Overview of NASA research in fiber optics for aircraft controls

Abstract

The challenge of those involved in aircraft control system hardware development is to accomodate an ever-increasing complexity in aircraft control while limiting the size and weight of the components and improving system reliability. A technology that displays promise towards this end is fiber optics. The primary advantages of employing optical fibers, passive optical sensors, and optically controlled actuators are weight/volume reduction, immunity from electromagnetic effects, high bandwidth capabilities, and freedom from short circuits/sparking contacts. Since 1975, NASA/Lewis has been performing in-house, contract, and grant research in fiber optic sensors, high-temperature electro-optic switches, and “fly-by-light” control system architecture. Passive optical sensor development is an essential yet challenging area of work and has, therefore, received much attention during this period. A major effort to develop fly-by-light control system technology, known as the “Fiber Optic Control System Integration” (FOCSI) program, was initiated in 1985 as a cooperative effort between NASA and the DOD. Phase I of FOCSI, completed in 1986, was aimed at the design of a fiber optic integrated propulsion/flight control system. Phase II will provide subcomponent and system development and system testing. In addition to a summary of the benefits of fiber optics, the FOCSI program, sensor advances, and future directions in the NASA/Lewis program are discussed.