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About this book

These proceedings gather outstanding papers presented at the China SAE Congress 2019. Featuring contributions mainly from China, the biggest carmaker as well as most dynamic car market in the world, the book covers a wide range of automotive topics and the latest technical advances in the industry. Many of the approaches included can help technicians to solve practical problems that affect their daily work. In addition, the book offers valuable technical support to engineers, researchers and postgraduate students in the field of automotive engineering.

Table of Contents

Frontmatter

Study on Air-Conditioning Refrigeration Performance of Electric Vehicle Based on Flow Field Optimization

Considering the attractive appearance and reduction of aerodynamic drag, more and more electric vehicles adopt the closed front grille, which causes the insufficient air intake of the condenser and weakens the heat exchange performance of the condenser. Through looking for the new air intake passage between the front cabin and the condenser, the heat exchange performance of the condenser is improved. The refrigeration effect of air-conditioning system before and after the improvement of the air intake passage of condenser is compared and evaluated by CFD numerical simulation and environmental chamber test method. CFD numerical simulation results show that the air intake mass per second of the condenser of optimized electric vehicle increased by 15.17%, and air-conditioning refrigeration performance of environmental chamber tests show that the average cabin temperature decreased by more than 3 °C under various operating conditions. The measures to look for a new air intake passage for condenser can significantly improve the refrigeration effect of air-conditioning of electric vehicles and the comfort of cabin environment. The new scheme has been successfully applied to mass-produced vehicles.

Lefang Ding, Yong Zheng

Three Dimentional Anemometer Using Thin Film Temperature Elements

Two different types of three dimensional anemometers were proposed in order to analyse airflow in engine compartment. It consists of multiple thin film temperature elements formed on a sphere surface. The measurement principles of each anemometer were established. Feasibilities of the principles were confirmed.

Takafumi Matsumoto, Xiaolin Guo, Hirohito Matsui, Yukikatsu Ozaki, Yasutaka Kamiya, Koji Kondo, Hirotaka Miyano

Design of Front Subframe Fixture Based on System Identification and Fatigue Life Calculation of Front Subframe

Aiming at the road spectrum simulation test rig of the front subframe of a car, the design of the test rig fixture based on multi-objective Optimization and the simulation prediction of the fatigue life are introduced in detail. Our engineers optimize the stiffness of the test rig by using the finite element software, so that the stiffness of the car body can be accurately simulated, and the force characteristics of the subframe on the test rig are the same as on the real car, thus the validity and accuracy of the bench test results are ensured. The fatigue test of the subframe is simulated by using the fatigue life software FEMFAT and the fatigue life of the subframe is predicted, greatly reducing the test time.

Peng Tang, Lingshan Jiang, Jianhong Huo, Ying Zhang, Xiang Qi, Weimin Yao

Fatigue Analysis of Truck Frame Using Virtual Proving Ground

Aiming at the problems of long test cycle, high cost and unable to evaluate the development scheme of vehicle in the early stage, the durability solution based on virtual proving ground has been widely used in vehicle development. In this paper, the fatigue analysis of truck frame is proposed based on VPG. Three key technologies, high precision laser scanning of pave, tire parameter identification and full vehicle modeling are discussed. The dynamic model of a truck with flexible frame is established. Based on the durability test criterion of the proving ground, the dynamic load decomposition of the frame is completed, and then the fatigue life evaluation of the frame is carried out, which verifies the feasibility of this new technical scheme.

Chao Fang, Tian-bing Li, Hao-ren Wang, Xiao-jie Sun

A Digital Road Construction Method Applied in Virtual Proving Ground Technique

In recent years, virtual proving ground (VPG) technique has been widely used in vehicle multi-body dynamics analysis. This paper mainly focuses on the method to construct the digital roads incorporated in the virtual proving ground. At first, the Mobile Road Scanning System was introduced to acquire point clouds of the physical test roads of an actual proving ground located in southwest of China. Then, considering both road characteristics and development requirements, a CRG road surface model construction methodology was proposed. In the end, digital surface models of the physical test roads were constructed and coupled in full-vehicle simulations. As a result, the simulation based on the proposed method can predict the external loads of wheel parts under various loading cases, by comparing with load data acquired by experiments. In consequence, our research will assist in providing an efficient tool for the analysis of vehicle system/sub-system loads.

Shuai Zhou, Yunping Zhou, Jian Shao, Hua Wang, Zhongling Jiang

Research on Evaluation Methodology of Durability of the Plastic Tray System for Battery

We study the evaluation method of durability of the plastic tray system for battery mainly based on the background of the battery tray gradually transforming from metal parts to plastic parts. Durability of the plastic tray system for battery refers to the ability to maintain good quality for a long time which is usually characterized by service life. After the impact of vehicle load and climatic factors such as temperature and humidity repeatedly, the performance index of battery plastic system will gradually decrease. The paper proposes that the modal is used as the main index to evaluate the durability of the plastic tray system for battery based on the study of acceleration power spectrum density and resonance mechanism of typical vehicles, and we compare the CAE analysis results with the local modal experimental results of the plastic tray system. Finally, the standardized modeling method of the plastic tray system is formed, and the modal target of durability of the plastic tray system for battery is preliminarily determined.

Junjie Duan, Hailong Mei, Guangyao Wang, Chengzhi Sun, Shizhan Zhang

Test and Analysis on Distance Measurement Accuracy of Commercial Vehicle Forward Collision Warning System

The distance measurement accuracy is directly related to the safety margin of forward collision warning system (FCWS) warning time, which affects the safety of vehicles and pedestrians. Distance measurement accuracy of a commercial vehicle equipped with different FCWS sensing schemes was tested and analyzed according to relevant regulations and standards on the basic of the analysis of the distance measurement principle of FCWS sensor scheme. The test results show that the distance measurement accuracy of millimeter wave radar and camera information fusion has the preferable performance. Besides, we pointed out some problems existing in the test and evaluation of distance measurement accuracy for commercial vehicle FCWS and put forward some feasible suggestions.

Chengyong Niu, Zhanling Su, Kunlun Wu, Xiong Hu, Jianxun Xu

Car Body Durability Analysis Based on Modal Superposition Method

Common car durability developing methods are firstly introduced, and then focus on simulation methods. Generally, there are two simulation methods to get structural stress in time-domain: quasi-static method and modal superposition method. The former cannot consider structural dynamic response while the latter can do, which is used to calculate car body stress and damage with fatigue curves. According to comparing results between test and simulation, results of modal superposition method has better consistency with test results than quasi-static method where local modes predominated. Furthermore, it is easy to use modal superposition method to search countermeasures without extra software and calculation resources, which has good application prospect.

Zichun Zhang, Changpeng Wu, Zhaoming Wu, Yanbing Lei

Virtual Proving Ground Simulation in Practice for Vehicle Durability and Ride Comfort Performance

A procedure of virtual proving ground simulation in practice for vehicle durability and ride performance is introduced in this paper. Digital road models including of durability and ride performance roads are created by a way of 3D laser scanning on proving ground. Then a high-accuracy full vehicle multi-body dynamic model is built, using complete vehicle design parameters. Meanwhile, due to its well-known ability to deal with medium and high frequency dynamic problems, FTire is incorporated in building the full vehicle model. Based on the road load data acquisition, driver control programs are developed to make the MBD model traveling with same track and speed as the test car, and then VPG simulation and validation are fulfilled. Comparing with test results, simulation results make a good prediction on wheel center forces, spring displacements, damper forces, and so on. Hence, the VPG simulation technology provides a powerful tool to meet the demand of vehicle durability and ride comfort analysis.

Jian Shao, Yunping Zhou, Hua Wang, Shuai Zhou, Zhongling Jiang, Wenjuan Wang

Research on Optimization Analysis Method of Exhaust System Under Multiple Loading Conditions

The exhaust system is connected to the engine and mounted on the body-in-white with lifting lugs and rubbers. The vibration of the engine can be transmitted to the exhaust system through the bellows, which affects the NVH performance of the vehicle. Optimal design of the vibration isolation, the stiffness of the lifting lugs, the strength and other performance parameters should be taken into account. The exhaust system has many variable parameters, including the stiffness of the bushing, the shape of structure, the thickness of the exhaust pipes, and so on. It is difficult to find the optimal parameters of the exhaust system based on conventional method. In order to solve the problem, In order to solve the problem, the HyperWorks software was used to simulate the exhaust system. With HyperStudy, the DOE design method is used to create a response fitting approximate model, and the optimal solution is obtained by genetic algorithm. Then in the finite element model of the exhaust system, the size and shape optimization design were carried out to obtain the global optimal solution. The results revealed that this analytical method is practical and suggestive for multi-objective optimization analysis of exhaust system.

