Multi-robot system for inspection of underwater pipelines in shallow waters

Shallow Water Inspection & Monitoring Robot (SWIM-R) is designed to quickly and safely inspect oil and gas pipelines in extremely shallow waters. Divers clean and inspect pipeline joints. However, diving operations are slow in shallow waters as diving support ships cannot access shallow depths. Remotely operated vehicles (ROVs) that can perform cleaning and inspection are typically suited for deeper regions and are too large for smaller boats that navigate in shallow areas. To resolve this challenge, two SWIM-R vehicles and a companion Autonomous Surface Vehicle (ASV) were developed as a multi-robot system to minimize the reliance on divers for pipeline inspection. A unique mission architecture is presented that avails three operating modes depending on the depth; direct control from the shore, relayed control via the ASV, and direct control from a small zodiac. The mission architecture includes two ROVs; a Cleaning SWIM-R fitted with a water-jet nozzle to clean marine growth from the surface to be inspected, and an Inspection SWIM-R fitted with a neutrally-buoyant multi-functional robotic arm to inspect the surface and crawling tracks to traverse the seafloor. This multi-robot system was field tested, which proved its efficacy in inspecting oil and gas assets in shallow waters.