Image-Based Visual Servoing of Micro Aerial Vehicles With Robust Observation and Output Feedback

An output feedback control method is proposed in the article with state observers for robust image-based visual servoing (IBVS) regarding micro aerial vehicles (MAVs). Specifically, image features are first selected from the perspective image moments and are projected onto a suitably defined image plane so as to provide decoupled kinematics for translational motion. In order to address the problem of low quality and even unavailability of linear velocity information, the image moment error observer is designed as a foundation based on an image filter, and then the MAV body velocities are estimated by designing a robust observer to obtain translational optical flow of virtual image features. An adaptive law is proposed for the unknown depth information of the visual target and is combined with observers in output feedback controller design to enhance system robustness. Stability analysis shows that all states of the system are uniformly ultimately bounded (UUB) and converge to zero asymptotically. Comparative simulation and experimental results demonstrate the performance of the proposed method.