-voltage electronic devices. However, traditional SPDs have some shortcomings such as too many components that are big in size. Aiming to overcome these shortcomings, a simplified circuit is proposed when the circuit of traditional SPD is analyzed in this paper. Simulation analysis of the lightning transient response of traditional and simplified circuit is performed with PSCAD/EMTDC, and furthermore, the simulation results of two circuits are compared. It shows that the simplified circuit has a qualified protective performance and can be applied to lightning overvoltage protection of electronic devices in low-voltage AC power system by comparison.

Huiping Liu, Xiaoqing Zhang, Kejie Huang

Investigation of Load Distribution Among Teeth of an Aero-engine Spline Coupling

Involute spline coupling is a significant part in power transmission system, and the research on the rules of the load distribution among the teeth of it is extremely important for the working reliability. The work reported here calculated the actual meshing teeth, using the method loaded step by step considering the backlash, calculated the deformation and load distribution of spline coupling by the method, established the finite element model, simulated it for the deformation of teeth, and validated against the deformation calculated using the method loaded step by step. The results show that due to the large backlash under the working conditions given in this paper, the actual meshing teeth of spline is less, deformation obtained by finite element method is consistent with the deformation obtained by the method loaded step by step, and the first meshed tooth is out of shape seriously, whereas the second tooth will most likely to fail. It is concluded that increasing the actual meshing teeth and then reducing fretting wear can improve stability and reliability of spline coupling as well as reduce the failure.

Xiangzhen Xue, Sanmin Wang, Jian He, Hui Wu

Dynamics Analysis of Linear Array Deployable Structure Based on Symmetrical Scissor-Like Element

Based on the Cartesian frame, the dynamic model of the linear array deployable structures was established, the motion constraint equations were completed by the constraint conditions of the scissor-like element (SLE). The numerical calculation was carried out using multi-step Runge–Kutta method, the law of velocity and acceleration during the motion process were obtained, and the constraint default stabilization method was also utilized to avoid the divergence of the results. The results show that the velocity, acceleration, and reaction force of the scissor mechanism along y-axis presents better symmetry properties because the horizontal constant force is in x direction. Meanwhile, at the side of the mechanism withstanding the external force, the dynamic properties of each node along x direction change more obviously; however, the changing amplitude of the velocity, acceleration, and other physical quantities are very small along x-axis on the non-force side.

Bo Li, San-Min Wang, Ru Yuan, Chang-jian Zhi, Xiang-zhen Xue

Research and Development Analysis of Information Security in Smart Grid Construction

Information and communication technology, which is accelerating the integration, has been already widely used in smart grid construction, so information security risk has become increasingly prominent. In this paper, a brief description of information security in the electric power system was introduced, information security risks were analyzed in detail, and then, the solution suggestions were given, in order to build information security protection architecture of the power system and to ensure safe and stable operation of the smart grid.

Yixin Ding, Ming Li, Li Yan, Junwei Ma

The Multiobjective Optimization Model of Open Mill Mastication Parameters

Through the analysis of the efficiency and energy consumption of the mastication process of open mill, the time and carbon emission objective function of the process is established. Considering the actual constraint in the process of open mill performance and mastication parameters, a multiobjective optimization model is established, which takes the open mill linear speed of roller, roller spacing, and roller ratio as the variables and the minimum processing time and the lowest carbon emission as the optimization objectives. An improved genetic algorithm is utilized to solve the optimization model. The validity of the proposed model is verified by an example, and the sensitivity of the optimization results and the optimization variables are analyzed.

