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About this book

This Proceedings volume gathers outstanding papers submitted to Proceedings of China SAE Congress 2018: Selected Papers, the majority of which are from China – the largest car-maker as well as most dynamic car market in the world. The book covers a wide range of automotive topics, presenting the latest technical advances and approaches to help technicians solve the practical problems that most affect their daily work.
It is intended for researchers, engineers and postgraduate students in the fields of automotive engineering and related areas.

Table of Contents

Frontmatter

Performance Simulation Study of Vehicle Engine Cooling System

The cooling system is an important subsystem of the engine, and its performance directly plays a key role in engine performance. In this paper, the vehicle cooling system model is built up with AMESim, which taken the CFD simulation results of the wind speed field and temperature field as input, to simulate the cooling system under the limit steady-state conditions such as low-speed and high-load, high-speed climbing, and NEDC transient conditions. We can calculate the water temperature rise curve of the transient condition, and balanced water temperature of steady-state conditions, and then compared with the test. The result verifies the correctness of the cooling system model. Simulation and test were carried out on a car with I-type radiator and U-flow radiator respectively. The final result shows that the I-type radiator is equipped with better cooling performance.

Xin Li, Liang Zhu, Yongcheng Zhu, Zhixin Zeng, Jujiang Liu

Study on Thermal Simulation Technology of Liquid-Cooled Power Battery Pack Based on Coupling of Equivalent Circuit and Heat Flow

In the process of electric vehicle operation, the heat generated by the battery charge and discharge will cause the temperature of the battery to rise, and the temperature will affect the performance, service life and even combustion explosion of the battery. In the development of power battery pack, it is necessary to simulate and analyze the temperature field in the battery pack and combine the test of the battery bed to ensure that the thermal performance meets the requirements in the operation process. In this paper, the thermal simulation analysis model of the battery pack based on the coupling of equivalent circuit and the heat flow was established, and its simulation results were an agreement with test results. It is shown that the simulation method is correct, which can provide advices and suggestions for the design and development of EV power battery pack.

Weimin Wang, Yisu Ye, Jinpeng Yu, Kun Zhou, Yang Xia, Hongtao Li, Renhe Xu

Crack Analysis and Structure Optimization of Torsion Beam Mounting Point

The torsion beam mounting point, one of the important connection points between the car body and the chassis, is very important for the normal running and safety of passenger cars. The rear torsion beam structure is a very mainstream chassis-rear suspension system. The reliability of torsion beam mounting point is related to passenger’s safety, which should not be ignored. So, the study of the factors for the strength and durability of the torsion beam installation point, ensuring the performance meeting the durability and strength demand is very important. In this paper, by analyzing the stress and strain of the structure and using structure comparison and topology optimization method, we summarized the affecting factors and the optimization ways of the durability of the torsion beam mounting point, which provided guidance for the torsion beam mounting point design of further vehicles.

Yan Li, Junfei Yan, Ming Gao, Lizhong Mao, Hongsheng Tian

Measurement and Modeling of Hysteresis in Pneumatic Actuator Under Different Loading Rate

A hysteresis model under different loading rate is proposed based on measurement results with simple polynomial method. This model will be used for better control and compensation of pneumatic actuator in actual application. The hysteresis model is achieved using simple polynomial method based on measurement data. Six groups of testing data are collected under different loading rate from quasi-static (2 kPa/s) to 25 kPa/s at growth rate of 5 kPa/s. History independence research is also conducted in order to understand more detailed hysteresis feature of pneumatic actuator. Based on measurement results, it is concluded that the hysteresis model is effective to describe the effect of stroke and loading rate on the hysteresis. The history independence of hysteresis study validates the model is robust enough.

Yunbin Gong, Henry Guo

Airflow–Resistance Analysis of Cooling Module Based on CFD Method

To explore the relationship between the supply air rate and the resistance of the cooling module itself, this paper provides a simulation method for cooling front module and single cooler supply air rate and wind resistance. Using the matching method, the monomer with the same characteristic structure is simplified to porous medium, and its characteristic parameters are obtained, the CFD is used to simulate the problem, and the accuracy is verified by the test; and the wind speed–resistance characteristics are simulated by the superposition of multiple monomers, and the results are verified. This method can accurately predict the wind resistance of the cooling system during the design stage and provide a basis for the selection of the scheme.

Yao Zhang, Bin Liu, Bo Liu, Hongtao You, Yan Zhao

Numerical Simulation and Experimental Study of a Vehicle Exhaust Heating Heat Exchanger

Shell-and-tube heat exchanger is a product with simple structure, mature technology, and convenient use. The heat exchanger mentioned in this study is used in a vehicle exhaust heating system, which uses the exhaust heat of the engine to heat the air inside the vehicle, improve the internal heating effect of the vehicle in the cold season, realize waste turning into treasure, save energy, and reduce emissions. In this study, CATIA three-dimensional software is used to carry out detailed modeling of heat exchangers. The flow path which is extracted from ANSYS software and simplified is divided into mesh. The appropriate boundary conditions are used to calculate the CFD three-dimensional numerical simulation, calculating the velocity field, temperature field, and pressure field inside the fluid heat exchanger at different temperature inlets. The test platform is used to test the temperature field of the heat exchanger. The simulation results are in good agreement with the experimental test data, which provides a good research method for heat exchanger design and performance prediction.

Yan Zhao, Wenjie Hu, Jianjun Meng, Hongtao You, Yao Zhang

Research on Road Simulation Accelerated Durability Test Method for Front Swingarm

Ability to reproduce the fault of proving ground and user use is poor, which uses the traditional durability test method of the front swingarm bench. However, the road simulation test method is able to accurately reproduce the real road load spectrum of the swingarm, which has good validation results. The article focuses on accelerated editing the target response signal of swingarm, a new method for compressing and reconstructing the time-domain load spectrum, is put forward based on the intensified extrapolation and superposition of the load rainflow matrix according to the experimental conditions so as to further shorten the bench test period. The mean cycles of the load rainflow matrix were corrected, according to the Goodman method. And the S-N curve of the swingarm is calculated according to the nominal stress method. The damage degree of the measuring point load of the swingarm is compared before and after accelerated editing. The equivalence relation between the reconstructed spectrum of rainflow matrix and the original load spectrum was verified. Finally, the results showed that the speed-up ratio of the simulation iterative target response signal of the swingarm reaches 78.8 times compared with the road test at the proving ground, which is 2.4 times compared with the traditional bench test standard. A bench test was performed to verify that this accelerated editing method is effective.

Zhenliang Yang, Songbo Zhang, Jianke Jia, Junjun Fu, Jiangtao Zhai

Optimization and Investigation on SNR of Engine Mass Airflow Sensor

In this paper, aiming at the problem of the signal-to-noise ratio exceeding the target of the mass airflow sensor in an engine air intake system test, it is analyzed to the overall flow state of the air intake system via the CFD analysis software STAR CCM+. Based on the K−ε turbulence model, the reason for the signal-to-noise ratio exceeding the target is studied through numerical analysis. The rationality and feasibility of various optimization proposals are explored. Finally, the optimization proposal of the rectifier grid is adopted. The optimized results are tested and verified that signal-to-noise ratio of the optimized intake system meets the design requirements.

Zhaojing Wang, Xiaomao Zhang, Ming Chen, Zheng Xu

Luggage Retention Optimization Design for Rear Seat of Vehicle

This paper focuses on a vehicle with rear seat adjustable backrest, analysis of validation phrase rear luggage retention test failure, to find the weak position of the rear seat frame structure. Optimize the backrest frame from two aspects, collide energy transfer direction and frame structure strength, and release reasonable structure improvement proposal from the perspective of cost reduction and lightweight, combining simulation analysis and physical verification. Optimized structure of the rear seat frame can meet the design specification, saving project cost, shorten the development cycle, reduce development risk.

Junhui Liu, Jianjun Huang, Miao He, Zhaoliang Gou, Chi Dai, Zhou Zhang

Analyzing and Optimization the Resistance Welding Spots of a Trunk Lid Hinge Reinforcement Plate

Based on the finite element method (FEM), this research focused on the trunk lid hinge reinforcement plate welding spot crack problem. The number of the resistance spot welding (structure adhesives) and the structure of the hinge reinforcement plate are analyzed, and we found the method to solve the trunk lid hinge reinforcement plate welding spot crack problem. The stress of trunk lid inner panel was reduced from 128 to 80 Mpa, the fatigue life was increased to more than 10,000,000 from 248,000 by CAE simulations, and the CAE simulations have been effectively verified with the prototype test.

