Nonlinear Model Predictive Control Under the Constraints of a Double Pendulum Overhead Crane

In ports, an overhead crane is essential for moving goods or ships between docks, warehouses, and shipyards quickly. Oscillations provide a serious concern while moving containers with an overhead crane. These motions increase the possibility of unfavourable events by creating load imbalances and collisions with other objects. Effective management of these oscillations becomes crucial to ensuring the safety and stability of the container transportation process. This article will represent the overhead crane as a double-pendulum system, where the payload is the spreader and the container. Subsequently, the obtained nonlinear model will be discretised for further analysis. Furthermore, a Nonlinear Predictive Model Controller (NMPC) will be developed to effectively move the containers while eliminating the residual oscillations caused by the cable. This controller offers theoretical guarantees for meeting oscillation constraints and ensures that the actuators do not become saturated during the process. More specifically, the control strategy incorporates constraints on the angles of the overhead crane and the acceleration of the trolley. The simulation results, carried out using a MATLAB environment, validate the significance and effectiveness of the proposed control scheme.