Researchers developed a sensor and software application to detect and avoid energized power lines in the vicinity of unmanned aerial systems (UAS). The goal is to provide drones sufficient time and distance to react, avoid wires, and navigate follow-on maneuvers.
The approach uses a unique configuration of field and 3D sensors in conjunction with low-power processing methods. This resulted in detecting power lines and informing the device's autopilot to prevent collision with the wires. Power lines generate large fields that can be easily detected with low-power, low-cost, passive electric- and magnetic-field sensors. This method allows UAS equipped with the sensors to use smaller, lower-power, and lower-cost sensors to detect the location and Poynting vector (i.e. the directional energy flux density) of nearby power lines. This allows the UAS to autonomously avoid or navigate alongside the detected power lines.
While existing wire-detection and wire-avoidance technologies that use radar and/ or optical sensors have had commercial success, they are known to be expensive, bulky, and power-intensive with technical limitations. The detection algorithm will result in size, weight, power, and cost reduction. By combining both sensing modalities in one sensor, the researchers estimated the direction of power flow, something no traditional sensor can do.
The technology also is useful for mapping out power grids or locating damaged wires after a hurricane or as part of a nation-building effort. The same technology is beneficial to power companies that require routine and emergency inspection of many miles of power lines to detect tree encroachment, excessive sag, and other issues.
A drone-based system could detect power lines at a distance and determine their precise location to enable safe navigation. This will overcome the factors that limit the efficacy of drones in the vicinity of power lines and unleash their full potential for autonomous power line inspection as well as other operations such as freight delivery.
For more information, contact DEVCOM, Army Research Laboratory Public Affairs at 703-693-6477.