Detector for applied force to aircraft control lever - utilises piezo-resistive bars, and torsion tube attached to principal shaft

摘要

Forces applied by a pilot to an aircraft control stick (5) are measured to oppose action from automatic pilot. Sensors are integral with the control stick hub to avoid errors created by mechanical resistances and moving parts. The measuring sensor (1) comprises a torsion tube (2) with shoulder permitting attachment onto a principal shaft (4) of control stick. A plate (6) on the shoulder carries a tube (7) which extends inside the torsion tube. A piezo resistive bar is attached to a base (8) and via a part fixed to the torsion tube shoulder. A second piezo resistive bar is fixed to ends of parallel spring blades (11, 12) via attachments (13, 17) to the control stick. The piezo resistive detectors are each coupled to a Wheatstone bridge to measure applied forces.