Table of Content

25 July 2019, Volume 41 Issue 7 Previous Issue    Next Issue

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Real-time Functional Model and Verification of Intelligent Vehicle Sensors Zhan Jun, Dong Xuecai, Hong Feng, Guan Xin ,Wang Zhangu 2019, 41 (7):  731-737.  doi: 10.19562/j.chinasae.qcgc.2019.07.001 Abstract ( 949 )   PDF (3578KB) ( 739 )   Save The sensor model is an important part of intelligent vehicle virtual verification. In this paper, the real-time functional models of millimeter wave radar, lidar and camera are established for the requirements of intelligent vehicle verification in large-scale virtual simulation environment. Firstly, the model develops an effective management and fast search engine for simulation data based on the gridding method, and studies a fast object extraction method to meet multi-vehicle sensor requirements in large-scale simulation environment. Secondly, a fast algorithm for judging the occlusion relationship between objects in a two-dimensional plane is studied based on the shadow volume algorithm, and the occlusion effect between objects is simulated. Thirdly, according to the outputs of the sensors, the object coordinates in the inertial coordinate system are converted to the sensor coordinates to form a standard output. Finally, a noise simulation model is established according to the noise characteristics of sensors. The models of Delphi ESR millimeter wave radar, Ibeo four-line lidar and Delphi IFV300 monocular camera are established in the virtual test platform. The function and performance of the models are simulated and verified. The results show that the sensor functional models established in this paper can accurately simulate the detection of obstacles, and the detection accuracy meets the requirements. The simulation time achieves sub-millisecond on normal computers and the simulation meets real-time requirements References | Related Articles | Metrics

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An Experimental Study on the Effect of Electric Supercharger on the Performance of a Turbocharged Miller Cycle Gasoline Engine Feng Hao, Qin Bo, Lin Sicong ,Sun Yunlong 2019, 41 (7):  738-743.  doi: 10.19562/j.chinasae.qcgc.2019.07.002 Abstract ( 350 )   PDF (3365KB) ( 685 )   Save To improve the brake thermal efficiency (BTE) and power response performance of gasoline engines, an experimental study is conducted on a 3-cylinder turbocharged Miller cycle gasoline engine with electrical supercharger (e-SC) to investigate the effects of e-SC on the fuel economy and power response performance of engine. Results show that e-SC can significantly enhance the capability of engine in introducing low-pressure exhaust gas recirculation (EGR) at low-speed high-load conditions. Under a condition of a rotational speed of 2 000 r/min and a BMET of 1.4 MPa, the maximum low-pressure ERG rate can increase from 15% to 25% and the engine achieves a BTE of 39.5%, due to the reductions of heat transfer loss, exhaust heat loss and unburned HC loss. At a rotational speed of 1 500 r/min, the switching-on of e-SC markedly increases the pressure rise rate of engine, with the transient response time shortened by 58%. In addition, e-SC gains a 12 kW engine power pay-off by consuming 3 kW of electric power, playing a role of amplifying engine power References | Related Articles | Metrics

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A Research on Parking Space Detection Algorithm Based on Image Recognition Zhu Wangwang, Huang Hongcheng ,Ma Jinxing 2019, 41 (7):  744-749.  doi: 10.19562/j.chinasae.qcgc.2019.07.003 Abstract ( 859 )   PDF (3198KB) ( 877 )   Save A parking space detection algorithm based on right-side single-channel camera is proposed in this paper for automatic parking. Firstly, a scheme of top-hat transformation combined with histogram equalization is adopted to reduce the effects of uneven illumination and varying light intensity on the robustness of algorithm. Combined with parking condition, the worthless area is ignored based on prior knowledge, the parameter range of Radon transform is compressed, and while getting the coordinates in Radon space, the dimensions of Radon transform is reduced. Then the element values in Radon matrix are optimized by using threshold segmentation for more accurately and effectively getting cluster centers in K-means clustering, and non maximum suppression is used to achieve pixel-level location of parking lanes in the 2D neighborhood of cluster centers. Finally, hierarchical finite state machine is designed, and the classification of parking space is fulfilled by setting up the classification rule base for parking space. The results of experiments show that the computational efficiency of this method is higher than that of the classical method based on Radon transform, and the algorithm has stronger robustness References | Related Articles | Metrics

