Mid-Air Conflict Avoidance and Recovery: An Acceleration-Based Approach for Unmanned Aircraft

We describe a novel technique for increasing the minimum separation between two aircraft by using a constant acceleration based speed change. The technique predicts the required acceleration each aircraft should execute in order to obtain a safe separation—while accounting for each aircraft's acceleration and velocity limits. In addition, we present a method for each aircraft to recover to its original trajectory, once the conflict has been mitigated, without reducing the obtained minimum separation. The theory presented in this letter demonstrates that it is indeed possible to accomplish the task of avoidance and recovery independently (without any aircraft-to-aircraft communication) in an elegant, feasible, and mutually beneficial manner. Both techniques are validated in a virtual environment, which incorporates a real quadcopter's dynamics, as well as in an indoor test arena with two quadcopter platforms.