scholarly journals New Time-Varying Sliding Surface for Switching Type Quasi-Sliding Mode Control

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3811
Author(s):  
Katarzyna Adamiak ◽  
Andrzej Bartoszewicz
Keyword(s):  
Sliding Mode Control ◽  
Continuous Time ◽  
Sliding Mode ◽  
Representative Point ◽  
Time Varying ◽  
Sliding Surface ◽  
External Disturbances ◽  
Mode Control ◽  
Switching Type ◽  
Time Systems

This study considers the problem of energetical efficiency in switching type sliding mode control of discrete-time systems. The aim of this work is to reduce the quasi-sliding mode band-width and, as follows, the necessary control input, through an application of a new type of time-varying sliding hyperplane in quasi-sliding mode control of sampled time systems. Although time-varying sliding hyperplanes are well known to provide insensitivity to matched external disturbances and uncertainties of the model in the whole range of motion for continuous-time systems, their application in the discrete-time case has never been studied in detail. Therefore, this paper proposes a sliding surface, which crosses the system’s representative point at the initial step and then shifts in the state space according to the pre-generated demand profile of the sliding variable. Next, a controller for a real perturbed plant is designed so that it drives the system’s representative point to its reference position on the sliding plane in each step. Therefore, the impact of external disturbances on the system’s trajectory is minimized, which leads to a reduction of the necessary control effort. Moreover, thanks to a new reaching law applied in the reference profile generator, the sliding surface shift in each step is strictly limited and a switching type of motion occurs. Finally, under the assumption of boundedness and smoothness of continuous-time disturbance, a compensation scheme is added. It is proved that this control strategy reduces the quasi-sliding mode band-width from O(T) to O(T3) order from the very beginning of the regulation process. Moreover, it is shown that the maximum state variable errors become of O(T3) order as well. These achievements directly reduce the energy consumption in the closed-loop system, which is nowadays one of the crucial factors in control engineering.

scholarly journals Adaptive Moving Sliding Mode Control for SISO Systems: Application to an Electropneumatic System

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Assil Ayadi ◽  
Soufien Hajji ◽  
Mohamed Smaoui ◽  
Abdessattar Chaari
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Sliding Surface ◽  
External Disturbances ◽  
Single Input Single Output ◽  
Mode Control ◽  
Single Output ◽  
Single Input ◽  
Electropneumatic System ◽  
Siso Systems

This paper aims to propose and develop an adaptive moving sliding mode controller (AMSMC) that can be applied for nonlinear single-input single-output (SISO) systems with external disturbances. The main contribution of this framework consists to overcome the chattering phenomenon problem. The discontinuous term of the classic sliding mode control is replaced by an adaptive term. Moreover, a moving sliding surface is proposed to have better tracking and to guarantee robustness to the external disturbances. The parameters of the sliding surface and the adaptive law are deduced based on Lyapunov stability analysis. An experimental application of electropneumatic system is treated to validate the theoretical results.

Finite-time H∞ sliding mode control of uncertain T-S fuzzy system with time-varying delay based on observer

2021 ◽  
Vol 40 (1) ◽  
pp. 983-999
Author(s):  
Huan Li ◽  
Pengyi Tang ◽  
Yuechao Ma
Keyword(s):  
Sliding Mode Control ◽  
Finite Time ◽  
Sliding Mode ◽  
Linear Matrix ◽  
Time Interval ◽  
Sliding Mode Controller ◽  
Time Varying ◽  
Sliding Surface ◽  
State Estimator ◽  
Mode Control

In this paper, a class of observer-based sliding mode controller is designed, and the finite-time H∞ control problem of uncertain T-S fuzzy systems with time-varying is studied. Firstly, an integral-type sliding surface function with time-delay is devised based on the state estimator, and sufficient criteria of finite-time bounded and finite-time H∞ bounded can be obtained for the T-S systems. Moreover, the proposed sliding mode control law is integrated to ensure the dynamics of controlled system into the sliding surface in a finite-time interval. Then, according to the linear matrix inequalities (LMIs), the desired gain matrices of fuzzy sliding mode controller and state estimator are derived. Finally, effectiveness gives some illustrative examples may be used to display the value of the current proposed method as well as a significant improvement.