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Equivalent Consumption Minimization Strategy Adaptive to Various Driving Ranges for Fuel Cell Vehicles Lin Xinyou, Xia Yutian, Li Xuefan ,Lin Haibo 2019, 41 (7):  750-756.  doi: 10.19562/j.chinasae.qcgc.2019.07.004 Abstract ( 558 )   PDF (3544KB) ( 736 )   Save In order to enhance the fuel economy of plug-in fuel cell vehicles, the electric energy consumption rate of the traction battery is controlled by adjusting the objective cost function through the adaptive rule of equivalent coefficient S and driving range based on the equivalent hydrogen consumption minimization strategy (ECMS). Meanwhile the reference SOC is introduced to modify the equivalent coefficient for enabling the traction battery get as much electric energy as possible from power grid in the course of driving, and avoiding the excessive discharge of the battery, thus to achieve the adaptiveness of the control strategy to various driving ranges. Then the simulation model for the plug-in fuel cell vehicle is established with Matlab/Simulink and the results of simulation show that when the mileage exceeds the pure electric driving range, the strategy can control the traction battery with its SOC reaching the target value at the end of driving course. The results of contrastive hardware-in-the-loop test indicate that the hydrogen consumptions in the total mileage of 100,150 and 200 km with mileage adaptive ECMS are 8.75%, 14.21% and 16.63% respectively less than that with CD-CS-based ECMS References | Related Articles | Metrics

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Standard Analysis and Experimental Study on Energy Consumption of 48 V Vehicle Liu Guibin, Liu Zhichao, Lu Chun , Cao Dongdong 2019, 41 (7):  757-762.  doi: 10.19562/j.chinasae.qcgc.2019.07.005 Abstract ( 484 )   PDF (553KB) ( 433 )   Save This paper analyzes the standards of the test methods of fuel consumption of conventional and hybrid passenger cars. Based on the validity and applicability of the standards and other relevant standards at home and abroad, this paper puts forward the suggestion that the 48 V vehicles should be classified as hybrid electric vehicles. In order to carry on the fuel consumption experimental research, four mainstream 48 V models in our country are selected. Firstly, energy-saving of the 48 V system is theoretically analyzed according to the operating characteristics of the engine and the motor and the power output / input of the power system during the test. According to the test results of the four models, it can be concluded that the 48 V system can reduce the vehicle fuel consumption by 0.47 L/100km, which is equivalent to fuel saving of 6.48% References | Related Articles | Metrics

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A Research on Visual Preview Longitudinal and Lateral Cooperative Control of Intelligent Vehicle Wang Ruochen, Wei Zhendong, Ye Qing, Cai Yingfeng , Chen Long 2019, 41 (7):  763-770.  doi: 10.19562/j.chinasae.qcgc.2019.07.006 Abstract ( 494 )   PDF (1025KB) ( 605 )   Save In view of high nonlinearity and the coupling problem of longitudinal and lateral motion control of intelligent vehicle path tracking control, a new preview MPC path tracking control method is proposed based on visual preview model and model predictive control theory. Firstly, the nonlinear prediction model is locally linearized and the MPC optimization problem is transformed into a quadratic programming problem. Then, in each control time domain, the vertical speed and the preview distance are regarded as known. The exponential model is used to describe the vertical speed, and the preview distance generator is designed based on the road curvature and the actual speed. The simulation and experimental results show that compared with the traditional MPC tracking control method, the preview MPC control method proposed in this paper reduces the lateral deviation and direction deviation in the tracking process at different vehicle speeds and improves the tracking accuracy, which is more obvious at high speed References | Related Articles | Metrics

