An Effective Strategy for Collision Avoidance of Multiple UAVs With Unknown Acceleration

Abstract

In this article, an effective strategy using mixed 3-D geometric and the miss distance approach is proposed for the collision avoidance between multiple UAVs with unknown acceleration. At each time sampling, conflict detection of multiple UAVs is first performed. If the conflict exists, the expected heading angle or/and expected elevation angle of UAV are computed. Then, UAV begins to perform the avoidance maneuvers. The heading angle or/and elevation angle of UAV are uniformly adjusted to the expected value. The condition required for successful collision avoidance is derived for the proposed strategy. To enhance safety during execution of avoidance maneuver, a simple and feasible modify measure is presented. In the case of multiple UAVs, a logic to allocate the avoidance prioritization of each UAV is proposed. The trajectory recovery algorithm is presented to ensure UAV to return to the planning flight paths. For the proposed strategy, it is not assumed that all UAVs have constant ground speeds and direction of the velocity. Thus, it is very suitable in reality application. Numerical simulation results show the efficiency and superiority of the proposed strategy.

Keywords

• Collision avoidance
• trajectory recovery
• prioritization logic
• multiple UAVs
• 3-D space