经纬仪轴系伺服系统滑模控制仿真研究

在经纬仪轴系伺服控制技术优化的研究中,为保证经纬仪自动、快速、准确瞄准目标,传统的轴系控制多采用PID技术,但由于实际应用中存在摩擦、参数摄动、及不确定干扰等多种非线性因素,PID控制的精度难以满足测量要求。文中提出自适应反步滑模控制,引入反步的虚拟控制量重新设计切换函数,利用自适应算法估计不确定性的上界,运用非线性观测器计算摩擦干扰,可在抑制滑模抖振的情况下,提高系统控制精度。运用Lyapunov稳定性理论证明了控制系统的全局渐进稳定性和误差的收敛性。仿真结果表明,非线性因素作用下的轴系位置跟踪精度能够达到系统要求,证明了上述控制策略的有效性。

水平式望远镜轴系刚度分析及轴系误差的修正

为了解40cm水平式望远镜经纬轴系的刚度,并解决轴系误差检测值与实际使用中轴系精度之间的矛盾,本文采用有限元法,对经纬轴系关键性部件进行了模态分析和重力变形分析,分析结果表明结构刚度满足设计指标要求。利用不同经度角下经轴轴系支撑结构的重力变形分析结果,计算出重力变形引起的经轴晃动误差,并与检测结果进行比较,得出两者均具有随经度角改变而正弦变化的相同规律。利用计算值对检测值进行误差补偿,使得经轴轴系晃动误差PV值从7.2″降到2.6″,RMS值从0.7″降到0.3″,补偿后的经轴晃动误差更符合实际使用状态下的轴系精度情况,可作为经轴轴系性能是否满足指标要求的准确判据。

Visible and Infrared Band Tracking and Measuring Control System

This paper describes a new tracking and measuring control system for optical and electronic theodolite.This control system can provide automatic flying object tracking and measuring in visible and infrared band.It also can provide real-time output of the measured results.By using the multi-mode measuring methods and the on-axis tracking control technique, the stability of automatic tracking,tracking accuracy and the comprehensive tracking performance of the theodolite can be improved.At the same time the smooth switch-over among several tracking modes can be carried out.New tracking techniques have been developed to deal with angular tracking rate that exceed 60 deg/s in velocity and 90 deg/s 2 in acceleration.At the present the tracking and measuring control system has been successfully applied in the optical and electronic theodolite.