Cooperative Control of Active Suspension and Four-Wheel Steering for Intelligent Electric Vehicles With Corner Module Structure on Severe Roads

The Corner Module Architecture (CMA) integrates a steering system, a drive/brake system, and an active suspension system at each wheel. Since electric vehicles are characterized by simple structure, high control precision, and fast response speed compared to conventional vehicles, electric vehicles are an excellent carrier for CMA intelligent vehicles. CMA vehicles can fully utilize the vehicle's maneuverability and passability on severe roads after rain and snow by coordinating the control of the four-wheel steering (4WS) and active suspension system (ASS). However, the unknown road conditions when the CMA vehicle is traveling on severe road surfaces, and the cooperative control of the 4WS and the ASS all place high demands on the control system. To address the above challenges, a robust controller for CMA vehicle dynamics based on the TakagiSugeno (T-S) fuzzy model is proposed. To adequately simulate the severe roads, fuzzy rules were designed for the road adhesion coefficient and longitudinal speed as variable parameters, and then the parallel distribution compensation method is used to design the fuzzy controller. Then linear matrix inequality is utilized to solve the solution that satisfies the H _∞ performance index under the action of the fuzzy controller. Finally, the effectiveness of the control strategy is verified through simulation, and the results indicate that the proposed control strategy can effectively improve the adaptive ability of the CMA vehicle and the stability of the vehicle under severe road surfaces.