基于层次分析法的汽车半主动悬架LQG控制研究

Study on LQG Control for Vehicle Semi-active Suspension Based on Analytic Hierarchy Process

建立了考虑座椅的五自由度车辆动力学模型,应用最优控制理论设计了车辆半主动悬架的LQG控制器。以座椅加速度、车体加速度、车体俯仰角加速度、前后悬架动行程及前后轮胎动位移等作为评价指标,采用层次分析法(AHP)确定了各指标的加权系数。利用MATLAB/Simulink搭建车辆仿真模型,分别在A级路面90 km/h和B级路面60 km/h两种工况下验证LQG控制的有效性。结果表明:与被动悬架相比,采用LQG控制器的半主动悬架能有效地减缓车辆的振动,改善车辆的乘坐舒适性与行驶平顺性。基于层次分析法确定加权系数的LQG控制器使车辆半主动悬架对工况的适应性较好,具有良好的应用前景。

The vehicle dynamics model with five degrees of freedom considering the seat is developed, and the theory of optimal control is adopted to design the LQG controller for semi-active suspension. The evaluation elements are seat acceleration, body acceleration, pitch angular acceleration, suspension dynamic deflection and tire dynamic displacement, based on which the weighted coefficient of each index is determined by Analytic Hierarchy Process（AHP）. The vehicle model is established by MATLAB/Simulink, and the result proves the effectiveness of the LQG controller with 90 km/h on A-grade highways and 60 km/h on B-grade highways. The result shows that compared with the passive suspension system, the semi-active suspension with LQG controller can effectively reduce vehicle vibration and improve ride comfort of the vehicle. With weighed coefficient determined by AHP, the LQG controller has strong adaptability for various working conditions, and has good application prospects.