光电跟踪平台干扰分析与控制器设计

Disturbances Analysis and Controller Design of Photoelectric Tracking Platform

光电跟踪平台受轴系安装误差、轴系间的非线性摩擦力矩、质量不平衡力矩、风阻力矩、线缆约束力矩、动态耦合、反电势干扰力矩等因素的影响。由于在实际系统中很难得到上述未知干扰的精确模型,难以通过基于精确干扰模型的前馈补偿的方法进行控制,提出了一种基于干扰观测器的控制方法。设计中把模型失配以及上述未知干扰因素当作系统的总扰动,通过构造干扰观测器来预测系统总干扰,并根据预测到的干扰信息对各个轴系进行补偿以消除干扰对系统的影响。仿真和实验结果表明,所提出的基于干扰观测器的控制方法有很好的抗干扰能力,提高了光电跟踪平台的鲁棒性和跟踪性能。

Photoelectric tracking platform is influenced by different kinds of affects,such as installation error of shaft system,nonlinear friction torque,mass unbalance moment,moment of wind resistance,cable constraint moment,dynamic coupling,anti EMF interference,etc.As it is difficult to apply feedforward compensation based on the exact model of the above unknown disturbances,a kind of control method based on the disturbance observer is presented.In the design,the model mismatch and the above unknown disturbance factors are taken as the total disturbance of the system,and the total disturbance is predicted by constructing a disturbance observer.The DOB is designed to estimate and compensate the lumped disturbances of each axis to reduce the effects of the unknown disturbance factors.Simulation and experiment are presented to verify the effectiveness of the proposed control scheme.It is shown that the proposed control method base on the DOB offers several advantages such as large robustness to parameter variations and external disturbances which can improve tracking precision.