Real-Time Speed Control of an Electrically Powered Wheelchair by Using Fractional Order Model Reference Adaptive System Control

Abstract

In this study, speed and direction angle control technique based on the fractional order model reference adaptive system (FO-MRAS) are proposed for controlling an electrically powered wheelchair (EPW) system for the first time in the literature. The model reference adaptive system (MRAS) technique has been used to achieve the estimated value of any system's velocity information. In general, the control of the MRAS technique is usually performed by the PI based controller. However, the classical PI controllers are unable to meet the demands of high precise trajectory control during the motion. In this study, to increase the effectiveness of the PI based MRAS controller, this technique is combined with a fractional-order (FO) calculus to obtain an accurate and a robust trajectory tracking performance for an EPW. The proposed FO-MRAS controller has been compared experimentally with the conventional PI based MRAS method to show the effectiveness of using FO-MRAS method in terms of trajectory tracking accuracy and error levels. The experimental outcomes demonstrate that the proposed FO-MRAS controller gives a better trajectory tracking performance as well as having a smaller speed error.