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.

Surveillance UAS

The military utilized Unmanned Aerial Systems (UAS) in different roles throughout the history of flight.  However, the applications evolved over time from performing simplified drone roles to the highly autonomous capabilities of nowadays systems like the global hawk RQ-4.

One civilian application for an UAS in the fiend of naval surveillance is shark detection and early warning for beachgoers. Typically, UAS are a suitable replacement for the dull missions of continuous loitering and surveillance. Additionally, the cost and noise signature of a manned aircraft flying continuously at low altitudes highly favors an UAS alternative.  To further cut down cost and, simplify operations, and reduce ancillary equipment, an autonomous option with a reprogrammable route is preferable (Capizzi, Boxoen, Blake, & Shen, 2007).

In Australia, the state of New South Wales decided to implement a shark-spotting program.  A helicopter-like, long range, and battery powered aircraft was chosen to fulfill the program objectives.  The payload consists of advanced visual sensors and shark identification algorithms.  The aircraft will undergo tests for delivering life saving devices to people in emergencies (Bogle, 2016).

A comparable military vehicle is MQ-8B and MQ-8C Fire Scout.  This UAS fulfills the purpose of Intelligence, Surveillance and Reconnaissance (ISR), target-acquisition, laser designation, and battle management to tactical users.    The aircraft’s baseline payload equipment consist of electro-optical/infrared sensors, a laser designator, and UHF/VHF communication for data transfer across the network participants and voice communications relay (Petty, 2016).  A ground control station can provide support to several aircraft at the same time. The size, payload, and engine type are significantly different from civilian models.  The two models are based on two different airframes. 

 References 

 August 2016, from http://mashable.com/2016/02/28/shark-spotting-drones-australia/#DgHSG1fSKZqs

Bogle, A. (2016). Shark-spotting drones to patrol the skies above Australian beaches.Mashable. Retrieved 16  

Capizzi, V., Boxoen, T., Blake, M., & Shen, A. (2007). ICSV14.

Petty, D. (2016). The US Navy -- Fact File: RQ-8A and MQ-8B Fire Scout Unmanned Aerial Vehicle (UAV). Navy.mil. Retrieved 16 August 2016, from http://www.navy.mil/navydata/fact_display.asp?cid=1100&tid=2150&ct=1