遥感机构数字伺服控制系统采样周期的确定  

Determination of sampling period on the digital servo control system

作　　者：谢妮慧 王淳[1] 林喆[1] 

机构地区：[1]北京空间机电研究所,北京100094

出　　处：《电子测量技术》2017年第7期165-169,共5页Electronic Measurement Technology

摘　　要：采样周期是影响数字伺服控制系统控制性能的很重要的因素之一,但采样周期的最终确定又是由很多因素共同决定的。香农采样定理给出了选择数字控制系统采样周期的指导原则,针对复杂的伺服控制系统设计远远不够。为了使离散系统的控制效果尽量接近于连续控制系统,采样周期应尽可能短,但是采样周期太短可能无法完成复杂的运动控制规律和控制算法。通过计算和分析发现,离散化过程中由于零阶保持器的引入而改变闭环系统极点的分布,有可能导致系统不稳定;采样周期值过大或者过小会使PID控制器的积分环节或者微分环节失效;干扰信号具有不同的频谱宽度和频率大小,所以为了有效的抑制干扰应根据不同干扰信号选择不同的采样周期值。Sampling period has important influence on the control performance of digital servo control system,and the sampling period is determined by a lot of factors including servo stability,hardware,interfering signal and so on.Shannon sampling theorem is only aguiding principle to choose sampling period.According to the sampling theorem,the higher the sampling frequency of digital control system,the closer of the control effect of the discrete control system to the continuous control system,but in practical applications,if the sampling frequency is too high and the sampling period is too short,it may not be able to perform complex control algorithm and complex rule of the motion control.It may lead to instability of the system because of the addition of zero order retainer during the process of discretization,and it cannot obtain the optimal effects of PID controller if the sampling period is too long or too short,and in order to restrain the interference signal effectively,it ask for different sampling period because of interference signal has different frequency size and it may be a narrow-band or a broad-band.

关 键 词：数字伺服控制系统 采样周期 零阶保持器 PID控制器 

分 类 号：TP273[自动化与计算机技术—检测技术与自动化装置] TN98[自动化与计算机技术—控制科学与工程]