Fast 3D Collision Avoidance Algorithm for Fixed Wing UAS

This paper presents an efficient 3D collision avoidance algorithm for fixed wing Unmanned Aerial Systems (UAS). The algorithm increases the ability of aircraft operations to complete mission goals by enabling fast collision avoidance of multiple obstacles. The new algorithm, which we have named Fast Geometric Avoidance algorithm (FGA), combines geometric avoidance of obstacles and selection of a critical avoidance start time based on kinematic considerations, collision likelihood, and navigation constraints. In comparison to a current way-point generation method, FGA showed a 90% of reduction in computational time for the same obstacle avoidance scenario. Using this algorithm, the UAS is able to avoid static and dynamic obstacles while still being able to recover its original trajectory after successful collision avoidance. Simulations for different mission scenarios show that this method is much more efficient at avoiding multiple obstacles than previous methods. Algorithm effectiveness validation is provided with Monte Carlo simulations and flight missions in an aircraft simulator. FGA was also tested on a fixed-wing aircraft with successful results. Because this algorithm does not have specific requirements on the sensor data types it can be applied to cooperative and non-cooperative intruders.