机载天线伺服系统鲁棒控制器设计

Design of Robust Controller for Airborne Antenna Servo-System

机载天线对中伺服系统要求根据上位机发出的控制指令实时调整天线姿态,隔离扰动对天线指向的影响,保证天线始终高精度对中目标卫星。如何测量系统的随机扰动并进行补偿控制,保证伺服系统的动态跟踪性能是设计的一大难题。为解决上述问题,提出了一种利用干扰观测的鲁棒控制器方法,采用极点配置法设计干扰转矩观测器,将观测到的干扰前馈到控制信号输入端进行补偿控制,为了抑制观测器误差对伺服系统性能的影响,设计鲁棒H_∞控制器来保证整体反馈系统鲁棒稳定性。通过对伺服系统进行仿真分析,动态跟踪误差可以控制在±0.2。范围内,说明带有干扰观测的鲁棒控制器能够有效地补偿外部扰动,提高天线稳定跟踪的精度。

For the purpose of adjusting antenna attitude according to the control command from the upper machine on time, airborne antenna servo system needs to isolate disturbance and ensure high accuracy of the targeting on satellite. Measuring the random disturbance and compensating to the system to ensure dynamic tracking performance of the servo system is a big problem . To solve this problem, a robust controller with disturbance observer is proposed. The disturbance observer is design based on pole placement method, the observed torque is used as compensation feed - forward to control signal. To remove affects of disturbance observer error, a robust H∞ controller is designed to improve robust stability of feedback system. The simulation result verifies that the tracking error can be controlled within ± 0.2°, the robust controller with disturbance observer can realize high accuracy positioning and tracking control.