Optical Control Technology

This paper presents the results of research at Bell Helicopter Textron (BHT) which have been aimed at using fiber optics to make fly-by-wire control systems immune to EMI, RFI, lightning, and other electrically related disturbances. The following text will present an introduction into fiber optic operation, practical signal transfer techniques, and the rationale for selecting a fiber optic (FO) control signal path. A research project involving embedding the fiber optic material into the composite helicopter structure will be discussed. The design and flight test of an optical position encoder, decoder, and FO cable will be presented. Finally, several electrically passive FO position transducers will be discussed.