Overview of NASA research in fiber optics for aircraft controls

Abstract

N a t i o n a l A e r o n a u t i c s and Space A d m i n i s t r a t i o n Lewi s Research Center Cleveland, O h i o 44135 SUMMARYThe challenge o f those i n v o l v e d i n a i r c r a f t c o n t r o l system hardware development i s t o accommodate an e v e r -i n c r e a s i n g c o m p l e x i t y i n a i r c r a f t cont r o l , w h i l e l i m i t i n g t h e s i z e and w e i g h t o f t h e components and i m p r o v i n g system r e l i a b i l i t y . A t e c h n o l o g y t h a t d i s p l a y s promise towards t h i s end i s f i b e r o p t i c s . The p r i m a r y advantages o f employing o p t i c a l f i b e r s , p a s s i v e o p t i c a l sensors and o p t i c a l l y c o n t r o l l e d a c t u a t o r s a r e weightlvolume r e d u c t i o n , immun i t y f r o m e l e c t r o m a g n e t i c e f f e c t s , h i g h bandwidth c a p a b i l i t i e s and freedom f r o m s h o r t c i r c u l t s l s p a r k i n g c o n t a c t s . Since 1975, NASA Lewis has been perf o r m i n g In-house, c o n t r a c t and g r a n t r e s e a r c h i n f i b e r o p t i c sensors, h i g h temperature e l e c t r o -o p t i c switches and " f l y -b y -l i g h t " c o n t r o l system a r c h i t e ct u r e . Passive o p t i c a l sensor development i s an e s s e n t i a l y e t c h a l l e n g i n g area o f work and has t h e r e f o r e r e c e i v e d much a t t e n t i o n d u r i n g t h i s p e r i o d . A major e f f o r t to develop f l y -b y -l i g h t c o n t r o l system technology, known as t h e " F i b e r O b t i c C o n t r o l System I n t e g r a t i o n " (FOCSI) program was i n i t i a t e d i n 1985 as a c o o p e r a t i v e e f f o r t between NASA and t h e DOD. Phase I o f FOCSI, completed i n 1986, was aimed a t t h e d e s i g n o f a f i b e r o p t i c i n t e g r a t e d p r o p u l s i o n l f l i g h t c o n t r o l system. Phase I 1 w i l l p r o v i d e subcomponent and system development, and system t e s t i n g . I n a d d i t i o n t o a summary o f t h e b e n e f i t s o f f i b e r o p t i c s , t h e FOCSI program, sensor advances, and f u t u r e d i r e c t i o n s i n t h e NASA Lewis program w i l l be discussed.