Optimal Motion Strategies Based on Critical Events to Maintain Visibility of a Moving Target

In this paper, we consider the surveillance problem of maintaining visibility at a fixed distance of a mobile evader using a mobile robot equipped with sensors. Optimal motion for the target to escape is found. Symmetrically, an optimal motion strategy for the observer to always maintain visibility of the evader is determined. The optimal motion strategies proposed in this paper are based on critical events. The critical events are defined with respect to the obstacles in the environment.