Novel Sliding Mode Vibration Controller With Simple Model-Free Design and Compensation for Actuator’s Uncertainty

Ansei Yonezawa,Itsuro Kajiwara,Heisei Yonezawa

doi:10.1109/access.2020.3047810

Ansei Yonezawa, Itsuro Kajiwara + Show 1 more

Open Access

https://doi.org/10.1109/access.2020.3047810

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Abstract

This study proposes an active vibration control method with a simple design process without using a plant model. The proposed method is robust against the actuator’s parameter uncertainty. To realize model-free control of the controlled object, a virtual structure represented by a single-degree-of-freedom system is inserted between the controlled object and the actuator. A controller, which compensates for the uncertainties of the actuator’s parameters, is designed using the sliding mode control theory. By designing a controller using a model composed of the virtual structure and the actuator, model-free design can be easily performed with few design variables. After the virtual structure is introduced, the controller can be designed using the same process as a traditional model-based control theory. An advantage of the sliding mode control system is it can provide high robustness against the uncertainty in the actuator’s parameters. The robustness to the actuator’s uncertainty and vibration suppression performance of the proposed method are verified by controlling a two-degree-of-freedom time-varying system. Finally, the applicability of the proposed method to an actual mechanical system is confirmed by vibration control experiments.

Highlights

Vibration control technologies have become increasingly important to improve performance, downsize, and reduce the weight of mechanical systems in recent years
The proposed method indirectly suppresses vibration without a model of the actual controlled object by inserting a virtual structure defined as a SDOF system between the actuator model and the controlled object
A sliding surface which minimizes the fluctuations of the state on the sliding surface was designed for the system composed of the actuator and virtual structure

Summary

INTRODUCTION

Vibration control technologies have become increasingly important to improve performance, downsize, and reduce the weight of mechanical systems in recent years. The actuator’s parameter uncertainty in the model-free vibration control system using the virtual structure proposed in this study satisfies the matching condition. This study constructs a model-free vibration control method with a simple controller design procedure and high robustness to the actuator’s parameter uncertainty. The proposed method accomplishes the model-free design procedure using the virtual structure and compensates the actuator’s parameter uncertainty using SMC. Based on SMC theory and the Lyapunov function method, a model-free controller with robustness against the actuator’s uncertainty is designed without using any parameters of the controlled object. Compared to the traditional model-free approaches such as NNs and fuzzy inference, the proposed method, which derives a controller by using the virtual structure instead of actual plant models, does not require the complicated design processes with a lot of time and preparations. In actual feedback control, the observed output is the vibration of the actual controlled object x1, which is almost the same as xv by (4)

DESIGN OF THE VIRTUAL STRUCTURE

CONTROL INPUT DESIGN AND REACHING LAW

Findings

CONCLUSION