Zhiqiang Huang, Li Han, Yujie Tian, Kai Kang, Junping Qiao

Cross-Sectional Optimal Design of 6082 Aluminium Alloy Anti-collision Beam Based on the Crash Simulation Analysis Using LS-DYNA

Four cross sections of 6082 aluminium alloy anti-collision beam were designed for one car. Based on the crash simulation analysis using LS-DYNA, the deformation and energy absorption parameters of 6082 aluminium alloy beam were obtained.The results of crash simulation for a rear low-speed impact indicated that the invasion of the collider was minimum and the effect of energy absorption was optimum, when the tangent angle of cross section between arc rib and horizontal plane of the anti-collision beam was twenty degree.Finally, the pendulum test revealed that the performance of this 6082 aluminium alloy beam satisfied with performance requirements, when the tangent angle of arc rib cross section of the anti-collision beam was designed to the twenty degree.

Zhimin Liu, Jingchen Huo, Chunxiang Liu, Bensheng Xiong, Bo Gao, Junping Qiao, Zhuqing Cheng

Management and Innovation of Robot in Automobile Production Line

Automobile automatic production cannot be separated from a large number of industrial robots, but robots will have a variety of problems in practical applications. Aiming at this problem, this paper makes a breakthrough from innovation of robot management, innovation of maintenance technology and skilled talent training, lists the innovative methods used in the robot management, shares the technological innovation and inventions in the maintenance work, and shows several items for the innovation and reuse of the scrapped robot. In the face of mass use of industrial robots, the equipment management methods and special talents training ways of automobile manufacturing companies are discussed in all directions.

Feng Chang, Maowei Jie, Wei Liu

Design of Automatic Feeding System for White Body Welding Production Line

In order to solve the problem of automatic feeding of multi-model and heterogeneous body sheet metal parts, this paper designs a system for automatic assembly of top cover sheet metal parts. The system adopts the key technologies such as reliable picking, precise feeding and automatic replacement of material rack. Moreover, the special system is incorporated into the automated welding line. Finally, a comprehensive comparison is made between the technological process before and after the improvement. From the efficiency, economy, reliability and other comparison results, it can be seen that the new technology has a significant advantage, to enhance the white body welding production capacity.

Lin Yang, Xiaobo Wang, Xuefeng Zhu

ODISSEE Test of ABS Anti-lock Braking System

The hardware composition and software testing principle of ODISSEE communication equipment for ABS anti-lock braking system of car are studied. According to the function test requirement of ABS, ABS initialization test and ABS start test, ABS static test, ABS dynamic test, ABS stop test, ABS write process, ABS result test, WSS wheel speed sensor test, etc are carried out in turn. According to the value of ABS dynamic test, the braking force of the four wheels is calculated to meet the requirements of the regulations; the operator interface during the testing process shows the test steps, the operation of the test requirements and the test results in time, which is convenient for the operator to operate the test. This paper can be used as reference for equipment maintenance technicians and automobile testing technicians.

Ruicheng Zhang

Design, Development, and Application of Industrial Engineering in New Factory Assembly Workshop

Established on October 18, 2002, Beijing Hyundai Motor Co., Ltd. It is the first Sino-foreign joint venture project in the field of automobile production approved after China’s accession to the WTO. Beijing Hyundai Motor Co., Ltd needs to have a production capacity of 1.8 million units by 2020 to ensure its market share of Beijing Hyundai Motor Co., Ltd as passenger vehicles in China have been growing at a growth rate of more than 7% in recent years. Therefore, on the basis of the original three factories, two complete vehicle manufacturing plants with an average annual capacity of 300,000 capacity will be added. As the department with the most complex production process and the largest number of operators, the final assembly workshop, its scheme in the design stage of the new factory will directly affect the operating efficiency of the lean production of the whole factory. Therefore, this thesis to Beijing modern new factory in assembly workshop in the industrial engineering design improvement project of systematic application as the research object, using all kinds of basic design method of industrial engineering discipline and philosophy, emphatically analyzes the old assembly workshop design, internal logistics operation man–machine design defects existing in the operation, at the same time, combining with the plant design in front of the stage as a whole, put forward the improvement in the material system, reduce the man–machine operation fatigue strength, improve production efficiency, and so on comprehensive application of basic industrial engineering work method research strategy, action analysis and economic improve study method; based on the application of industrial engineering expertise, the optimized system design scheme is obtained, which provides systematic basis for the planning decision of final assembly workshop material design.

Yangwen Zhu

Design of Rear Floor of Automobile Flexible Automatic Welding Production Line

With the increasing production capacity of DongFeng Honda second factory, the cost of labor, workers labor intensity, quality, and process stability faces enormous challenges. DongFeng Honda no. 2 welding department promotes to sustain economic restructuring automation project step by step to achieve goals to reduce manual labor costs and improve the quality of body. The no. 2 welding department promotes to carry out the manual line renovation project of rear frame and rear panel to flexible automatic production line. Through the optimization of design by installing 10 welding robots, 3 handle robots, 1 gluing robot, and 1 stud welding equipment to realize 6 models of vehicle production in the same flexible line. Through the automation renovation project, we can realize cutting 22 workers and welding points automation rate increase 4.25%,and it cut down labor cost 2.48424 million RMB per year. It is not only achieved to reduce manual labor cost and improve the quality of the body, and the purpose of ensuring process stability, but also the automation can provide strong quality guarantee and cost reduction for the follow-up new model introduction.

Zhiyang Wan

White Body Flexible Welding Line Development and Application

Dongfeng Renault’s multi-type welding line project in the Chinese city of wuhan will be summarized in this article. And we will focus on the new process scheme, process layout and its program features applied in the Dongfeng Renault project and the realization of multi-variety model mixed-flow production. A variety of solutions was introduced, and the features of each line in the project were explained. It will provide a high reference value for the development of welding lines for multi-variety models of similar welding equipment projects in the future.

YongSheng Fu, Xiang Li

Probability Density Evolution Method for Vehicle Dynamics Analysis Under Uncertainty

Because of the uncertainties and highly nonlinear characteristics of intelligent vehicles, how to control the motion of intelligent vehicles more accurately and effectively has become the key to the development of intelligent vehicles. In this paper, based on the nonlinearity and parametric uncertainty of the suspension system, the probability density evolution method is used to analyze the variation of the probability density of the suspension dynamic response over time, in order to facilitate more effective motion control. Combining the dynamic random state equation of the suspension and the probability conservation principle in the conservative stochastic system, the generalized probability density evolution equation for vehicle random vibration is established. Considering the nonlinear stiffness of the hydro-pneumatic spring in the suspension system and the uncertainties of the parameters, such as the suspension and the tire, the stochastic vibration response analysis was performed with the sprung-mass acceleration response as an example. The random probability space is discretely selected by the number-theoretic method. Finite-difference method such as Lax-Wendroff scheme and TVD (Total Variation Diminishing) scheme is used to numerically solve the generalized probability density evolution equation, and the variation of the probability density of the response is obtained. The probability density evolution method has good calculation accuracy and can give specific probability distribution information, which lays a foundation for subsequent motion control.

Xiaokai Chen, Hao Lei, Cheng Zhang, Jiahui Liu

A Study on the Influence of Mass Change on Vibration Characteristic of ISD Suspension

In order to study the influences of mass variation on vibration response characteristics of ISD suspension, the ISD suspension composed of four elements is established. Body acceleration, suspension travel and dynamic tire load as the assessment criteria are studied in the time and frequency-domain simulation with sprung and unsprung mass increased and decreased by 50%, respectively. The results show that the root mean square (RMS) of body acceleration reduces and the RMS of suspension deflection increases with the increase of the sprung mass. The RMS of dynamic load increases with the increase of unsprung mass. In the low frequency (0–5 Hz), the peak value of low-frequency resonance of suspension dynamic travel and dynamic tire load increases significantly. In the high frequency (5–15 Hz), the resonant frequency decreases and amplitude increases with the increase of the unsprung mass. Compared with the traditional passive suspension, when the sprung mass is increased by 50%, the RMS of body acceleration, suspension dynamic travel and dynamic tire load are decreased by 6.92, 4.48 and 4.02%, respectively. When the unsprung mass is increased by 50%, three factors are decreased by 6.31, 20.32 and 5.96%, respectively. It indicates that ISD suspension possesses better ride comfort and handling stability when the mass varies due to the coupled vibration effect of inerter.

