中文摘要：

为了系统地分析非线性四轮转向车辆的动力学行为,并同时考虑实际车辆运行工况的复杂性,建立了具有非线性特征的四轮转向车辆动力学模型.选择质心侧偏角和横摆角速度作为控制变量,基于滑模控制理论和最优反馈控制理论,分别设计控制器抑制外部扰动;在J-turn的操纵模式下,比较2种控制算法的优越性,基于Matlab/Simulink环境下实现仿真结果的对比.结果表明,滑模控制下四轮转向车辆具有更优的操纵性能,将质心侧偏角控制在稳定范围内,并能较好地跟踪车辆的期望横摆角速度,可较理想地提高高速环境下四轮转向的抗干扰能力.

英文摘要：

To analyze systematically the non-linear dynamic behavior of four-wheel steering（4WS） vehicles and to take account of the complexity of the practical running vehicle,a four-wheel steering vehicle dynamic model based on non-linear characteristic is built.The sideslip angle and yaw rate are chosen to be the main control variables to maintain the 4WS system stability.The robust controllers are designed to resist the disturbance based on sliding-mode control theory and optimal control theory;Base on J-turn manoeuvre,the effectiveness of the control methods are validated in the Matlab/Simulink environment.The results show that the sliding-mode controller is provided with better performance and is effective on maintaining the sideslip angle and the yaw rate within the optimal range for four-wheel steering vehicle.It is also proved to strengthen 4WS stability and manoeuvrability performance.