Robust Positioning Control Law for a 3D Underactuated Crane System

Abstract An existent risk in automated gantry cranes is that the payload, attached to the end of the suspension cable, can swing randomly due to the acceleration of the trolley, by the perturbation of external disturbances, among other unpredictable factors. In this paper, we design second order sliding mode payload position controllers via collocated partial feedback linearization to address such problem. In particular, a super-twisting controller was synthesized to drive the position of the trolley to the desired point, and a twisting controller was derived to stabilize the height of the cable. The proposed sliding surface makes the zero dynamics locally asymptotically stable. We tested the results on an experimental gantry crane system which is affected by matched and mismatched disturbances.