Xiaofeng Yang, Hongchang Li, Yanling Liu, Yi Yang, Wentao Zhao

A Study on the Mechanical Properties of Tire in the High-Speed Frontal Impact Condition

The simulation accuracy of the tire model has an important effect on ensuring the simulation accuracy of the vehicle model in vehicle frontal crash simulation. A tire sub-model is set up based on the data of a Changan vehicle tire, and dynamic impact analysis for the tire is performed with a certain velocity. Tires’ acceleration, speed, and deformation parameters of mechanical properties are acquired and compared with the tire impact test data. Then, the tire finite element model is optimized through comparing the tire performance parameters with the test results. After that, it is applied to the simulation model of high-speed frontal crash condition to analyze the effect of tire simulation method on the consequences. Comparative analysis is performed between simulation and test. The results show that the vehicle acceleration and tire deformation in the vehicle crash model are more consistent with the test after optimization of the tire model, thus improved the simulation precision of tire model in simulation analysis.

Fangxia Yang, Taisong Cui, Bo Dian, Bo Wei

A Method for Estimating the Vertical Load of Tires

The vertical load of tire affects the lateral force and longitudinal force of the tire, thus affecting the longitudinal dynamic characteristics and lateral dynamic characteristics of the vehicle. In vehicle dynamics control, real-time and accurate estimation of wheel vertical load is the basis for calculating other important vehicle motion state parameters. However, there are many shortcomings in the formula of estimating the vertical load of tires at present. One is strong pertinence and poor universality; two is too much simplification and low estimation precision; three is different expression form, poor readability, and poor normalization. Aiming at these problems, the formula for calculating the vertical load of tire is given in detail and verified by CarSim. The simulation results confirm the advantages of the formula.

Kaifeng Zheng, Zhaoyang Mi, Chao Wang, Yuanxiang Liu, Xiaoce Sun

The Characteristic of Transient HC Emissions During Cold Start on A Port-Fuel-Injection Gasoline Engine

The percentage of HC emission before catalyst light-off is beyond 90% in WLTC driving cycle. It is a big challenge to reduce the HC emission during cold start phase due to poor mixture preparation from port injection spark ignition engines. This study focuses on cold start period to investigate HC emissions based on cycle-by-cycle method, using fast FID HC analyzer (HFR500) and cylinder pressure indicating system. The results have been compared with two different types of fuel injectors installed on a 1.5-L port-fuel-injection gasoline engine. The transient HC emission of first 10 cycles has been analyzed. The test results also show that HC emissions of the type B injector (8-hole) are 11% lower than that of the type A injector (6-hole) under same fuel injection strategy.

Huan Chen, Chuanhui Cheng, Honglin Xu, Tao Wu, Zheng Xu, Yunchao Wang

Research on Hybrid Electric Vehicle Engine Heating-Up Process and Fuel Consumption by Applying Auxiliary Heaters

Based on an engine of hybrid electric vehicle, the effect of auxiliary heating system on heating-up time and fuel consumption during the heating process of engine cooling system is investigated by the combination of experiment and simulation. The experimental results show that the auxiliary heating can obviously shorten the heating-up time and reduce the fuel consumption of system, regardless of synchronous heating or preheating. The fuel heater has a shorter heating-up time, while the PTC heater is more economical and green. The simulation results show that the body temperature has a great influence on the heating-up time of the cooling system, and the heating-up time of the coolant can be shortened obviously by using the auxiliary heater. In this research, the experiment and simulation are complementary and related to each other. The influence of auxiliary heating on the heating-up time and the fuel consumption are quantified. The purpose of this research is to find a way to shorten the heating-up time and improve fuel economy of hybrid power system.

Ping Sun, Chuanzhao Yao, Wei Dong, Shaozhen Liu, Ling He, Xiumin Yu, Huichao Zhao

Adaptive Steering Stability Control for A Four In-Wheel-Motor Independent-Drive Electric Vehicle

This paper proposes an adaptive steering stability control strategy for a four in-wheel-motor independent-drive electric vehicle (4MIDEV) to improve its stability on the road with different adhesion coefficients, such as on the joint road. The proposed strategy is designed as a hierarchical structure whose upper control level takes the road adhesion coefficient into account in the yaw moment control and realizes the integrated control of the yaw rate and sideslip angle. The lower control level adopts a weight-based optimal allocation algorithm to achieve different weight control of each motor torque according to road adhesion coefficient. The proposed stability control strategy was validated in a co-simulation of the Matlab/Simulink and Carsim, the results of which indicate that the proposed strategy can effectively adapt to different adhesion coefficients and achieve good steering stability control effect.

Rufei Hou, Li Zhai, Tianmin Sun

Comparative Study on the Performance Prediction of Fuel Cell Using Support Vector Machine with Different Kernel Functions

The performance attenuation characteristics of fuel cell stack show a strong nonlinearity, but there is still no good model to predict its nonlinear attenuation characteristics. Support vector regression (SVR) is used as linear regression algorithm and realizes nonlinear regression function by introducing kernel function. Based on the test data of 4 kW fuel cell stack running 600 h on the bench, the results of using the SVR model with Gaussian radial basis kernel function (G-RBF), sigmoid kernel function, polynomial kernel function, and mixed kernel function to predict fuel cell performance are compared. The results show that the SVR model with polynomial kernel function has higher prediction precision.

Hanqi Ye, Xiaojun Ma, Tianxin Yang, Yongping Hou

Magnetic Field Distribution of Resonance Coupling Coils of 7.7 kW Wireless Charging System

This paper designs a 7.7 kW power resonance wireless charging system for electric vehicles. The resonant frequency of this system is 85 kHz, and the coupling coil adopts LCC compensation circuit. A wireless charging system circuit model was built and simulated by MATLAB/Simulink to obtain the currents on the primary and secondary coils. The 3D FEA software ANSYS Maxwell was used to model circular coils with ferrites to predict the magnetic field distribution in the vehicle environment. According to the SAE J2954, four points on the body and the surrounding area and four points on the driver’s seat were selected as markers, respectively. Studying three working conditions of the alignment and offset of the coupling coil, the magnetic field distribution of the entire coupled coil and each marker are observed. A pair of aluminum shielding shells was designed for the magnetic field distribution of the coupling coils. The magnetic field strength of the coils with or without shielded aluminum shells was simulated and compared. Then, the inhibitory effect of the shielding shell on the leakage magnetic field of the resonance coupling coils was verified. Safety of magnetic field distribution of a wireless charging system with a shielded aluminum shell was explained.

Guangyuan Zhong, Li Zhai, Guixing Hu, Yu Cao, Liwen Lin

Fatigue Design of Rubber Mount for Automobile Powertrain

In this paper, taking the vehicle powertrain anti-torsion mount as the research object, the stress and strain curves of its rubber material were first tested, and then the Ogden hyperelastic constitutive model was used to simulate its mechanical performance. Based on the accurate simulation of its stiffness characteristics, the finite element model in Abaqus was calibrated. Based on the theory of strain fatigue of rubber material, the ε-N fatigue curve of its rubber material was determined by the experiments, and its rig fatigue life was calculated and optimized. The rubber material fatigue curve has been corrected according to the durability test results of the rubber structure, and then its fatigue life on the vehicle driving endurance test is forecasted eventually.

Xiaoqiang Deng, Haoju Hu, Junjie Qiu, Shubin Ye

Study on the Green Wave Optimal Speed Guidance System Based on V2X

In order to improve the city’s traffic efficiency, this paper presents a green wave optimal speed guidance system based on V2X (Vehicle-to-Everything) and the method to calculate the optimal velocity. All vehicles of the system should be equipped with V2X-Boxes which can broadcast the ID, time, location and speed of the vehicle while receiving the messages from other V2X-Boxes and the traffic light status from roadside unit (RSU) in real time. The V2X-Box calculates the optimal speed by acceleration guidance method and deceleration guidance method, which not only increases the number of vehicles passing through the green light, but also provides green wave optimal speed guidance for vehicles entering the arterial road from the bypass. This system guarantees all road-running vehicles through traffic lights without stopping.

