Finite-time nonsingular terminal sliding mode control: A time setting approach

Abstract

This article proposes a combination of linear and nonlinear sliding surfaces to design a new structure for terminal sliding mode control, capable of accepting a definite final time as an input data. The structures of both single-input-single-output and multi-input-multi-output systems are expressed. The controller operates in two modes: first, reaching the states to linear sliding surface, defining control parameters and rise time; second, switching to nonlinear sliding surface and defining a convergence time. Sum of rise time and convergence time, both of which as inputs, sets the final time. The control gains are adaptively tuned and parameter uncertainty in dynamics is considered in the design. The proposed method is implemented theoretically and experimentally on Scout robot in point-to-point motion and trajectory tracking. The results are compared to conventional terminal sliding mode control and finite-time state-dependent Riccati equation to assess the improvement.