Adaptive sliding mode control using monitoring functions

Abstract

In this chapter, we propose an adaptive sliding mode control approach based on monitoring functions, to deal with disturbances of unknown bounds. An uncertain linear system is considered as well as a quite general class of non-smooth disturbances. Global tracking is demonstrated using only output feedback. The proposed adaptation method is able to make the control gain less conservative, but large enough when the disturbance grows and allows it to decrease if the latter vanishes, leading to reduced chattering effects. Simulations are presented to show the potential of the new adaptation scheme in this adverse scenario of possibly growing, temporarily large, or vanishing disturbances.