Implicit Discrete-Time Adaptive First-Order Sliding Mode Control with Predefined Convergence Time

Abstract

This brief proposes an adaptive first-order sliding mode control (SMC) with a predefined convergence time in a digital framework. It is based on an implicit Euler discretization of the set-valued signum function in SMC and a time-dependent adaptive gain scheme. Two typical cases are discussed and their stability analysis is provided, simple affine systems with first-order SMC and LTI systems with equivalent control-based sliding mode control (ECB-SMC), both in the presence of unknown perturbations. Numerical simulations show that, compared with the conventional SMC, the proposed implicit discrete-time SMC guarantees the convergence of the states within any predefined arbitrary time. © 2004-2012 IEEE.