Fuzzy tuning sliding mode control of transporting for an overhead crane

As an effective transportation tool, overhead crane is considered for transporting payloads effectively and safely. Two sliding mode controllers are designed for two control inputs of overhead crane system: one is proposed to control hoisting and lowering suspended payload, and the other 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 tuning algorithm is proposed to dynamically adjust the coupling factor between the two DOFs to improve system performance. These two controllers guarantee that the payload track the predefined trajectory, are transported safely as fast and accurately as possible with minimum swing angle, and are placed at the appropriate position. Simulations are performed with these two proposed sliding mode controllers and the results show their effectiveness.