Autonomous Inspection and Maintenance Operations employing Multi-Robots: Preliminary Results

Deploying multi-robot systems for Inspection and Maintenance (IM) operations offers several advantages, including covering a large mission area and providing redundancy against individual failure. These features are particularly relevant for IM operations in offshore oil and gas platforms due to the extensive number of sensors and equipment involved, as well as the high level of fault-tolerant resilience required. This paper presents preliminary experimental results of a multi-robot mission planning system designed for performing autonomous inspection at Equinor’s K-Lab Test Centre in Haugesund, Norway. The high-level action planner is based on the Simultaneous Task Planning (STP) algorithm. The STP planner has the capability to compute plans for multi-robot systems, as it allows for concurrent actions. The system can take into account high-level actions and their expected durations, such as "visiting a specific location", "inspecting a sensor", or "taking a picture of a specified component". Additionally, STP can replan in real-time in case of events such as the need to revisit a waypoint or low battery status. Communication with the robots is achieved through Equinor’s Integration and Supervisory Control of Autonomous Robots (ISAR) framework, ensuring a fast and secure Wi-Fi connection. The collision avoidance, guidance, and control system is handled at the low-level layer of each robot. The proposed technique was validated through field experiments involving two unmanned ground robots performing an inspection round, which includes visiting a sequence of predefined waypoints and incorporates replanning for low battery situations. Two types of experiments were conducted: one scenario where robots collaborated by overlapping capabilities; and another scenario where robots collaborated by combining capabilities.