Heave and horizontal displacement and anti-sway control of payload during ship-to-ship load transfer with an offshore crane on very rough sea conditions

Abstract

Ship-to-ship load transfer with offshore cranes is challenging in rough sea conditions because of the difficulty in compensating for the increased position-velocity-acceleration errors and the restriction of the unloading area.This study proposes an efficient solution by integrating the combined vertical, horizontal, and anti-swing control system, experimentally validated mathematical hydraulic system and ship motions on irregular waves, the dynamic model of the crane, and an innovative control strategy. Particle Swarm Optimization-Proportional-Integrative-Derivate (PSO-PID) Trajectory Route Control System ensures safe unloading by advancing in the desired vertical position and speed route. The operation's horizontal positioning is realized even for very rough sea conditions with the support of the PID-controlled main and elbow boom. An extra added telescopic boom is used for anti-swing control with Particle Swarm Optimization Proportional-Derivative-Second Derivative (PSO-PDD2) control system.Simulations with different sea conditions were made and analyzed to verify the study's system model's effectiveness. The simulation results revealed that the system model is a valid and successful solution.