Table of Content

25 January 2019, Volume 41 Issue 1 Previous Issue    Next Issue

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An Adaptive Capacity Estimation Scheme for Lithium-ion Battery Basedon Voltage Characteristic Points in Constant-current Charging Curve Lai Xin, Qin Chao, Zheng Yuejiu, Han Xuebing 2019, 41 (1):  1-6.  doi: 10.19562/j.chinasae.qcgc.2019.01.001 Abstract ( 2581 )   PDF (2252KB) ( 1872 )   Save To improve the online capacity estimation accuracy of lithium-ion batteries, an adaptive capacity estimation scheme combining the online capacity identification based on the features of a few charging curves with Arrhenius capacity decay model is proposed. In view of the seldom situations of complete charging in battery electric vehicles, an online capacity identification scheme based on voltage characteristic points of constant-current charging curves is put forward. The scheme uses genetic algorithm to optimize the voltage characteristic points of the scaled and translated charging curves first and then online identify the present capacity of the battery by monitoring the constant-current charging data regarding the two fixed voltage characteristic points. For further enhancing the accuracy of online capacity estimation, an incremental PID algorithm is used to fuse the online capacity estimation and Arrhenius model to perform the closed-loop correction of model parameters. Finally, the results of cycle life experiment under alternating temperature condition show that the maximum estimation error of the proposed adaptive estimation scheme is less than 2%. References | Related Articles | Metrics

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State Estimation of Vehicle Based on Multi-sensors Information Fusion Zhou Weiqi, Qi Xiang 2019, 41 (1):  7-13.  doi: 10.19562/j.chinasae.qcgc.2019.01.002 Abstract ( 615 )   PDF (1099KB) ( 630 )   Save To ensure vehicle adaptive safety control, it is necessary to accurately estimate the vehicle driving state information. For some parameters,it is difficult to measure directly for both technical and economic reasons. This paper proposes an information fusion estimation strategy using low-cost sensors to estimate vehicle driving state. A 3 DOF nonlinear vehicle dynamics model including yaw, lateral and longitudinal directions is established. In order to reduce the impact of noise on the system, an adaptive unscented Kalman filter (AUKF) information fusion algorithm is established, and the fusion result in the sense of minimum variance of vehicle state is given. Low-cost sensors signal such as longitudinal acceleration, lateral acceleration and steering wheel angle is fused to obtain the required hard-to-measure sideslip angle of mass center, yaw angular velocity and longitudinal vehicle speed. The estimation algorithm is validated by the joint simulation of Matlab/Simulink-CarSim and the real vehicle test. The test results show that the algorithm can accurately estimate the sideslip angle, yaw angular velocity and longitudinal vehicle speed. Compared with UKF, the algorithm improves the estimation accuracy and real-time performance. References | Related Articles | Metrics

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A Study on Minimum Instantaneous Energy Consumption Control Strategy ofDM-EV Based on Mode Switching Prediction Algorithm Lin Xinyou, Wang Liming, Zhai Liuqing 2019, 41 (1):  14-20.  doi: 10.19562/j.chinasae.qcgc.2019.01.003 Abstract ( 460 )   PDF (1066KB) ( 430 )   Save In order to improve the economy of electric vehicles and extend the driving range, a new type of multi-mode dual-motor coupled drive electric vehicle (DM-EV) is taken as the research object, and the system configuration and working mode of the electric vehicle are analyzed, aiming at minimizing the instantaneous energy consumption, a control strategy based on the mode switching predictive algorithm is studied. The effectiveness of the proposed control strategy and drive configuration is verified by simulation and bench tests. The simulation results show that under urban congestion conditions, the urban general conditions and the highway conditions, the car energy utilization rate can increase by 2.2%,3.6%,1.7% respectively using the mode switch prediction algorithm. The bench test results show that compared with the general single motor drive system, the energy efficiency of the proposed drive system is improved by 14.2%,11.5%,10.1% respectively. References | Related Articles | Metrics

