Efficient control of a 3d overhead crane with simultaneous payload hoisting and wind disturbance: design, simulation and experiment

Abstract

This paper proposes a new control scheme for a 3-dimensional (3D) overhead crane having simultaneous payload hoisting and persistent wind disturbance. Control of the 3D crane system under those effects is highly challenging as it results in a high unwanted payload sway and inaccurate payload positioning. The proposed control structure which combines a new adaptive command shaping technique designed based on output signals and an integral sliding mode (ISM) control provides a precise crane positioning and low payload sway. The two independent controllers are designed such that they can practically be combined and implemented without affecting the overall stability of the closed-loop system. To test the effectiveness of the proposed method, simulations and experiments on a laboratory overhead crane are carried out under various conditions with different payload masses, various cable lengths, payload hoisting and external wind disturbance. Under all operating conditions, by comparing with an ISM control, the combined controller gives smoother and more satisfactory transient responses with two to four-fold reductions in the overall payload sway. In addition, the controller provides substantial reductions in the overall chattering of the control signal and sliding manifold which resulted in smoother control signals and system responses.