PMLSM Nonlinear Integral Sliding Mode Control Based on Gain Time- Varying Reaching Law

2020 ◽  
Vol 13 (5) ◽  
pp. 743-750
Author(s):  
Chao Zhang ◽  
Liwei Zhang ◽  
Bo Peng ◽  
He Zhao
Keyword(s):  
Sliding Mode Control ◽  
Permanent Magnet ◽  
Sliding Mode ◽  
Dynamic Performance ◽  
Linear Motor ◽  
Time Varying ◽  
Sliding Surface ◽  
Reaching Law ◽  
Mode Control ◽  
Global Robustness

Background: The permanent magnet synchronous linear motor is a strongly coupled, nonlinear system. It has been applied in many fields, especially in the field of machining lathes and rail transportation. In order to ensure the permanent magnet synchronous linear motor has good dynamic performance and robustness, sliding mode control is gradually applied to the control system of permanent magnet synchronous linear motor. However, in the traditional sliding mode control, the convergence speed is slow, and the robust performance is poor when the sliding surface is not reached. Objective: The main purpose of this paper is to improve the dynamic performance and robustness of the permanent magnet synchronous linear motor during the process of approaching the sliding surface. Methods: Firstly, the type of nonlinear curve with "small error reduction, large error saturation" is introduced to design a nonlinear integral speed controller with global robustness. Secondly, the gain rate time-varying reaching law is introduced to reduce "chattering". Finally, using a symbolic tangent function instead of a sign function in designing a sliding mode observer reduces fluctuations in load observations. Results: Finally, the correctness and effectiveness of the control method are proved by simulation. Conclusion: The results of the simulation show that the nonlinear integral sliding mode controller based on gain time-varying reaching law is shown to have good global robustness and dynamic performance.

Sliding-Mode Control of Large-Scale Fuzzy Interconnected Systems

2017 ◽  
pp. 176-194
Keyword(s):  
Sliding Mode Control ◽  
Discrete Time ◽  
Continuous Time ◽  
Large Scale ◽  
Sliding Mode ◽  
Interconnected Systems ◽  
Mode Control ◽  
Continuous Time Systems ◽  
Time Systems ◽  
Design Result

This chapter will study the decentralized SMC for large-scale fuzzy interconnected systems. The design result on the decentralized sliding mode control of the continuous-time systems is derived in terms of LMIs. We also extend the result to discrete-time systems. Two simulation examples are provided to validate the advantage of the proposed methods.

A Variable-Gain Discrete Sliding Mode Control Strategy With PID-Type Sliding Surface for an Ultra-Precision Wafer Stage

2016 ◽  
Author(s):  
Min Li ◽  
Yu Zhu ◽  
Kaiming Yang ◽  
Chuxiong Hu ◽  
Haihua Mu
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Frequency Noise ◽  
Main Concern ◽  
Sliding Surface ◽  
External Disturbances ◽  
Variable Gain ◽  
Mode Control ◽  
Ultra Precision ◽  
Discrete Sliding Mode Control

The ultra-precision wafer stage is an important mechatronic unit in a wafer scanner for manufacturing integrated circuits while its motion control is still the main concern. To overcome the performance-limiting trade-offs of fixed-gain discrete sliding mode control (DSMC), a novel variable-gain DSMC strategy with PID-type sliding surface is proposed for an ultra-precision wafer stage. Specially, PID-type sliding surface is employed to avoid the steady-state error induced by external disturbances. Via the exponential reaching law approach, DSMC with PID-type sliding surface is synthesized. Variable-gain control methodology is newly introduced into DSMC, and the control gain varies with the trajectory phase that the wafer stage is in and the tracking error magnitude. Performance assessment on a developed wafer stage validates that with nano-scale tracking accuracy the proposed strategy not only improves the low-frequency tracking ability without the amplification of high-frequency noise, but also possesses the excellent robustness to external disturbances.

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