Yan Qiao, XinTian Qu, GuiQi Yu, ShuangXi Zhan, WenJun Kang

Optimization Design of Sealing Strip Section Based on Finite Element Analysis

This paper describes the constitutive equation of rubber material, and analyzes the compression load (CLD), 3D corner deformation and lip deformation effect of the seal strip by using MARC analysis ware in the design stage. After products’ development, the test results are compared with the design analysis results. For the lip deformation of body seal and the deflection of door seal strip, using MARC software to reproduce the problem phenomenon, the improvement scheme is analyzed. We will fully explain the necessity of Finite Element Analysis in this paper.

LiPing Ma, ShuGuang Xu, JunPing Qiao

Parametric Modeling and Structure Optimization Technology of Automobile Twist Beam

This research completes torsion beam parametric modeling, which could realize torsion beam shape transforming. Base on stiffness, durability and abuse performance, integrating ISIGHT, SFE, NASTRAN software, this research completes twist beam parametric and multi-objective optimization design in the early age of project, and achieves a better structure of twist beam, which has been validated in the rig-test.

Nuo Xu, Chengzhi Sun, Xiao Wang

Investigation of Vehicle Water Drainage in Virtual Shower Room

Based on the STAR CCM+ software, the Lagrangian method, Volume of Fraction Model (VOF) and Film model are combined to build the model of the vehicle in virtual shower room and to investigate the water depth at the bottom of vehicle cowl cover. The motion track of rain particles sprayed by the nozzles is presented with the Lagrangian method. The interaction between the rain particles and the vehicle surface like adhesion, rebound and formation of liquid film are considered. Meanwhile, the transition between the liquid film phase and VOF phase are considered with the Resolved fluid film model as well. The simulation results show a good agreement with the experiment and the wave range of water level is within 2 mm. Besides, there was no water intrusion risks of the air conditioning (AC) inlet and the wiper motor.

Guohua Zhuang, Chang Qiu Liang, Kai Xu, Xiao Liu, Jun Ni, Zhi Ding

Research and Improvement on Welding Joint Failure of Subwater Tank Installation Bracket

Aiming at the problem of solder joint opening between front wheel cover plate and auxiliary water tank mounting bracket assembly in the process of PAVE test of a vehicle body structure, this paper finds out the failure reason of solder joint through structural stress analysis, and investigates several types of vehicle, combines CAE simulation analysis and vehicle’s own characteristic structure, puts forward two improved design schemes, considers each factor synthetically, and chooses the development scheme. A scheme with better cost and development cycle. The validation of the improved scheme shows that it not only effectively solders the solder joint opening problem between the front wheel cover plate and the auxiliary water tank mounting bracket assembly, meets the vehicle PAVE road test target requirements and improves the vehicle body reliability, but also takes into account the structural weight, setting cost and other factors, which is conducive to the lightweight design of the car body in white, and proves the effectiveness of the improved scheme.

Jie Ren, Dexia Zhu, Shixing Chen, Jingru Bao

Research on the Influence of Lightweight Design of DAB Performance

Driver airbag (DAB for short) lightweight design is the inevitable trend of development. Based on the research of DAB development trend and design challenges, this paper studies the effect of lightweight design on the performance of DAB. In the paper, a project of Dong Feng Peugeot Citroen Automobile Company LTD (DPCA for short) DAB has been adopted as an example, some specific issues have been discussed. Then, the accordingly provide some designs and proposal verifications as well as some analytic ideas and design measures for the development of other DAB.

Ding An

Research on the Optimization Method of Body Torsional Stiffness Base on Flexible Joint Simplified Model

Aiming at the problem of fast and accurate prediction of torsional stiffness of vehicle body, an optimization method based on the simplified model of flexible joint is proposed. Primarily, a simplified model of flexible joint is established by using mathematical model and simulation analysis method. On this basis, an accurate and reliable whole vehicle wire frame model is established by combining with flexible joint and beam element. In the task of new vehicle development, two joints which need to be optimized are positioned quickly by using the model and sensitivity analysis. And then, orthogonal test is designed to calculate the optimization degree of joint stiffness under the optimal cost and weight conditions. The results show that the optimization method based on the simplified model of flexible joints improves the torsional stiffness of the vehicle body by 17%, reduces the cost of components by 12%, and reduces the weight by 0.5 kg compared with the traditional method, which achieves the effect of improving the quality and reducing the cost.

Chengjie Huang, Shusheng Di, Xuemei Zhao, Dan Zhang, Zhixin Zhao, Changchu Wang

Design and Application of Flexible and Collective Painting for Truck Beds

According to the characteristics of the commercial truck bed products, the process flow, data input, rhythm design, main points of design, etc. of the flexible collinear design for the truck bed painting are introduced. The painting line of this paper has the advantages of high rhythm, low investment, convenient maintenance and space saving, etc. At the same time, It can also meet the requirement of the co-production of the different sizes and types of the truck bed products.

Fujia Zhang, Wenping Xing, Jin Li

Construction of Virtual Simulation System for General Assembly Process Based on Digital Factory

On the basis of the research on the development tendency of modern automobile industry and the analysis of the present situation of new product’s development and management in Dongfeng Honda, the paper discusses the necessity and importance of the establishment of a virtual simulation system for general assembly based on digital factory under the situation of SPEED development process. And it expounds how Dongfeng Honda apply virtual manufacturing technology to the new products to achieve rapid industrialization from the perspectives of virtual technology and digitalization.

Gong Jian, Wang Long, Dong Feixiang, Li Qiang

Application of Three-Dimensional Collision Detection in Painting Shop Project

This paper discusses the application of three-dimensional interference inspection in the painting shop project, including data interaction, information sharing, model lightweight, working mode, inspection content, combined with three-dimensional laser scanning, etc.

Yang Dong

Development and Application of Flexible Welding Line in Overseas Factories

The paper based on the development and application of flexible welding line in overseas factories, mainly introduces the application of the flexible welding line of the new process scheme, process arrangement and its characteristics, and to implement many kinds of models adopted by the mixed flow production are introduced, various solutions to the project done shows that the characteristics of each line in the body for the future similar welding project many kinds of models of the development of the welding line is of high reference value.

Yongsheng Fu

Instant Centre Impact Loads Transfer on Double Wishbone Suspension While Car Traveling Straight

This paper focus on studying how the instant centre impacts loads transfer in double wishbone suspension model when vehicle moving straight (brakes or accelerates), instant center could further affects loads transfer by affecting inverse geometry values, worldwide specialists defined different ways to prove that instant centre has massive influences on the anti-geometry values. This paper by creating the double wishbone suspension Adams model and relatively auxiliary model to verify those theories and compare the results to find out the most accurate way to calculate anti-geometry value. Furthermore, this paper also proves the change of anti-geometry will affect tyre vertical and longitudinal loads transfer to resist the dive and squat of vehicle body when car brakes or accelerates.

Yongchen Zai, Weiguo Liu, Wenlin Chen, Bo Li, Hongxi Lu

Vehicle Side Slip Angle Estimation Using Stiffness-Update Method and Extend Kalman Filter

For vehicle side slip angle estimation, a new method which can update the stiffness is proposed to improve the accuracy of the estimation. The design of the estimation loop is formalized into three main steps: vehicle model, the calculation of the key updating parameter K, the Extend Kalman Filter. Finally, the outcome of the designed estimation method is showed and compared with the real condition.

Guangxu Che, Mengjian Tian, Bingzhao Gao

Study of the Subjective and Objective Correlation on Vehicle Ride Comfort

The ride comfort is a critical attribute in the process of vehicle design and performance development. Determining the objective metrics that can effectively represent subjective feelings is an important precondition for vehicle dynamics CAE simulation and analysis. In this paper, the correlations between vehicle ride subjective ratings and objective tests are studied. A total of 7 characteristics of the subjective ratings, which include primary ride, secondary ride and impact, are selected and defined after the customer survey. The subjective ratings are collected by driving four cars on four different road surfaces with three different drivers. For the objective metrics, the R.M.S. (Root Mean Square) method was adopted with different frequencies for vehicle’s body motion and secondary vibration. In addition, the impact data was characterized by the peak to peak value instead of the VDV (Vibration Dose Value) method. Through regression analysis and verification, 13 objective metrics that have a strong positive correlation with the 5 subjective characteristics were determined.

