Second-order sliding mode control of 3D overhead cranes

This study proposes a second-order sliding mode controller for 3D overhead cranes in an extremely complicated operation. Three actuators composed of trolley moving, bridge travelling, and cargo-hoisting forces simultaneously drive five outputs comprising bridge motion, trolley translation, cable length, and two payload swing angles. Simulation and experiment were performed to investigate controller qualities. The proposed controller asymptotically stabilizes and consistently maintains system response even when some system parameters were widely varied.