Research Of Coordinated Control Of Automobile Electronic Suspension And Electrical Power Assisted Steering System

Electronic suspension and electrical power assisted steering system (EPS) are two important subsystems of the automobile chassis. Adavanced electronic suspension not only can isolate passengers from vibration,shock arising from road roughness, suppress the hop of the wheels so as to maintain firm and uninterrupted contact of wheels to road but also can reatrain the automobile body position movement. EPS offers distinct advantages over conventional hydraulic assist steering system in terms of fuel efficiency, modularity, tunability of steering feel and environmental friendliness.The mutual relationship between electronic suspension and EPS is analysised and researched deeply at the aspect of the systems engineering. In order to supply the academically support for the cricual technique of the integrated system included electronic suspension and EPS, a coordinated controller is presented based on the analysis of the single subsystem. The main contents in this paper are as follow.1. The dynamic model of the electronic suspension is established. Depended on the fuzzy control logical theory, the fuzzy controller is designed. Under the tool software environment of the MATLAB/Simulink, the result of the control system is estimated in the time domain and frequency domain respectively.2. The dynamic model of the EPS is built. With the consideration of the robust control advantage, the H∞robust controller is designed for EPS and the simulation result is estimated in MATLAB.3. The integrated system included electronic suspension and EPS is set up. According to some coordinated rulers, a coordinated controller based on automobile state identification is designed and the effect of the coordinated controller is analyzed.4. The whole automobile virtual model which is composed of Mcpherson suspension and EPS system is built in ADAMS. The co-simulation between MATALAB/Simulink and ADAMS is carried out so as to verify the effect of the coordinated control.The results show that the coordinated controller can balance the subsystem difference between the electronic suspension and EPS system, improve the ride comfort, steering handiness and handling stability at the same time.