A Second-Order Sliding Mode Control of Switched Reluctance Motor

Abstract

This paper proposes a straightforward second-order sliding mode control (SMC) approach to minimize current distortions and torque ripples of a switched reluctance motor (SRM). In the first step, conventional SMC is briefly recalled and detailed. Then, a special attention is paid to the synthesis and the implementation of a second-order (SM2) approach. Stability analysis of these two approaches is ensured. It will be shown that the proposed second-order SM approach offers a lower harmonic distortion of the motor currents, a reduction of the torque ripples, and the elimination of chattering phenomena. The effectiveness of the proposed SM2 is verified by simulation results then validated by experiments.     

Chattering‐free sliding mode control for a class of nonlinear mechanical systems

Second‐order sliding mode control (2‐smc) and dynamic sliding mode control (dsmc) eliminate the disturbing characteristic of chattering in static sliding mode control under the assumption that the derivative of the sliding surface is available or complex inequalities at the acceleration level can be constructed. In this paper, passivity‐based adaptive and non‐adaptive chattering‐free sliding mode controllers are proposed assuming that the upper bound of the norm of the derivative of the sliding surface is available, a weaker and easy to implement assumption in comparison to those of 2‐smc and dsmc. The closed‐loop system accounts explicitly for the invariance condition without reaching phase, and therefore for a desired transient response with global exponential convergence of tracking errors. Preliminary experiments are presented. Copyright © 2001 John Wiley & Sons, Ltd.     

Frequency domain analysis of noise‐induced control chattering in sliding mode controls

The switching sliding mode control is robust with respect to disturbances, but its control signal has the so‐called chattering phenomenon that can damage the actuator and the system. To remove the chattering phenomenon, it has been proposed that one can use a continuous boundary layer design to replace the switching control. This paper shows, via the frequency domain analysis, that even when a boundary layer design is used, stochastic measurement noise can still induce the chattering phenomenon in control signals. Such noise‐induced chattering is almost unavoidable in noisy environments when the control accuracy requirement is high. Copyright © 2010 John Wiley & Sons, Ltd.     

Fuzzy discontinuous term for a second order asymptotic DSMC: An experimental validation on a chemical reactor

In this work, a second order asymptotic discrete sliding mode control with a fuzzy supervised discontinuous term is proposed. The on line variation of the discontinuous term amplitude enhances the convergence rapidity of the sliding function and reduces the chattering phenomenon. These improvements are shown by a numerical simulation and by a real time temperature control of a chemical reactor. Good performances in terms of chattering suppression and reaching phase duration's reduction are noted. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society     

永磁直线电机伺服系统模型参考离散滑模控制

针对高精度永磁直线同步电机(PMLSM)伺服系统存在的参数变化、端部效应和负载扰动等诸多不确定性问题，设计了模型参考离散滑模(MRDSMC)位置跟踪控制器.将伺服问题转化为调节问题，并采用一步延迟扰动近似来补偿未知扰动，此外，为了抑制由高频未建模动态引起的抖振，在MRDSMC设计中加入低通滤波器.理论推导与仿真结果表明，该方案能有效地抑制PMLSM伺服系统的参数变化和阻力扰动的影响，具有很强的鲁棒位置跟踪性能.     

建筑结构离散变结构控制的组合趋近律方法

抖振问题是离散变结构控制方法应用于土木工程结构振动控制中的突出障碍。为了能较好地解决离散变结构控制的抖振问题,采用了一种含有组合趋近律的离散变结构控制方法对地震作用下建筑结构的振动控制问题进行了研究。依据所采用的组合趋近律推导了控制律的表达式,并且针对最大控制力受到限制时的情况,引入了饱和控制方法。以一个3层剪切型建筑结构模型为例验证所提出的离散变结构控制方法的有效性,算例分析结果表明,所提出的离散变结构控制方法能够有效地减小结构的地震峰值响应,同时控制系统的抖振很小,从而保证控制系统具有稳定的性能。     

基于滑模变结构的倒立摆系统稳定控制

利用滑模变结构控制对一级倒立摆系统进行了有效控制.首先对一级倒立摆系统的模型进行线性化处理,再利用滑模变结构控制方法对此模型中摆的镇定、台车位置的调节和系统参数不确定性设计了具体的控制规律,并使用饱和函数的方法抑制系统的抖振.最后在Matlab/Simulink上进行了仿真实验,实验结果说明滑模变结构控制方法是有效的.     

不确定系统离散变结构控制及在位置伺服系统中的应用

研究有界不确定离散时间系统的变结构控制设计问题.对利用传统离散趋近律设计变结构控制器时出现的稳态抖振现象进行分析,提出一种能有效减弱抖振的控制策略,并将研究结果用于设计某位置伺服系统变结构控制器.理论分析及仿真结果表明,所设计的控制器可以有效减弱抖振,并使伺服系统具有良好的跟踪能力和很强的鲁棒性.     

APPLICATIONS OF A SUB-OPTIMAL DISCONTINUOUS CONTROL ALGORITHM FOR UNCERTAIN SECOND ORDER SYSTEMS

In this paper the authors present a couple of algorithms, one for the case of analogue devices and one for the case of digital devices, that realize a nonlinear controller performing a second order sliding mode. These algorithms allow the finite time stabilization of uncertain second order nonlinear systems with incomplete state measurements. Two different applications of this technique are presented. In the first we deal with the problem of chattering avoidance in sliding mode control of uncertain nonlinear systems without using any observer. The second application shows that the developed algorithms allow the hybrid force/position continuous control of a two arms constrained planar manipulator even when the accelerations are not available. © 1997 by John Wiley & Sons, Ltd.     

SMOOTH SLIDING CONTROL OF UNCERTAIN SYSTEMS BASED ON A PREDICTION ERROR

This paper addresses the problem of designing sliding control of uncertain systems which are free of chattering and result in smooth control signals. Both state and output feedback are considered. The proposed approach relies on some appropriate prediction error and can be easily applied to modify the usual state feedback VSC for chattering avoidance. It can also be applied for devising new output feedback VSC laws. The robustness improvement, with respect to unmodelled dynamics, even allows one to reconsider the so far rejected utilization of approximate differentiators for VSC output feedback. The theoretical results are illustrated by simulations. An experimental evaluation is briefly discussed. © 1997 by John Wiley & Sons, Ltd.