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Automatic Lane Keeping Control Based on Safety Barrier Monitoring Chen Yawei, Shao Yiming, Shu Haibo , Hao Xixiang 2019, 41 (7):  771-778.  doi: 10.19562/j.chinasae.qcgc.2019.07.007 Abstract ( 431 )   PDF (1182KB) ( 331 )   Save For the problem of how to guarantee the safety of lane keeping control in realizing stable steering, this paper proposes a method of preview lane keeping control which is monitored by safety barrier. Using tracking error and future lane curvature, the preview controller generates steering instructions in a limited preview window, and then designs a safety protection controller to guarantee the bounded error. When and only when the tracking error is close to the safety boundary, the safety barrier control is activated and carries out steering intervention. The control algorithm proposed in this paper is small in scale and less in calculation time, which can improve the operation efficiency of online solution. In order to verify the effectiveness of the control algorithm, the related simulation and road experiments are carried out. The simulation and experimental results show that the proposed safety barrier monitoring and preview control can achieve coordinated control of vehicle safety and lane keeping , showing certain advantages References | Related Articles | Metrics

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A Research on an Algorithm for Real-time Detection and Classification of Road Obstacle by Using 64-line Lidar Lou Xinyu, Wang Hai, Cai Yingfeng, Zheng Zhengyang , Chen Long 2019, 41 (7):  779-754.  doi: 10.19562/j.chinasae.qcgc.2019.07.008 Abstract ( 424 )   PDF (652KB) ( 533 )   Save In view of the poor real-time performance of unmanned autonomous vehicle in detecting obstacles due to the huge volume of 64-line lidar data, an object detection and classification algorithm with good effectiveness and real-time performance is proposed. The algorithm separates the road, obstacle and suspended object by multi-feature / multi-layer elevation map. Then the grid clustering algorithm based on dynamic distance threshold is used to cluster the obstacles, with the clustering results corrected according to the motion state information of two adjacent obstacles to enhance clustering accuracy. Finally, SVM is adopted to detect and classify obstacles. The experiment results show that the algorithm attains a best identification rate of 89.77% with a duration of 95 ms, meeting the real-time requirements of unmanned vehicle in detecting obstacle on road, while ensuring the accuracy of detection and classification, having a significant engineering application value. References | Related Articles | Metrics

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A Research on TESW Parameters Base on Coach Occupant Injury Wu Changfeng, Zhang Junyuan, Na Jingxin, Su Liang, Lan Pinghui ,Lu Linzhao 2019, 41 (7):  785-791.  doi: 10.19562/j.chinasae.qcgc.2019.07.009 Abstract ( 266 )   PDF (1290KB) ( 391 )   Save Based on the principle of equivalent square wave and finite element analysis method, the relationship between the acceleration waveform parameters of a 12 m coach and the occupant injury in frontal crash is studied in this paper. Firstly, taking a seat sled system as the object of research, the occupant injuries with three types of commonly used tipped equivalent square waves (TESWs) (rising type, horizontal type and falling type) are compared. Then the effects of the recoil moment parameter tm in falling TESW on the weighted injury criterion (WIC) of occupant are studied. The results show that for a 12 m coach, the falling TESW is superior to the other two types of TESWs. In falling waveform, with the increase of tm, the WIC exhibits a spoon-shaped changing pattern, which can be fitted into a cubic regression equation. Combined with the deduction process of simplified TESW model, an expression of the relationship between tm and the vehicle overall collision deformation C can be obtained, providing references for coach structure design and occupant injury research References | Related Articles | Metrics

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Simulation and Test of Stability Control for Distributed Drive Electric Vehicles Liu Zhiqiang ,Liu Guang 2019, 41 (7):  792-799.  doi: 10.19562/j.chinasae.qcgc.2019.07.010 Abstract ( 464 )   PDF (876KB) ( 694 )   Save In order to enhance the handling and stability performance of electric vehicles, a control strategy with three layers is established. Dynamics modeling layer calculates the actual value and desired value of variables. Compensating torque determination layer combines the advantages of extension control and sliding mode control, sets up the adaptive sliding mode algorithm, coordinates the control weightings of parameters and determines compensating torques. While wheel torque distribution layer applies constraints on compensating torques and distributes them to four wheel-hub motors. Software Carsim and Simulink are used to build the model and conduct co-simulation. The results of simulation show that the vehicle control strategy has good real time performance and adaptability. Finally, a rapid prototyping test is also carried out, which verifies that the control strategy adopted achieves the desired goal of improving vehicle stability References | Related Articles | Metrics

