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2017-03-28
Technical Paper
2017-01-1494
Weinan Tao, Bingzhao Gao, Hongqing Chu, Mengjian Tian, Hong Chen
Steer-by-wire technology is considered as a next step in steering system evolution. The substitution of electronic systems in place of mechanical components simplifies the car interior design and saves larger space for driver cabin. But the absence of the force coming from the road directly challenges us to model an optimal steering feel. Referring to the structure of the conventional steering systems, the forces transmitted to the driver through handwheel consist of steering system friction and aligning torque. In the paper, the steering system friction is simulated by the Stribeck friction model. The accurate friction model is important for simulating feedback torque during stand-still, low speed and low lateral acceleration conditions. Besides that, the elasticity of steering column should be taken into consideration, which helps to improve the dynamic response performance of the system especially in the condition that the steering angle changes rapidly.
2017-03-28
Technical Paper
2017-01-0624
Jiaxin Liu, Sicheng Qin, Yankun Jiang, Shumo He
In this work, a XD132 Road Roller from XCMG in China was employed as the research basis to study the heat exchange performance for the heat dissipation module under varied working conditions. The module in XD132 consists of a cooling fan and a radiator group. At first, a numerical investigation on the elementary unit of the radiator was performed to obtain Colburn j factor and Fanning f factor, which was used for the -NTU method that predicts the radiator performance. The fan was numerically tested in a virtual tunnel to acquire the performance curve. The performance data from both investigations were transformed into the boundary conditions for the numerical model in a virtual tunnel. A field experiment was carried out to validate the simulation accuracy, and the performance regularity under four working conditions were discussed.
2017-03-28
Technical Paper
2017-01-1119
Fangwu Ma, Ying Zhao, Yongfeng Pu, Jiawei Wang
Gear transmission is one of the most widely used form in mechanical transmission system and plays an important role in Automobile industry. Manufacturing errors, assembly looseness, gear wear issues in gear transmission system may result in backlash of gear, noise and fatigue damage, which seriously affect the efficiency and service life of gear transmission. For the gear transmission assembled, it is of great importance to obtain the desired results monitoring the condition of gear meshing and prevent the occurrence of dangerous situations. How to determine whether there are some issues of gear tooth wear, misaligned bearing, gear eccentricity and backlash and how to define gear sets with problems and find the specific problems which already exist on gear transmission are of great value and significant to ensure the quality and design of product.
2017-03-28
Technical Paper
2017-01-1565
Xiangkun He, Kaiming Yang, Xuewu Ji, Yahui Liu, Weiwen Deng
Abstract A vehicle dynamics stability control system based on integrated-electro-hydraulic brake (I-EHB) system with hierarchical control architecture and nonlinear control method is designed to improve the vehicle dynamics stability under extreme conditions in this paper. The I-EHB system is a novel brake-by-wire system, and is suitable to the development demands of intelligent vehicle technology and new energy vehicle technology. Four inlet valves and four outlet valves are added to the layout of a conventional four-channel hydraulic control unit. A permanent-magnet synchronous motor (PMSM) provides a stabilized high-pressure source in the master cylinder, and the four-channel hydraulic control unit ensures that the pressures in each wheel cylinder can be modulated separately at a high precision. Besides, the functions of Anti-lock Braking System, Traction Control System and Regenerative Braking System, Autonomous Emergency Braking can be integrated in this brake-by-wire system.
2017-03-28
Technical Paper
2017-01-0406
Jindong Ren, Xiaoming Du, Tao Liu, Honghao Liu, Meng Hua, Qun Liu
This paper presented an integrated method for rapid modeling, simulation and virtual evaluation of the interface pressure between driver human body and seat. For the simulation of the body-seat interaction and the calculation of the interface pressure, in addition to body dimensions and material characteristics, an important aspect was the posture and position of the driver body with respect to the seat. The correct simulation results could be acquired only by realistic setting of the body posture, by introducing posture prediction models. To ensure accommodation of the results to the target population, usually several individuals were simulated, whose body anthropometries covered the scope of the whole population. The multivariate distribution of the body anthropometry and the sampling techniques were adopted to generate the individuals and to predict the detailed body dimensions.
