Bearing-only circumnavigation by a unicycle agent based on a fully actuated system approach

Based on the fully actuated system (FAS) approach, this paper investigates the bearing-only circumnavigation (BOC) problem where one unicycle agent is supposed to circumnavigate one stationary target. Five types of unicycle agent models are studied, including a general unicycle model and four high-order unicycle models. In the BOC problem considered here, only the bearing information to the target is available as the target-related measurement, while the agent-target distance is not accessible. With the scalar estimator for the estimation of the unknown distance between the agent and the target, the FAS models are derived and their corresponding FAS controllers are designed for each type of the unicycle agent models. The convergence proofs of the estimator and the stability proofs of the FAS controllers in each unicycle model case are provided.