考虑时滞的主动悬架系统控制策略对比研究

Comparison of Control Strategies for Active Suspensions With Time Delay

本文以二自由度四分之一汽车悬架系统为研究对象,采用不同控制策略对考虑时滞的悬架系统控制特性进行研究,并对控制效果进行对比分析.首先,采用第二类拉氏方程建立考虑时滞的二自由度悬架控制系统的动力学模型;然后分别基于状态变换法和H_(∞)控制理论,设计系统的时滞反馈控制律.其中状态变换法主要通过系统状态变量的转换,将系统时滞控制方程转换成不显含时滞的动力学方程,然后采用传统的二次型最优控制方法对系统进行控制.H_(∞)控制主要通过使用Lyapunov-Krasovskii泛函和自由权矩阵法,设计考虑时滞的H_(∞)控制律;最后在Matlab/Simulink平台上对控制系统进行仿真分析,并在相同时滞下对两种控制结果进行对比.研究表明,两种控制策略在考虑时滞的情况下均可保证系统的稳定性,且H_(∞)控制相比于状态变换法有更好的控制效果.

A two-degree-of-freedom quarter vehicle suspension system is taken as the research object.Different control strategies are used to study the control characteristics of the suspension system with time delay,and the control effects are analysed by comparision.First,the dynamic model of a two-degree-of-freedom suspension control system with time delay is established by the second kind of Lagrange equation.Then,based on the state transformation method and H_(∞)control theory,the time-delay feedback control strategy of the system is designed.The state transformation method is mainly through the transformation of system state variables,the system time delay control equation is transformed into a dynamic equation without time delay,and then the traditional quadratic optimal control method is used to control the system.H_(∞)control strategy with time delay is designed by Lyapunov-Krasovskii functional and free weighting matrix method.Finally,the control system is simulated and analyzed on Matlab/Simulink platform,and the two control results are compared under the same time delay.The research shows that both control strategies can ensure the stability of the system when considering the time delay,and the H_(∞)control has better control effect compared to the state transformation method.