The Effective Chattering Suppression Technique with Adaptive Super-Twisted Sliding Mode Controller Based on the Quasi-Barrier Function; An Experimentation Setup

Rajko Svečko,Andrej Sarjaš,Dušan Gleich

doi:10.3390/app10020595

Abstract

The paper presents a modified adaptation algorithm for the super-twisted sliding mode controller structure, based on the barrier function method. The aim of the paper is to reduce the chattering phenomena of the controller, which limited the use of the controller in different applications. The chattering phenomena are mostly caused by the overestimated controller gain due to the assumed disturbance bound, which is mostly inaccurate. The chattering origins are also the unknown parasitic dynamic of the system and discrete implementation of the controller. The proposed method with the Barrier function is used to alleviate the chattering phenomena with the adaptation of the controller parameters. The novelty of the method is using an adaptation procedure only in prescribed regions of the sliding variable, otherwise, the adaptation is not used. The advantage of the method is the proper rejection of the chattering phenomena in the vicinity of the manifold of the sliding variable, regardless of the order of the system. With proper selection of the adaptation boundary, the effect of discrete implementation, especially for a longer sampling time of the algorithm, can be suppressed efficiently, as well as the effect of the overestimated controller parameters. The proposed method is verified and compared with a standard version of the algorithm in simulation and real-time environments.

Highlights

Electro-mechanical systems (EMs) are used widely in various industrial and home applications.The main advantage of the system is its high accuracy, high reliability, robustness, and low power to weight ratio
Before we describe the proposed adaptation strategy, the barrier function (BF)’s definition needs to be presented
The simulation was performed by the Feedforward integration technique for the plant discretization and preselected solver-integration time, Tsim = 0.1 ms

Summary

Introduction

Electro-mechanical systems (EMs) are used widely in various industrial and home applications.The main advantage of the system is its high accuracy, high reliability, robustness, and low power to weight ratio. Electro-mechanical systems (EMs) are used widely in various industrial and home applications. The EMs are unmissable components of the robotic, machine tool and feeder systems. The control design strategies for such kinds of systems mostly use a 2DOF control structure with inner and outer feedback loops [1,2,3]. The aforementioned special 2DOF approach is well-known, like the disturbance-observer algorithm (DBA), and can be found in different structures within several control paradigms [4,5]. Most of the approaches use a nominal model in the inner feedback loop. The more convenient and straightforward method of DBA is a Q-filter design, and the more advanced is based on a robust internal compensator (RIC) [2,5]

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Results

Conclusion