Assessment of Collision Avoidance Strategies for an Underwater Transportation System


Underwater transportation using multiple autonomous vehicles with detection avoidance capability is useful for military applications. To ensure collision avoidance of external obstacles, sensor-based and path planning methods were investigated for a transportation system of four Hovering Autonomous Underwater Vehicles (HAUVs). In particular, sensor-based wall-following and hard-switching collision avoidance strategies and an offline RRT* path planning solution have been introduced. The sensor-based wall following method was found to be better than sensor-based hard switching method in terms of time and power efficiency. Moreover, the hard switching method produced higher yaw moments and required higher PID gains which were sensitive to even small variations. The comparison between the offline RRT* path planning and wall following methods showed that the fuel efficiency of the former is higher whilst its time efficiency is poorer.