An Experimental Study on Model Reference Adaptive Control with Fractional Order Adjustment Rules for DC Rotor Control

Abstract

Due to changing dynamics of flight conditions, Model Reference Adaptive Control (MRAC) strategies find application in flight control. This paper demonstrates an application of Fractional Order Adjustment Rule MRAC (FOAR-MRAC) with the modification of error dead zone for adaptive PID control of DC rotor. Previously, Vinagre et al. (2002) modified the conventional MRAC structure by using fractional order integrator to improve tracking performance. In the current experimental study, we employ a model approximation error modified by using a piecewise linear, near-zero dead zone function to manage adaptation process in practical application. When the control system approximates to reference model, adaptation process can be interrupted. This modification improves quasi-stabilization of updating rule by omitting low level errors and contributes to applicability of MRAC in real applications. Moreover, the FOAR-MRAC structure is used to implement adaptive PID control of DC rotor of Twin Rotor Multi-Input Multi-Output (MIMO) System (TRMS). Simulation and experimental results obtained for TRMS setup are presented to show effectiveness of the proposed method.