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Point by Point Model Calibration of Diesel EngineBased on Important Operating Points Ma Lei, Wang Minglu, Chen Ke 2019, 41 (1):  21-28.  doi: 10.19562/j.chinasae.qcgc.2019.01.004 Abstract ( 422 )   PDF (1554KB) ( 441 )   Save The calibration of the electronic control diesel engine needs to consider comprehensively factors such as fuel consumption, emission and intake and exhaust temperature. However, with the implementation of the China Ⅴ emission regulations, the difficulty of calibration is increased exponentially. The traditional calibration method needs huge work and high cost. On the basis of model calibration, a point by point model calibration method based on important working points is proposed. Through cluster analysis and analysis of the actual emission characteristics, the important working conditions in the NEDC cycle are selected. Experimental design of the working points is completed by the space filling method, and engine test data is collected by the bench test. On the basis of the response model, the optimal combustion parameters combination at each working point is obtained by genetic algorithm. MAP mapping is completed according to the cubic polynomial fitting. MAP is optimized based on the universal characteristic test, and the vehicle drum emission test is carried out simultaneously. The results show that the MAP generated by the calibration model has good fuel economy and better emission performance, which can accurately predict the engine response parameters, with the fuel consumption 15% lower than that of artificial calibration. References | Related Articles | Metrics

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A Research on the Influence of Structural Parameterson the Performance of Urea-SCR System Wang Jun, Zhao Chen, Dong Yan, Zhao Chuang, Zhu Lei 2019, 41 (1):  29-35.  doi: 10.19562/j.chinasae.qcgc.2019.01.005 Abstract ( 235 )   PDF (1431KB) ( 297 )   Save A numerical model for selective catalytic reduction (SCR) system is established, on which the spray decomposition of urea water solution (UWS) and the chemical reaction process on the catalyst surface of diesel SCR system are simulated. Bench tests are also conducted to study the influence of the nozzle injection angle α, the expansion angle β of catalyzer and the mixer and its location on the NOx conversion rate, the NH3 distribution uniformity and the liquid film mass of SCR system. The results show that the influence rule of the nozzle injection angle α and the expansion angle β of catalyzer are rather complicated so they should be chosen according to specific situations, while the adding of mixer can produce apparent exhaust swirl, effectively extend the motion trajectory of UWS drops, promote their good mixing with exhaust gas and greatly increase the NOx conversion rate of SCR system, and it is more reasonable to install the mixer at a location 100-200mm downstream of the nozzle. References | Related Articles | Metrics

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A Study on Crash Failure Simulation of Vehicle Engine Mounts Wu Changpeng, Xie Bin, Pan Feng, Luo Kun, Zhang Kunlun, Zhang Sipeng 2019, 41 (1):  36-41.  doi: 10.19562/j.chinasae.qcgc.2019.01.006 Abstract ( 342 )   PDF (1888KB) ( 634 )   Save Vehicle engine mounts have crucial influence on side rail deformation in frontal impact. In order to correctly predict the fracture failure behavior of engine mounts, a mechanical property test on cast aluminum material is conducted. Cast aluminum material card with failure criteria is set up based on CrachFEM tenacity failure criteria. Through the drop hammer test and simulation, the correctness of cast material card and the reliability of engine mounts modeling are verified. The results of vehicle crash simulation show that CrachFEM failure model can accurately simulate the fracture failure process of engine mounts, enable the deformation mode of side rail and the acceleration responses of car body closer to test results and enhance the accuracy of engine crash simulation, providing simulation assesement means for crashworthiness development. References | Related Articles | Metrics

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Research and Development of a Novel Crash Test Device and Its Control System Song Zhiqiang, Cao Libo, Chen Long, Zhang Jianqiang 2019, 41 (1):  42-49.  doi: 10.19562/j.chinasae.qcgc.2019.01.007 Abstract ( 209 )   PDF (2868KB) ( 427 )   Save In order to reduce the test cost of new car and its components at development stage, a new type of crash test device, head-on colliding sled, is developed in this paper. Firstly, a 3D model for each module of colliding sled is established with software SolidWorks. Then software HyperWorks and LS-dyna are used for mesh creation and finite element analysis to obtain the deceleration waveform of collision. Next, on the basis of simulation results the test device designed is produced with an electric control system developed for realizing four main functions of test sled: reset, pre-release, release and braking. Finally, the suitable buffering and energy-absorbing module is chosen according to simulation results to perform collision test for verification. The results show that the test device developed can operate normally and reproduce the collision deceleration waveform meeting the requirements of the national and international regulations, achieving the expected results. References | Related Articles | Metrics

