光通信精瞄系统的时滞鲁棒非脆弱H_∞控制

Delay Dependent Robust Non-fragile H_∞ Design for Fine Pointing System of Optical Communication

采用加性不确定性描述了精瞄系统快速倾斜镜(FSM)的非线性滞环特性,将执行器驱动过程中的蠕变特性看作系统状态具有时滞依赖,并对卫星平台振动及抑制问题进行了分析.考虑到控制器也会出现参数摄动的情况,利用线性矩阵不等式(LMI)方法推导了模型摄动与扰动抑制下的非脆弱H∞控制器求解方法.精瞄模型的仿真结果表明,控制器设计方案能在摄动和时滞时间有界的条件下保持闭环系统二次稳定并能有效地去除卫星平台扰动.

The nonlinear hysteresis loop characteristic of fast steering mirror （FSM） of the fine pointing system is described by additional uncertainty, and the creep behavior in driving process of actuator is regarded as time delay-dependent state. The platform vibration of satellite model and vibration attenuation method are analyzed. Simultaneously, the perturbation of controller parameters is considered, and the solution of non-fragile H∞ controller is deduced by linear matrix inequality （LMI） when model perturbation and disturbance exist. The simulation on fine pointing system model proves that the controller design scheme can keep closed-loop quadratic stable and suppress the satellite disturbance efficiently in condition of finite perturbation and delay time.