A Simulation Framework for Establishing Detect, Alert, and Avoid Requirements.
Wednesday, October 07, 2020: 1:00 PM - 1:45 PM
Performance requirements for Detect, Alert, and Avoid (DAA) systems for Remotely Piloted Aircraft Systems (RPAS) are under development by many regulatory agencies and standards bodies. Existing published DAA-specific standards are limited to performance requirements for air-to-air radar (DO-366, TSO-C212). At present, comprehensive requirements for a DAA system and sensor modalities, other than radar, have yet to be published. The ‘right of way rules of the air’ state that an aircraft that does not have the right of way shall keep out of the way of another, and avoid passing over, under or in front of the other, unless well-clear. Standards bodies have been actively investigating several candidates' well-clear volume definitions. A DAA system is also responsible for avoiding near mid-air collision (NMAC) with other traffic, which occurs when an intruder aircraft penetrates a collision volume around the RPAS. DAA can be decomposed into three functions, namely, ‘Detect’ - situational awareness, determination of traffic that may be in conflict, evaluation of the de-conflicting flight path; ‘Alert’ - informing the pilot-in-command; and ‘Avoid’ – avoidance maneuver execution, and determination of ‘clear of conflict’. The ‘Avoid’ component of a DAA system depends on the RPAS performance, pilot reaction (for manual maneuver execution), airspace specifics, and size of the protection volume. These factors impact the time required to conduct an avoidance maneuver that will guarantee a prescribed miss distance, and dominate the ‘Detect’ requirements of a sensor (e.g., minimum detection range, maximum estimated position uncertainty, required sensor field-of-regard, etc.). The relationship between these factors and the sensor requirements are best investigated using simulation studies. This paper describes the results of modeling and simulation of encounter geometries for a variety of ownership and intruder performance envelopes. Timely ‘Collision Avoidance’ and ‘Remain Well-Clear’ maneuvers, conducted by the ownership, guarantee the specified miss distance, between ownership and intruder, based on time to the closest point of approach. The results of the simulations are then used to establish the minimum requirements for a DAA sensor for chosen ownership maneuvering characteristics and airspace restrictions. Future work will incorporate known airspace models and RPAS/intruder mission profiles in order to establish additional sensor requirements (e.g. robustness, reliability, etc.).
Analyst,Engineering/Technical,Research & Development
Air,Virtual Reality,Navigation,Airspace Integration