3 - Adaptive variable structure control

Abstract

Publisher Summary This chapter proposes a new adaptive variable structure scheme for model reference adaptive control (MRAC) problems for plants with unmodeled dynamic and output disturbance. The chapter provides the complete version of adaptive variable structure design for solving the robustness and performance of the traditional MRAC problem with arbitrary relative degree. A detailed analysis of the closed-loop stability and tracking performance is given. It is shown that without any persistent excitation the output-tracking error can be driven to zero for relative degree-one plants, and to a small residual set asymptotically for plants with any higher relative degree. Furthermore, under suitable choices of initial conditions on control parameters, the tracking performance can be improved, which is hardly achievable by the traditional MRAC schemes, especially for plants with uncertainties.