制动工况下含预瞄信息的主动悬架变权重LQG控制

VariableWeight LQG Control of Active Suspension with Preview Information under Braking Condition

为提高车辆在制动工况下的乘坐舒适性,建立1/2车辆主动悬架制动模型。针对传统LQG控制器中的权重系数难以确定的问题,以车辆的各项性能指标为约束条件,利用改进的粒子群算法对不同路面等级下的控制器权重系数进行优化。在此基础上,将最优控制与轴距预瞄控制相结合,基于线性系统二次型最优控制理论,设计制动工况下包含预瞄信息的主动悬架变权重LQG控制器。仿真结果显示:相比于固定权重的LQG控制,变权重LQG控制能够更好地适应路面等级的变化,有效改善悬架的性能。此外,含预瞄信息的变权重LQG控制和无预瞄信息的变权重LQG控制相比于被动悬架,车身垂直加速度均方根分别优化51.2%、43.9%,车身俯仰角加速度均方根分别优化42.7%、18.0%。由此可知,含预瞄信息的主动悬架变权重LQG控制能够使车辆获得更好的舒适性,且整体振幅也得到明显降低。

In order to improve the ride comfort of vehicles under braking condition,a 1/2 vehicle active suspension braking model was established.Due to the difficulty of determining the weighting coefficients in traditional LQG controllers,an improved particle swarm algorithm was used to optimize the controller weighting coefficients for different road grades with various performance indicators of the vehicles as constraints.On this basis,the optimal control and wheelbase preview control were combined,and a variable weight LQG controller with preview information was designed for braking condition based on the linear system quadratic optimal control theory.Simulation results show that compared to constant-weight LQG control,variable-weight LQG control can better adapt to the changes in road grades and effectively improve suspension performance.In addition,compared to passive suspension,the root-mean-square vertical acceleration and pitch acceleration of the vehicle body can be optimized by 51.2%and 43.9%,and 42.7%and 18.0%,respectively for variable-weight LQG control with preview information and variable-weight LQG control without preview information.It can be seen that the variable weight LQG control of active suspension with preview information can make the vehicles get better comfort and the overall vibration amplitude is obviously reduced.