AFRL Researchers Test Sense-and-Avoid Technology Published June 4, 2007 By Air Vehicles Directorate AFRL/VA WRIGHT-PATTERSON AIR FORCE BASE, Ohio -- In an effort to improve the safety and expand the reach of unmanned air vehicles (UAV), AFRL scientists conducted a series of Sense-and-Avoid Flight Tests (SAAFT) in Niagara Falls, New York. AFRL established the SAAFT program to demonstrate autonomous collision avoidance capabilities in both cooperative and noncooperative air traffic. The intent of the Sense-and-Avoid (SAA) program is to equip UAVs such as the Global Hawk and Predator with collision avoidance capabilities and thus allow them the same access to national and international airspace that manned aircraft have. AFRL researchers are developing electro-optical (EO)-based "sense" (i.e., detection sensor) technology for noncooperative traffic detection. They are developing autonomous "avoid" (i.e., maneuvering) technology, and also using information from the Traffic Collision Avoidance System (TCAS), to detect cooperative, conflicting traffic. In order to evaluate the performance of the systems, AFRL engineers installed the SAA hardware and software in a Calspan Learjet (LJ) acting as a surrogate Global Hawk-like UAV. The LJ flew in various one-on-one encounter scenarios, with a Federal Aviation Administration (FAA) Beechcraft King Air and Convair 580 alternately acting as intruder aircraft on a collision course. The SAA system successfully controlled the entire sequence of open- and closed-loop flight tests, from detection through avoidance and return-to-course activity. The researchers first tested the individual capacity of the EO system, as well as that of the TCAS, to detect the intruder aircraft; they then employed the systems together. The team's objective was to predictably and reliably control the UAV in the same manner as a normally piloted aircraft. Pilots reported positive, humanlike system performance. Future scheduled flights will evaluate avoidance algorithm capabilities during collision scenarios involving multiple and maneuvering intruders. AFRL also plans to conduct additional flights to investigate the use of autonomous dependent surveillance broadcast for cooperative traffic detection and long-wave infrared cameras for noncooperative traffic detection. The SAAFT team consists of personnel from Northrop Grumman-Integrated Systems; Calspan Corporation; Bihrle Applied Research; C2Projex; Defense Research Associates; AFRL; and, through a memorandum of agreement with the FAA, pilots and engineers from the Hughes Flight Test Center (Atlantic City, New Jersey).