An Integral Sliding–Mode Robust Regulation for Constrained Three–Wheeled Omnidirectional Mobile Robots

Abstract

This paper proposes a solution to the regulation problem for a three–wheeled omnidirectional mobile robot (OMR) with input saturation, state constraints, parameter uncertainties, and external disturbances. The proposed robust control is composed of a linear and a nonlinear part, which can be designed independently due to the use of an integral sliding–mode control approach. The linear control deals with the input saturation, the state constraints, and the parameter uncertainties, while the nonlinear part is also saturated and can compensate the effect of some matched disturbances. Also, a safe set where the system trajectories do not transgress the state constraints and input saturation is provided. The proposed scheme guarantees asymptotic convergence to zero of the regulation error coping with the system constraints and disturbances. A constructive and simple method, based on linear matrix inequalities (LMIs), is proposed to compute the controller gains. Some simulation results illustrate the feasibility of the proposed scheme.