A novel approach to obstacle avoidance for an I-AUV

This paper presents a general obstacle avoidance framework for I-AUV using the Task-Priority kinematic control algorithm. The proposed framework is divided into two modes: (1) Navigation and Inspection and (2) Intervention. For each mode, the algorithm takes into account several key points at the I-AUV and several obstacles. For navigation we fully wrap the I-AUV with a small number of safety spheres, while, for intervention the number of safety spheres used increases, having smaller diameters to allow for more precise motion of the I-AUV near the intervention areas. The framework was implemented and simulated with a 8-DOF I-AUV (GIRONA500) in an Inspection, Maintenance, and Repair (IMR) scenario like those commonly encountered in oil and gas industry. The subsea infrastructure used in the scenario was represented by an Octomap, with each occupied cell being considered an obstacle. The I-AUV performed a mission, inspecting the infrastructure in Inspection Mode and later on, turning a valve in Intervention Mode, without colliding with the environment and ensuring a safe distance to obstacles at all times.