Type-2 fuzzy load regulation of a servomechanism with backlash using only motor position measurements

This paper addresses the analysis and design of an observer in order to ease the difficulty of working with various variables for the design of type-2 fuzzy controllers. In this paper Fuzzy Lyapunov Synthesis, based on the observed system, is extended to the design of type-2 fuzzy logic controllers for nonsmooth mechanical systems. The output regulation problem for a servomechanism with nonlinear backlash is proposed as a case of study. The problem at hand is to design a feedback controller so as to obtain the closed-loop system in which all trajectories are bounded and the load of the driver is regulated to a desired position while also attenuating the influence of external disturbances. The servomotor position is the only measurement available for feedback; the proposed extension is far from trivial because of the nonminimum phase properties of the system.