Bo Yang, Ying Zhang, Zhijun Cai, S. Ted Huang, Qigao Feng

Automatic Driving Joint Simulation Technology and Platform Design

In order to improve the production development of automatic driving technology ability, this paper puts forward a hybrid platform to establish virtual joint simulation technology. This platform includes sensor module, vehicle dynamics module, scenario module and control algorithm module in order to solve the automatic questions including roads of all weather conditions, sensor-type selection design, automatic control algorithm, driving performance testing and other difficulties which are complex to validate. Through the virtual joint simulation platform, autonomous driving performance can be improved in the simulation, and it is a reasonable method to realize automatic mass production.

Ji Song, Rongjun Huang, Wei Zhang, Qinghe Liu

Research on the Decision Control Methods and Ride Comfort of Autonomous Vehicle

In this paper, the comfort of automatic driving vehicle is improved by optimizing the decision control algorithm, and the comfort of the vehicle in different acceleration conditions is analyzed by experiment and simulation. According to the standard of ISO2613, ISO15622 and passenger somatosensory response, the riding sense grade of automatic driving vehicle is divided, and the rationality of ride sense classification is verified by real car test.

Pingfan Jin, Guilong Li, Caijing Xiu, Guoqi Zhong, Jishun Guo

A Research on the Adaptive Cruise Controller for Electric Bus

The intelligent trend of vehicles became irresistible, and the application of adaptive cruise control systems to different vehicles, especially to electric vehicles, became a trend. The application of adaptive cruise control systems played a significant role in environmental protection, road-traffic efficiency and safety. In this paper, we proposed a hierarchical controller for the adaptive cruise system of the electric bus. Based on millimeter wave radar, target tracking and recognition algorithms for straight and curved conditions had been performed. In the upper controller, a proportional differential control algorithm had been adopted based on the vehicle spacing with variable time-headway, and its stability had been proved. In the lower level controller, the lookup table for acceleration and braking had been designed based on test data and a switching rule for acceleration and braking had been formulated. The results of offline simulation and hardware-in-loop (HIL) simulation showed that the adaptive cruise controller designed with mature control strategy can achieve faster and more accurate control response, real-time performance and was suitable for application on real vehicles.

Xiaoliang Li, Xudong Zhang, Yuan Zou, Tao Zhang, Shouyang Wei

Combustion System Design and Development on 1.4L Miller Gasoline Engine

In order to meet fuel consumption regulation China Phase 4 and emission regulation China 6, China FAW (First Automobile Work) developed a 1.4L GDI miller engine. The cam profile and turbocharger were optimized and designed by one-dimensional thermodynamic analysis. A delicate design of high compression ratio, spray target, and intake port was realized by Computational Fluid Dynamics (CFD) analysis of in-cylinder flow, atomization and mixing. The combustion system was finally settled based on optical and thermodynamic engine with the primary target: The specific power is 79 kW/L, the specific torque is 168 N m/L, the Brake-specific fuel consumption (BSFC) is 225 g/kW h and the maximum thermal efficiency is 37.5%.

Zhanfeng Wang, Yaodong Liu, Haie Chen, Pinghui Huang, Yunfeng Han, Ziming Liu

Diesel Engine Cylinder Deactivation Experimental Research on Asymmetric Exhaust System

The exhaust temperature could be increased to heat DOC and promote DPF regeneration by part of cylinder deactivation in low load condition. In the article, with asymmetric exhaust system and EGR valve, cylinder deactivation can be achieved. The advantages and disadvantages of diesel engine cylinder deactivation are analyzed by experimental and modeling methods. Besides the keys factors are given. For test engine, cylinder deactivation can raise the exhaust temperature by 160 °C. Totally, the fuel consumption drops by 3%. In theoretical extreme situation, the airflow ratio of half deactivated cylinder and normal condition is located from 1.29 to 1.34, which is influenced by booster efficiency in greatest degree. The fuel consumption and NOx emission increase in some conditions for lower air-fuel ratio and not optimized injection parameters, and further calibration and booster efficiency promotion are helpful.

Peng Zhou, Jianrui Zhang, Zhengxing Zhang, Baoyu Hao, Yun Lu

Combustion and Emission Characteristics of Soybean Oil Biodiesel (SOB) and Gasoline Blends in a Partially Premixed Compression Ignition Engine

In the previous studies, partially premixed compression ignition (PPCI) combustion can obtain good combustion controllability, performance and emissions in diesel engines with gasoline. This article focuses on achieving soybean oil biodiesel (SOB)/gasoline PPCI combustion in a single cylinder diesel engine through moderate and low operating loads. Combustion and emission characteristics of SOB and gasoline blends in a PPCI engine have been studied. The results show that low temperature ignition property of gasoline can be improved by doping SOB. The best SOB addition is 30% in volume fraction which has the highest indicated thermal efficiency: 52%, and better emission characteristic compares to pure gasoline. Further experiments on PPCI combustion of 30% SOB/gasoline blend with different fuel injection timings and exhaust gas recirculation (EGR) ratios have been carried out to find out impacts of fuel injection timing and EGR on PPCI combustion. The results show that both the fuel injection timing and EGR can affect performance and emissions of the PPCI engine. For the consideration of engine emissions and efficiency, 12 ºCA BTDC fuel injection timing is the best choice. 26% hot EGR (EGR without cooling) and 40% Quasi-EGR (CO2 as an EGR simulation gas) are the best for low load (0.158 MPa BMEP) and moderate load (0.395 MPa BMEP), separately. When EGR ratio increases to 50%, both hot EGR and Quasi-EGR could reduce NOx emission more than 70% while the fuel consumption increases slightly.

Qian Li, Jing Lang, Xianghong Nie

The Deblocking Function Optimal Design for a Continuous Variable Valve Lift System

In order to optimize the deblocking characteristics for a hydraulic motor-driven CVVL system, we abstracted the working process of internal shaft actuator and investigated the parameters which could significantly affect system deblocking characteristics by simulation and test methods. The results show that: (1) Increasing the locking pin clearance can extend the time length of rotation movement under the same unlocking speed, which is able to improve system deblocking performance. (2) Replacing step unlocking signal by slope unlocking signal will restrain rotation and unlocking movement simultaneously, while rotation movement is affected more obviously due to the differences in oil chamber volume. (3) Stick issue has been solved after lower limit of locking pin clearance was adjusted to 0.5°, and the signal slope was well restricted. The optimal design method mentioned in this paper can be popularized in similar systems and brings more conveniences on the deblocking study and critical parameters definition.

Mingxi Liang, Cheng Liu, Wenxin Cai, Cheng Meng, Jian Wan, Liu Hong

Research on the Design Method and Vibration Reduction Performance of Dual-Mass Flywheel

This study introduces the operating principle of dual-mass flywheel (DMF) and establishes the dynamical equations of transmission system based on the theory of forced vibration and vibration reduction. Coupling with empirical parameters, the rotary inertia distribution of DMF and the torsional stiffness design of DMF are also established. The second-order torsional vibration natural frequency (8.5 Hz) and other main order frequencies of engine under idle speed are proved to be deviated from the excitation frequencies through the modal analysis. The test shows that the resonance appears at around 255 r/min under starting condition, which matches well with the simulation. Under idle speed, the engine angular acceleration fluctuation decreases by 83.5% by using DMF. Under driving condition, the angular acceleration of gearbox input shaft is much lower than that of engine, while under driving WOT of second gear condition, the gearbox angular acceleration is only 141 rad/s2 compared with 1947 rad/s2 of the engine maximum angular acceleration, and the two angular accelerations of the transmission system with CTD, both around 430–930 rad/s2, have no great difference. The result shows that the method of designing DMF is reliable, providing a new design concept of DMF.