Yi Lu, Lifa Ma, Jianjun Guo

Study on Vehicle Driving State Estimation for Four-Wheel Independent Drive and Steering Electric Vehicle

For the driving state estimation problem of four-wheel independent drive and steering electric vehicles, the algorithm based on cubature Kalman filter was studied. The driving state estimation model was established for the four-wheel independent drive and steering electric vehicle. Take advantage of that the four-wheel drive torque can be measured easily to calculate the longitudinal force and the Dugoff tyre model was used to compute lateral force. The low cost sensor signals are used. According to the four-wheel independent drive and steering electric vehicle’s dynamic control characteristics and the advantages of multiple information sources, the longitudinal velocity, lateral velocity and sideslip angle of the electric vehicle were estimated accurately through the application of dynamic theory and cubature Kalman filter theory. The algorithm was verified by CarSim and Matlab/Simulink co-simulation. The results show that the vehicle driving state of the four-wheel independent drive and steering electric vehicle can be estimated accurately using the vehicle driving state estimation algorithm based on cubature Kalman filter theory.

Li Gang, Fan Dongsheng, Wang Ye

Ride Comfort Optimization Method for Commercial Vehicle Based on Nonlinear Damping and PSO

This paper proposes a nonlinear optimization approach for the ride comfort based on nonlinear damping to improve the optimized reliability of ride comfort of the commercial vehicle. First, a vibration model of a commercial vehicle is established and followed by a road excitation model and a nonlinear damping model that can provide nonlinear damping force by using compression velocity rather than linear force. The weighted Root Mean Square (RMS) from previous comfort models is then obtained and compared with experimental data. The result indicates that the ride model based on nonlinear damping leads a more accurate result and is closer to the experiment than the model based on the equivalent one. A optimization approach for ride comfort based on nonlinear damping to the commercial vehicle is further proposed. The sum of weighted RMS of the vertical vibration acceleration of driver seat at 30 km/h, 60 km/h, and 90 km/h is taken as the objective function with the stiffness and nonlinear damping gradient of suspension as the design variables. Afterwards, the particle swarm optimization (PSO) is utilized to improve the ride comfort. And the optimal stiffness and nonlinear damping are obtained. Finally, the effectiveness of the presented approach is evaluated by the comparison of the logarithmic power spectral density and the weighted RMS before and after optimization. It is shown that the optimization method can reduce the average peak of power spectral density and the average weighted root mean square by 29.9% and 10.2%, respectively.

Keren Chen, Shuilong He, Enyong Xu, Wei Wang, Zhansi Jiang

Study on Real Road Driving Emission Characteristics of Light-Duty Gasoline Vehicles

In November 2018, the real driving emissions (RDE) package 4 of European Commission regulation was released, and the RDE test method was improved, the data processing method and cold start data processing were different from the China 6 light-duty vehicle standards. In some congested cities of China, the average speed of vehicles during morning and evening rush hours is lower than that in the RDE urban phase. In order to evaluate the impact of data processing methods, cold starting data processing and congestion conditions on RDE test, the real driving emissions from 5 light-duty GDI gasoline vehicles were measured on the GB6 RDE test route and the typical urban test route respectively. It was found that CO, NOx and PN specific emissions based on EU package 4 data processing methods were 22, 46 and 29% higher than the moving average window method results of GB6. For the CO, NOx and PN emissions, the reserved cold starting test results of 5 test vehicles are 18, 42 and 15% higher than the results excluding cold starting data. For the vehicle A, CO and PN emissions under the typical urban road are greater than GB6 RDE road test emissions, as NOx and THC emissions are roughly the same. The CO, THC and PN emission results increased in congested road conditions, which were 2.8 times, 2.9 times and 3.5 times higher than those in the condition of smooth road. Emissions of CO, THC and CO2 along the two test journeys show a decreasing trend with the increase of average speed, as PN emissions show an increasing trend with the increase of average positive acceleration of the travel. NOx emission decreases with the increase of average positive acceleration of the travel.

Qinggong Zhu, Dongdong Guo, Fulu Shi, Zhengjun Yang, Jiaxin Luo

Extraction and Analysis of High Emission Conditions of Heavy Diesel Vehicles Based on Real Road Driving Conditions

In order to explore a method for judging the on-board emission level of heavy-duty diesel vehicles and to study the emission level of heavy-duty diesel vehicles, in this paper, we used OBD system data acquisition terminal to transport five heavy-duty vehicles on actual drive based on the subject of “Research and application of key technologies for emission monitoring in actual operation of heavy-duty diesel vehicles”. By collecting the data and consulting Beijing Local Standard, China VI Standards for heavy duty diesel vehicles and the method of driving cycle construction, AME (Averaging Window Method), NTE (Not-To-Exceed) method and short-trip method were used to analyze the collected data segments respectively. Comparing the segment data obtained by three methods and the proportion of segments exceeding the limit value, it is concluded that the short-trip method can effectively extract the operating segments with emission exceeding the limit. A further analysis of the short trips of 5 vehicles exceeding the emission limit showed that, compared with vehicle speed and acceleration, VSP can better identify vehicle emissions exceeding the standard in the actual driving process, and VSP of the emission exceeding segments was concentrated in the range of 0–2.5 kW/ton. The duration of high emission segments was mainly within 300 s, and the idle proportion of high emission segments was concentrated in 0–5%, the acceleration proportion of more than 80% segments was within 22%, and the distribution law of deceleration proportion and uniform proportion was not obvious. The average speed of high emission segments is mainly distributed at low and medium speeds and the high emission segments with maximum acceleration of 1–1.3 m/s2 account for a large proportion, The possible reason is that the lower speed running segment basically appears in the process of vehicle deceleration to zero immediately after a short acceleration. At this time, the acceleration of the vehicle is larger, and the reaction of the post-processing system is delayed, so the exhaust emission cannot be reduced in time.

He Lyu, Jingyuan Li, Mengliang Li

Analysis of PHEV Utility Factor and Fuel Consumption Based on Real Road

The revision of the test methods for comprehensive fuel consumption of PHEV (GB/T 19753-2013) determines to replace the fixed mileage weighting with the variable weighting using the Utility Factor, and modify the test procedure of condition A. 1.3 million kilometers real road driving data of 40 private PHEVs and large numbers of private ICEVs in the CATC platform is studied to analysis travel characteristics, and establish the UF(TC) used for FC calculation. Finally, discuss the fuel consumption under different scenes of standard revision based on UF(TC), UF(CN6) and procedure of condition A.

Xiaopan An, Yu Liu, Jingyuan Li, Yan Yan

Crash Failure Analysis of a Carbon Fiber Full-Wrapped Hydrogen Cylinder with an Aluminum Liner and the Optimal Design of Its Layers

Hydrogen fuel-cell vehicles have broad application prospects because they use clean and sustainable energy. However, their crashworthiness has drawn considerable attention. In this study, full-scale crashes with a hydrogen cylinder were simulated based on the LS-DYNA platform. Then, the crash acceleration curves were input into a detailed model of a hydrogen cylinder based on the ABAQUS platform. The results showed that the maximum stress occurs in the outermost layer of the geometric center from the front view. Finally, the angle of the helix layers and the inner pressure, which significantly affect the stress distribution, were discussed. The stress peak increased with increases in the inner pressure, whereas the stress fluctuation initially decreased and subsequently increased. In addition, with increases in the angle of the helix layers, the stress of the circumferential layers increased, whereas the stress of the helix layers decreased.

Chen Liang, Ping Chen

Design and Implementation of Full Speed Range Control of Permanent Magnet Synchronous Motor for Electric Vehicle

In order to control electric vehicle PMSM (Permanent Magnet Synchronous Motor) stably run in whole speed range, this paper designs a control algorithm combining linear interpolation look-up method MTPA (the Maximum Torque per Ampere) control and modulation hysteresis loop flux weakening control. So the purpose of stable control is achieved when the motor speed and the torque changed at any time during the operation. The algorithm uses flux weakening algorithm to compensate the instruction current of MTPA control, then correct the current vector trajectory and speed up the motor. Finally, the bench test and driving experiment on the electric vehicle shows that the algorithm can run steadily and achieve the desired goal.

Kai Xu, De-qian Tang, Zhi-fei Sun

Model-Based Peak Power Estimation of Lithium-Ion Batteries for Electric Vehicles

The accuracy estimation of the peak power can guarantee the battery’s safety, and make full use of the battery performance during the allowed safe range, thus improving the safety, power and quick charge performance. Up to now, the peak power in the electric vehicles is usually acquired by the peak power, SOC and temperature map, thus requiring a lot of offline experiments, and not taking the real-time polarization into account. Besides, the map method is strongly influenced by the accuracy of SOC and battery aging. In response to these circumstances, this paper has developed a model-based method for peak power online estimation. Firstly, the one order resistance-capacity equivalent circuit model has been employed to model the battery; Secondly, the parameters of the model have been on-line estimated by the particle swarm optimization (PSO) method; Thirdly, through the model-based method, the peak power of the battery has been obtained; Finally, a simplified version of the federal urban driving schedule (SFUDS) with inserted pulse experiment has been conducted to verify the peak power estimated. The result indicates that the proposed method is accurate and reliable with the 25 W maximum absolute error of the peak power.