2017-03-28
Technical Paper
2017-01-0432
Bing Zhu, Zhipeng Liu, Jian Zhao, Weiwen Deng
Abstract Adaptive cruise control system with lane change assistance (LCACC) is a novel advanced driver assistance system (ADAS), which enables dual-target tracking, safe lane change, and longitudinal ride comfort. To design the personalized LCACC system, one of the most important prerequisites is to identify the driver’s individualities. This paper presents a real-time driver behavior characteristics identification strategy for LCACC system. Firstly, a driver behavior data acquisition system was established based on the driver-in-the-loop simulator, and the behavior data of different types of drivers were collected under the typical test condition. Then, the driver behavior characteristics factor Ks we proposed, which combined the longitudinal and lateral control behaviors, was used to identify the driver behavior characteristics. And an individual safe inter-vehicle distances field (ISIDF) was established according to the identification results.
2017-03-28
Technical Paper
2017-01-0438
Zhenhai Gao, Tianjun Sun, Lei He
Abstract A multitude of recent studies are suggestive of the EV as a paramount representative of the NEV, its development direction is transformed from “individuals adapt to vehicles” to “vehicles serve for occupants”. The multi-mode drive control technology is relatively mature in traditional auto control sphere, however, a host of EV continues to use a single control strategy, which lacks of flexibility and diversity, little if nothing interprets the vehicle performances. Furthermore, due to the complex road environment and peculiarity of vehicle occupants that different requirement has been made for vehicle performance.
2017-03-28
Journal Article
2017-01-0368
Ying Zhao, Fangwu Ma, Longfan Yang, Yueqiang Wang, Hongyu Liang
The conventional hood with single material and stiffener structural form conceals some limitations on pedestrian protection and lightweight, not satisfying the requirements of structural strength, pedestrian protection and lightweight contradictory with each other at the same time. In this paper, a novel type hood is proposed to develop sandwich structure using architected cellular material with negative Poisson's ratio (NPR) configuration based on the decoupling thought of structural strength and energy absorption. Core-layer aluminum alloy material with NPR is used to meet the requirement of impact energy absorption, inner and outer skin using carbon fiber is selected to achieve high structural stiffness needed. This paper starts from the relations between geometric parameters of core-layer architected cellular material and mechanical properties, on this basis, the optimal geometric parameters can be expected using the multiobjective optimization method.
2016-11-08
Technical Paper
2016-32-0061
Da Wang, Dingchao Qian, Bo Wang
Abstract This paper summarized the development methodology and technical experiences on Formula Student racecar engines acquired by Jilin University from 2011 to 2015. This series of engines are all based on 600cc 4-cylinder motorcycle gasoline engines and were modified to turbocharged engines which met the Formula Student technical regulations, in order to achieve higher power output, wider torque band as well as lower fuel consumption. During the development process, multiple research projects have been conducted surrounding the turbocharging technology. These research projects have covered multiple areas including the matching of the flow rate characteristics of the engine and the turbocharger, the design of intake and exhaust systems, research on the wastegate as well as its actuator, the tuning and control of the boost pressure as well as the design of the lubrication system for the turbocharger, etc.
2016-10-17
Technical Paper
2016-01-2345
Guoyu Feng, Wenku Shi, Henghai Zhang
Abstract In order to study the static and dynamic characteristics of the thrust rod. Based on the multi-body dynamics theory, the dynamic model of the thrust rod and the vehicle system is established by using ADAMS software. The limit braking condition is simulated, and the limit braking load of the thrust rod is obtained. Thrust rod finite element model is established, the load calculation value and rubber test data as a finite element analysis of input conditions, using ABAQUS software to carry on the stiffness and strength analysis, analysis results show that the strength meets the requirement, and the stiffness and strength calculation result is in good agreement with the sample test, accurately describes the finite element model. The analytical method used can be used to predict the stiffness of the thrust rod.
