Alterable Assist Characteristics Design and Simulation Analysis of the Flow Controlled ECHPS System for Heavy Commercial Vehicle

Abstract

Assist characteristics design is one of the key technologies of ECHPS system.For the problem of poor steering safety in high speed caused by HPS with fixed assist characteristics in heavy commercial vehicle, design requirement of alterable assist characteristics is analyzed, and simulation models of ECHPS system, including mechanical model ,hydraulic model and three degrees freedom vehicle dynamic model are established by taking the bypass flow ECHPS of heavy commercial vehicle as the research object. Assist characteristics of ECHPS under different speeds are achieved by simulation models.Simulation results show that, ECHPS system can not only improve the steering easiness at low speed but also keep good road feel and handling stability at high speed.