基于H_∞方法的伺服系统二自由度鲁棒控制

Servo System 2-DOF Robust Control Based on H_∞ Method

针对高炮伺服系统存在模型摄动和强外力干扰问题,设计了一种具有二自由度结构强鲁棒性的位置控制器。采用频域方法,通过对转动惯量摄动和高频未建模动态的结构分析,描述了影响伺服系统稳定性的两类主要的不确定性;基于鲁棒控制原理,将位置控制器的设计转化为标准的H∞控制器问题,并通过LMI凸优化方法得到输出反馈次优H∞控制器。仿真结果表明:采用该方法设计的伺服控制系统能实现精确的稳态跟踪,且对模型摄动和外力干扰具有较强的鲁棒性。

Aimed at problems of model perturbation and great external disturbance existed in AA gun servo system, a kind of 2-DOF robust controller was designed. By means of frequency domain method, through structural analysis of rotating inertia variation and high frequency no-modeling dynamics, two kinds of major uncertainties that had influence on servo system stability were described. Focused on robust control theory, the design of positioning controller was transformed into standard H∞ controller problem, and the output feedback sub-optimal H∞ controller was acquired by use of LMI convex optimization method. Simulation results showed that the proposed servo system can not only ensure the system stability and tracking performance, but also has stronger robustness to overcome model perturbation and external disturbances.