Xiang Shun, Zheng Ying, Hong Munan, Zhu Qian, Guo Yazhou, Liu Bo, Yang Bo

Study on Maneuverability Control of Four In-Wheel Motor Electric Vehicle

This paper mainly studies the improvement of the maneuverability of four In-wheel motor Drive (4IWD) electric vehicle by torque vector control (TVC) under normal working conditions. A TVC algorithm is proposed based on the theory of feed-forward control and feedback control. It includes four control modules: the calculation of the vehicle state parameters and variables, the design of vehicle steering characteristic, the control of additional yaw moment and the allocation method of drive torque. The control method of additional yaw moment and the control method of allocation method of 4IWD are emphatically studied. The TVC algorithm is verified by using simulation experiments where the 4IWD electric vehicle model is established based on CarSim and Simulink joint simulation method. Results show that maximum value of the yaw rate, lateral acceleration and sideslip angle with TVC are 35%, 23.79%, 54.87% lower than that without TVC, respectively. It means that the maneuverability of the 4IWD under normal working conditions can be enhanced effectively by the proposed TVC algorithm.

Zeyang Zhang, Jianpeng Shi, Chunlai Zhao, Qiulai Wang, Hongtao Li

Fuel Consumption Optimization for Dual-Motor Planetary Coupling PHEV Based on Adaptive Multi-target Compensation Factor

This paper presents a new Equivalent Consumption Minimum Strategy (ECMS), combing with Particle Swarm Optimization (PSO) to optimize oil-electric equivalent factor. First, a dual-motor planetary coupling plug-in hybrid vehicle (PHEV) is selected as a platform to optimize the fuel consumption. Considering the coupling mechanism between multiple power sources, an Adaptive Equivalent Fuel Consumption Minimum Strategy (A-ECMS) is established. Moreover, this paper further considers the influence of initial SOC and driving mileage on the equivalent factor, and optimizes the equivalent factor by Particle Swarm Optimization. Finally, ECMS optimized by Particle Swarm Optimization (PSO-ECMS) is established. The simulation result of ECMS and A-ECMS are contrasted to the outcome of PSO-ECMS, fuel consumption per 100 km decreased by 6.5 and 3.4% respectively, which demonstrating the effectiveness of the proposed methodology.

Cong Liang, Xing Xu, Feng Wang, Zhiguang Zhou

Power Performance and Efficiency Analysis of Two Electric-Continuously Variable Transmission for Hybrid Electric Bus

This paper proposes two different electric-continuously variable transmission (EVT) configurations for a typical hybrid electric bus (HEB) during city conditions based on the Input-split Configuration with Single Planetary gearset (ICSP) which has been widely used to passenger cars. Then the power performance and efficiency of these configurations are analyzed and compared based on the lever analogy. The analysis indicates that the practical application of the Input-split Configuration with Dual Planetary gearsets (ICDP) is difficult because the efficiency in high-speed area is low and the motor speed has exceeded the reasonable range when the vehicle runs at the maximum velocity. But the ICSP equipped with a Clutch (C-ICSP) has good applicability to the HEB. Finally, the C-ICSP and the ICSP are compared through MATLAB/Simulink and Cruise co-simulation platform. Results show that the total electric path power of C-ICSP is reduced by 13% compared with ICSP, hence the fuel consumption is reduced by 6%.

Xiaohua Zeng, Xingqi Wang, Dafeng Song, Guanghan Li

Comparative Study on Energy Consumption Characteristics of EV and FCV

As an important future transportation, both fuel cell vehicle and electric vehicle had advantages of their technical characteristics. In this paper, a fuel cell electric vehicle and an electric vehicle were selected in the benchmark database which had similar driving resistance. Then technical characteristics of those vehicles were analyzed, the energy consumption test method, characteristics, and control strategy were compared. Based on analysis, summing up a method can evaluate both energy consumption characteristics of fuel cell electric vehicle and electric vehicle. Adopting this method, energy conversion, transmission, distribution and loss were analyzed in depth. The differences were analyzed from the perspective of system function and control strategy. Based on energy flow test and analysis results, this paper provides a method to provide suggestions and references for the selection of R&D routes and development process of car companies.

Tian Yang, Yanxin Nie, Xu Wang, Peiliang Yu

Driving Condition Recognition and Optimisation-Based Energy Management Strategy for Power-Split Hybrid Electric Vehicles

Power-split hybrid electric vehicles (PSHEVs) have the advantages of low fuel consumption, low emissions, and no mileage limitations, and their performance is largely determined by the control strategy. The purpose of the study was to solve the problem of driving condition recognition and energy management strategy (EMS) of PSHEVs. For this purpose, the parametric description method for the driving cycle conditions, the driving condition recognition method based on learning vector quantisation (LVQ) neural network (NN), and the energy management optimisation strategy for hybrid power systems based on predictive information were studied. Energy management optimisation under certain conditions was carried out by using Pontryagin’s minimum principle. A test bench platform for hybrid power systems was built to verify the effectiveness of the energy management and control strategy for HEVs based on condition recognition. Computer simulation and experimental results show that the presented EMS can effectively control hybrid power systems and significantly improve fuel economy compared with other control strategies.

Weida Wang, Qian Chen, Changle Xiang, Zhongguo Zhang, Haonan Peng, Zehui Zhou

Research on Lateral Active Collision Avoidance Algorithms for Intelligent Vehicles

Vehicle lateral obstacle avoidance technology is one of the key technologies of intelligent driving. In view of the current situation that there are few studies on vehicle lateral collision risk degree and its description, this paper proposes a description method of vehicle lateral collision risk degree by analyzing the mechanism and kinematics model of vehicle lateral collision, and proposes a lateral active collision avoidance algorithm based on this method. In order to verify the rationality of the proposed risk description method and collision avoidance algorithm, a lateral simulation experiment is designed for typical lateral collision conditions. The simulation results show that the proposed lateral collision risk description method and the lateral active collision avoidance algorithm have good effectiveness and robustness.

Jiaxiang Qin, Rui He, Yan Liu, Weiwen Deng, Sumin Zhang

Research on Classification of Vehicle Driving

Pavement Characteristics Based on Intelligent Perception

The current research direction of active suspension is primarily focused on the design of feedback control based on pavement information, whilst research effort in actively detecting driving pavement information is rarely put in. Good pavement information recognition system is especially important for the development of suspension technology. This text adopts the binocular vision system to obtain the road two-dimensional image. Firstly, the Semi-Global Block Matching(SGBM)is used for stereo matching and three-dimensional reconstruction. Secondly, the “cleansing” algorithm is then used to remove the erroneous data points in the road vertical contour model. Finally, Multi-class support vector machines (SVM) are trained by using road feature data sets. Vector machine. The research results show that the road two-bit image acquired by the binocular vision system can provide the road surface feature basis for the control of the active suspension system and classification model of road feature data set training can also extract useful information from road images and classify them correctly.

Shuang Chen, Ziyang Zhu, Yuan Wang, Xiaozhen Qu, Yang-shan Tang

Research on Trajectory Tracking Lateral Control of Intelligent Vehicle Based on Nested Sliding Mode

The trajectory tracking lateral controller designed based on the traditional vehicle model make the performance degradation when the vehicle travels on the road with low adhesion coefficient or high speed. Therefore, a trajectory tracking lateral controller based on nested sliding mode is designed, which a PI control method is adopted for the outer layer to generate a yaw angular velocity reference signal, and the inner layer makes use of the strong robustness of the sliding control method. Finally, this paper carried out the joint simulation with Matlab/Simulink and Carsim,and the real vehicle tests to verify that the proposed trajectory tracking lateral control method can still make the vehicle track the target path stably under the extreme conditions, such as low adhesion coefficient and high vehicle speed.

Bingli Zhang, Pingping Zheng, Jie Zhang, Wei Tang, Gan Shen

Driver Drowsiness Analysis Based on Eyelid Feature

Definition of different drowsiness levels has been a problem for driver monitoring system. This paper proposes a new method of analyzing driver drowsiness. Based on extracted eyelid feature and vehicle speed and with consideration that emergency occurs randomly, a probabilistic damage model is built. For a long time before, drowsiness levels are defined according to experiences. In this paper, for the first time, effect of driver drowsiness on road safety is analyzed and resulting probabilistic model provides a possibility to deduce thresholds of drowsiness levels reversely.

