Hye-Won Lee, Myung-Il Roh, Seung-Ho Ham, "Control of the Underactuated Gantry Crane for the Block Erection Operation in the Shipyard", MIM(Manufacturing Modelling, Management and Control) 2019, Berlin, Germany, 2019.08.28-30
|Ships and offshore structures are constructed by joining several parts called blocks, which are the basic unit for production in the shipyard. The block erection operation includes block lifting, turnover, and lowering procedure, and generally conducted by cranes such as gantry crane. During the operation, the position and the orientation of the block should be precisely controlled by the crane to avoid any potential risks such as collision. However, the control of the gantry crane, which consists of crane girder, upper and lower trolleys, and several hooks is a challenging problem as it is an underactuated mechanical system. The underactuated mechanical system has a lower number of control inputs than the degrees of freedom, and many traditional non-linear control methods are not directly applicable to the control problem of inverse dynamics. In this study, the trajectory tracking control for the block erection and turn-over operation by the gantry crane is simulated. For the trajectory tracking control, the desired system outputs are modeled as servo constraints, and the differential algebraic equations (DAEs) for the underactuated system are formulated using the constraints. Then, the index reduction by the minimal extension method is adopted to reduce the index of the DAEs for stable numerical integration. Finally, the control method is applied to the multibody dynamics formulation, and the simulation based on the multibody dynamics is performed for the block erection and turn-over operation. The results show that the motion of the block is successfully controlled to the target trajectory during the operation.