The Integrated Control of Electronic Suspension and Steering System Based on Fuzzy Logic Method in Vehicle

As well known, electrical power assisted steering system (EPS) can improve driver´s steering operation and vehicle maneuverability by creating reactive torque, otherwise, semi-active suspension system (SAS) can improve the ride quality and handling performance within a given suspension stroke limitation through varying the damping forces continuously according to the road disturbance. Usually, EPS and SAS perform independently to improve maneuverability in steering and the ride comfort respectively. However, as the electronic control subsystems of the chassis in vehicle, they often work together, the performances of vehicle depend not only every subsystem but also the relationship of these subsystems strongly. In this paper, the full vehicle model, the SAS model and EPS model are established, then the integrated control of EPS and SAS is investigated and the fuzzy logic control strategy is presented to control the integrated electronic control system. Numerical simulations are carried out to identify the effectiveness of the integrated control system of EPS and SAS. The simulation results show that the integrated control system can obviously improve vehicle maneuverability and ride quality much more than EPS and SAS control system only.