Haipeng Luo, Guangquan Wu, Qi Wu, Wenfeng Zhan, Jiang Yang, Lin Xu

The Influence of Methanol Mass Ratio and Compression Ratio on Combustion Characteristics of Dual-Fuel Engine

A study was conducted in a dual-fuel engine to explore the influence of methanol mass ratio and compression ratio on the combustion characteristics, and a set of methanol injection device was installed on a single cylinder diesel engine. The results show that, with the increase of the methanol mass ratio, the in-cylinder pressure gradually decreases, the pressure rise rate and the heat release rate increase firstly and then decrease, the start of combustion gradually postpone and combustion duration gradually short. The decrease of the compression ratio causes the increase of the peak heat release rate, but it has complex effects on the peak in-cylinder pressure, the peak pressure rise rate, start of combustion and combustion duration. When the compression ratio is 15.9, the peak in-cylinder pressure and the peak pressure rise rate are highest, the start of combustion is earliest and the combustion duration is longest.

Peng Li, Jianjun Zhu, Wenjie Wu

Mechanical Properties Research on Cylinder Head Based on Simulation of Secondary Dendrite Arm

Firstly, the qualitative relationship is verified by test data between secondary dendrite arm spacing (SDAS) and tensile strength (σb), and the quantitative equation is $$ \sigma_{b} = 641.75({\text{SDAS)}}^{ - 0.2 8} $$ , deduced by the linear regression method. Meanwhile, Furer–Wunderlin formula is equivalently transformed to $$ {\text{SDAS}} = A^{ *} \times \left( {T_{\text{s}} } \right)^{1/3} $$ by modifying the constant part to A*. Then, the method is deeply studied to get SDAS rapidly and accurately. The first step is to obtain actual local solidification time (Ts) by calibrating solidification temperature by casting simulation and measurement. The second step is to calculate SDAS by modified theoretical formula ( $$ {\text{SDAS}} = A^{ *} \times \left( {T_{\text{s}} } \right)^{1/3} $$ ). The third step is to calibrate proper A* by SDAS test data. Finally, the research method is applied to the same kind of aluminum alloy cylinder head development, the head passed the reliability test one time and reduced test cost-effectively and improved the quality significantly. One of the study results is that SDAS and tensile strength ( $$ \sigma_{b} $$ ) have quantitative relationship: $$ \sigma_{b} = 641.75({\text{SDAS)}}^{ - 0.2 8} $$ . SDAS sample is obtained easier than tensile strength specimen and breakthrough the limitation of the tensile strength specimen from the product. SDAS can be as an indicator to evaluate tensile strength in the early stage of product development. The other is that the method to get SDAS is innovative and feasible by combining with cast simulation and modified theoretical formula ( $$ {\text{SDAS}} = A^{ *} \times \left( {T_{\text{s}} } \right)^{1/3} $$ ), but it is necessary to calibrate two key parameters of local solidification time Ts and A*, and the proper A* is ranged from 6.5 to 7.5 for aluminum alloy cylinder head.

Zhengfeng Jia, Tao Liu, Qingqiang Zeng, Huibin Qing, Huixian Shen

Analysis of Energy Absorption Characteristics of Typical High-Strength Steel Based on Drop Test

The drop test is an important method to analyze the energy absorption characteristics of materials, which causes the sample to collapse axially and absorb energy by initial energy impact. Hat-shaped beam is a typical structure of energy absorber of front longitudinal beam of automobile. It is widely used for its lightweight, high strength, and good energy absorption. Select four typical high-strength steels: HC340LAD + Z, HC420/DP780D + Z, HC550/DP980D + Z, and TRIP690, the cap girder structure is obtained through stamping and welding, and the test is taken based on the drop test. According to the test results, evaluation indexes such as energy absorption ratio, load ratio, maximum load, and average load are obtained, and the energy absorption characteristics of the materials are compared and analyzed. The results show that the energy absorption characteristics of different materials are quite different, and the energy absorption ratio of the materials tends to decrease gradually as the material strength increases.

Wei Zhang, Chunguang Li, Jianwei Yang, Lixian Liu, Qing Chen, Fulin Wei

Research on Comprehensive Performance of the PTFE Alloy Materials

The PTFE was used as the main body, and the PEEK was used as the organic filler, using mechanical mixing—cold forming—prepared by the sintering process with PTFE alloy materials. The best formulation of PTFE/PEEK alloy sealing material was determined by test and analysis. The addition of the PEEK organic fillers improved the thermal and mechanical properties of the alloy system and showed good rigidity of high-temperature mechanics. This paper provides a theoretical basis for the application of PTFE alloy in the field of high-performance composite materials.

Bo Lin, Gongqi Jia, Zhi Li

Cracking Mechanisms of Hot-Dip Galvannealed Coatings on CP1000 Steel

In recent years, ultra-high-strength steels are used as structural components more and more. For automobile industry and for different carmakers, different coating layers are chosen for corrosion resistance, such as galvanized (GI) and galvannealed (GA) layers. In this study, a hot-dip galvannealed complex phase 1000 MPa grade (CP1000) steel was chosen as the model material. Different GA parameters were adopted to get different Fe–Zn coating microstructures on CP1000, and bending and tensile loading were loaded on CP1000. Microstructure of the coating layers was investigated using SEM, and the cracking mechanisms of the coating layers were also observed using SEM. It was found that, with increasing GA time, ζ phase decreased on the surface of the coating layers, and more and more δ phase was formed from ζ phase on the surface. Furthermore, with increasing GA temperature, the formation velocity of δ phase got faster and faster. Bending tests showed that cracks could be found at the interface between the coating layers and CP1000 steel, especially when GA temperature was 550 °C. Cracks in δ phase, which were perpendicular to the interface, could also be found. Tensile tests showed that when the tensile strain was low enough, interface delamination could not be found. At the interface, when the GA temperature was 510 °C, cracks perpendicular to the interface could also be found.

Huasai Liu, Libin Liu, Haiquan Wang, Yun Han, Chunqian Xie, Yinghua Jiang

The Influence of Combined Hygrothermal Environment and Load on the Performance of Adhesively Bonded CFRP–Aluminum Alloy Joints

To provide reference and guidance for the design of the adhesive structures of the CFRP–aluminum alloy in the actual service environments, the aging laws of the adhesive joints under the hygrothermal environment and the load were studied in this paper, and a prediction method considering different aging conditions was proposed based on the cohesive zone model. The structural adhesive Araldite® 2015 was selected to fabricate the CFRP–aluminum alloy butt joint, and the durability tests were carried out under the condition of hygrothermal cycle, combined hygrothermal cycle and static load, and combined hygrothermal cycle and alternating load. The residual strength and failure modes of the joint after aging were analyzed. The results showed that the strength of joints decreased markedly after 60 h of hygrothermal cycle. The load further aggravates the aging of the joint, the adverse effect of dynamic alternating load on the failure strength of joint is more obvious than that of the static load; at the same time, the failure mode of joint has changed after aging, and compared to the selected CFRP, adhesive performance decreased more obviously; The damage factors under different aging conditions were defined, combined with the failure criterion obtained by the test, the classical double linear traction–displacement cohesion rule is modified, and the residual strength of the adhesive joint after aging is predicted by numerical simulation analysis.

Jingxin Na, Wenlong Mu, Guofeng Qin, Wei Tan

Shear Stress Analysis and Optimization of Dual-Zone Adhesive-Bonded Steel/Al Joints

As one of the fundamental joints, adhesive joint can be applied to hybrid joints for the complex structures. To improve the material utilization of adhesive, the stress distribution of dual-zone adhesive-bonded joints was studied and optimized. Considering the elastic deformation of adhesives, the analytical models for shear stress of single- and dual-zone adhesive joint were deduced. The analytical model of single-zone adhesive joint for steel/Al was validated by FEA model and test data. Based on the analytical model, the shear stress distribution of dual-zone adhesive-bonded steel/Al joints was optimized. Results of optimization show that the stress level in dual-zone adhesive is higher than the traditional adhesive joint structure, which means the mechanical potential of adhesive can be realized better. The adhesive usage amount in dual-zone structure can be reduced 11.7% by keeping the overlapping length constant and the strength of joints not decreasing. In addition, the adhesive length close to lower stiffness material is longer than the other side which can remedy the defect of stiffness imbalance of adherends.

Xiaokai Chen, Dong Fu, Ziyu Guo, Mengqiang Li

The Study on Lightweight and Cost Control in Vehicle Stamping SE of Material Technology

Automotive simultaneous engineering (SE) plays an important role in the whole cycle of automobile product development, shortening the product development greatly and reducing the cost. As a basic discipline, the major of material has provided technical support in the work of stamping simultaneous engineering and promoted the development of stamping SE. This paper introduces the characteristics of stamping SE and the role which is played by material engineers in various stages of stamping SE. Also, the paper introduces the emphasis on knowledge accumulation, the establishment of material database, material lightweight proposal, and material cost reduction proposal, etc.

