Fractional data-driven control for a rotary flexible joint system

Maher H Alsereihy,Ubaid M Al-Saggaf,Rachid Mansouri,Maamar Bettayeb,Khalid Munawar,Ibrahim M Mehedi

doi:10.1177/1729881421998580

Abstract

As one of the most promising topics in complex control processes, data-driven techniques have been widely used in numerous industrial sectors and have developed over the past two decades. In addition, the fractional-order controller has become more attractive in applied studies. In this article, a fractional integral control is implemented for a rotary flexible joint system. Moreover, an adjusted virtual reference feedback tuning (VRFT) technique is used to tune the fractional-order integrator. In this method, fractional integral control is designed based on state feedback control. Then, VRFT is adjusted and applied to the fractional integral controller. The effectiveness of the proposed adjusted VRFT method is discussed and presented through simulation and experimental results. The tracking performance of the rotary arm and the minimization of the vibration tip is evaluated based on the proposed method. In this article, the comparison of our proposed VRFT fractional scheme is made with the classical state feedback as well as a recently developed state feedback-based fractional order integral (SF-FOI) controller. The current investigations determine the performance improvement of our proposed scheme of comparable structure to the recent SF-FOI, with the introduction of the VRFT to the SF-FOI scheme.

Highlights

Over the last few years, flexible joint manipulators have received extensive attention in fractional control studies
A data-driven approach is proposed for a fractional-order integrator based on state feedback control
Performance of three control structures is demonstrated in this investigation

Summary

Introduction

Over the last few years, flexible joint manipulators have received extensive attention in fractional control studies. The VRFT scheme chooses the optimal parameter value for the fractional integral control (Ki and a). One idea to select a reference model is to use Bode’s ideal control loop.[13] In this work, unit feedback control with Bode’s ideal transfer function is calculated inside the plant. To obtain a desired fractional-order reference model, the first-order reference model is selected, and the value of l is selected so that 0 < l < 1.17 Note that the fractional integral is approximated using CRONE approximation.[22,23] The implementation of the proposed VRFT for fractional integral control based on state feedback control is summarized as follows: Step[1]: Design a controller in which Bode’s ideal transfer function-based fractional integral action is introduced as in the previous work.[16,17]. Note that tf must be greater than the time constant of the simulation or experiment (0.002 s)

20.5 SF-FOI-VRFT

Experimental results

Declaration of conflicting interests

Conclusion