The Co-simulation Study On Electric Power Steering System

Automobile steering system, which has a direct influence on comfort, security, and stability of steer, is one of the main subsystem in the vehicle. Electric Power Steering System(EPS) is the current development trend of steering system. The EPS is a power steering system which provides assist torque by a motor. With respect to Hydraulic Power Assisted Steering System(HPS), the EPS doesn’t have steering oil pump, flexible tube, hydraulic oil, conveyer belt and so on. As the car comfort and security demand have widely been paid attention, more and more automobile manufacturers start to concentrate more on the application of EPS aims at environmental protection, energy saving, security and comfort.The development of computer technology provides a more convenient and effective research platform about EPS. ADAMS has got the status of the world’s most widely used mechanical system simulation software, which enables building and testing of virtual prototypes. ’ extension tool for modeling, simulating and analyzing dynamic, multi-domain systems.This paper firstly describes the development and current research status of EPS, presenting research content and direction. By studying on the multi-body dynamics system, the paper analyzing methods to build up full vehicle model in ADAMS. Then, be based on the dynamics of rigid multi-body, the paper refers to vehicle parameters to build up these subsystems and assemble them into complete vehicle in ADAMS/Car. In addition, the paper experimentally check to see if the vehicle model is actually correct by using the simulation module. Next, the paper focuses on analyzing mechanical model and motor model, deducing mathematical formula. By doing some research on assist curve as well as using the PID control arithmetic, the paper build up control model of EPS including the required assist curve in software. Eventually, the co-simulation method used here is implemented by using ADAMS/Control software for simulation of the mechanical system andfor control system. The co-simulation is completed by the two different simulation programs exchange parameters and data with each other at a preset time step.