Transient Improvement of Variable Structure Controlled Systems Via Multi-Model Switching Control

A solution is presented in this note to the problem of improving the transient response of a MIMO nonlinear system driven by a VSC law, in the presence of large plant uncertainties. The proposed control scheme is given interms of a supervisor and of a deterministic time-varying compensator, built using sliding-mode control and assuming a finite number of possible different configurations. The task of the supervisor is that of guiding the scanning among the elements of the family, according to a suitably defined experimental test. The proposed approach noticeably improves the performances of sliding-mode control in the presence of large plant uncertainties, and has the substantial advantage of a great simplicity of design and implementation. Moreover, even in case of a large number of configurations constituting the stabilizing family, it has been shown to be able to attain the stabilizing controller in an arbitrarily small time interval. Another appealing feature of the paper consists in the inclusion of an intelligent adaptation scheme in the control algorithm.