Simulation On Electric Hydryaulic Power Steering System Of New Energy Bus

Energy saving environment protection and safety are current trend for automobile tech development. New energy bus is drawing attention from \ governments and society worldwide due to its prominent advantage, such as energy-saving, environmental protection etc. Currently, domestically-developed new energy bus are mostly equipped with EHPS powered by electric pump. There is still large room for promotion for energy saving and steering performance due to lack of electrical control on motor. Analysis and research has been made on EHPS of new energy bus in this paper to meet command of energy saving and environment protection.First, the structure of EHPS is confirmed. Necessary calculation is made to select main components of EHPS system.Then, the principles of key parts of EHPS is specifically interpreted. EHPS Model excluding motor is established in AMEsim according to type-selection based data and analyzing on mathematical model. Simulation of the non-motor model in AMEsim demonstrates its correction. After analyzing primary principles and approaches of speed control of asynchronous motor, open-loop flux vector control system of motor is modeled in Simulink to reach needs of excellent following performance and quick response to ordered speed from electrical control unit. Thus, timely and appropriate assisted steering power is supplied.Plus, practical needs of assisted steering power, energy loss and inherited assist characteristic of EHPS is profoundly explored, speed curve of motor control is designed with input of car velocity and steering wheel angle and EHPS control program is rooted in combined with signal of open-and-close condition of bus door.At last, co-simulation analysis is done on EHPS system with tests on steering performance in different velocity period, showing that EHPS designed in this paper is well operated with remarkable following characteristic and proved to be qualified of the command of portability.