Terminal tracking control of mobile harbor crane subject to actuator saturation

In this paper, the tracking control of mobile harbor crane at the terminal time with considering actuator saturation is proposed for accurate position control. During loading/unloading operation of mobile harbor crane in open-sea condition, it is difficult to control the container position on the desired position due to an unwanted swing motion and a continuous movement of container ship caused by external disturbances such as wave and wind. Several researches have been already studied to develop to suppress the swing motion of ship-board crane system but the tracking problem to moving target is emerging newly in ocean engineering. The tracking control system of ship-board crane should be designed although this system has complex dynamics, various external disturbances, and the limited power of actuators. In the proposed control system, constrained model predictive control(MPC) with changing input and output constraints in real-time is applied for the only terminal tracking control. The numerical simulations are performed to verify the overall terminal tracking control performances of the proposed constrained MPC.