基于降阶观测器的四轮转向车辆扰动操纵稳定性控制

考虑在实际中车辆受到不确定情形的外扰及车辆质心侧偏角和侧倾角难以直接测量，建立四轮转向(Four-wheel steering , 4WS)车辆控制系统数学模型，提出一种基于降阶观测器的前轮和四轮转向车辆扰动操纵控制策略，应用最优控制理论设计反馈控制系统，进行高速动态仿真。结果表明该降阶观测器跟踪性能良好、速度快且估计误差小；系统具有良好的动态特性和鲁棒性，4WS车辆更能有效地提高车辆扰动操纵稳定性和安全性。

DISTURBANCE HANDLING STABILITY CONTROL FOR FOUR-WHEEL STEERING VEHICLE BASED ON REDUCED-ORDER OBSERVER

To take account of the practical difficulties for measuring the sideslip and roll angles of a vehicle and the vehicle is always subject to a large range of uncertainties because of external disturbances, an optimal control strategy for a four-wheel steering (4WS) vehicle is proposed, which is based on a reduced-order observer control model. Feedback control system is designed using optimal control theory to enhance the disturbance handling stability of the vehicle, and the simulation of disturbance handling stability with high vehicle speed is performed. The results show that the reduced-order observer has the excellent characteristics in the considered speed range in tracking path and so the control system has fine dynamic characteristic and strong robustness, and the 4WS vehicle with the proposed control strategy can provide greater disturbance resistance ability.