Robust adaptive fuzzy control for a class of uncertain servomechanism systems

In this paper an adaptive fuzzy control technique is presented for a class of uncertain mechanical systems. The uncertainties are mainly caused by mechanical friction and unbalanced load. The fuzzy logic system is employed to compensate the effect of the friction and the unbalanced load. The technique does not require a complete mathematical model or a priori knowledge about the system structure. By combining with a sliding mode control strategy, the adaptive fuzzy controller guarantees the stability of the closed loop system as well as the convergence of tracking errors. In this work we also constructed an actual mechanical plant to test the performance of the designed controller. Experimental results verify that the dynamic behaviors of the proposed control systems are robust with regarding to uncertainties and significantly improve tracking accuracy over a conventional adaptive PD controller.