Executed By A Sense And Avoid System Installed On An Unspecified Unmanned Aircraft System

The the first ADS-B based, fully autonomous collision avoidance sequence, executed by a sense and avoid system installed on an unmanned aircraft system (UAS) has been demonstrated by R³ Engineering (R³E). On Friday August 10th, 2012, an AWSAS C’s All Weather Sense and Avoid System installed on a research UAS, with no external command or control inputs, commanded the UAS’s auto-pilot to depart from its programmed flight path, execute an internally computed maneuver to avoid a potential collision, and then return to the original planned flight path when well clear of the intruder.

ADS-B messages received and processed by the AWSAS internal computer indicated that the aircraft was on a collision course with another ADS-B equipped target. The AWSAS embedded SAA (Sense And Avoid) algorithm analyzed the flight tracking data, determined that a potential breach of the aircraft’s “collision volume” was imminent, determined an optimum collision avoidance maneuver, and sent commands directly to the autopilot.

The UAS’s auto-pilot responded to the commands, turning the aircraft away from the intruder, and when clear of the conflict, returned the aircraft to its preprogrammed flight path. This entire sequence was autonomous, with no command or control inputs from outside the unmanned aircraft.

The autonomous flight test was conducted at the former Naval Base in Argentia, Newfoundland, in cooperation with Memorial University of St. John’s Newfoundland, following an increasingly complex series of flight tests that took place in Florence, AZ, San Diego, CA and Grand Forks, ND. The tests are demonstrating the ADS-B based AWSAS capability to develop target tracks from data it receives, project potential conflict(s) at a future time, compute and recommend to the ground based remote pilot maneuvers such as course or speed change that will maintain safe separation; and if absolutely necessary, send collision avoidance maneuvers directly to the aircraft autopilot. The test series included potential collision scenarios between the UAS and stationary hazards, moving ground hazards, and between two UAS aircraft.

The flight test series is scheduled to expand with testing later this year in Restricted Airspace that will incorporate non-cooperative target data from sensors such as radar and EO/IR into the AWSAS’ SAA process. R³E’s team of researchers and engineers is led by Test Director and design team leader, Dr. V. Michael Contarino, a retired senior scientist from NAVAIR. Development and initial testing of the AWSAS prototypes has been funded by the Office of Naval Research, the Department of Defense’s DSOC (Defense Safety Oversight Council) Aviation Safety Technologies program, and NAVAIR.   

FMI: www.navair.mil