Shu Wang, Zhao Zhang, Zheng Wu, Jie Liu, Chunmei Mo

A Unified Spatio-Temporal Description Model of Environment for Intelligent Vehicles

Beneficial from fusion of various external sensors such as LiDAR and camera, intelligent vehicles are able to be informed of their surroundings with details in real time. The characteristics of each type of sensors determine its specificity in raw data, leading to inconformity of content, precision, range and timing, which eventually increases the complexity of environment descriptions and effective information extraction for further applications. In order to efficiently describe the environment, as well as remain the diversity of necessary information, we propose a unified description model independent of specific sensors for intelligent vehicle environment perception, containing 3D positions, semantics and time. The spatio-temporal relationship between different types of collected data are established to express all the elements in the same system. As a potential implementation scheme, we take advantages of LiDAR point cloud and color images to acquire the positions and semantics of the environment components. Semantic segmentation based on convolutional neural networks (CNN) provides rich semantics for the model, which could also be enhanced with the fusion of LiDAR point cloud. We validate the effectiveness of our proposed model on the KITTI dataset and our own collected data and exhibit qualitative results.

Sijia Wang, Kun Jiang, Shichao Xie, Yuanxin Zhong, Pengwei Guo, Qun Wu, Diange Yang

Effect of Air-Flow Organization in Cylinder of Gasoline Engines on Particles Emission

It’s the biggest technical difficulty to meet both PM and PN emissions. It can only be possible to achieve CHINA 6 emission regulations by adopting both pretreatment and aftertreatment purification. Inlet guide optimization and flat-head piston are beneficial to form unified large-scale vortex, to enhance tumble ratio and turbulent kinetic energy, and thus to increase flame propagation rate. It’s shown by test that there is significant reduction in combustion duration and in PM and PN emissions.

Wenzhong Zhao, Chao Zhang, Dongyu Qian, Liangchao Zhang, Renyu Ruan

Optimization Analysis of Buckling Strength of Connecting Rod for Internal Combustion Engine

Buckling strength is one important indicator of connecting rod design. With the increasing of power density of internal combustion engine, the compressive load of connecting rod becomes larger and larger, and bending fracture becomes one of the failure forms under unusual conditions. In this paper, combined with a case of bending fracture of the connecting rod in the development process of a new engine, a design method to ensure the safety of connecting rod is summarized as followed: according to the ultimate stress method, the stress at the middle section of the connecting rod is calculated, the additional stress caused by longitudinal bending is required to be between 10% and 15% of the normal stress, and the structural safety factor is evaluated based on them. Then the buckling test is carried out to obtain the actual buckling load and consequently the experimental safety factor of the connecting rod is reckoned. Through this method, the buckling strength of many connecting rods of several engines are tested and analyzed statistically. Thus it is concluded that the experimental safety factor of the buckling strength should be greater than 1.5, which provides an optimization method for the design and development of the connecting rod.

Kunpeng Xu, Guangquan Wu, Lin Xu

Impact Analysis of the Aging Silicone Oil in the Damper on the Torsional Vibration of the Crankshaft of the Heavy-Duty Vehicle Diesel Engine

The silicone-oil damper of the diesel engine has significant effects on reducing the torsional vibration and the torsional stress of the crankshaft. The nature to maintain viscosity of the silicone oil is an important indicator when we evaluate the reliability of a silicone-oil damper. With a heavy-duty vehicle diesel engine which meets China 6 emission standards as an object of research, this paper used AVL EXCITE to establish the torsional numerical model of the crankshaft which considers coupling effect of the non-linear stiffness and the damping of the silicon-oil damper, and discussed the impacts of the silicon oil in different viscosities on the amplitude of the torsional vibration and the dynamical tangential stress. The numerical results were also compared with the measurements in the dynamical durability test in which applying the time variable. The results indicate the measurements in which the diesel engine run 953 h turn out to be close to the simulation and demonstrate the accuracy of the dynamical numerical model. If the viscosity of the silicone oil reduces not more than 40%, its impacts on the torsional vibration and the torsional stress of the crankshaft are limited. However, with the viscosity increasing to 70%, the 6th-order vibration amplitude approach to the requirement limit, so that should be taken into consideration. Objectively speaking, the changes of the silicone oil viscosity will not have great impacts on the damper under normal use. For optimal performance, there should be the enhanced durability to the silicone oil in the damper and should take some effective measures to avoid the overquick decrease of the silicone oil viscosity.

Liming Zhai, Enzhen Wang, Weiguo Xu, Chenghai Huang, Zhenguo Yang

Experimental Study on Ethanol Gasoline Flash-Boiling Spray Characteristics Using Multi-hole GDI Injector

The effects of ethanol/gasoline blended fuel composed of gasoline with ethanol as additives in volume basis, on spray characteristics were experimentally investigated. Tests were carried out under various ambient pressure and fuel temperature. The results show that the spray would convert to superheated states by reducing the ambient pressure or increasing the fuel temperature. The influence of ambient pressure and fuel temperature on the macroscopic spray patterns become more significant with higher ethanol fraction fuels. At the end of the injection, the E85 spray penetration under the cold-jet condition is about 11% shorter than that with gasoline, and the E85 spray penetration under flash-boiling condition is about 20% longer than that with gasoline. The spray penetration rate increases and the total penetration extends obviously with higher injection pressure. Under the flash-boiling conditions, the spatial structure close to the injector tip presents a hollow cone structure, but the spatial structure far from the tip is obviously different for various fuels due to the different degree of flash-boiling collapse.

Jiakun Du, Hong Chen, Yuhuai Li, Lin Ye, Genkun Li

Lightweight Optimization for Engine Hood Based on Forward Design

The load path and main section is constructed based on forward design. The hood inner plate is set as weight reduction object. The main load path is obtained by topology optimization. And the finite element model is reset based on topology optimized model. Then the parametric hood is established based on the reset finite element model. The main sections of strengthening rib and frame are set as design variables. There are 10 design variables in the engine hood optimization. The samples are generated by Optimal Latin hypercube design (Opt LHD). The surrogate model is constructed by Radial Basis Function (RBF). The optimized solution is obtained by Non - Dominated Sorting Genetic Algorithm (NSGA-II). Forward design could obtain the reasonable load path and main section structure. Therefore, the optimization solution has better lightweight effect. After forward design, the mass of engine hood inner plate reduce 0.585 kg, the lightweight rate as high as 9.16%. The bend stiffness, torsion stiffness, lateral stiffness and corner stiffness of optimized engine hood satisfy objectives.

Chuan-qing Wang, Li-ling Zhang, Lei Tian, Cun-li Jia

Lightweight Research of the Rear Apron Assembly Based on Cross-Section Torsion Coefficient and Shape Characteristic Factor

Based on the primary parameters of cross-section, analyzed comparatively the lock hook cross-sections of the rear apron assembly in a variety of benchmark cars, and obtained the target value of the cross-section parameters of the vehicle by introducing the cross-section torsion coefficient λ and the shape characteristic factor μ. Then analyzed the impact of the section parameters from the sheet metal panels of the rear apron assembly by orthogonal experiment design, and optimized the structure of the rear apron assembly. Using the finite element software, the first torsion modal, the stress distribution under the twisting and bending conditions of the rear apron assembly, the back door opening deformation were compared between the original and optimized schemes. The analyzed results showed that the optimized results were improved significantly. Finally, the optimized method was testified by using the omnibus road reliability test.

Bensheng Xiong, Yongping Jiang, Yugong Wei, Zhimin Liu

Optimization Design of the Structure of the Automobile Bonnet Made of Fiber Composite Material

In this research, carbon fiber and glass fiber reinforced materials were used to conduct the empirical laminate design, sample manufacturing and modal experiment for the automobile bonnet. The experimental results were compared with the metal parts. The results showed that the fiber reinforced bonnet can not only meet the requirements of stiffness and modal, but also effectively reduced the weight, with a lightweight ratio of 51.2%. In different working conditions, the finite element method was used to analyze the modal and stiffness of the bonnet and compared with the metal parts to verify the effectiveness of the design. Based on the finite element model, according to the top-down design process, a new composite material structure optimization method was adopted, which used the finite element optimization technology. This method was divided into three stages: concept design, system design and detail design. The research showed that the new optimization design scheme can ensure the modal and stiffness of the automobile bonnet meet the requirements. At the same time, the lightweight effect was more obvious, which further reduced the weight of the automobile bonnet by 18% compared with the experiential laminate composite material.

Hui Ye, Chang Liu, Kangkang Yan

The Application Practice of Inner Diameter Pneumatic Probe in Automobile Manufacturing

The selection of the nozzle shape of inner diameter pneumatic probe, the number of nozzles and the amount of nozzle sinking design have a great effect on the uncertainty of the inner hole diameter measurement. According to the structural characteristic of tested part, the scientific design of the machining technology and the application requirements is to ensure the key to measurement accuracy of the inner diameter; In addition, how to use the inner diameter pneumatic meter correctly in the production process, how to change the pneumatic probe correctly, how to reduce the influence of inner hole surface roughness on the measurement results is also an important measure to ensure the accuracy of the inner diameter measurement; one to one reply is given in this paper, to design inner diameter pneumatic probe and to use in the site has certain guidance significance.

