Sense and Avoid in UAS

The regulatory authorities require the human operator to be capable to see and avoid obstacles and other traffic.  The FAA requires all unmanned aircraft to fulfill the certification requirements of manned aircraft including the see and avoid capability.

Since the unmanned vehicle will not transport humans in the near future, the purpose of a sense and avoid function does not necessarily aim towards saving the vehicle, rather than to prevent collision with other traffic and save humans and property from collateral damage.

A sense and avoid function requires a set of sensory equipment to perceive an impending threat and a computational tool to produce the adequate avoidance resolutions.  A sense and avoid function will continuously monitor the surroundings and provide information to allow the vehicle to operate within a zone of adequate separation or command a maneuver to escape a collision zone.

The available technologies can fall into cooperative or non-cooperative categories.  The cooperative technologies involve a negotiating process between two converging traffic.  The non-cooperative requires one traffic to react to another traffic solely based on its sensory capabilities.

Angelov, P. P., & Books24x7, I. (2012). Sense and avoid in UAS: Research and applications(Second;1; ed.). Hoboken: John Wiley & Sons.

Hottman, S. B., Hansen, K. R., & Berry, M. (2009). Literature review on detect, sense, and avoid technology for unmanned aircraft systems.