Design and Implementation of Controller for EHPS of Intelligent Electric Bus

In order to meet the needs of bus electrification and intellectualization, a controller for the steering power system of an intelligent electric bus is studied in this paper. The contents mainly include: based on the structural principle and control strategy of the EHPS system, Luenberger observer is designed, which is applied to the sensorless control system of PMSM. Then, a controller with STM32F103zet6 chip as its core is designed and manufactured. The hardware design of the controller includes the minimum system circuit, power supply circuit, signal acquisition circuit, integrated driver module circuit, CAN communication circuit, fault and high temperature alarm circuit of the single chip computer; combining the design of each hardware part, the controller of EHPS system is made. In the aspect of software implementation, the control decision-making part, a motor drive control part, fault diagnosis, and transmission part are mainly designed. Finally, the bench test and vehicle test of the controller are carried out. The purpose of the bench test is to test the control effect of the controller on the motor. The bench test results show that the target speed response of the motor is fast and the output is stable. The controller developed in this paper realizes the control of PMSM. The purpose of the real vehicle test is to test whether the controller meets the actual application requirements of the steering power system of the vehicle. The actual vehicle test results show that the steering wheel's torque decreases obviously, and the steering power system has good power-assisting performance when the EHPS system controller works. With the increase of vehicle speed, the power-assisting torque decreases accordingly. EHPS system realizes the dynamic change of power-assisting and meets the requirements of the conventional power-assisting mode of the car. In addition, the controller can realize the active steering control by controlling the electric power assistant device, which provides a platform for the realization of lane auxiliary maintenance, automatic parking, unmanned driving, and other functions.