Adaptive uncertainty and disturbance estimator based model reference adaptive dynamic sliding mode control for overhead cranes

This paper proposes a model reference adaptive dynamic sliding mode control (MRASMC) scheme with an adaptive uncertainty and disturbance estimator (AUDE), the scheme is then applied to two-dimensional overhead cranes control with uncertainties, to ensure the payload can be transported to the desired position rapidly while its swing angle can be eliminated simultaneously. Firstly, a desired reference model for improving transient performance is designed. More specifically, a novel chattering-free reaching law along with adaptive integral sliding mode surface is designed to achieve fast convergence of system state variable errors, thereby improving system transient performance. In addition, the designed novel moving sliding mode surface can adjust its slope in real time according to the state variable errors. Moreover, to suppress the uncertainties occurring in overhead cranes system, such as matched disturbances, unmatched disturbances. An adaptive uncertainty and disturbance estimator (AUDE) technique is employed to estimate these disturbances, then the estimated disturbances are taken as feedforward control term to overcome the chattering phenomenon. The stability and convergence of the control system is strictly analyzed using Lyapunov theory. Simulation results are presented to illustrate the effectiveness of the proposed controller.