Applied Mechanics and Materials Vols. 494-495

Abstract: Based on the analysis the theoretical of regenerative braking and energy flow of the pure electric vehicle, the main influence factors of braking energy recovery were obtained. Ignoring the energy loss and the efficiency of system components as well as the response delay of the hydraulic braking system, two different regenerative braking control strategies were established without regard to the braking force distribution restrictions of the relevant brake laws. The simulation model was built on MATLAB/Simulink platform to analysis the effect of control strategies, vehicle mass and driving cycle for pure electric vehicle braking energy recovery. It was guidance for the development of pure electric vehicle braking energy recovery control strategy.

Abstract: In this paper, the Hybrid Electric Bus (HEB) equipped with Compressed Natural Gas (CNG) engine is taken as the research object on the basis of logic threshold control strategy and the Genetic Algorithm (GA) is adopted to optimize the HEB control thresholds at a typical operating condition of a Chinese city bus. The simulation results show that the overall efficiency of GA optimize is higher than the original control thresholds, the engine operating point moves to the high efficiency region which can be considered optimal threshold by GA makes the overall efficiency has been effectively improved, so as to achieve without lowering the vehicle dynamics and SOC balance of the premise, the gas consumption decreased and increased HEV economy.

Abstract: A new kind of algorithm of controller for eddy current retarder is designed in this paper. The eddy current retarder control system with traditional PID controller can't achieve a perfect performance in the rapid response. Back propagation (BP) neural network is one of artificial neural networks which has a good learning ability with a simple and recurrent structure, so it is suitable for controlling complicated eddy current retarder system. This paper introduces the principle, characteristics and learning algorithm of the BP neural network and designs the control system of eddy current retarder based on BP neural network PID controller by combining BP neural network and traditional PID. Making use of MATLAB, simulate this new kind of controller for eddy current retarder in the rapid response. Simulation results show it can improve the dynamic response performance and enhance the static precision compared to the traditional PID controller.

Abstract: Hybrid power systems provide high-performances and high-efficiency power for electric bulldozer. This paper firstly constructs the mathematical model of driving motors system based on the design of dual-motor-driving propulsion system for bulldozer. Secondly, by using the setting values from a bulldozer, simulation work is implemented, and parameters of the hybrid power system are matched, and finally, based on MATLAB/Simulink ,dynamic models for the dual-motor-driving hybrid power system is established, and the simulation results are discussed. Simulation results demonstrate the validity of the hybrid power system model and the matching of the parameters of the hybrid power system is reasonable.

Abstract: This paper studies the electric-drive mechanical transmission-EMT which integrates motor and mechanical transmission system. The system follows the principle of power-train integration, the paper uses the CATIA software for virtual manufacturing and assembling, through the written simulation program, using Matlab software transmission to design module simulation studying of the institution, to verify that the three grades EMT system is better in efficiency and fuel economy performance, to provide theoretical research guidance for the product designing.

Abstract: Electric vehicle power battery is one of the key technologies for electric vehicle charging and discharging. This paper summarized the characteristics of lithium iron phosphate battery firstly, then adopted intermittent discharge method to get the battery OCV-SOC curve under experimental tests, determined the parameters of OCV-SOC models, analyzed the advantages and disadvantages of commonly used cell performance model, finally built electric vehicle battery charging model.

Abstract: With the development of automotive electronics industry, the car which has electronically controlled air suspension is gained wide application. we designed an electronic control unit of automobile electronically controlled air suspension system (ECAS) including the hardware system which include the speed signal collection and processing circuit, the solenoid valve drive circuit, the CAN communication design, height detection circuit, Freescale microcontroller etc and the control strategy while propose some the basic ideas, based on Freescale microcontroller, after introducing the composition and the principle of electronically controlled air suspension. The ECAS can improve vehicle fuel economy, ride comfort and traffic-ability.

Abstract: Based on the genetic algorithm (GA), a novel type of parameters identification method on battery model was proposed. The battery model parameters were optimized by genetic optimization algorithm and the other parameters were identified through the hybrid pulse power characterization (HPPC) test. Accuracy and efficiency of the battery model were validated with the dynamic stress test (DST). Simulation and experiment results shows that the proposed model of the lithium-ion battery with identified parameters was accurate enough to meet the requirements of the state of charge (SoC) estimation and battery management system.

Abstract: Based on the Defective Automobile Product Recall Management Regulations newly issued by the State, an information management system for defective automobile products recall is analyzed and designed in this paper. At first, according to the requirements of the Regulations, the recall flow chart is offered, and demands of industrial environment, consumers, governmental departments and manufacturing enterprises are explored. Then, overall structure of the information system is proposed, including technical structure and application structure. Finally, relevant functions of the information system are designed.

Abstract: High voltage system as power source is applied to electric school buses. In this paper, failures and potential risks of high voltage system are analyzed according to the electric school bus high voltage system configuration, and the high voltage safety management system is designed with ISO26262 as a functional safety standard. The strategies of system diagnostics and safety management are proposed to achieve the safety requirements to electric vehicles, which improve the reliability of electric vehicles and reduce the cost of maintenance.