Wencai Xie, Xueshuang Wang, Hong Zheng, Zhuang Fu, Mingqi Xu

Application of Shared Concepts in 3D Virtual Assembly

At present, an important direction of intelligent manufacturing is the product’s Digital Twin, “Digital Twin” means virtual three-dimensional models exactly like real objects, so as to help enterprises optimize, simulate and test in the virtual environment before actually putting into production. If the enterprises have a number of product variants and part type and adopt traditional 3D model assembly method, it will occupy a lot of human resources, and limited by a lot of “constraint command”, it is difficult to quickly modify the 3D model of product variant. This is also one of the important reasons that many companies are difficult to achieve the Digital Twin for their full range of products. In this paper, take powertrain as an example use the shared concepts to introduce the 3D virtual assembly method of a platform. This method can build the accurate and real-time Digital Twin with the help of PDM software. The innovation is: (1) the “without Piles Located on” mode of space positioning method for CAD model is implemented; (2) the platform method for the skeleton model is set up; and (3) the platform management standards for 3D model assembly are set up. It is especially suitable for large-scale virtual assembly models such as automobile and powertrain.

Shuaitao Zhang, Junjun Wang, Ning Tian, Hongguang Zhou, Tao Chen, Fei Liu, Shuang Liu

Vehicle Doors Leakage Issue Control and Solve

Leakage issue in production line significantly influences assembly shop FTC and leads to rework cost and risks. For the leakage defect cars, research on rivets’ damage force, rivet sequence, and also use complete car CMM measurement methods can find out the main reason that results in the defect, next use short-term solution to temporarily control the batch issue. At last, optimize the unqualified supplier parts and change rivet sequence to totally solve this issue. Engineering verification shows the whole methods and process are stable and effective.

Zhiqiang Xu, Li Tao, Jinchao Ruan, Tianxin Yang

Microstructures and Mechanical Properties of Butt Joint of A356/6005A Dissimilar Aluminum Alloy by Pulse MIG Welding

The microstructures and mechanical properties of the butt joint between cast A356 aluminum alloy and wrought 6005A aluminum alloy welded using ER5356 welding wire by the method of DC pulse metal-inert arc gas (MIG) welding were investigated by optical microscopy (OM), scanning electron microscopy (SEM), equipped with energy dispersive spectrometry (EDS) and tensile property tests. The fracture occurred at the heat effected zone and weld zone mainly for the A356/6005A welded joint. Its ultimate tensile strength, elongation and welded joint strength coefficient were 219 MPa, 6.21% and 0.7, respectively. And the welding strength coefficient was about 0.7. The fusion zone was characterized by dendritic structure and composed of α-Al, Mg2Si and Mg5Al8 phases. The fusion zones in the A356 and 6005A alloys showed different microstructure characteristic. For the fusion zone in the A356 side, its width was over 500 μm and consisted of island-shaped (α-Al + Al–Si) eutectic and coarse Si particles. The fusion zone in the 6005A side which exhibited transition microstructures and consisted of (α-Al + Al–Mg–Fe–Si + Al–Fe–Si) mixed phases was about 80 μm in width.

Guangshan Hu, Yun Cheng, Mingzhu Zhang, Yi Zhang

Experimental Study on Bolt Tightening of Torsional Vibration Damper

In engines, torsional vibration is inevitably caused by the fluctuation of the engine torque. Therefore, the establishment of torsional vibration damper is the necessary measure to diminish the torsional vibration. In this paper, an experimental study was carried out in a gasoline engine to analyze the bolt tightening of torsional vibration damper. The influence of the friction coefficient of the bolt of the torsional vibration damper, the material properties of the torsional vibration damper, and the axial force calibration were studied. The results show that the changes in the friction coefficient of the bolt and the material of the torsional vibration damper have great impacts on the bolt torque. It is effective to improve the bolt tightening state by checking the axial force and establishing suitable tightening parameters.

Fan Dong, Mingrui Wang, Xingtao Sheng, Qing Sun

The Heat Treatment Deformation Law and the Improvement of Accuracy of the Transmission Gear

Transmission is one of the core assembly units of automobile, and its performance has a decisive effect on the overall performance of automobile. And gear accuracy has the biggest influence on the performance of transmission, and to improve gear accuracy is the key point to improve the performance of transmission. But the heat treatment deformation of gear has become the tiger on the road (means the obstacle on the road) to improve gear accuracy, especially for the shaved gear which would not have finish machining after heat treatment. The heat treatment deformation quantity can directly influence gear accuracy, and as the factor of heat treatment is complicated and sophisticated, the deformation can be diminished as far as possible, but cannot be eliminated, usually we can try to diminish the deformation and analyze and summarize the deformation law to make a reverse machining, we do both at the same time to improve gear accuracy. This thesis through the analysis and researches on deformation law of gear heat treatment, tested and verified by gear shaved in FAW shaft and gear manufacturing center, finally made a summarization on the deformation law of gear heat treatment, and with this law, we can direct the machining of white parts, make a reverse modification to counteract the heat treatment deformation finally to achieve the goal of improving finished gear accuracy. Here are the researches done: 1. The influence of heat treatment deformation on gear common normal line; 2. The influence of heat treatment deformation on gear involute; 3. The influence of heat treatment deformation on gear helical line; 4. The influence of heat treatment deformation on gear tooth spacing; Through this research, the gear deformation law of heat treatment is summarized, and under the direction of this law, we can make a reverse modification machining to improve gear accuracy, and then to improve the performance of transmission.

Peng Sun, Di Pang, Xuechun Qi, Ningming Luo

Analysis of the Influence of the Cylinder Body on the Position of the Base Face System

Diesel engine cylinder’s main bearing cover is tightened by torque Angle method, the bolt is subjected to high preload, and the crankcase wall is thin, which leads to deformation and displacement of the cylinder’s bottom face. As the processing of the bottom face system of the cylinder block was completed before the main bearing cover was assembled, the position of the bottom face system changed after the cover was installed, which finally showed that the position of the bottom face system was qualified in the process inspection, but it was out of tolerance in the finished product inspection. In this paper, the stress and deformation of 36D cylinder are calculated by finite element method. The actual displacement direction and displacement amount of the base face system were verified by analyzing the data collected by the process test. In this way, the machining process is compensated and the position of the bottom face of the cylinder block product is out of tolerance.

Wang Hong, Sun Lin

Case Design and Implementation of Hypothesis Test Analyses for Attribute Measurement Systems

This paper is written by the author on the basis of a thorough understanding of the Measurement Systems Analysis (MSA) reference manual and summarizing its successful experience in the production practice of Weichai Power Co., Ltd. The typical attribute measurement system (go/no go gage) commonly used in the production site was chosen, and the consistency is determined by the Kappa value–Cross-tabulation method. This paper elaborated the detailed operation flow of the attribute MSA systematically and detailed introduce the specific design and implementation of each process, including the sample choosing, the determination of the random sequence of data collection, calculation, analysis, and the conclusion.

Shuxian Zhao, Yuanyuan Qi, Yanling Liu, Bin Fu

Research on the Materials and Production Process of Low Odor and Environmental Automotive Sealing Strips

To improve the air quality in an automotive cab, after analyzing each impact from materials and production process of automotive sealing strips, we confirm the harmful ingredients in each additive and can provide some solutions to produce low odor and environmental automotive sealing strips.

Shuchen Wei, Yi Zhu

Study of the Influence of Structural Adhesive on Durability of Vehicle Body

Based on the stiffness results of the tensile shear joint of structural adhesive, a reasonable modeling method of structural adhesive was obtained. A finite element (FE) model of the thin peeling specimen was established on this method. Then, the FE analysis and the fatigue test results of the peeling specimen were compared. Finally, spot-welding fatigue analysis of SUV vehicle body was conducted, and the structural adhesive was used to optimize the spot welding.

