Underactuated crane control for the automation of block erection in shipbuilding

Block erection is one of the most common operations for moving a block in a shipyard. During the operation, the position and orientation of the block need to be precisely controlled to avoid accidents. However, the operation is performed manually, which is inefficient and potentially dangerous. Furthermore, the sophisticated cranes used for block erection are difficult to control. In this study, the control of a gantry and a floating crane was performed for the block erection operation. The underactuated mechanical system control theory was used, and the concept of servo constraints was applied for trajectory tracking control. Subsequently, the inverse dynamics solver was formulated, including the dynamics equations of the cranes and motion planning. A combination of feedforward and feedback controls was adopted, and reliable control was achieved using both a gantry and floating crane under various environmental conditions. The results show that the suggested method can be applied for the appropriate control of the block erection operation. [Display omitted]