Integrated control of automotive electrical power steering and active suspension systems based on random sub-optimal control

This paper addresses the problem of integrated control of electrical power steering systems (EPS) and active suspension systems (ASS). Through integrating EPS with ASS, a full car dynamic model is established. Based on the integrated model, a random sub-optimal control strategy based on output feedback is designed to fulfil the integrated control of both EPS and ASS. The characteristics of the integrated control system are analysed using Matlab/Simulink and a series of comparisons are made with the system without control and the ASS-only/EPS-only system. The simulation results show that the integrated control scheme can not only enhance the steering quality, but also significantly isolate the road excitation. Moreover, the integrated control system has a great improvement on anti-roll and anti-pitch abilities. The proposed research provides a theoretical solution for simultaneously improving the multiple vehicle performance indices including manoeuvrability, handling stability, ride comfort, and safety.