Chao Qi, Xianhong Mao, Hua Wang, Binjiao Deng

A Research on Vibration Performance of Light-Duty Truck Doors Based on Road Load Spectrum

Based on the vibration problem of some users’ light truck door frame, road load spectrum in similar pavement condition is obtained and extracted as the target signals. Including the doors, the multi-body dynamics model of cab suspension system is built so as to do virtual load iteration to get the real displacement driver of the cabin. By fixing the elastic element system features, more accurate system dynamic response is acquired. By means of structure optimization on the key points of the door, the door frame dynamic response in all kinds of harsh conditions can meet user’s requirements. At the same time, the scientific and reasonable method of product forward design is provided for the door system.

Xin Yan, Di Jiang, Yangyang Bai, Weitian Yi, Zhenyu Guo, Zhaochuan Jiang

Analysis and Optimization of Vehicle Interior Noise Caused by Tire Excitation

Tire is one of the main excitation sources of automobile vibration and noise, and it is the main factor of road noise and other abnormal noises in vehicle. In this paper, the road noise caused by the tire force transfer characteristic, the resonant band problem of the interior noise caused by the tire cavity mode, and the problem of the beat frequency caused by the tire uniformity are analyzed and studied. The problems of vehicle interior noise are improved by means of reasonable selection of tire, acoustic treatment of tire cavity, suspension dynamic absorber, and other related structural parts’ optimization. The results show that the reasonable control of the tire structural transmission characteristics and modal peak response can effectively reduce the vehicle noise level and improve the road noise. The optimization of tire uniformity and the modal avoidance of the tire and other accessory structures can avoid the problem of abnormal noise caused by beat frequency.

Jianghua Deng, Jianying Sun, Aofei Li

Diagnosis of Road-Induced Drumming Noise of Passenger Car Based on Multiple Coherence Method

Due to the fact that the vehicle suspension system is complicated, how to identify the structure-borne path of road noise efficiently and accurately is the key point of road noise diagnosis. In this research, a transfer path diagnosis approach for road noise diagnosis is proposed. In terms of methodology, the proposed method is based on the multiple coherence method, and it also needs to take into account the mechanical transfer paths of road noise. Therefore, the numerical implementation of multiple coherence method is presented first and then the classification of mechanical transfer paths of road noise. As for the practical application, first of all, the presented approach is used to investigate the transfer paths of a 79 Hz road-induced drumming problem of a vehicle. And then the mechanism for above-mentioned problem is predicted combining the modal results of relevant components. Furthermore, the predicted result is validated by adding a tuned 78 Hz damper to the lower control arm on both sides of the rear suspension. The experimental result indicates that the peak value at 79 Hz corresponding to road-induced drumming noise reduces by 10 dB(A), which proves the correctness of the inference for drumming noise and further demonstrates the validity of the proposed diagnosis approach.

Shichao Gong, Bo Peng, Daijun Chen, Yongqiang Tang, Pengfei Wang

A Fault Identification Method of Rear Axle Bearing Under Lateral Dynamic Load of Vehicle

As an important component of automobile, rolling bearing has a great impact on the safety of vehicle and occupants. At present, most of the literatures have studied the damaged bearing on the bench, and there is little research on the bearing failure resulted from the change of the vehicle posture. In this paper, taking the abnormal noise of the rear axle hub bearing induced by the axial load of rear axle in steering condition as an example, a method of fault identification and data analysis for the rolling bearing in the whole vehicle state is presented. First of all, the subjective evaluation of vehicles is carried out and the fault location is analyzed with the transfer path of the abnormal noise. Then, an objective test is designed to collect the vibration acceleration data of the rear axle bearings and the data is analyzed by wavelet packet. The appropriate wavelet base function and the number of decomposition level are selected to decompose the signal into different frequency bands. The frequency band containing the most information of bearing fault is determined by calculating the energy distribution of frequency bands. Envelope analysis for the fault frequency band is used to extract the characteristic frequency of the fault bearing. The correctness of the analysis results is verified by disassembling the hub bearing, and it also shows that this method can be effectively used to judge the fault location and identify the fault type of rolling bearing under the condition of the whole vehicle.

Xin Wan, Jun Zhang, Zhongming Xu, Mi Shen, Zhao Yang

Curb Vehicle Mass Target Formulation Based on Regression Analysis

A method of curb vehicle weight (CVW) target setting based on linear regression analysis algorithm was presented in this research. The curb mass target model based on unitary linear recursive analysis and multivariate linear recursive analysis methods is built by analyzing the effects of vehicle performance factors. The vehicle mass target is generally defined by engineers according to the benchmark vehicles, which is not comprehensive and able to meet the development requirements. The method raised by this paper based on the large data processing and regression analysis algorithm takes a good advantage in establishing vehicle mass target.

Xiaoya Jiang, Jing Li, Fan Zeng, Qiong Yang, Huijuan Yu

The Research of Friction Coefficient of Seatbelt’s Through Ring and Webbing Based on Orthogonal Test Matrix

With the in-depth understanding of vehicle’s safety knowledge and the increase of seatbelt’s wearing rates, people pay more and more attention to seatbelt’s wearing comfort and rapid retraction performance. Also, the Chinese market’s complaint about seatbelt is increasing. From the IQS result, the main part of seatbelt’s IQS complaint in Chinese market is about seatbelt’s retraction performance, and it shows an upward trend. The friction between seatbelt’s through ring and webbing is an important factor that influences the performance of seatbelt’s retraction, but there is no enough research result or selection standard about the friction coefficient of the through ring and webbing. In this paper, we analyzed the layout of seatbelt and the main factors affecting webbing’s retraction, set orthogonal test matrix for the combination of different through rings and webbings, obtained the friction coefficients, and analyzed its influence to the webbing’s pull-out and retract force. This work will provide a lot of convenience for the development of follow-up vehicles.

Guangyi Huang, Chengjing Zhou, Hongji Chen

Application of Color Variance with Angular Variation Effect in the Vehicle Color Exploitation

The article is about an innovative method for color designing. Through magnifying the color variance with angular variation effect, we scheme out a new type of vehicle colors, which show different colors depend on light and movement.

Huajie Xun, Chaofu Jiang, Xiaoqiang Qin, Zhongqiong Xu, Yu Xiao

The Process and Application of 3D Collision Checking for New Paint Shop Projects

This paper introduces HLS and the standard process for 3D collision checking used by FAW-Volkswagen during preliminary planning stage of new paint shops. Taking a new paint shop project as an example, it introduces the actual result of 3D collision checking.

Chao Wang, Ge Zhang, Xingyu Jiang

Monocular Vision-Based Real-Time Vehicle Detection at Container Terminals

We present a practical approach to vehicle detection at container terminals based on a single camera and prevailing convolutional neural network models in computer vision domain. Aiming at container terminal scenarios, we introduce a specialized data labelling strategy for network training, as well as an optimized setting of crucial hyperparameters, leading to a significant improvement on results. Our solution achieves 83% precision with 90% recall for semitrailer trunks within 30 m ahead of the vehicle-mounted monocular camera, at a speed of 32 frames per second (FPS) on a Nvidia Titan X for 416 × 416 image input, also providing more alternatives of fairly easy speed/accuracy trade-off. Compared to traditional lidar-based vehicle detection method for autonomous driving, our solution is more robust for particular container terminal scenarios while still maintaining a real-time performance by completely eliminating the region proposal stage.

Zijian Liu, Tianlei Zhang, Bei He, Yu Liu, Li Sun, Wenyang Tang

Chassis Control in Zero Radius Steer Mode of Four-Wheel-Independently Actuated Unmanned Ground Vehicle in Remote Control Mode

This paper describes a heavy-class four-wheel-independently actuated unmanned ground vehicle, which is able to achieve zero radius steer (ZRS) based on the independent steered technique. The major novelties of the unmanned ground vehicle are introduced, especially the mechanisms to achieve independent steer. To enhance the performance of the vehicle to negotiate the complex terrains, a chassis controller for ZRS is proposed. The chassis controller includes a yaw moment controller and a tyre slip ratio controller. The yaw moment is determined by the ground command station, which is remotely controlled by the human operator. The tyre traction forces are distributed according to the tyre vertical load, and a sliding mode slip ratio controller is applied. Finally, the experiments based on the unmanned ground vehicle developed by the authors are conducted to verify the performance of the proposed controllers.

