Dynamic Image-Based Impedance Control of Aerial Manipulator for Sliding Inspection

Sliding inspections at heights and in harsh environments generally pose significant challenges for the autonomous operation of unmanned aerial manipulator (UAM). This article investigates the issue of reliable physical interaction by UAM for sliding inspections under uncertain disturbances. First, a second-order image dynamics model is derived using the virtual camera image moment to provide a foundation for autonomous positioning. Next, a sliding-mode disturbance observer is designed to estimate the uncertain disturbances from environments. Then, a hybrid image-based compliant control strategy is proposed to meet the physical interaction requirements of UAM. Particularly, a visual positioning controller is adopted to maintain precise positions of UAM, while a visual impedance control method is introduced to achieve reliable force tracking performance in the contact direction. The stability of the proposed strategy is analysed through Lyapunov theory. Finally, physical in-loop implementation and real-world experimental studies are conducted to validate the feasibility and performance of the developed method, demonstrating accurate tracking performances in both position and force and thereby, exhibiting the potential of proposed approach to work for sliding inspection effectively.