Modeling a prototype optical collision avoidance sensor for unmanned aerial vehicles

Abstract

Sense and avoid systems for civilian unmanned air vehicles (UAVs) are essential in controlled airspace under visual flight rules (VFR). A prototype optical sensor accomplishes the task with attractive performance specifications. Key requirements include long-range detection (up to 10 km), wide field of view, discrimination of small threats against the background and tolerance of direct solar illumination. We demonstrate a prototype system based on a network of independent camera modules equipped with local processing. Availability of a flyby-wire helicopter configured as a UAV emulator allows for realistic field tests with consumer components. Aspects of the design, implementation and evaluation of the prototype sensor are presented here, as are preliminary measurements to clarify the roles of platform motion, system optical point-spread, noise, direct sunlight and target highlighting.

Characterization of an optical collision avoidance sensor

“…Measuring the module's ability to resolve point-like targets is desired, as the ability directly correlates to the "range-atfirst-detection" figure of merit outlined in [7]. Determining relative orientations of camera modules is also desired.…”

Preliminary architectonic design for a smart solar-powered UAV

“…The navigation processor implements the navigation system equations. Navigation-aiding sensors can use satellite-based systems such as (for position and velocity) Global Positioning System (GPS) and wide-area augmentation [26], optical-vision-based (elevation and azimuth angles) [27], ground-based (such as VHF omnidirectional range navigation system) , or any combination at all. Inertial Navigation System (INS) is also a navigation aid that measures UAV state based on calculation of acceleration (via accelerometer motion sensors) and angular rates (via gyroscope rotational sensors) in the body frame .…”