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Reliability Estimation of Vehicle Lateral Dynamics Under Vehicle-road-environment Coupling Actions He Yi, Xiao-Yun LU, Chu Duanfeng , Wu Chaozhong 2019, 41 (7):  800-806.  doi: 10.19562/j.chinasae.qcgc.2019.07.011 Abstract ( 252 )   PDF (3074KB) ( 443 )   Save Vehicle lateral dynamics aims to study the prediction and control of vehicle active safety. According to the influence of excitative load of road and environment on vehicle lateral dynamics, a vehicle-road-environment coupling model is built, and the limit equation of vehicle risk state is established with concurrent considerations of vehicle dynamic parameters and road and exterior environment parameters. On this basis, according to the distribution function of parameter perturbation under the action of excitative load, the reliability of vehicle dynamic system is solved and Monte Carlo approach is adopted to verify the model. The results show that the model built has good accuracy. Finally, a case study is given to analyze the lateral dynamics response characteristics of vehicle under the action of excitative load of road and environment References | Related Articles | Metrics

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Road Roughness Identification Based on NARX Neural Network Li Jie, Guo Wencui, Gu Shengfeng, Zhao Qi 2019, 41 (7):  807-814.  doi: 10.19562/j.chinasae.qcgc.2019.07.012 Abstract ( 532 )   PDF (700KB) ( 388 )   Save For applying NARX neural network to identify road roughness, NARX neural network and its training process and structure design are analyzed. Correlation coefficient and root mean square error are used as evaluation indicator of identification effect of NARX neural network. The white noise model of road roughness and four DOF planar model for vehicle ride comfort are established, on which a simulation is conducted to get the road roughness and vehicle responses. With measurable vehicle responses as the input of NARX neural network, a method for determining the input scheme of NARX neural network is proposed by using orthogonal experimental design, and the road roughness for the front wheel of a car running on a common-grade road with common speed is identified. The results show that with measurable vehicle responses as the input of NARX neural network,combined with orthogonal experimental design can solve the problem of determining the optimal input scheme of NARX neural network References | Related Articles | Metrics

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Development of Longitudinal Driver Model for Driving Cycle Tracking Based on ANFIS Shen Peihong, Zhao Zhiguo ,Guo Qiuyi 2019, 41 (7):  815-822.  doi: 10.19562/j.chinasae.qcgc.2019.07.013 Abstract ( 331 )   PDF (6346KB) ( 498 )   Save In view of the poor results of driving cycle tracking with PI control-based longitudinal driver model, the longitudinal driving behavior data of a tested PHEV are collected, the longitudinal driver models with two input parameters and preview longitudinal driver models with consideration of the effects of future expected vehicle speed are established by using adaptive network-based fuzzy inference system (ANFIS). The results of simulation show that the ANFIS-based preview longitudinal driver model has the best tracking effect of operation conditions with a root mean square error of 0.993 0 km/h, and the accelerator pedal travel, gear position and desired torque worked out are closest to the results of real vehicle test References | Related Articles | Metrics

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A Research on the Correlations Among Basic Performances of Aluminum-alloy Body Platform Wang Zhenhu, Xia Erli, Zhang Songbo, Qiu Sawei , Li Luoxing 2019, 41 (7):  823-830.  doi: 10.19562/j.chinasae.qcgc.2019.07.014 Abstract ( 432 )   PDF (1039KB) ( 467 )   Save The quantitative relationships of static stiffness, lightweight factor and modal parameters of aluminum-alloy body platform are derived according to modal theory, to provide a guidance for the lightweight design and the performance objective setting of aluminum-alloy body platform in early concept-design stage. Then based on the finite element model, the former 50 orders of modal parameters are extracted and the approximate solutions of bending stiffness, torsion stiffness and lightweight factor of aluminum-alloy body platform are calculated, which are very close to that of finite element analysis with their relative errors being only 4.32%, 1.85% and 1.78% respectively. So, it can be found that the static compliance of aluminum alloy body platform can be approached by the sum of the modal compliance of each order, and the vibration mode with the most contribution to bending (torsional) stiffness is right the first order bending (torsional) mode, being a conclusion as an important way of modal identification. Finally, the bending and torsional stiffnesses and lightweight factor obtained by finite element analysis and modal theory algorithm are compared with that by test and it is quite evident that the error of modal theory algorithm is smaller than that of finite element analysis. They are as small as 1.85%, 1.82% and 1.89% for bending stiffness, torsional stiffness and lightweight factor respectively References | Related Articles | Metrics