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Development of Anti-rollover Control Strategy for Liquid Tank Semi-trailer Zhao Weiqiang, Ling Jinpeng, Zong Changfu 2019, 41 (1):  50-56.  doi: 10.19562/j.chinasae.qcgc.2019.01.008 Abstract ( 191 )   PDF (790KB) ( 515 )   Save In view of the problem that the coupling between liquid sloshing in the tank and vehicle movement results in the low rolling stability and the proneness to rollover of liquid tank semi-trailer (LTST), an anti-rollover control strategy for LTST is proposed in this paper. An equivalent simple pendulum model is adopted to simulate the dynamic process of liquid sloshing in the tank, its parameters are identified, and a dynamic simulation model for LTST is established. Based on the 6 DOF linear simplified model for LTST, a LQR anti-rollover state feedback controller is designed and the additional yaw moment is generated by using differential braking. A simulation is conducted with the simulation model for LTST to compare the state responses under the step condition of the turning angle of steering wheel with and without control. The results show that the control strategy proposed can effectively prevent LTST from rollover. References | Related Articles | Metrics

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Front Vehicle Tracking Based on VGG-M Network Model Liu Guohui, Zhang Weiwei, Wu Xuncheng, Song Xiaolin, Xu Sha, Wen Peigang 2019, 41 (1):  57-63.  doi: 10.19562/j.chinasae.qcgc.2019.01.009 Abstract ( 476 )   PDF (1616KB) ( 519 )   Save Aiming at the low accuracy of front moving vehicle tracking in complex scenes, the huge VGG-M network model is applied to real-time tracking, and the online observation model is used to achieve stable and accurate tracking of front vehicles. By improving the sample generation scheme and optimizing the network training set, the efficiency of network training is enhanced. Furthermore, with adaptive update model adopted, the network update frequency can be adjusted in real time according to the aspect ratio of target profile, internal information entropy and the confidence of tracking scale. Experimental results show that the online VGG-M tracking model achieves better performance than the traditional vehicle tracking methods. References | Related Articles | Metrics

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Friction Force Analysis on Pilot Solenoid Valve Plunger ofIntegral Electro-hydraulic Module in Automatic Transmission Xue Dianlun, Zhou Jiahao 2019, 41 (1):  64-68.  doi: 10.19562/j.chinasae.qcgc.2019.01.010 Abstract ( 228 )   PDF (998KB) ( 330 )   Save Aiming at the problem of adaptability of the pilot solenoid valve of integral electro-hydraulic module in automatic transmission to environment, a thermo-fluid-solid coupling simulation on the main plunger of pilot solenoid valve is performed to contrastively analyze the influence of heat generation of solenoid valve in operation on the deformation of clearance between valve and plunger, and based on which the sticking condition and frictional force of plunger are analyzed. The results show that the thermal deformation of aluminum alloy valve sleeve is relatively significant, resulting in a corresponding increase in the friction force of plunger, and the sticking up of plunger may occur when there are particulate matters with larger size in the fluid, so the strict control of fluid contamination is essential. The analysis results of friction force also provide a basis for the analysis on the dynamic response characteristics of solenoid valves. References | Related Articles | Metrics

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A Study on Core Variables of Enclosed CavitysInterior Sound Field and Its Application Gao Shuna 2019, 41 (1):  69-74.  doi: 10.19562/j.chinasae.qcgc.2019.01.011 Abstract ( 168 )   PDF (1368KB) ( 309 )   Save Aiming at reducing the interior noise, to quickly lock the key areas of vehicle body structure and put forward improvement, the premise is to get a clear understanding of core variables of car interior sound field. Therefore, in this paper, based on the calculation formula of interior sound field, relationship between variables and parameters and sound pressure response is analyzed. It is found that nodal line distribution is the core variable and increase of nodal line number can decrease the interior sound pressure. A prototype car is made and the conclusion is verified by the physical test. The conclusion is applied to the interior sound pressure control of a certain type of vehicle, which successfully reduces the interior sound pressure of the vehicle. It shows that the interior sound pressure can be controlled quickly based on the nodal line distribution. References | Related Articles | Metrics

