Date of Award


Document Type


Degree Name

Master of Science in Aeronautical Engineering


Department of Aeronautics and Astronautics

First Advisor

Frederick G. Harmon, PhD


A collision avoidance algorithm is developed and implemented that is applicable to different types of unmanned aerial systems ranging from a single platform with the ability to perform all collision avoidance functions independently to multiple vehicles performing functions as a cooperative group with collision avoidance commands computed at a ground station. The collision avoidance system is exercised and tested using operational hardware and platforms and is demonstrated in representative missions similar to those planned for operational systems. The results presented are the first known flight tests of a global, three-dimensional, geometric collision avoidance system on an unmanned aircraft system. Novel developments using an aggregated collision cone approach allows each unmanned aircraft to detect and avoid collisions with two or more other aircraft simultaneously. The collision avoidance system is implemented using a miniature unmanned aircraft with an onboard autopilot. Various test cases are used to demonstrate the algorithms robustness to different collision encounters. Two-ship encounters at various engagement angles are flight tested. The flight test results are compared with ideal, software-in-the-loop, and hardware-in-the-loop tests.

AFIT Designator


DTIC Accession Number



Alternative title: Umanned Aerial Systems Collision Avoidance Algorithm that Minimizes the Impact on Route Surveillance