COLREGs-Compliant Unmanned Surface Vehicle Collision Avoidance Control for Submarine Cable Inspection

In recent years, the unmanned surface vehicle (USV) have become increasingly prominent for submarine cable inspection missions. However, these cables are often buried in complex and dynamic coastal waters, where there are both dynamic ship obstacles and potential static obstacles. Therefore, the USV must avoid these obstacles to ensure safe and effective inspection. In particular, when encountering regular shipping vessels, the USV should adhere to the International Regulations for Preventing Collisions at Sea (COLREGs) to avoid collisions. In addition, during the collision avoidance process, the USV must ensure that the multibeam sonar maintains adequate coverage of the submarine cable, as excessive deviation from the inspection trajectory could lead to incomplete data and reduce inspection quality. To address these challenges, we propose an improved model predictive control (MPC) method for USV collision avoidance. This method integrates both the COLREGs and the constraints of the multibeam sonar scan range, ensuring safety while maintaining inspection quality. Numerical simulations were conducted for USV collision avoidance with both dynamic and static obstacles. The results demonstrate that the improved MPC method not only ensures compliance with COLREGs but also prevents sonar signal loss by minimising deviations from the inspection trajectory during collision avoidance.