Taipeng Wang, Yuzhuang Zhao, Jun Ni, Sizhong Chen

Construction of F-PSG Analysis Model Based on Automobile Modeling Design Language

With the continuous development of economy and society, the rapid progress in science and technology, and the upgrading living standards of modern people, automobiles are no longer tools just used for transportation, but something more and more attached to people’s needs for diversified and individualized designs. However, different designers produce different styles. Design is something very subjective, and the language itself is vague. Therefore, for a long time design style has been described in an abstract way. The absence of scientific description on design makes the design language of automobiles an obstacle, which will reduce the effect and efficiency of analysis and communication between designers, or between designers and other related staffs. The existing analysis method of automobiles’ design language is mainly understood and adopted by users with professional background knowledge, so it is difficult to use the method to deliver design concept to collaborators and consumers for their lack of specialized design knowledge. Given that, based on the technique of semantic cognition, a new analytical method, the F-PSG analytical method is proposed in this paper, which hopefully will be a solution to the problem.

Jingfeng Shao, Jianliang Shi, Leqing Huang, Feijiao Huo, Shaojie Gao

Lifecycle Assessment and Prediction of Proton Exchange Membrane Fuel Cell Vehicles for 2020

Currently, fuel cell vehicles have attracted the attention of China and even the world, which perhaps will become the commanding point of technical competition in the automotive industry. By modeling with GaBi software, the prediction and quantitative analysis are made on lifecycle energy-saving and emission reduction for fuel cell vehicles in China in 2020 based on the 2020 target of China and the US Department of Energy 2020 plan. Finally, sensitivity analysis was conducted for selected key factors. The result shows that the total resource depletion, energy consumption, and environmental impact for fuel cell vehicles of China in its complete life cycle were 0.354 kg Sb-Eq., 7.38 × 105 MJ and 4.48 × 104 kg CO2 eq. In 2020, the impact of the power generation on the environment will decrease as the proportion of thermal power generation in the power structure declines, and it will provide a possibility for large-scale electrolysis of water to produce hydrogen.

Yisong Chen, Zhensen Ding, Jiahui Liu, Jinqiu Ma

Analysis on Contact Strength of Needle Roller Bearing of Transmission and Effect of Surface Modification

Needle roller bearing is one of the most widely used parts in transmission; however, it often fails due to wear. In order to investigate the mechanism of fatigue damage, the three-dimensional model based on the sixth shift needle roller bearing of a six-speed manual transmission was established with Romax Designer. Then, the distribution of the contact stresses on bearing raceways was simulated under different loads. It is found that the stress concentration caused by the deflection of the needle rollers will increase the contact stress and lead to the indentations on the raceway surface. The composite surface modification of the roller raceway was employed, and the loading cycle test was carried out on the transmission test rig. The results show that the composite surface modification technique can improve the fatigue intensity of the contact surface and effectively prevent the indentation. Relevant experimental results provide technical guidance and theoretical basis for the optimization of needle roller bearings’ raceway strength.

Yong Chen, Kai Li, Libin Zang, Yang Zheng, Sen Jia, Huidong Zhou, Miao Yu, Boren Xue

Development of Longitudinal Slope Estimation Algorithm for Premium SUV

In this paper, a longitudinal slope estimation algorithm for a premium SUV is developed. First, the longitudinal dynamic vehicle model is established, and two longitudinal slope estimation methods are proposed. Furthermore, the longitudinal acceleration is corrected by suspension displacements from semi-active suspension system. Then, two Luenberger observers for longitudinal slope estimation are proposed based on variable of vehicle information. Then, the algorithm prototype is proposed by MATLAB/SIMULINK, and the code is generated and embedded into the vehicle ECU. Finally, the experiment system is established, and the performance of the proposed algorithm is verified by road test.

Jian Zhang, Wang Yu, Liu Ye, Wang Kang

Scheme Design of Engine Anti-theft System Based on RFID Technology

This article for the auto theft crime occurs frequently, and domestic automobile anti-theft system’s safety performance is low; this paper proposes an engine anti-theft system scheme based on RFID technology, and it is mainly composed of a highly integrated ignition key, IMMO controller and engine management controller. Key components of engine anti-theft system hardware design and software design in detail, at the same time to multiple test validation of guard against theft system, theory and practice fully proves that the system safe and reliable, cost-effective, have broad application prospects, and application in bulk in some SUV vehicle models.

Chao Rao, Jiawu Ling

Thermal Problem Solution of Vehicle DRL LED Driver

The thermal problem of vehicle lamp DRL LED driver is investigated. The root cause of flickering is analyzed, and theoretical way to solve thermal problem is provided. Finally, low-cost solution is applied on this issue and is validated by measurement. This solution can also be applied on other DC-DC headlamp driver projects to solve thermal problem.

Jiefei Xiong, Yuantao Hou

Research and Verification of Cooperative Regenerative Braking Function Based on Electrical Brake Booster System

The regenerative braking technology is an effective means to increase the mileage of electric vehicles and reduce the energy consumption per hundred kilometers and is a key issue in the research of electric vehicles. With the development trend of intelligent and electrified vehicles, electrical brake booster system is undoubtedly the best choice for automotive boost brake. This article proposes a control scheme of cooperative regenerative braking function based on a domestic home appliance electrical brake booster system. The program refers to the functional framework and communication interface of the VDA360 standard. The main controller is a vehicle control unit. The motor system and the electrical brake booster system act as actuators. At the same time, based on the wheel hub test and real vehicle road test, the control scheme was verified by multiple conditions. The results show that the cooperative regenerative braking function greatly improves the vehicle energy recovery rate, and the development of this function lays the groundwork and foundation for the subsequent development of intelligent driving functions and active braking functions.

Yanjing Wang, Mingwei Xie, Dihua Yi

Dual-Redundancy Steering by Wire Control System with High Safety

Steering by wire control system cannot be applied to mass production cars because of the low safety. A structure of dual-redundancy steering by wire control system with high safety and redundancy management method are proposed in this paper. By applying the redundancy theory to the design of steering by wire control system and combining the redundancy management method, when any single random electrical fault occurs, no system failure can be achieved. The whole system has a working mode of “fault-safe-forewarning,” thus the safety of steering by wire control system is enhanced, increasing the possibility of applying the system to mass production cars.

Junnan Mi, Tong Wang, Zhikai Cai, Xi Chen, Xiaomin Lian

Super Knock Control Logic Design and Verification for Turbocharged Gasoline Direct Injection Engine

During development of turbocharged gasoline direct injection engine, super knock is a common and dangerous phenomenon. The development of super knock suppression strategy involves in three points. First, super knock control logic design; second, super knock with proper frequency induction on test bench. Third, system which super knock logic embedded verification should be done, including whether the super knock is detected, whether proper steps are taken by the system to suppress super knock. These issues are discussed in the paper. It has been proved by bench test result that the super knock control logic described in the paper can give appropriate protection to turbocharged gasoline direct injection (GDI) engine.

Rui Xu, Long Chen, Han Yun Tuo, Wen Tao Xiao, Bai Qi Li, Feng Yuan

Improvement of Sound Quality in Car Based on the Third-Party Sound Effect

Sound quality of cars is an important part of the automobile information and entertainment system for user’s experience. The enclosed space of cars combined with the multi-channel stereo audio source can create the sound effect like a moving concert hall. With the development experience of automobile audio system, this paper analyzed the influence factors of the sound quality in low-cost passenger vehicles, and it introduced the classification and technical characteristics of some sound effects, and how to integrate the third-party sound effects to improve the sound quality in car. With the mass production verification, it obtained development method, test, and evaluation criteria, which could provide reference for the sound quality improvement of the audio entertainment system.

Zilong Liang, Zebing Tang, Ying Cai, Jin Yang, Haixia Hu

A Practical Path Planning Strategy for Automatic Parking in Constrained Parking Space

A practical automatic parking strategy of path planning in constrained parking space is stated in this paper. The path planning algorithm is designed by reversing a retrieving path that consists of two steps. First, a sequence of forward and backward moving is implemented from the final parking position, until the vehicle reaches a configuration of states from which it can pull out of the parking slot with one maneuver. Second, a continuous path is generated from this configuration to the vehicle original states. The constraints of parking space and vehicle dynamics are considered in both steps.

Hui Lu, Kangxi Xu, Huanran Wang, Cheng Qi, Dazhi Wang
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