两相混合步进电机开环性能优化与闭环控制研究

发布时间：2018-01-14 02:07

本文关键词：两相混合步进电机开环性能优化与闭环控制研究　出处：《华南理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：步进电机是一种在工业上应用非常广泛的伺服系统，但是由于其自身固有的缺陷以及传统控制方式的不足使得它在应用中会存在一些不可忽略的问题，例如开环启动时容易失步或者堵转、低速时平稳性较差以及中高速时快速响应能力和抗负载扰动能力欠佳等。这在一定程度上使步进电机伺服系统在工业中的应用受到制约。因此，寻找更有效的控制方式对于步进电机的实际控制系统具有非常深远的现实意义。针对步进电机开环启动容易失步等问题，本文提出了一种改进的指数型速度曲线。通过对步进电机的运行特性进行分析以及对步进电机速度曲线的研究，，本课题在指数型速度曲线上加以改进，从而设计出优化的指数型速度曲线。改进后的速度曲线既保留了原本指数型速度曲线的优点又易于在工业应用上实现。本文还通过仿真和实验说明了此速度曲线的有效性。本课题采用滑模变结构控制方法来提高混合步进电机的抗负载扰动能力。滑模变结构以其极高的鲁棒性而受到广大学者的关注。计算机控制技术的发展为滑模变结构控制的应用提供了良好的发展机遇，而DSPIC和ASIC的快速发展和完善，使滑模变结构在电机速度、位置控制系统方面的应用具有更加优良性能。然而这种控制方法存在着系统抖振，因此，在基于滑模控制器的电机控制系统中，如何削弱抖振是研究者应该高度重视的问题。减少抖振的其中一种方法是趋近律法，这种方式可以改善滑模运动的动态特性，从而削弱抖振。本文分析了若干种典型趋近律的数学模型及其特性，并针对一般指数趋近律在靠近滑模面时抖振较大、在滑动模态区时收敛性较差等问题，提出了一种改进的指数趋近律，即具有时变切换增益的指数趋近律。该方法在原来固定切换增益的基础上增加了时变修正因子，使得切换增益在滑模运动阶段随着系统状态减小而衰减至零，从而削弱了系统抖振、提高了系统收敛性、改善了系统运动品质。最后，本文针对步进电机滑模控制系统进行了仿真和实验研究，仿真与实验结果表明，与传统PI控制器相比，基于滑模算法的步进电机控制系统具有响应速度快以及鲁棒性高等优势。同时实验还说明了该改进的指数型趋近律方法能有效地削弱系统抖振同时还使系统可靠地收敛于原点。
[Abstract]:Stepping motor is a kind of servo system which is widely used in industry. However, due to its inherent defects and the shortcomings of traditional control methods, there are some problems that can not be ignored in its application. For example, when the open loop starts, it is easy to lose step or block the turn. The stability at low speed and the ability of fast response and anti-load disturbance at medium and high speed are poor, which restricts the application of stepper motor servo system in industry to a certain extent. It is of great practical significance to find more effective control methods for the practical control system of stepping motor. An improved exponential speed curve is proposed to solve the problem that the stepping motor is easy to lose step when it starts in open loop. By analyzing the running characteristics of the step motor and studying the speed curve of the step motor. This subject is improved on the exponential velocity curve. Thus, the optimized exponential velocity curve is designed. The improved speed curve not only retains the advantages of the original exponential speed curve, but also is easy to be realized in industrial application. The paper also shows the speed curve by simulation and experiment. The effectiveness of. In this paper, sliding mode variable structure control method is used to improve the anti-load disturbance ability of hybrid stepping motor. Sliding mode variable structure has attracted the attention of many scholars because of its extremely high robustness. The development of computer control technology is the development of sliding mode. The application of variable structure control provides a good opportunity for development. With the rapid development and perfection of DSPIC and ASIC, the application of sliding mode variable structure in motor speed and position control system has better performance. However, there is system buffeting in this control method. Therefore, in the motor control system based on sliding mode controller, how to reduce buffeting is a problem that researchers should pay great attention to, and one of the ways to reduce buffeting is to approach the law. This method can improve the dynamic characteristics of sliding mode motion and weaken buffeting. In this paper, the mathematical models and characteristics of some typical convergence laws are analyzed, and the general exponential approach law is larger when it is near the sliding mode surface. In this paper, an improved exponential approach law is proposed to solve the problem of poor convergence in sliding mode region. In this method, the time-varying correction factor is added to the original fixed switching gain, which makes the switching gain attenuate to zero with the decrease of the system state in the sliding mode phase. Thus, the chattering of the system is weakened, the convergence of the system is improved, and the quality of the system motion is improved. Finally, the simulation and experimental research on the sliding mode control system of stepping motor are carried out. The simulation and experimental results show that compared with the traditional Pi controller. The step motor control system based on sliding mode algorithm has the advantages of fast response speed and high robustness. The experiments also show that the improved exponential approach law method can effectively weaken the buffeting of the system and make the system reliable. The ground converges to the origin.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM383.6

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