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Parity Space Approach for Fault Diagnosis of Lithium-ion Battery Sensor for Electric Vehicles Pan Fengwen, Ma Bin, Gao Ying, Xu Mingwei ,Gong Dongliang 2019, 41 (7):  831-838.  doi: 10.19562/j.chinasae.qcgc.2019.07.015 Abstract ( 539 )   PDF (3584KB) ( 525 )   Save Based on the first-order equivalent circuit model of the battery, this paper couples the heat generation and heat transfer equations of the battery, and establishes an electro-thermal model that reflects the dynamic response and thermal characteristics of the battery. Based on this, the parity space method is used to detect the fault of the battery output sensor and a fault isolation method based on system matrix operation is proposed. With the random current excitation as the input signal, the battery output sensor fault is analyzed. The results show that the residual generator designed by the parity space approach can accurately detect the battery output sensor fault, and its response to the fault signal is much larger than the oscillation caused by modeling accuracy. The improved residual generator can accurately isolate the fault source based on the detection of the output sensor fault References | Related Articles | Metrics

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Model-based Fault Diagnosis of Automotive Electric Power Steering System Chen Qi, Wang Jincheng, Qadeer Ahmed, Yao Zhigang , Chen Wuwei 2019, 41 (7):  839-850.  doi: 10.19562/j.chinasae.qcgc.2019.07.016 Abstract ( 533 )   PDF (801KB) ( 455 )   Save In order to realize the state monitoring and key faults diagnosis of electric power steering (EPS) system, the theory of fault diagnosis with model-based structural analysis (SA) is introduced in this paper. By combining with the mathematical model of EPS and the key faults of system, the fault model of system is established. Structural analysis methods such as the structural representation of system, Dulmage-mendelsohn decomposition and fault isolation matrix are employed to analyze the detectability and isolability of faults, to get the optimal sensor configuration of fault diagnosis system for EPS, and to obtain five minimal structural over-determined sets (MSO sets).The residuals for five MSO sets are designed, the fault diagnosis system is constructed with MATLAB/Simulink, the signal features and fault states of five residuals are checked, and the effectiveness of the fault diagnosis design system for EPS is verified, laying a foundation for follow-up test verification References | Related Articles | Metrics

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Phase Change Heat Transfer Simulation and Structural Optimization of Micro-channel Condenser Li Ming, Zhao Zhiqiang, Xu Ming, Hou Kun ,Luo Yuan 2019, 41 (7):  851-857.  doi: 10.19562/j.chinasae.qcgc.2019.07.017 Abstract ( 389 )   PDF (2746KB) ( 453 )   Save To improve the flow uniformity in the refrigerant side of micro-channel condenser and enhance its heat exchange capacity, the Optimate+module is adopted to conduct a multi-objective multi-parameter optimization on 3D condenser model, with the insertion depths of flat tubes and the insertion depth and position of inlet tube as design variables and the flow uniformity, pressure drop and outlet temperature as objectives. The directed mesh is used to discretize the flat tube model for raising the mesh accuracy and computation speed. A phase transition simulation is performed on the whole condenser with volume of fluid model and evaporation-condensation model to study the phenomenon of flow unevenness in refrigerant tube. The structural optimization finally leads to the lowering of outlet temperature by 1.7 K and a reduction of pressure drop by 39 kPa for the whole condenser References | Related Articles | Metrics