汽车四轮独立转向稳定性控制策略研究

Research on Four-Wheel Independent Steering Control Strategy of Automobile Stability

为深入研究四轮独立转向对汽车操纵稳定性与运动协调性的影响,考虑阿克曼转向定理,推导出各车轮间转向角关系,并建立阿克曼定理的四轮独立转向模型;建立线性二自由度四轮转向理想参考模型;利用carsim建立多自由度整车模型。提出一种前馈采用阿克曼定理,反馈采用模糊控制的四轮独立转向联合控制策略,设计方向盘斜坡转向输入工况,通过Carsim与Simulink进行联合仿真,仿真结果表明,多自由度整车模型的质心侧偏角与横摆角速度都能接近理想状态。设计的阿克曼前馈与模糊反馈的四轮独立转向联合控制策略即实现了车辆转向的运动协调性,又改善了车辆操纵稳定性。

In order to deeply study the influence of four-wheel independent steering system on automobile han- dling stability and movement coordination, considering the Ackerrnan＇s steering theorem, the steering, angle relation- ship between the wheels were derived and then four-wheel independent steering model of Ackerman＇s theorem was built. The linear two-degree-of-freedom four-wheel independent steering model and the multi-degree-of-freedom vehicle model were established. A feedforward control strategy based on Ackerman＇s theorem and a feedback control strategy based on fuzzy control were proposed. The simulation condition of steering wheel slope steering was designed, and the joint simulation of Carsim and Simulink were adopted. In conclusion, the centroid sideslip angle and yaw rate of multi-degree-of-freedom whole vehicle model are close to ideal state. The design of Ackerman feedforward and fuzzy feedback＇s four-wheel independent steering joint control strategy not only considers the movement coordination of the vehicle steering but also improves the vehicle handling stability.