Ye Zongmao, Zhao Yanhui

Solutions to Common Problems of Forged Steel Piston

This article focuses on two forged steel piston products of different structures and materials, through the mold stress analysis simulation mold structure optimization, die life is greatly improved, while solving the piston skirt crease, underfill, ejector pin distortion and other technical problems. Piston products for quenched and tempered steels and micro alloy have been adjusted to optimize the heat treatment process, reducing the proportion of scraps in the form of quenching cracks, skirt deformation, and uneven hardness distribution.

Jianjun Wang, Xinshuai Hu, Yi Yao, Denghe Chen, Guohui Cao, Jun Gu, Chengzhong Yang

Research on the Control Method of Empty Stroke of the Brake Pedal

At present, there are many kinds of researches on the brake disc, brake drum and brake performance in the field of commercial vehicles, but few researches on the brake pedal, especially in the empty stroke control of brake pedal. When the car is braking, the driver applies force on the brake pedal, and the stability of the brake pedal will affect the safety of the vehicle directly. Therefore, as an important security part of the vehicle, the brake pedal has attracted more and more attention from various automobile manufacturers. In the design and manufacture process of the brake pedal, the empty stroke will be generated because of the structure of the product, so accurate analysis and control of the empty stroke of the brake pedal is very important for improving the braking performance of the vehicle. In this paper, starting from the theoretical research on the empty stroke control of the pedal assembly, and combining with the production process to design the stroke control equipment, provide a solution to solve the reasonable stroke gap of the pedal assembly before it leaves the factory.

Qimin Yang, Lisheng Tian, Xiuren Li

Research and Application of Innovative Automotive Wax Injection Process

In order to meet the increasing demand of customers for car quality and interior environment, Changan Automobile has carried out innovative research on the traditional car wax injection process, jointly developed a new environmentally friendly cavity wax, and adopted a precise wax injection process to reduce the smell of the car. VOC, to enhance anti-corrosion performance, and promote the application of innovative automotive wax injection technology in various bases of Changan Automobile, and practice the concept of “fully promoting green manufacturing and increasing advanced energy-saving and environmental protection technology” in “Made in China 2025”.

Huigang Pan, Haibo Zhou, Xuebing Xiang, Yalei Zhang, Zhongqiong Xu, Liye Sun, Jun Sun

The Innovation & Practice of New Model Early Verification Based on the Target of Smoothly SOP

Smoothly SOP is one of main target of new model R&D and trial production, and new model early verification is the most approach to reach this target. By expounding the innovation and practice of new model verification system in the early new model trial production, this paper explains the verification system’s basic environment, main business tool and its key points, and demonstrates the effect and importance of new model early verification.

Hong Wang, Weihua Zhuo, Weimin Gong, Ze Lu

Application of Advanced Measurement Technology and Equipment in Transmission Manufacturing

In recent years many new measurement technologies have sprang up in automobile manufacturing field, the main characters of which are that, they can complete the measurement of workpieces between operations with high speed, high efficiency, high accuracy and high flexibility [1], and thus guarantee the manufacture engineering. Application of advanced measurement technologies in vehicle transmission are introduced, e.g. measurement technologies of transmission shafts, gears and housing.

Xiaolong Geng, Hongbing Yang, Zhengqi Li, Yingsu Li

The Effect of Si, Mg and Mn/Fe on the Fluidity of AC2B Alloys

This article researches the effect of Si, Mg and Mn/Fe on the fluidity of AC2B alloys through the metallurgical microscope and the device used to test the fluidity of alloy. The result shows that the increase of Si content can improve the fluidity of AC2B alloys; with the increase of Mg content, the fluidity of AC2B alloys could be down; when the content of Mn is 0.5%, the variety of Mn/Fe has little effect on the fluidity of AC2B alloys.

Weizheng Wang, Siyu Li, Jiajie Ning

Application of Air Quenching Technology to Engine Cylinder Head

This paper mainly introduces the application technology of air quenching in the engine cylinder head casting process of our company. After the casting is pushed out of the mold, air quenching is carried out immediately, and then T5 aging treatment. In the continuous production with air quenching, the start cooling temperature is 494 °C, the final cooling temperature is 122 °C, the cooling rate is 33.8 °C·min−1. Compare the mechanical properties and residual stress of T5 air quenching and T7 water quenching, the tensile strength and elongation of air quenching are reduced by 6.6% and 46.1% respectively, with a small difference in hardness and a reduction in residual stress by 62.2%.

Weizheng Wang, Jiajie Ning, Zhengwu Yan, Rui Hu

Promote In-Process Measurement Technology Application in Intelligent Grinding Production

The requirements to grinding tool from the various industries are essentially the same: smaller tolerances, better surfaces, shorter production times and fast reactions to product changes. The advances in grinding technology and innovative help to offer new and viable solutions for these sectors realized. For example, controlled dimensional accuracy using in-process gauging, controls with “Learning Function”, including automatic compensation of roundness deviation and dimensional errors is critical we usually use. MARPOSS measurement system has been designed for gauging workpiece on all type of grinding machines. Its ability to control workpiece during the machining process renders the system extremely flexible and contributions to a significant increase in productivity. In this paper, we focus on as end users how to independently finish the MARPOSS P7ME measurement system adjustment through mastering the measurement programming and adjustment technology to shorter production retrofit time. Future-oriented for precise and intelligent processes, flexibility, digitalization and an increased competition for innovation are the topics that concern machine tool maker as well as end user. Intelligent factories focus on quality. We give some plan to upgrade measurement technology during machine tool intelligent retrofit, to give old machines a new life in intelligent manufacturing production to promote in-process measurement technology application.

Qi Yang

Development of New Environmentally Friendly Waterborne Coating for Engine Use

This paper is describing the formulation design, preparation and testing of waterborne primers and coatings suitable for MC series engines. The developed products can substitute solvent-based coatings, and it meets the production requirements of MC11/13 engine. The coatings can not only withstand 380 bar liquid flushing, its VOCs also complies with environmental regulations.More and more attention has been paid to the air pollution caused by volatile organic compound (VOCs) emitted from automobile painting process. The environmental protection department has issued multitude of regulations to limit VOCs emissions.Environment-friendly coatings such as waterborne coatings and powder coatings have become the development trend. Currently, only MC11/13 cylinder head and crankcase are coated with solvent-based paint. In order to expand our company’s production capacity, a new coating line will be developed. Meanwhile, environmental protection departments require the use of environmentally friendly coatings. Given the surface of the coating components has a three-dimensional structure, electrostatic shielding will affect the adsorption of concave powder; only water-based coatings can be considered. Therefore, an environmental friendly waterborne coating has been developed.

Yuning Li, Zhen Wang

Simulation Study on the Idle Shake Control of a Vehicle

In this paper, a 16-DOF model of a vehicle including powertrain and its mount system is established. The simulation study of seat shake during idle condition is carried out. It is found that the shake is mainly caused by the resonance between the engine excitation frequency and the rigid body mode of the mount system. The effects of DMF unbalance, mount stiffness and idle speed on idle vibration of the vehicle are analyzed. It is found that idle shake can be significantly improved by properly increasing engine speed through simulation. The simulation results are verified by experiments.

Bocong Lu, Zheng Xu, Ming Chen, Xiaohu Zhang, Shuaiju Zhang, Lin Liu, Wenjie Zhao

Experimental Study on Mechanism of Cavity Filler Block to Reduce Interior Noise

To determine the interior noise reduction mechanism of car body cavity filler block, the noise reduction researches were conducted experimentally. By comparing the BIW modal characteristic and transfer functions before and after removing cavity filler block, the influence of cavity filler block on vehicle low frequency vibration was investigated. To investigate the effect of cavity filler block on engine noise and road-tire noise, a full vehicle test using drum tester was carried out. Another full vehicle test in the wind tunnel was conducted to determine how it influences wind noise. Based on the above test results, the noise reduction mechanisms were analyzed. On the one hand, it helps to increase the damping of BIW, thus suppress the vibration and reduce low frequency noise. On the other hand, it cuts off the propagation of the noise outside the vehicle which may invades the passenger compartment, thereby reducing the high frequency noise.

Dejian Meng, Ziyi Wang, Lijun Zhang

A Study of Diagnosis Method for Turbocharger Abnormal Noise

Based on the problem of abnormal noise of a turbocharger model in acceleration condition, the study starts from the spectrum characteristics of the abnormal noise. Combined with subjective evaluation and analysis of transmission paths and noise and vibration frequency of various components of engine compartment, this paper elaborates on the excitation characteristics of the turbocharger. According to the generation mechanism of abnormal noise, considering factors such as spatial layout, performance matching and cost constraints, a pneumatic buffer has been set reasonably to eliminate or reduce the influence of turbocharger abnormal noise on riding comfort during acceleration. By integrating principle, analysis and improvement, a set of diagnosis methods for abnormal noise of turbocharger is developed. After being improved and verified, the proposed methods have been applied.