2016-09-27
Technical Paper
2016-01-8044
Guoyu Feng, Wenku Shi, Henghai Zhang, Qinghua Zu
Abstract In order to predict the fatigue life of thrust rod heavy duty commercial vehicle balanced suspension, based on the continuum mechanics theory, the fatigue life prediction model of rubber with equivalent effect as damage parameter is established. Based on the equivalent stress and fatigue cumulative damage theory, the fatigue damage evolution equation of rubber material expressed by stress is derived by using the strain energy function. The general fatigue life model is established by using the maximum logarithmic principal strain as the damage parameter. The finite element model of the thrust rod is established, and the stress distribution of the spherical hinge rubber layer and the easy damage area are analyzed. Based on the equivalent stress calculation results and the axial tension stress and strain data of the rubber material, the accuracy of the results of the finite element calculation is verified.
2016-09-27
Technical Paper
2016-01-8051
Jixiu Zhang, Shuming Chen, Dengfeng Wang
Abstract In order to predict the interior noise of a commercial vehicle cab, a finite element model of a heavy commercial vehicle cab was established. An acoustic-structure coupling model of the cab was built based on experimentally validated structure model and acoustic model of a commercial vehicle cab. Moreover, based on the platform of Virtual. Lab, the acoustic field modes of the acoustic model of the commercial vehicle cab and the coupled modes of the acoustic-structure coupling model were analyzed by using the acoustic-structure coupling analysis technique. The excitation of the vehicle cab was tested at an average speed on an asphalt road. Then, the interior noise of the heavy commercial vehicle cab was predicted based on FEM-FEM method and FEM-BEM method with all the parameters and excitation. Furthermore, the predicted interior noise of the commercial vehicle cab was compared with the tested interior noise.
2016-09-27
Technical Paper
2016-01-8113
Xiaohua Zeng, Guanghan Li, Dafeng Song, Sheng Li, Xianghua Li
Abstract To improve traditional heavy commercial vehicles performance, this paper introduces a novel hydraulic hub-motor auxiliary system, which could achieve auxiliary driving and auxiliary braking function. Firstly, the system configuration and operation modes are described. In order to achieve coordinating control and distribution of the engine power between mechanical and hydraulic paths, the paper proposes an optimal algorithm based on enhance of vehicle slip efficiency and the results show that displacement of hydraulic variable pump relates with the transmission gear ratio. And then the hydraulic pump displacement controller is designed, in which the feedforward and feedback strategy is adopted. Considering the characteristics of hydraulic hub-motor auxiliary system, a layered auxiliary drive control strategy is proposed in the paper, which includes signal layers, core control layers and executive layers.
2016-09-14
Journal Article
2016-01-1892
Jiao Guo, Weiwen Deng, Sumin Zhang, Shiqian Qi, Xin Li, Chenghao Wang, Jun Wang
Abstract The conventional radar modeling methods for automotive applications were either function-based or physics-based. The former approach was mainly abstracted as a solution of the intersection between geometric representations of radar beam and targets, while the latter one took radar detection mechanism into consideration by means of “ray tracing”. Although they each has its unique advantages, they were often unrealistic or time-consuming to meet actual simulation requirements. This paper presents a combined geometric and physical modeling method on millimeter-wave radar systems for Frequency Modulated Continuous Wave (FMCW) modulation format under a 3D simulation environment. With the geometric approach, a link between the virtual radar and 3D environment is established. With the physical approach, on the other hand, the ideal target detection and measurement are contaminated with noise and clutters aimed to produce the signals as close to the real ones as possible.
2016-09-14
Technical Paper
2016-01-1902
Xiaoyu Wang, Yun Zhao, Yufeng Lian, Yantao Tian
Abstract A new lateral stability control method, which is based on vehicle sideslip angle and tire cornering stiffness estimation, is proposed to improve the lateral stability of the four-in-wheel-motor-driven electric vehicle (FIWMD-EV) in this paper. Through the lateral tire force information, vehicle sideslip angle can be estimated by the extended kalman filter (EKF). Using the estimated vehicle sideslip angle, tire cornering stiffness can be also estimated by forgetting factor recursive least squares (FFRLS). Furthermore, combining with the vehicle dynamics model, an adaptive control target model is proposed with the information on vehicle sideslip angle and tire cornering stiffness. The new lateral stability control system uses the direct yaw moment control (DYC) based on dynamic sliding mode is proposed. The performance and effectiveness of the proposed vehicle state estimation and lateral stability control system are verified by CarSim and Simulink cosimulation.
