Autonomous Capabilities for Small Unmanned Aerial Systems Conducting Radiological Response: Findings from a High‐fidelity Discovery Experiment

Abstract

This article presents a preliminary work domain theory and identifies autonomous vehicle, navigational, and mission capabilities and challenges for small unmanned aerial systems (SUASs) responding to a radiological disaster. Radiological events are representative of applications that involve flying at low altitudes and close proximities to structures. To more formally understand the guidance and control demands, the environment in which the SUAS has to function, and the expected missions, tasks, and strategies to respond to an incident, a discovery experiment was performed in 2013. The experiment placed a radiological source emitting at 10 times background radiation in the simulated collapse of a multistory hospital. Two SUASs, an AirRobot 100B and a Leptron Avenger, were inserted with subject matter experts into the response, providing high operational fidelity. The SUASs were expected by the responders to fly at altitudes between 0.3 and 30 m, and hover at 1.5 m from urban structures. The proximity to a building introduced a decrease in GPS satellite coverage, challenging existing vehicle autonomy. Five new navigational capabilities were identified: scan, obstacle avoidance, contour following, environment‐aware return to home, and return to highest reading. Furthermore, the data‐to‐decision process could be improved with autonomous data digestion and visualization capabilities. This article is expected to contribute to a better understanding of autonomy in a SUAS, serve as a requirement document for advanced autonomy, and illustrate how discovery experimentation serves as a design tool for autonomous vehicles.

Communicating Directionality in Flying Robots

“…Powering high-fidelity screens may drastically cut into flight time, which is currently a primary consideration limiting the deployment of flyers. While future systems might combine fixed-wing gliding with agile multirotor movements to conserve battery [31] or make use of exotic power systems such as laser beaming [1], current systems generally have flight times between 10-50 minutes [9].…”

State-of-the-Art Mobile Radiation Detection Systems for Different Scenarios

“…Even though this SUAS had autonomous vehicle and navigation capabilities its operation relied on the human-robot teaming. Since radiation intensity is inversely proportional to the square of distance and it is attenuated by the medium (air), it is important to consider SUAS due to their capability to fly at low altitudes and in close proximity to structures [69]. Missions where unmanned fixed-wing are superior compared to other unmanned platforms include radioactive plume tracking, sampling of airborne radioactive material, fallout mapping of large areas, and searching of unshielded sources, e.g., material out of regulatory control, both stationary and moving, from large areas.…”

“…For indoor environments, GPS signal is not available. • Data-to-decision process-improvement is needed in autonomous data analysis (visual and radiation data) for prompt use by mission commanders [69].…”

Designing a radiation sensing UAV system

“…A radiation sensor was attached to the system for this specific mission as it was not part of the original design. Time stamps from the radiation data were matched with the vehicle's built-in GPS navigation to analyze the amount of radiation at a particular location [3] [7].…”