Reference Optimization-Based Compliant Control for Aerial Pipeline Inspection Using a Hexacopter With a Robotic Contact Device

This article proposes a reference optimization-based compliant control framework for aerial pipeline inspection using a hexacopter with a robotic contact device. The system dynamics is modeled, and the aerial interaction performance is quantified by a cost function, which is regulated by the trajectory tracking error and the interaction force. Then, the iteration-based reference learning scheme is introduced to minimize the cost function and realize the optimal interaction performance without the knowledge of the contact environment. Next, a command filter-based adaptive backstepping trajectory tracking controller is designed to avoid the complexity explosion problem as well as implement stable and accurate tracking performance under external wrenches. Simulation studies and real-world experiments illustrate the feasibility of the proposed framework and provide promising results.