2016-04-05
Technical Paper
2016-01-1671
Dejian Han, Zhen Yan, Feng Xiao, Shaokun Li
Abstract Direct yaw moment control can maintain the vehicle stability in critical situation. For four-wheel independently driven (4WD) electric vehicle with in-wheel motors (IWMs), direct yaw moment control (DYC) can be easily achieved. A fairly accurate calculation of the required yaw moment can improve vehicle stability. A novel sliding mode control (SMC) technique is employed for the motion control so as to track the desired vehicle motion, which is it for different working circumstances compared to the well-used traditional DYC. Through the weighted least square algorithm, the lower controller is used to determine the torque properly allocated to each wheel according to the desired yaw moment. Several actuator constraints are considered in the control strategy. In addition, a nonlinear tire model is utilized to improve the accuracy of tire lateral force estimation. Then, simulations are carried out and the values of vehicle states are compared.
2016-04-05
Technical Paper
2016-01-0153
Qingkun Jiang, Weiwen Deng, Bing Zhu
Abstract This paper reports an effort to improve plan of vehicle trajectory using an approach with rapidly-exploring random trees (RRT), which has been widely adopted in the prior art for complex and dynamic traffic environment. Design and implement of an integrated threat assessment is presented that evaluates threats of the trajectory. A node and trajectory evaluation index was introduced into the proposed RRT algorithm to connect an appropriate node and select the best trajectory. The contribution of this paper is on the threat assessment that takes into account not only obstacle avoidance but also stability. The simulation is conducted and the results show that the proposed method works as expected and is valid and effective.
2016-04-05
Technical Paper
2016-01-0440
Li Jie, Wang Wenzhu, Gao Xiong, Zhang Zhenwei
Abstract The ride comfort of heavy trucks is related to many factors, which include vehicle operating scenarios and vehicle structure parameters. An investigation of the influence of different factors on the ride comfort of heavy trucks was conducted. Based on the elastic theory of a uniform Euler-Bernoulli beam with both ends free, a 6 degree of freedom (DOF) half rigid-elastic vibration model of the vertical dynamic response was developed. The rigid-elastic model is more suitable to describe the actual movement of heavy trucks. The DOFs include vertical displacements of the body and each of two axles, the pitch displacement of the body, and the first and second order bending displacements of the body. The root mean square (RMS) values of body accelerations, dynamic deflections and relative dynamic loads form the evaluation index. Based on the rigid-elastic model, the influence of different factors on the ride comfort of heavy trucks is analyzed in the frequency domain.
2016-04-05
Technical Paper
2016-01-0471
Jian Zhao, Jun Huang, Bing Zhu, Jingwei Shan
In the past decades, the stability of vehicles has been improved significantly by use of variety of chassis control systems such as Antilock Braking System (ABS), Electric Stability Program (ESP) and Active Front Steering (AFS). Recently, in order to further improve the performance of vehicles, more and more researches are focused on the integration control of multiple degrees of freedom of vehicle dynamic. However, in order to control multiple degrees of freedom simultaneously, the nonlinear problems caused by the coupling between different degrees of freedom have to be solved, which is always a difficult task. In this paper, a three-degrees-of-freedom single track vehicle model, in which some nonlinear terms are considered, is built firstly. Then, the nonlinear model is processed by the fuzzy technique and the T-S fuzzy model is designed.
2016-04-05
Technical Paper
2016-01-1647
Jing Li, Xiong Yang, Hui Miao, Zheng Tang Shi
Abstract A program of integrated electro-hydraulic braking system is proposed, and its structural composition and working principle are analyzed. According to the structural and mechanical characteristics of all key components, through some reasonable assumptions and simplifications, a motor, a brake master cylinder, four brake wheel cylinders, solenoid valves and an ESP (Electronic Stability Program) algorithm model is set up and simulations of typical braking conditions are carried out based on the Matlab/Simulink. Finally, after the assembly of each sub-model is complete and combining a vehicle which is set up in CarSim software environment, simulation tests and comprehensive performance analysis of the active safety stability control for a vehicle in double lane change and single lane change situations are carried out respectively.
