Tracking Control for an Underactuated Two-Dimensional Overhead Crane

In this paper, the tracking control problem is considered for the payload transportation with an underactuated two-dimensional overhead crane. Two sliding mode controllers are designed to perform the trajectory tracking. One is proposed to control hoisting and lowering the suspended payload, and the other one is proposed to control both trolley positioning and payload swaying. Considering the second sliding mode controller is used to control two degrees of freedom (DOFs), a fuzzy inference algorithm is proposed to dynamically adjust the coupling factor between the two DOFs. The two controllers make the payload track a predefined trajectory and be safely transported as fast and accurately as possible with a small swing angle, and then place the payload at the desired position. Simulations are performed with the proposed controllers and the results show their effectiveness.