基于道路误差动力学模型智能车辆横向切换LMIs/H_∞转向控制策略

Lateral Switched LMIs/H_∞ Steering Control Strategy of Intelligent Vehicle Based on Path Error Dynamics Model

基于道路误差动力学模型对不确定线性车辆模型设计了横向切换转向控制器,所提出的控制律包括车道中心线到车辆质心距离的切换PIDey控制和车辆相对车道方向误差的切换PDeψ控制,以车辆理论横摆角速度作为扰动项,控制策略利用状态反馈γ-次优H∞范数和线性矩阵不等式LMIs约束获得线性目标函数凸优化问题的最优解和相应的最小扰动抑制度γ。采用CarSim中的Alt3from FHWA道路模型和D-Class/Sedan车辆模型获取参考速度,为了简化模型,仅以时变速度子模型作为横向切换转向控制器的切换信号,在低附着系数道路上以10自由度车辆动力学模型验证了基于道路误差动力学模型比基于L2WVM(linear two-wheel vehicle model)所设计的横向控制律具有更高的路径跟踪精度和稳定性,通过改变车辆模型参数验证了基于道路误差动力学模型切换H∞控制器比L2WVM控制器具有更好的鲁棒性。

Based on the path error dynamics model,a lateral switched steering controller was de-signed for an uncertain linear model of the vehicle,which included switched PIDe y control of the dis-tance from the centerline of the lane to the center of mass of the vehicle,and switched PDey control of the direction errors from the lane to the vehicle.Setting the vehicle theoretic yawing angular velocity as the disturbance,the optimal solution of convex optimization problems of linear objective function, and the corresponding minimum disturbance rejectionγ were acquired for the control strategy,which the state feedbackγ-suboptimum H ∞ norm and linear matrix inequalities（LMIs）were used.The road model of Alt3 from FHWA was acquired from CarSim,and the reference velocity was obtained from the vehicle model D-Class/Sedan.In order to simplify the model,a sub-model with time-varying ve-locity was selected as the switching signal for the lateral switched steering controller.On the road with low adhesion coefficient,there were both verified with 10 degrees of freedom vehicle dynamics model,which was based on the path error dynamics model of the lateral control law and have higher path tracking accuracy and stability than L2WVM（linear two-wheel vehicle model）.With the changed structure parameters of vehicle model,it is verified that the switched H ∞ controller based on the path error dynamics model has better robustness than the L2WVM.