Flap angle measurement system for an active rotor control system

摘要

A flap angle measurement system is disclosed for a helicopter rotor blade. The blade includes a trailing edge and a flap hinged to at least a portion of the trailing edge about a pivot axis. The flap angle measurement system includes a Hall effect sensor mounted to the trailing edge of the rotor blade. The Hall effect sensor has a sensing face. A magnet is mounted to the flap at a location spaced apart from the pivot axis. The magnet has a pole axis that is located parallel to the sensing face of the Hall effect sensor. A power source supplies power to the Hall effect sensor. A controller receives output signals from the Hall effect sensor which are indicative of the location of the magnet with respect to the sensing face of the Hall effect sensor. The position of the flap relative to the trailing edge is determined based on the received signals from the Hall effect sensor. In one embodiment of the invention, there is a second Hall effect sensor mounted on the other end of the flap. The sensing face of the second Hall effect sensor points in a direction opposite from the sensing face of the first Hall effect sensor.