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A Study of the Obstacle Surmounting Performance ofHeavy Truck Considering the Tire Elasticity Wei Daogao, Song Junwei, Qu Wenming, Wu Peibao, Ju Gang, Gao Xianfeng, Chen Xinghua 2019, 41 (1):  75-79.  doi: 10.19562/j.chinasae.qcgc.2019.01.012 Abstract ( 242 )   PDF (753KB) ( 402 )   Save Design and calculation of multi-axis vehicle obstacle surmounting performance has been a difficult problem in vehicle product development. Therefore, this paper takes an 8× 8 heavy truck as the prototype vehicle and considers the tire radial elasticity on the basis of preliminary model with the assumption of rigid tires. The step crossing mathematical model of each axis is established and the numerical calculation is carried out. The calculated results are agreeing with the experimental values, indicating the accuracy of the model. Finally, based on the established model, the influence of the adhesion coefficient, the vehicle center of mass position, the height of the center of mass on each axis obstacle surmounting performance is analyzed. References | Related Articles | Metrics

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An Experimental Study on Frequency-adjustable Micro-perforatedMuffler for Fuel Cell Vehicles Zhou Dawei, Zuo Shuguang, Liu Jingfang, Wu Xudong 2019, 41 (1):  80-85.  doi: 10.19562/j.chinasae.qcgc.2019.01.013 Abstract ( 199 )   PDF (1243KB) ( 455 )   Save A frequency-adjustable micro-perforated muffler for the air compressor of a fuel cell vehicle is proposed in this paper. Firstly, the relationship between the length of the perforated section of third cavity and the resonant frequency of muffler is fitted based on the transfer characteristics of the micro-perforated muffler designed, the two-phase hybrid stepping motor and ball screw are chosen as the actuator, and a photo-electric encoder is taken as the feedback module. Then, a fuzzy PID controller suitable for frequency modulation system is designed to achieve the real-time adjustment of perforated section length of third cavity for changing the resonant frequency and thus broadening the muffling frequency-band of the micro-perforated muffler. Finally, the test bench for the frequency-adjustable micro-perforated muffler system is built and a test is conducted to validate the noise reduction effect in both the steady and transient conditions of target air compressor. The results of test show that the frequency-adjustable micro-perforated muffler proposed can effectively reduce the order noise of air compressor with the sound pressure level reduced by more than 12dB, and its broadband vortex noise is also reduced by more than 6 dB. References | Related Articles | Metrics

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A Study on Transverse Bending Properties of CFRP Joint in Vehicle Body Wang Haifeng, Yu Ye, Xu Xianzhe, Hou Wenbin 2019, 41 (1):  86-90.  doi: 10.19562/j.chinasae.qcgc.2019.01.014 Abstract ( 209 )   PDF (1765KB) ( 343 )   Save A test is carried out to obtain the key transverse bending properties of a single hat shaped T-joint material (carbon fiber reinforced polymer, CFRP), to analyze the effects of structural failure modes on test results, and the test process is then simulated by finite element analysis with its results compared with that of test. The relative sensitivities of transverse bending properties to the mass of T-joint are calculated during the adjustment of its structural dimension parameters and ply numbers. The results of test show that the gradual damage of laminate causes the reduction of transverse bending stiffness of T-joint, and the large-area failure on the lower surface of T-joint leads to the final loss of its load-bearing capability. The results of finite element analysis agree well with that of test. The results of sensitivity analysis show that reasonable increase of dimensional parameters R and H can achieve the significant enhancement of the structural performance of T-joint with a minor cost of a little weight-gain References | Related Articles | Metrics

