Circumnavigation of an Unknown Target Using Range-only Measurements in GPS-denied Environments

This paper investigates the control problem of a Dubins-like robot to circumnavigate an unknown target with a prescribed radius in GPS-denied environments. Considering the sensing capabilities of small robots, the current distance to the target is the only measurement. A coordinate free range-only control law is devised to force the robot to achieve the objective of target circumnavigation. The proposed controller can guarantee global convergence irrespective of the initial states and locally exponential convergence near the equilibrium point. Furthermore, the selection of control parameters is independent of the initial states. The effectiveness and advantages of our approach are validated via simulations.