Integrated Control Of Vehicle Direct Yaw Moment Control And Active Suspension System For4WD Vehicle

With the rapid development of vehicle industry and the increasing popularity of theautomobile, people are increasing likely to choose the vehicles that possessing goodsafety and driving experience. Since four wheel drive technology can take fulladvantage of the wheels’ adhesion force, vehicle can obtain the greatest possible drivingforce and effectively avoid the skid phenomenon, so more and more limousines andsport utility vehicles are beginning to use this technology. This paper takes a four-wheeldrive vehicle as research object, and studies the integrated control of direct yaw controlsystem(DYC) and active suspension system(ASS) to improve the vehicle’s steeringstability and safety. The mainly research works carried on as follows：①Four wheel drive technology was analyzed. Four wheel drive torque distributionstructure, vehicle coordinate system and main structure of dynamics model for fourwheel drive vehicle were confirmed. A10-DOF nonlinear vehicle dynamicmathematical model including steering and suspension systems is established. Themodel includes driver model, engine model, driveline, tire model and other auxiliarycalculation module.②A2-DOF linear vehicle model was established and chosen as the referencemodel for DYC controller. According to the characteristics of the four-wheel drivevehicle, the DYC controller that based on distribution of driving force was designedusing sliding mode variable structure control method. The ASS controller that aiming atimproving the vehicle ride comfort was designed using a double-loop control structure.③Based on the analysis of the influence of suspension on the vehicle steeringperformance, integrated control of DYC and ASS is studied under steering condition.And integrated control strategy aiming at the improvement of vehicle’s handlingstability and ride comfort was proposed. In order to verify the effectiveness of theproposed integrated control strategy, Simulation was carried out under typical steeringconditions using the offline platform of Matlab/Simulink. The simulation resultsindicate that the proposed integrated control strategy can both improve vehicle ridingcomfort and vehicle stability.