Optimal bearing-only-information strategy for unmanned aircraft collision avoidance

This paper presents a novel collision-avoidance strategy for unmanned aircraft detect and avoid that requires only information about the relative bearing angle between an aircraft and hazard. It is shown that this bearing-only strategy can be conceived as the solution to a novel differential-game formulation of collision avoidance, and has several intuitive properties, including maximizing the instantaneous range acceleration in situations where the hazard is stationary or has a finite turn rate. The performance of the bearing-only strategy is illustrated in simulations based on test cases drawn from draft minimum operating performance standards for unmanned aircraft detect-and-avoid systems.