Yongjin Qiu, Fangyu Wang, Dong Ren

Research and Application of Reinforcement Beams Supporting Body Panel on Attenuation of Low Frequency Vibration and Sound Radiation

Due to the tendency of vehicle lightweight, the body panel becomes thinner. So the panel is much easily excited by engine and road excitations and radiates noise into the passenger compartment, which is frequently complained by the customers. The paper studies the combined structures including a body panel and different reinforcement beams and analyzes the characteristics of the panel vibration and sound radiation. The theoretical analysis and numerical calculation show that the combined structures are benefit to increase the panel’s stiffness and reduce its surface velocity, and further attenuate the panel’s sound radiation power and sound radiation efficiency. The paper analyzes the mechanism of generating the interior booming and provides the control method by tuning the structures of the reinforcement beams and the supporting ways to the panel. The analysis results are consistent with the testing ones, and the vehicle booming is attenuated. The control method is practicable, which provides help for vehicle body development.

Jie Zhang, Jian Pang, Yuping Wan, Liang Yang, Wenyu Jia

Modal Parameters Identification Research of Commercial Vehicle Drive Shaft Based on Experimental and Simulation Hybrid Modeling

Aiming at the noise problem of accelerating condition caused by the vibration of the drive shaft of a commercial vehicle, the modal analysis was carried out based on the low-order natural frequency and mode shape in this paper. The modal research process is divided into two parts, namely, simulation modal research and experimental modal research. Based on the finite element analysis method, an effective finite element model was established to simulate the free modal. Meanwhile, the rubber rope was used to hoist the drive shaft to simulate its condition of free constraint. Combined with the LMS Test. Lab test system, the modal test of the drive shaft was taken by hammering method. The test modal analysis results were compared with the simulation results, then, the finite element model was re-optimized. During the finite element model optimization process, the finite element model optimization method based on strain mode and genetic algorithm was considered. By comparing and analyzing the difference between the test and the simulation results, the natural frequencies and critical speeds of different orders of the drive shaft were obtained more accurately. And the research conclusions provide a theoretical reference for the NVH design of the drive shaft.

Boqiang Zhang, Xinping Wu, Zhentao Li, Tianpei Feng, Haiyang Yu

Analysis of the Exterior Rearview Mirror Layout and the Blind Area of the Forward Visibility

This paper analyzes the location of the exterior rearview mirror and the blind area of the forward visibility by aiming at the area shielding problem of the exterior rearview mirror on the right side of a certain car model. By analyzing the relative relationship between the peripheral parts of the exterior rearview mirror and the man-machine parameters of the location, the paper optimizes the layout of the exterior rearview mirror and obtains the optimal layout plan. Exterior rearview mirror layout plays a guiding role to improve the design efficiency and quality.

Gang Yang

Research on Development and Application of Virtual Reality System for Car Styling Review

This paper aims to illustrate the possible use of virtual imaging technology in automotive design by introducing the current virtual imaging technology, including the application of headsets and the different forms of projection. By comparing with the existing virtual reality technologies in the field of automotive design, the advantages and disadvantages of virtual imaging technology are discussed, and the future application is explored to address these problems accordingly.

Jingfeng Shao, Yunrong Zhang, Zhiqiang Yu

The Aural Discomfort Inside the Car Analysis and Control in the Instant the Door Closes

With the improvement of the vehicle leakage performance, the aural discomfort phenomenon appeared during closing door. The studies for closing door quality are more, but the studies for aural discomfort are very little. In this paper, through a large number of objective test and subjective evaluation of the vehicles, and it is systematically studied the relationship between leakage under positive pressure and aural discomfort during closing door. And it theoretically deduces to the minimum closing door speed, the Y-direction projection area, vehicle air leakage, cross-sectional area of the vehicle, decompression air vent ventilation area relationship with the aural pressure fluctuation inside the car, and the objective test data supports completely the validity of the deduction. In this paper, it puts forward originally the human aural comfort threshold definition of objective evaluation and it has directive significance to design and develop aural comfort in the instant the door closes.

Mao Guangjun, Xi Shuxiong, Zhang Kaige, Jiang Guang, Li Xin, Zhao Hualei

Study on Thorax Certification Evaluation Strategy of Thor-50M dummy

To improve the efficiency of THOR-50M dummy certification and make certification result is easy to satisfy the requirements of User Manual and Euro NCAP TB026, We researched the thorax stiffness of the THOR-50M dummy. The results show the THOR-50M’s thorax stiffness is existing in the impact tests and the thorax stiffness reflects dummy’s anthropomorphic characters. Come to conclusion that thorax certification evaluation of THOR-50M dummy would be done based on keeping the stability and the uniformity of thorax stiffness. The thorax stiffness of overlap region of User Manual and TB026 is 59–74 kN/m in the x-axis and that is 85–108kN/m in the z-axis if thorax certification evaluation is conducted by thorax stiffness.

Enyi Shang, Dayong Zhou, Dandan Yan, Xinkang Cui

Floor Impact Bench-Test Method Based on Mass-Spring Model

Based on the analysis of the movement and stress of the floor system in the process of vehicle blast, the movement of the floor is simplified, and a bench test method of floor impact test based on mass spring model is established. Comparing with the floor motion and the tibia force curve of the dummy leg in the vehicle blast test, the bench test method can reproduce the movement and force of the dummy leg in the vehicle blast test very well, which is in good agreement with the vehicle test. This method can evaluate the impact of floor and its accessories on the leg force of the dummy separately, avoiding the complexity and danger of vehicle test and reducing the development cost.

Dong Liping, Wang Xiaowei, Zhang Xinqi, Bu Shaoxian, Liu Guoqing

Research on Measuring Method of Dynamic Collapse Velocity of Steering Column in Vehicle Collision Test

The low-cost and easy-to-operate method for measuring the dynamic collapse velocity of steering column is realized, and the problem that the dynamic collapse displacement of steering column can not be measured in the vehicle crash test is solved. In other words, an acceleration sensor is installed on the upper and lower cylinder of the steering column to measure the collapse acceleration of the steering column when the dummy impacts the steering system. By modifying the measured acceleration and integrating the acceleration, the collapse velocity and the collapse time of steering column are obtained. Finally, the measurement results are validated by the sled test and high-speed video analysis. It is confirmed that this method can be used to measure the collapse parameters of steering column in the vehicle collision test.

Jiayao Li, Changqing Yin, Ai Xu, Xiaolei Li, Taisong Cui, Hui Zhao

Study on the Influence of Accelerometer with Damping and Without Damping on the Results of Head Impact Test at Front Windsheld

The influence of the acceleration sensor with or without damping on the results of head impact test of pedestrian protection at the front windshield is studied by means of experiment and theoretical analysis methods in this paper. The results demonstrate that, with the front windshield cracked due to the head impact, the acceleration peaks of the undamped sensor (Endevco 7264C) turn to be false and the HIC15 value deviates from the real ones when the sensor is stimulated by some excitation with high frequency. While the damped sensor (Endevco 7264H) can prevent the interference caused by resonance of the front windshield and the sensor, and improve the accuracy of the test results. It’s suggested that a damped acceleration sensor should be used in the head impact test at the front windshield.

Yinhui Wan, Dongdong Tan, Chengjing Zhou, Linchun Zhong, Fanjun Tai

Shenzhen Mobility Research for Different Travel Scenes

As an emerging city that has developed rapidly after China’s reform and opening up, Shenzhen’s urban appearance can not only reflect the general situation of China’s vast cities, but also have certain historical particularities. Based on the introduction of the status quo of Shenzhen’s urban development, this paper qualitatively studies the distance distribution and traffic structure characteristics of Shenzhen residents in the four travel scenarios of commuting, shopping, leisure and pick-up, and makes a portrait discussion on the current status of mobility in Shenzhen. And predicted the future development direction of Shenzhen’s transportation.