2016-04-05
Technical Paper
2016-01-0472
Lianhui Wang, Shuming Chen, Dengfeng Wang, Yang Jiang, Jing Chen
Abstract In recent years, the interior noise of automobile has been becoming a significant problem. In order to reduce the noise, porous materials have been widely applied in automobile manufacturing. In this study, the simulation method and optimal analysis are used to determine the optimum sound absorption of polyurethane foam. The experimental simulation is processed based on the Johnson-Allard model. In the model, the foam adheres to a hard wall. The incident wave is plane wave. The function of the model is to calculate the noise reduction coefficient of polyurethane foam with different thickness, density and porosity. The back propagation neural network coupled with genetic optimization technique is utilized to predict the optimum sound absorption. A developed back propagation neural network model is trained and tested by the simulation data.
2016-04-05
Technical Paper
2016-01-1385
Rongchao Jiang, Dengfeng Wang
Abstract This study presents a hybrid optimization approach of TOPSIS-based Taguchi method and entropy measurement for the determination of the optimal suspension parameters to achieve an enhanced compromise among ride comfort, road friendliness which means the extent of damage exerted on the road by the vehicles, and handling stabilities of a self-dumping truck. Firstly, the full multi-body dynamic vehicle model is developed using software ADAMS/Car and the vehicle model is then validated through ride comfort road tests. The performance criterion for ride comfort evaluation is identified as root mean square (RMS) value of frequency weighted acceleration of cab floor, while the road damage coefficient is used for the evaluation of the road-friendliness of a whole vehicle. The lateral acceleration and roll angle of cab were defined as evaluation indices for handling stability performance.
2016-04-05
Technical Paper
2016-01-1487
Zhenhai Gao, Chuzhao Li, Hongyu Hu, Chaoyang Chen, Hui Zhao, Helen Yu
Abstract At the collision moment, a driver’s lower extremity will be in different foot position, which leads to the different posture of the lower extremity with various muscle activations. These will affect the driver’s injury during collision, so it is necessary to investigate further. A simulated collision scene was constructed, and 20 participants (10 male and 10 female) were recruited for the test in a driving simulator. The braking posture and muscle activation of eight major muscles of driver’s lower extremity (both legs) were measured. The muscle activations in different postures were then analyzed. At the collision moment, the right leg was possible to be on the brake (male, 40%; female, 45%), in the air (male, 27.5%; female, 37.5%) or even on the accelerator (male, 25%; female, 12.5%). The left leg was on the floor all along.
2016-04-05
Technical Paper
2016-01-1149
Hanqi Yue, Xintian Lu, Xuesong Li, Bingzhao Gao, Hong Chen
Abstract A novel torque-coupling architecture for hybrid electric vehicles is proposed. The torque-coupling device is based on automated manual transmission (AMT), which is highly efficient and provides six gears for the engine and three gears for each motor to enable the engine and the motors to work at high-efficiency levels in most cases. The proposed power-shift AMT (P-AMT) does not have a hydraulic torque converter and wet clutches, which dampen the driveline shock. Thus, the drivability control of the P-AMT becomes a challenging issue. Accurate engine, motor model and transmission model have been built and the dynamic control of the gear shift process of PAMT in hybrid mode is simulated. The electric motors compensate for the traction loss during the gear shift of the engine.
2016-04-05
Technical Paper
2016-01-1215
Zhenhai Gao, Xiaoting Zhang, Hongyu Hu, Dalei Guo, Hui Zhao, Huili Yu
Abstract The poor low-temperature behavior of Li-ion batteries has limited its application in the field of electric vehicles and hybrid electric vehicles. Many previous studies concentrate on developing new type of electrolyte to solve this problem. However, according to recent research, the key limitation at low temperature is the low diffusivity of lithium ion in the anode electrodes. Hence, it is potential to study anode materials to improve low-temperature behavior of LIBs. ZnFe2O4 with higher theoretical capacity is low toxicity and abundance, contributing to its commercial application. Different ZnFe2O4 crystalline shapes have different particle sizes. Among them, the cubic ZnFe2O4 with smaller particle size will increase its own electronic and ionic conductance at lower temperature. In this regard, we evaluated low-temperature performance of LIBs with ZnFe2O4 cubes as anode materials at -25°C.
