An experimental and numerical investigation on the autopilot design of a KVLCC2 tanker

Ships in high seas are subjected to first and second-order wave forces and moments. The first-order forces are important for analyzing the seakeeping responses of the vessel and the second-order drift forces are important for manoeuvring in waves. Therefore, an autopilot designed for calm water conditions may not be effective in realistic sea states. In this paper, the performance of an autopilot system for heading control is experimentally investigated. The experiments are conducted on a scaled-down model of a KVLCC2 tanker in calm water in a wave basin. The developed autonomous onboard system is equipped with a main computer, suitable electronics, actuators, sensors, data acquisition system, and Wi-Fi-based communication system. Steering control algorithms such as PD and LQR controllers are tested on the physical model without waves. The experimental results for heading control are compared with that of a numerical model. The numerical simulations are further carried out for autopilot design in waves.