Zhang Liang, Wang Qidong, Zhu Lihong, Zhao Han

Precision Compensation Analysis of Spacecraft Assembly Parallel Mechanism

The pose of spacecraft can be adjusted automatically, intellectualized, high-precisioned by 6 DOF parallel spacecraft assembly platform, resolved the problem of high-precision spacecraft assembly. In digital assembly process, spacecraft assembly platform is used as the positioning mechanism for spacecraft, but it occurs structure deformation caused by spacecraft, which can affect the precision of assembly. This work focuses on the research about the deformation error and proposes a corresponding error compensation method in order to satisfy high-precision requirement in the procession of assembly. To take account of deformation of all parts in the assembly platform, finite element method is applied. Firstly, this paper verifies the feasibility of deformation analysis based on finite element comparing with the stiffness matrix method. Secondly, it establishes a posture error model for the platform. Finally, it proposes an error compensation method based on finite element analysis results and tests the compensation method.

Guangtong Liu, Guotao, Yanlei Zhang, Laiying Tang

Research on CAD/CAM Integration Methods Based on the STL Model

At present, data exchange between different CAD/CAM systems becomes an increasingly large issue for engineers and other technical personnel in enterprises. In this paper, in order to enable better integration of CAD/CAM systems applications, we put forward the CAD/CAM integration methods which are based on the STL model. The STL model is a generic interface for the current popular CAD/CAM systems; by means of analysis with the STL model, the integration methods for CAD/CAM have been accomplished, But also, the methods have been verified through examples that show that these methods are simple and practical.

Huiqun Zhou, Jianjun Wu

Investigation on the Characteristics of DC Air Discharge at Low Pressure Based on Hydrodynamics and Chemistry Model

Firstly, a presented model of hydrodynamics and chemistry which introduces an improved nonlocal collisionless electron heat flux and photoionization effect is used to simulate the low-pressure air discharge of DC. The plasma model is developed by COMSOL Multiphysics with plasma model and takes into account 12 species and 26 reactions which can accurately reflect the air discharge. Then, the characteristics and mechanism of air discharge under low pressure are analyzed. And this simulation model is validated by comparison between the experimental results and results in the current literature. The results show that N2+ and O2+ are the dominant positive ions; N2 ionization reaction is always higher than O2 ionization reaction; the cathode sheath has the greatest electron temperature due to the Joule heating in strong electric field; the main electron energy loss of volume in low-pressure air discharge is produced by inelastic collision.

Xing-hua Liu, Xue-Feng Sun, Ri-chang Xian, Yu-Feng Chen, Peng Yu

Research on IOT Technology Applied to Intelligent Agriculture

Internet of Things (IOT) technology has become one of the leading subjects of scientific research field because of its potential application. This paper briefly introduced the introduction of IOT technology and agriculture IOT technology. Agriculture development in China is transiting from traditional to modernization, and equipment with modern material conditions is urgently needed. In the first section, it describes the concept of IOT and agriculture of things, as well as some of the key technologies of agriculture networking applications, namely (a) agricultural sensor technology; (b) wireless transmission technology; (c) RFID technology; (d) agricultural product quality security technologies; (e) intelligent irrigation technology; and (f) precision seeding and spraying techniques. The second part introduces the development status of IOT technology in intelligent agriculture, and the use of resources in agriculture, agro-ecological monitoring of the environment, and agricultural production of fine management, application analysis and safety of agricultural traceability aspects. With the development and progress of science and technology, information technology in agriculture has become increasingly important, especially in recent years. With the development of new networking technologies, intelligent agriculture also shows a broad development prospect. The third part analyzes the intelligent microirrigation control technology. Followed by a discussion of the three aspects of IOT technology deficiencies in the existing practical applications, namely industry standards, information integration and business model aspects of the problem, and accordingly at the macro we give three suggestions. The last part gives the prospects of intelligent agriculture and its shift to wisdom of agriculture.

