基于PMAC的天文望远镜控制系统研究及应用  

A Study of a PMAC-Based Astronomical-Telescope Control System and Its Application

作　　者：黄垒[1,2] 魏建彦[1] 姜晓军[1] 卢晓猛[1] 周志中[1] 李红斌[1] 

机构地区：[1]中国科学院国家天文台,北京100012 [2]中国科学院大学,北京100049

出　　处：《天文研究与技术》2015年第1期44-53,共10页Astronomical Research & Technology

基　　金：国家科技部基础研究项目(2014CB845800);国家自然科学天文联合重点基金(U1331202)资助

摘　　要：天文望远镜为大型高精密仪器,对望远镜的控制系统性能提出了极高的要求。作为控制系统的核心器件,伺服控制器的性能决定了控制系统的性能。介绍了一种基于PMAC(Programmable Multi Axes Controller)控制器的天文望远镜控制系统,研究了PMAC伺服控制原理、PID参数整定方法及基于PMAC的天文望远镜运动控制系统基本原理,并以此为基础设计了天文望远镜伺服控制系统软、硬件体系。基于PMAC的天文望远镜控制系统主要特点在于,伺服系统采用了传统的PID反馈控制算法和前馈控制算法相结合的组合控制算法,有效地克服了外界扰动对望远镜控制过程的影响,获得了较好的动、静态性能;同时,针对望远镜不同的轴系传动方式,如直驱方式和齿轮传动方式,应用不同的PID参数整定方法,如阶跃整定法和基于速度测量+阶跃整定相结合的参数整定方法,可分别使系统获得较为理想的PID控制参数;另外,基于PMAC的天文望远镜控制系统,对于不同的驱动电机和不同的轴角测量元件,均具有较好的适应性。该系统已在国家天文台2.16 m天文望远镜上得到了应用,该项应用中,采用了"IPC+PMAC"的双CPU分级控制方式,并以VC++为软件平台,通过对于PMAC Pcomm32底层接口函数的调用,实现了基于工控机的望远镜界面操作和控制,同时,以PID反馈控制算法和前馈控制算法为基础,采用了PID参数自适应控制算法,保证了望远镜高速的运行平稳性,也实现了低速精确性和快速性的控制要求。技术研究和运行实践表明,基于PMAC的望远镜控制系统具有较高的控制精度和良好的通用性,可广泛应用在不同类型的天文望远镜系统。A large-aperture astronomical telescope is a precision instrument and it is a great challenge to achieve needed performance of its control system. As the core unit the servo controller determines the performance of the control system. In this paper we describe a PMAC-based auto-control system of motion of an astronomical telescope. In particular, we have first studied the principle of PMAC servo control, the methods of tuning PID parameters, and the principle of a PMAC-based motion control system of an astronomical telescope. Based on the study we have designed the software and hardware of a PMAC-based motion control system of an astronomical telescope. The main characteristic of our auto-control system is that its servo control system uses a combination of the traditional PID feedback control algorithm and forward-feeding control algorithm, so that influences of external disturbances are effectively reduced. This makes the system to perform excellently under dynamic and static conditions. In addition, different methods of tuning PID parameters, such as the step-function tuning and the method combining velocity-measurement and step-function tunings, can yield satisfactory results. The control system overall has a good adaptability either to different driving motors or to different components for measurement of shaft angles. The control system has been applied to the 2. 16m Astronomical Telescope at Xinglong. In this application the control system uses the IPC＋PMAC double-CPU hierarchical control method. The method achieves telescope-interface operation/control through an industrial personal computer under a VC ＋ ＋ platform. Certain PMAC Pcomm32 interface functions are called by the method for these. The self-adaptive algorithm for adjusting PID parameters as incorporated in the system ensures stability of the system in its high-speed running mode, as well as high-level accuracies and effieieneies in its low-speed running mode. Our research and operational practice show that our telescope control system base

关 键 词：天文望远镜 控制系统 PMAC PID参数整定 2.16m望远镜 

分 类 号：P111[天文地球—天文学]