Radio Frequency External Load Position Monitoring System

A common mission for helicopters is to move heavy loads suspended on a cable attached to a hook or winch system. During flight, the aerodynamic and inertial forces acting on the load can cause it to swing in the lateral and/or longitudinal directions. Load pendulum motions can also be excited as the helicopter maneuvers, potentially leading to dangerous situations resulting in loss of the load or endangering the helicopter and its crew. Modern manned and unmanned helicopters replace manual controls with fly-by-wire control systems that improve flight stability and reduce pilot workload by using feedback loops to compensate for changes in flight dynamics. SARA’s proposed Radio Frequency External Load Position Monitoring System uses an array of receiver antennas mounted on the helicopter lower fuselage to track dynamic motion of two small, low-power radio transmitters located on the load to provide accurate, reliable load dynamic motion feedback under all visibility conditions, including brown-out. This compact (<5 lbs) system uses proprietary superresolution pointing algorithms to provide angular measurement accuracy of better than 0.1 degree. Existing flight-proven hardware will enable demonstration of measurement range and accuracy during Phase I and speed transition to an operational system in Phase II