自动化专业外文翻译---步进电机的振荡、不稳定以及控制

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1、  PDF外文：http:/ 电子与信息工程学院    本科毕业论文 (设计 )  外  文  文  献  翻  译   译 文题目： Oscillation, Instability and Control of Stepper Motors                                     &

2、nbsp;                 学生姓名：        宋  海  军                                专     业：     电 气 工 程 及 其 自 动 化       &nbs

3、p;                        指 导教师：           李   东   京                                    2010 年 2 月     咸宁

4、学院本科毕业论文（设计）：外文翻译  Oscillation, Instability and Control of Stepper Motors LIYU CAO and HOWARD M. SCHWARTZ Department of Systems and Computer Engineering, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada (Received: 18 February 1998； accepted: 1 December 1998)  Abstract

5、: A novel approach to analyzing instability in permanent-magnet stepper motors is presented. It is shown that there are two kinds of unstable phenomena in this kind of motor: mid-frequency oscillation and high-frequency instability. Nonlinear bifurcation theory is used to illustrate the relationship

6、 between local instability and mid-frequency oscillatory motion. A novel analysis is presented to analyze the loss of synchronism phenomenon, which is identified as high-frequency instability. The concepts of separatrices and attractors in phase-space are used to derive a quantity to evaluate the hi

7、gh-frequency instability. By using this quantity one can easily estimate the stability for high supply frequencies. Furthermore, a stabilization method is presented. A generalized approach to analyze the stabilization problem based on feedback theory is given. It is shown that the mid-frequency stab

8、ility and the high-frequency stability can be improved by state feedback. Keywords: Stepper motors； instability； nonlinearity； state feedback 1. Introduction Stepper motors are electromagnetic incremental-motion devices which convert digital pulse inputs to analog angle outputs. Their inherent stepp

9、ing ability allows for accurate position control without feedback. That is, they can track any step position in open-loop mode, consequently no feedback is needed to implement position control. Stepper motors deliver higher peak torque per unit weight than DC motors； in addition, they are brushless

10、machines and therefore require less maintenance. All of these properties have made stepper motors a very attractive selection in many position and speed control systems, such as in computer hard disk drivers and printers, XY-tables, robot manipulators, etc. 咸宁学院本科毕业论文（设计）：外文翻译  Although stepper

11、 motors have many salient properties, they suffer from an oscillation or unstable phenomenon. This phenomenon severely restricts their open-loop dynamic performance and applicable area where high speed operation is needed. The oscillation usually occurs at stepping rates lower than 1000 pulse/s, and

12、 has been recognized as a mid-frequency instability or local instability 1, or a dynamic instability 2. In addition, there is another kind of unstable phenomenon in stepper motors, that is, the motors usually lose synchronism at higher stepping rates, even though load torque is less than their pull-

13、out torque. This phenomenon is identified as high-frequency instability in this paper, because it appears at much higher frequencies than the frequencies at which the mid-frequency oscillation occurs. The high-frequency instability has not been recognized as widely as mid-frequency instability, and

14、there is not yet a method to evaluate it. Mid-frequency oscillation has been recognized widely for a very long time, however, a complete understanding of it has not been well established. This can be attributed to the nonlinearity that dominates the oscillation phenomenon and is quite difficult to d

15、eal with. 384 L. Cao and H. M. Schwartz Most researchers have analyzed it based on a linearized model 1. Although in many cases, this kind of treatments is valid or useful, a treatment based on nonlinear theory is needed in order to give a better description on this complex phenomenon. For example,

16、based on a linearized model one can only see that the motors turn to be locally unstable at some supply frequencies, which does not give much insight into the observed oscillatory phenomenon. In fact, the oscillation cannot be assessed unless one uses nonlinear theory. Therefore, it is significant t

17、o use developed mathematical theory on nonlinear dynamics to handle the oscillation or instability. It is worth noting that Taft and Gauthier 3, and Taft and Harned 4 used mathematical concepts such as limit cycles and separatrices in the analysis of oscillatory and unstable phenomena, and obtained some very instructive insights into the socalled loss of synchronous phenomenon.