步进电机闭环运动控制系统研究

RESEARCH ON CLOSED-LOOP MOTION CONTROL SYSTEM FOR STEP MOTOR
Candidate： Supervisor： Academic Degree Applied for： Speciality： Affiliation： Date of Defence：
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哈尔滨工业大学工学硕士学位论文
目
录
摘要 ............................................................................................................................. I Abstract ...................................................................................................................... II 第 1 章 绪论 ...............................................................................................................1 1.1 课题背景及研究的目的和意义 .......................................................................1 1.2 步进电机简介 ...................................................................................................2 1.2.1 步进电机的构造 ........................................................................................2 1.2.2 步进电机的运转原理 ................................................................................3 1.2.3 步进电机的细分技术 ................................................................................6 1.3 步进电机的控制方式 .......................................................................................7 1.3.1 步进电机的开环控制 ................................................................................7 1.3.2 步进电机的闭环控制 ................................................................................8 1.3.3 步进电机开环控制和闭环控制比较 ........................................................8 1.4 论文主要内容 .................................................................................................10 第 2 章 步进电机的加减速控制 .............................................................................. 11 2.1 T型曲线加速与速度规划 .............................................................................12 2.2 S型曲线加速与速度规划 .............................................................................15 2.3 正矢曲线加速与速度规划 .............................................................................20 2.4 不同加速方法比较 .........................................................................................23 2.5 本章小结 .........................................................................................................24 第 3 章 步进电机的建模与仿真 .............................................................................. 25 3.1 运动平台的数学模型 .....................................................................................25 3.2 以电压为输入信号的仿真分析 .....................................百度文库...............................26 3.3 以位置—时间曲线为输入时的仿真分析 ......................................................29 3.4 本章小结 .........................................................................................................31 第 4 章 步进电机闭环运动系统的设计与分析 ...................................................... 32 4.1 步进电机闭环的运动系统的结构 ..................................................................32 4.1.1 对步进电机闭环的运动系统 ..................................................................32 4.1.2 对负载平台闭环的运动系统 ..................................................................33 4.2 步进电机闭环运动系统的控制 .....................................................................34
哈尔滨工业大学工学硕士学位论文
摘
要
步进电机具有起停速度快、调速范围宽等优点，是工业控制中的一种常用 执行机构。由于步进电机本身具备一定的定位能力，所以对其采用开环控制便 能够满足部分对精度要求不高的应用场合的需求。但是在开环控制中，控制器 只负责按照预定的方案发送一定数量的脉冲，而无法检测到电机转动的角度和 负载移动的距离是否和控制器的指令相符。于是当电机出现失步现象或者由于 机械结构引起过大的偏差时，控制器便在某种程度上失去了对负载的控制。为 了加强控制器对负载的控制，避免由于电机失步和机械结构引起的误差，本文 讨论了步进电机运动系统的闭环控制。 步进电机运动系统的闭环控制，核心是对步进电机转动速度的控制，因为 整个运行过程中速度的快慢决定着运动系统的运行效率，对位置的控制也是通 过控制速度来实现的。为了充分利用步进电机在低速运行时提供的大力矩，文 中首先讨论了步进电机的加减速控制，分析了三种加速曲线： T 型加速曲线、 S 型加速曲线和正矢加速曲线的特点。接下来对实验用的步进电机运动系统建立 了数学模型，通过 Matlab 仿真分析了采用不同加速曲线时步进电机加速的效 果。然后设计了以步进电机为被控对象、以负载平台为被控对象两种闭环控制 结构。为了在部分应用中减轻控制器计算的负担，设计了两种控制方法：部分 闭环控制和全程闭环控制，通过实验分析了两种控制方法的特点。在步进电机 闭环运动控制系统实现过程中，根据运算处理单元的不同，可以以上位机为运 算主体，也可以以控制器为运算主体，并分别在上位机和控制器中设计了闭环 控制器，通过实验比较了这两种闭环控制的性能。 关键词 ：步进电机；闭环；速度控制；运动控制器
硕士学位论文
步进电机闭环运动控制系统研究
RESEARCH ON CLOSED-LOOP MOTION CONTROL SYSTEM FOR STEP MOTORS
唐明
2011 年 12 月
国内图书分类号： TH113.2 国际图书分类号： 621
学校代码： 10213 密级：公开
工学硕士学位论文
步进电机闭环运动控制系统研究
硕 士 研 究 生 ：唐明 导 师：楼云江 副教授
申 请 学 位 ：工学硕士 学 科 ：控制科学与工程
所 在 单 位 ：深圳研究生院 答 辩 日 期 ： 2011 年 12 月 授予学位单位 ：哈尔滨工业大学
Classified Index: TH113.2 U.D.C.: 621
Thesis for the Master Degree in Engineering
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哈尔滨工业大学工学硕士学位论文
Abstract
Step motor has many advantages, such as it can start and stop quickly as well as its speed can be tuned in a wide range, so it is commonly used as an actuator in industrial control. As the step motor can locate at a limited accuracy, so it is appropriate for some applications which need low precision when worked at open-loop control state. But when it works at open-loop control state, the controller just takes charge of sending a series pulses according to predetermined program, while it can't detect whether the rotation angle of the motor or the distance of the load according to controller’s directive. So the controller may lost control to the load when the motor is out of step or the deviation becomes too large due to mechanical reasons. In order to make the controller strengthen the control to the load, the closed-loop motion system for the step motor is studied. The key to the closed-loop control for step motor motion system is how to control the speed of the step motor, because the average speed of movement in the whole operation routing determines the efficiency of the system, and another reason is that the position control is achieved by speed control. Firstly, in order to take full advantage of the available high-torque when the step motor running at low speed, the acceleration control of the step motor is discussed. Step motor can adopt three accelerated curves during accelerating, and these three curves’ characteristics are analyzed. Next, a mathematical model of the step motor motion system is established, which can be used for analyzing the accelerate effect through Matlab simulation when the step motor adopt different accelerating curve. Then two closed-loop frames have been designed: one is setting step motor as control objective, another is setting load flat as control objective. In order to alleviate the burden of the controller for calculating in some applications, two control methods are given: part-closed-loop and full-closed-loop. According to the difference between the processing units, closed-loop control could be divided into computer-based closed-loop control and controller-based closed-loop control. These two kinds of closed-loop control are implemented, and the effects of them are analyzed through experiments. Keywords: step motor, closed-loop, speed control, motion controller
Ming Tang Associate Professor Yunjiang Lou Master of Engineering Control Science and Engineering Shenzhen Graduate School December, 2011
Degree-Conferring-Institution： Harbin Institute of Technology