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Two-step Constrained Particle Swarm Optimization Algorithm and ItsApplication to Lightweight Design of New Energy Vehicles Li Zeyang, Liu Zhao, Zhu Ping 2019, 41 (1):  91-95.  doi: 10.19562/j.chinasae.qcgc.2019.01.015 Abstract ( 421 )   PDF (1267KB) ( 384 )   Save In view of the problem that during engineering optimization the optima generally are located at near constraint boundaries due to the limitation of resources, but current constrained optimization algorithms tend to focus on handling constraint mechanism and seldom to search near constraint boundaries, an algorithm of two-step constrained particle swarm optimization (PSO) algorithm is proposed in this paper. In the first step, PSO algorithm based on penalty function is adopted for optimization with a pointer for speed reset used to prevent optimization from falling into stagnation. In the second step, subset constraint boundary reduction equation is employed to acquire information of constraint boundaries, and sequential quadratic programming (SQP) is utilized to conduct local search on boundaries. Finally the results of two steps are compared and the better one is chosen as the global optimum. As an application, the modified algorithm proposed is used to perform body lightweight optimization on a fuel cell sedan under both side collision and roof crash conditions, resulting in a 10.92% mass reduction of some body panels taking part in optimization while ensuring the structural crashworthiness of the vehicle. References | Related Articles | Metrics

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Optimization of Die Face for Aluminum Alloy ClosurePanel Based on Orthogonal Experiment Chengpeng, Jin Feixiang, Shao Chenxi, Xiu Lei 2019, 41 (1):  96-102.  doi: 10.19562/j.chinasae.qcgc.2019.01.016 Abstract ( 238 )   PDF (2105KB) ( 325 )   Save In this paper, the die face structure of the outer panel of an AA6014-T4 aluminum alloy car bonnet is designed and optimized with Dynaform based on orthogonal experiment. The study shows that the most influencing factor for panel thinning rate is the draft angle of die face while that for thickening rate is its boundary extension. The optimum technological parameters obtained by optimization with other technological parameters fixed are: a boundary extension of 4mm, a punch radius of 20mm, a draft angle of 20 degrees and a die radius of 10mm. They are verified by simulation and test, and the resulting panel has good forming quality without cracking and wrinkling. References | Related Articles | Metrics

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Modeling and Experimental Study of Vehicle Permanent-magnetRetarder with Magneto-thermal Coupling Ye Lezhi, Liu Yupeng, Li Desheng 2019, 41 (1):  103-111.  doi: 10.19562/j.chinasae.qcgc.2019.01.017 Abstract ( 292 )   PDF (1603KB) ( 347 )   Save Aiming at the seriously overload braking problem of heavy truck, a permanent-magnet retarder based on the principle of permanent-magnet eddy-current braking is proposed as an auxiliary braking device, whose braking torque can be continuously adjusted. To solve the problem of braking torque decline and the magnet loss of permanent-magnet caused by high temperature due to long-time braking, a scheme of magneto-thermal two-way coupling is adopted and a magneto-thermal coupled model of the retarder is established with the magnetic permeability and conductivity of eddy disk as the mutual influencing factors in physical fields, and the braking torque characteristics of the retarder is studied with consideration of the effects of temperature, providing theoretical supports for the optimization design of the retarder. The trial manufacture and subsequent motoring bench test of several retarder prototypes with different materials and heat dissipation structures of eddy disk are conducted and the results show that with magneto-thermal two-way coupling, the simulated braking torque agree better with the tested one. References | Related Articles | Metrics

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A Research on Big-data Oriented Cloud Evaluationfor Complex Alliance of New Energy Vehicles Yin Lei, Jiang Jianguo, Lu Ruigang, Yin Andong 2019, 41 (1):  112-119.  doi: 10.19562/j.chinasae.qcgc.2019.01.018 Abstract ( 305 )   PDF (948KB) ( 397 )   Save A big data-oriented cloud evaluation method for the complex alliance of new energy vehicles is proposed in this paper based on cloud model theory. First of all, the big data-oriented evaluation model for new energy vehicle alliance is established and the alliance evaluation indicator cloud is generated by using reverse cloud generator and comprehensive cloud calculation. Then, on the basis of determining the weighting clouds of the evaluation indicators and tasks for the alliance, the evaluation clouds of both single-task alliance and multi-task complex alliance are created respectively by applying cloud computing rules, and cloud evaluation and optimization are performed on the alternative schemes of the complex alliance. Finally, a real example is given to verify the effectiveness and rationality of the method proposed. References | Related Articles | Metrics