Motor speed control by using a fuzzy logic model reference adaptive controller

DC motors are widely used in industry for various applications. At present, most of the existing industrial speed controllers for DC motor drives are largely based on classical approaches which do not guarantee satisfactory performance against machine parameter variations. Hence there is the need for adaptive control among which is Model Reference Adaptive Control (MRAC). Since its first appearance and subsequent intensive researches to apply MRAC to speed control, so far it has not been widely accepted in the industrial practice. It is thought partly due to the fact that the MRAC speed control system do not achieve consistent satisfactory performance over wide range of speed demand, especially at low speed, and there is no defined rule to guide designers to choose the adaptation gains. In this paper, a Fuzzy Logic Model Reference Adaptive Control (FLMRAC) is proposed where the adaptation gains are determined by the aid of fuzzy logic technique to maintain satisfactory response irrespective of the magnitude of the inputs. The FLMRAC is applied to control the speed of a DC motor drive and its superiority over conventional MRAC is demonstrated.