Juntao Li, Weihua Gu, Hang Yuan

Effective FPGA-Based Enhancement of Quantitative Frequent Itemset Mining

Frequent itemset mining (FIM) algorithms are widely used to discover common patterns in large-scale data sets. In conventional CPU-based systems, mining algorithms, which are usually data and memory intensive, often lead to critical power and latency issues growing even worse with a larger scale of data sets. Having identified the pipelining workflow behind the logic of frequent itemset mining, we propose a quantitative mining algorithm named Q-Bit-AssoRule and further design a pipelined FPGA-based implementation of Q-Bit-AssoRule algorithm to accelerate frequent itemset mining processing, achieving better performance, throughput, scalability as well as less hardware cost. Our evaluation result shows that our implementation outperforms other hardware approaches in terms of clock frequency and throughput.

Xiaoqi Gu, Yongxin Zhu, Meikang Qiu, Shengyan Zhou, Chaojun Wang

Image Classification Based on Deep Learning for Big Data of Power Grid

There are varieties of sensors and detection equipments in the power grid, generating large amount of data including pictures and videos captured by cameras and unmanned hovers. Automatic classifier is required to process massive number of images before accurate assessment of equipment status is made. As deep learning-based classifier has been used as a new effective tool in artificial intelligence domain recently, we construct an image classifier framework based on deep learning workflow on top of a deep learning engine CAFFE (convolutional architecture for fast feature embedding) to handle big data from power grid equipments. However, we identify a major drawback of CAFFE in our implementation that when the input training images stay in the same category in a continuous period, CAFFE’s model is invalid regardless of the size of the training set. To bridge the gap, we introduce a preprocessing mechanism into deep learning-based classifier. This mechanism improves the adaptability of classifier to images of arbitrary size and sequence, and reduces the time to convergence of training the classifier. Experimental results show that our framework is able to classify images of different devices more accurately with much less training time.

Jun Yin, Yongxin Zhu, Weiwei Shi, Yunru Qiu, Xingying Liu, Gehao Sheng

Whether the High-Voltage Transmission Lines Have Enough Load Capacity After Wildfire

Wildfire which caused by a variety of reasons seriously affects the safe and stable operation of the high-voltage transmission lines, and the load capacity research of the high-voltage transmission lines after wildfire is particularly important. In the experiment, the average tensile force of three kinds of aluminum cable steel reinforced (ACSR), which are new, actually burned by wildfire and burned by simulated wildfire with firewood, respectively, is tested. The results show that the safety value of load capacity of the transmission lines is 15 kN. In the case where the horizontal span, height difference, and the maximum sag are known, the lowest point’s horizontal tension of arc sag of the high-voltage transmission lines can be calculated. If it does not exceed 15 kN, even if the transmission lines subjected to wildfire, load capacity is greater than the tension of transmission lines. So it can usually operate safely. If the lowest point’s horizontal tension exceeds 15 kN, in the process of design and installation of the high-voltage transmission lines, by properly increasing maximum arc sag of transmission lines, the tension of the lowest point of arc sag is not more than 15 kN.

Tianzheng Wang, Zhen Tang, Xinwei Wang, Jinzhao Yang, Xiaogang Wu, Kechao Zhao, Chong Zuo, Weiyi Chen

Design and Analysis of the Hydraulic System of the Small Slide Loader

The working theory of chain shotcrete machines was introduced. By analyzing the relationship between plungers’ moving rules and beton throughput, as well as the relationship of the sending wind hole, we can acquire the best way and provide other designers the theoretical basis to design the chain shotcrete machines.

Kailin Feng, Guanguo Ma, Yipeng Chen

An Extended Kalman Filter Application on Moving Object Tracking

In this paper, the problem of moving object tracking on 2D plane is addressed by combining uncertain information from measurement of the object to accurately estimate its trajectory. Due to the nonlinear motion model of the tracked moving object, the extended Kalman filter technique (EKF) is applied. In particular, the models of object motion and measurement including noise are established. After substituting those models to the equations of EKF, an optimal estimated trajectory can then be rendered that stays as close to the expected one. An example is given to perform the process of EKF algorithm. Simulation results with Monte Carlo simulation are shown to verify the validity of the EKF in solving the moving object tracking problem.

Yuan Niu, Lisheng Hu
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