TRAJECTORY TRACKING CONTROL FOR A MECANUM WHEELED MOBILE ROBOT USING HIGHER ORDER SLIDING MODE CONTROLLER COMBINED WITH DISTURBANCE OBSERVER FOR MODEL UNCERTAINTIES

Abstract

Mecanum-wheeled mobile robots are capable of moving in any direction without changing the heading of the robot body. However, due to their nonlinear characteristics and slippage, controlling Mecanum robots requires advanced control methods. Sliding Mode Control (SMC) is a powerful nonlinear control technique that is commonly applied to omnidirectional mobile robots using Mecanum wheels. SMC ensures accurate trajectory tracking and stability in environments with disturbances and uncertainties, while also overcoming many limitations of other control methods. In this paper, the author proposes a Higher Order Sliding Mode Control - HOSMC combined with an uncertain function identifier, which is an improvement over traditional Sliding Mode Control (SMC), for trajectory tracking control of Mecanum-wheeled mobile robots. Although SMC provides good robustness against disturbances and uncertainties, it converges asymptotically and may cause chattering. The integration of a disturbance observer with the Higher Order Sliding Mode Control addresses these drawbacks by adapting to nonlinear components and reducing chattering, thus enabling smoother and more accurate control performance.