Zan Li, Fuquan Zhao, Zongwei Liu

Research on “Dual-Credits” Policy of Automobile Enterprises

The new energy automobile industry is the one of the seven strategic emerging industries in China, and its steady development needs the continuous support from government. On September 28, 2017, the Ministry of Industry and Information Technology, the Ministry of Finance, the Ministry of Commerce, the General Administration of Customs and the General Administration of Quality Supervision and Inspection jointly issued the “Measures for the Parallel Management of Average Fuel Consumption of Passenger Vehicle Enterprises and New Energy Vehicle Points”, establishing a dual-credits system. “Dual-credits” refers to “Car Average Fuel Consumption (CAFC)” and “New Energy Vehicle (NEV)”. Given the current “Dual-Credits” policy in the new energy vehicle market, this paper regarded the government and the vehicle enterprise as a whole respectively, and analyzed the maximum income of the vehicle enterprises and government with and without “Dual-Credits” policy. It proves that the “Dual-Credits” policy has a positive effect on the production of new energy vehicles and the automobile industry. Then correlation analysis was carried out on the government control parameters such as per vehicle credits, new energy credits ratio requirement, new energy vehicle amplification factor to provide a reference for the government to promote the development of new energy vehicles.

Yunlei Yin, Zhenfei Zhan

Software Development Management Research Based on Vehicle-Controlled ECU

In this paper, base on software development management strategy of a vehicle-controlled ECU as the research object, through the analysis of the vehicle software industry status and technical management bottleneck, put forward software development management process system and quality operation mode suitable for automotive ECU, namely “Double-V iteration mode”. Through verified by pilot project, which has achieved gratifying phased results. From the stage results, it has performed well and improved the quality management and configuration management level of the enterprise, and providing high-quality management strategy for the newly developed vehicle-controlled ECU software management.

Yun-lin Ma, Hui Zhang, Dong-ping He, Yu Zhou, Xiu-quan Tan

Investigation on the Gearbox Radiated Noise Optimization Under Acceleration Conditions of Electric Bus Based on Gear Micro-modification Methods

Because of the superior advantages of electric bus on energy saving and emission reduction than the traditional diesel bus, the electric buses are widely used in short-distance travel and urban public transportation. However, during the use of the electric bus, according to the reflection of the passengers and the drivers, the noise was abnormal under the two-gear and the three-gear acceleration conditions. Compared with the traditional diesel bus, the gearbox noise of electric bus is more prominent due to time varying loads effect and the absence of diesel engine masking effect under the acceleration condition, which deteriorates the NVH characteristics of the whole vehicle. Therefore, the gearbox of electric bus is researched as an object in this paper. The test results showed that the radiated noise of the gearbox under the three-gear acceleration condition was significantly higher than the two-gear acceleration condition, and the meshing noise of the shifting gear of the three-gear was found to be the main source of the gearbox radiation noise under the three-gear acceleration condition by order analysis, so the shifting gears of the three-gear were optimized as an object. In this paper, the boundary element radiation noise model has been established in the acoustic radiation software, and the radiated noise model has been verified by the bench test under the three-gear acceleration condition. In order to optimize the gearbox radiated noise under the three-gear acceleration condition, method of gear microscopic modification has been used to optimize the transmission error (TE) and the radiated noise.

Yong Chen, Ningning Qiu, Hai Liu, Miao Yu, Changyin Wei

Effects of Supporting Stiffness on Meshing Characteristics of Helical Gear Under Multiple Load Cases

The stiffness of the shaft of transmission has an important influence on the meshing quality of gear pair. Taking the 1st helical gears and shaft of an automatic transmission as the research object, two rigid-flexible coupling models for gearbox with different supporting span were presented, and the accuracy of the models was verified by comparing the contact pattern results of experiment and simulation. Based on this, the meshing misalignment and transmission error of the gear pair were calculated, and the influence laws of supporting stiffness on meshing characteristics of helical gear were analyzed under different torques and speeds. It is shown that when the supporting span is large, the meshing misalignment and transmission error are more sensitive to the change of torque. The thickness of the oil film on the meshing tooth surface is larger when the stiffness of the shaft is smaller. However, the meshing misalignment, transmission error and sliding velocity increase. Further more, the distribution uniformity of load along the direction of tooth width is even worse, and the contact temperature of tooth surface increases. By reasonably increasing the supporting stiffness of the shaft, the stability and reliability of the gear pair can be effectively improved.

Yong Chen, Libin Zang, Kai Li, Huidong Zhou, Wangyang Bi, Jinkai Li

Steady-State Thermal Analysis of Electric Vehicle Two - Speed Automatic Transmission

An energy loss during the operation of the Electric 2-Speed Automatic Transmission, which will generate heat and make the transmission bear a thermal load. Therefore, it is necessary to make a steady-state thermal analysis of transmission. In this paper, the mathematical model of transmission is established based on the theory of heat transfer. Based on the finite element theory, the temperature field distribution and heat flux distribution of the whole transmission are solved. The results show that the modification of the gear height on the addendum can reduce the temperature of the gear; Transmission lubrication system need to be further optimized; The heat convection between the wall surface of the box has little effect on the temperature. The temperature of each part conform to the requirements of the transmission. The analysis results provide a theoretical basis for the optimization of transmission efficiency.

Yong Chen, Yuheng Wang, Guangxin Li, Miao Yu

Four-Parameter Real-Time Thermal Model for Dry DCTs

Excessive temperatures tend to occur in dual clutch transmissions (DCTs) due to large amount of friction heat generated in the compact space, but seriously deteriorate shift quality and even reduce lifespans. In order to accurately obtain the DCT temperature in real-time, a four-parameter model is proposed to modify the previously studied static two-parameter model by introducing two dynamic coefficients. According to the deduction of energy balance equation based on a one-dimension assumption, the two dynamic coefficients are found to inherently change along with the friction heat and ambient temperature. Their changing rates constitute a four-parameter model. The new model is verified by dynamometer experiments, which show higher accuracy and better adaptability to working conditions than the static two-parameter model.

Zhiyang Qiu, Zhi-Lin Charlie Zheng, Dongxiao Miao, Li Chen

Determination of Throttle Setpoint Control of Turbo-Charged GDI Engine Based on Newton Raphson Iteration

For the purpose of responding the request engine torque and inhibiting the overshoots of intake air pressure (air density), target intake air pressure algorithm in the nonlinear character of engine intake system is firstly promoted based on Newton Raphson iteration method, and real-time recursive equation of target intake air pressure is obtained. Target intake pressure of transient operation condition is computed. And according to Tustin Derivative method, optimizing throttle efficient area change rate is taken into account. At last, throttle position control strategy is verified on the bench and vehicle. The result shows that the throttle position control strategy can meet engine request torque precisely.

Long Qin, Fanwu Zhang, Lei Liu, Chunjiao Zhang, Jianbo Zheng, Xue Lei, Liuchun Yang, Fengmin Tian, Fangxun Zhao

Analysis of Cruise Failure Caused by Multi-function Steering Wheel Switch

Based on the case that the multi-function steering wheel switch of a certain type of vehicle has abnormally caused the cruise function to be activated during the whole vehicle test, the analysis shows that the signal abnormality is generated when the walkie-talkie interferes, and the switch itself has insufficient anti-interference ability, resulting in sampling. Abnormal after the voltage is disturbed. According to the reasons, the corresponding measures are taken to improve the anti-jamming performance by changing the hardware circuit, and finally solve the problem and verify the effectiveness.

Qian Sui, Haihong Cao, Wei Yu, Hui Cao, Meilin Xiao, Yan Zhang, Yong Hu

Research on Fuzzy Energy Control Strategy for Four-Wheel Hubrid Elestric Vehicle

Aiming at the four-wheel drive hybrid structure, this paper aims at minimizing fuel consumption, takes full account of vehicle status, and designs a control strategy of working mode management and rule-based multi-power source energy allocation. In order to further improve the rationality of energy distribution, the ratio K of the demand torque to the optimal torque and SOC are the two inputs of the fuzzy controller, and engine torque working coefficient y is an output of fuzzy controller. The fuzzy control system is designed and the fuzzy control rules are established to optimize the engine working torque in real time. The simulation results show that the energy management strategy of the fuzzy optimal control accords with the demand of power train, realizes the smooth switching of working mode, reduces the speed error obviously, and improves the fuel economy by 7.81%.

Cheng Li, Xu Wang, Zhongwen Zhu, Qing Wei

Online Identification Strategy of Sand Terrain for SUVs

SUVs need to be driven on variety of terrains. Due to the unstable soil structure, the control parameters and strategies of chassis control systems when travelling on sand terrain are different from on hard surfaces. If travelling on sand can be identified automatically, it can provide basic information for online adjustment of each chassis subsystem. In this paper, a domestic SUV is used, and the strategy of sand terrain identification is studied. Only signals on CAN bus are used in the algorithm, and no additional sensors are necessary. Based on the analysis results of road experiments, driving resistance and wheel speed fluctuation are calculated, and the incremental factor calculation method of sand recognition counter based on fuzzy logic and the sand identification strategy are proposed. The road experiments on various roads and working conditions show that the strategy can effectively identify sandy land and avoid false recognition.

Jian Zhang, Yu Wang, Fei Xie, Sutie Zhang, Jian Zhao, Weixiang Wu
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