Control Strategy Design And Hardware In The Loop Test Of Pure Electric Bus

The development of pure electric vehicles is helpful to solve the problems of environmental pollution and energy security t in China.As the most important part of pure electric vehicle control system,vehicle control strategy has a great impact on the performance of the vehicle.Based on a 10-meter pure electric city bus development project of an enterprise,the vehicle control strategy is developed and verified.Based on the requirements of vehicle,the control system communication network topology is established,the control scheme is designed,and CAN communication protocol is formulated.Furthermore,the control strategy architecture including input signal processing,drive control,brake control and fault diagnosis and processing is established.In the aspect of drive control,the control strategies of starting,power,economy,hill-stop,overspeed,reversing and low power protection are designed.According to the power and economy mode,the torque control scheme of basic torque plus fuzzy compensation torque is formulated.In the power mode,the improvement of power performance of full pedal travel is considered,and in the economy mode,the driving experience is considered.Based on fuzzy control method,pattern recognition and automatic switching are realized.In terms of braking control,based on the structure of the braking system,a fully decoupled series braking scheme is developed.In the aspect of fault diagnosis and handling,occasional errors are eliminated through graded fault handling to enhance the robustness of the control system.In order to verify the control strategy,the vehicle model is built,the model-in-the-loop test is completed,the code is generated and optimized,and the software-in-the-loop test is completed.The code is compiled and downloaded,and the hardware-in-the-loop test is completed based on SCALEXIO rack system.The test results show that the vehicle control strategy can effectively process the input signal,while meeting the driving needs,it can comprehensively improve the power and economic performance of the vehicle,and can timely diagnose and respond to the faults in the process of driving,and the vehicle performance meets the requirements.