Fuzzy controller for mechanical systems

In many applications of motion control, the occurrence of nonlinear friction constitutes a fundamental obstacle in the design of satisfactory controlling systems. Since it is seldom possible to obtain a relatively accurate model of resistance to motion, a solution more and more often applied in practice is to introduce approaches that incorporate the inevitable imprecisions of the model in the form of uncertainties. This paper deals with the time-optimal (minimum-time) control for mechanical systems with a discontinuous and uncertain model of resistance to motion. A fuzzy approach is used in the design of suboptimal feedback controllers, convenient in practice thanks to their many advantages, especially in respect to robustness.