空间光通信中精跟踪控制器的设计

Design of fine tracking controller for free space optical communication

精跟踪伺服系统设计是APT的核心技术,决定了通信链路能否建立以及通信系统的性能。针对空间光通信中压电陶瓷驱动FSM偏转具有非线性、时变不确定性和纯滞后等特性,提出变论域自适应模糊PID控制方法。引入变论域思想,并通过对输入变量加入伸缩因子的方式来实现变论域的目的,自适应能力和抗干扰能力明显增强,可有效解决稳定性与准确性的矛盾。实验结果表明:模糊PID控制算法增强了伺服系统鲁棒性,并提高了伺服系统实时性;跟踪精度可达到5μrad,对卫星平台振动和大气湍流引起信标光斑抖动有一定的抑制作用,能够满足空间光通信精跟踪精度的要求。

The design of fine tracking servo system is a crucial technology of APT.It determines whether communication links can be established and the capability of communication system.According to the characteristic of nonlinearity,time -varying uncertainty and lagging of FSM actuated by PZT,the method of adaptive fuzzy PID controller based on variable field was introduced.Adaptive capacity and anti-jamming performance were significantly enhanced by adding flexibility factor to input variables.The conflict between stability and accuracy was solved effectively.Finally,experimental results demonstrate that the performance of robust and real time are improved in the fine tracking servo system.The absolute error of tracking precision is less than 5 μrad.The vibration of satellite platform and the facular tremble of beacon were effectively suppressed.The controller can satisfy the requirement of fine tracking accuracy for free space optical communication system.