2016-04-05
Technical Paper
2016-01-1203
Zhang Qiao, Weiwen Deng, Jian Wu, Feng Ju, Jingshan Li
Abstract This paper describes a novel power management control strategy of battery and supercapacitor hybrid energy storage system to improve system efficiency and battery lifetime. In the presented research, the high and low frequency power demand in the load is separated by a Haar wavelet transform algorithm to overcome the problem of battery overload work and associated degeneration in battery lifetime resulting from an ineffective distribution between battery and supercapacitor. The purpose of frequency distribution is that the supercapacitor is used to share high frequency power components of load power demand to smooth the power demand applied to battery. However, the sole frequency control often fails to realize the optimal utilization of supercapacitor because of the uncertain variation in the driving cycle.
2016-04-05
Journal Article
2016-01-1307
Yuntao Cao, Dengfeng Wang, Tonghang Zhao, Xining Liu, Yulei He, Hangsheng Hou
Abstract A vehicle vibration issue emerged for a hybrid prototype during low speed driving in EV mode. This work is focused on the effort to identify the root cause and resolve the issue. The endeavor begins by performing a motor test in moderate acceleration with an imposed constant torque load. All relevant information is simultaneously recorded, including vehicle speed, vibration of motor structure and seat track, motor rpm, voltage and current signals, etc. Then analyses are carried out to strive for a better understanding of the vibration characteristics and identify its mechanism. It is found that the torque ripple from the driving motor is the root cause of the low speed vehicle vibration in EV mode, and the torque ripple is found to be induced by the current distortion resulted from the current sensor drift and electromagnetic interference due to high current signals.
2016-04-05
Technical Paper
2016-01-1296
Yuntao Cao, Dengfeng Wang, Tonghang Zhao, Xining Liu, Chao Li, Hangsheng Hou
Abstract Noise excitation sources are different between electric vehicles and conventional vehicles due to their distinct propulsion system architecture. This work focuses on an interior noise contribution analysis by experimental measurements and synthesis approach using a methodology established based on the principle of noise path analysis. The obtained results show that the structure-borne noise from the tire-road excitation acts as a major contributor to the overall interior noise level, and the structure-borne noise from the power plant system contributes noticeably as well, whereas contributions from the electric motor and tire are relatively insignificant.
2016-04-05
Journal Article
2016-01-1653
Zhenhai Gao, Jun Wang, Hongyu Hu, Dazhi Wang
Abstract Vehicle Longitudinal Control (VLC) algorithm is the basis function of automotive Cruise Control system. The main task of VLC is to achieve a longitudinal acceleration tracking controller, performance requirements of which include fast response and high tracking accuracy. At present, many control methods are used to implement vehicle longitudinal control. However, the existing methods are need to be improved because these methods need a high accurate vehicle dynamic model or a number of experiments to calibrate the parameters of controller, which are time consuming and costly. To overcome the difficulties of controller parameters calibration and accurate vehicle dynamic modeling, a vehicle longitudinal control algorithm based on iterative learning control (ILC) is proposed in this paper. The algorithm works based on the information of input and output of the system, so the method does not require a vehicle dynamics model.
2016-04-05
Journal Article
2016-01-0459
Jian Zhao, Jing Su, Bing Zhu, Jingwei Shan
Abstract Proper tire pressure is very important for multiple driving performance of a car, and it is necessary to monitor and warn the abnormal tire pressure online. Indirect Tire Pressure Monitoring System (TPMS) monitors the tire pressure based on the wheel speed signals of Anti-lock Braking System (ABS). In this paper, an indirect TPMS method is proposed to estimate the tire pressure according to its resonance frequency of circumferential vibration. Firstly, the errors of ABS wheel speed sensor system caused by the machining tolerance of the tooth ring are estimated based on the measured wheel speed using Recursive Least Squares (RLS) algorithm and the measuring errors are eliminated from the wheel speed signal. Then, the data segments with drive train torsional vibration are found out and eliminated by the methods of correlation analysis.
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