Identification of Space Shuttle Main Engine Dynamics Original Page Is of Poor Qualky

Ahmet Duyar ' 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 L e w i s Research C e n t e r C l e v e l a n d , O h i o 44135 Ten-Huei Guo S v e r d r u p Techno logy I n c . NASA L e w i s Research C e n t e r Group C l e v e l a n d , O h i o 44135 W a l t e r C. M e r r i l l 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 L e w i s Research C e n t e r C l e v e l a n d , O h i o 44135 0 Sys tem i d e n t i f i c a t i o n t e c h n i q u e s a r e u s e d t o g r e p r e s e n t t h e dynamic b e h a v i o r o f t h e Space Shu t A t l e M a i n E n g i n e . The t r a n s f e r f u n c t i o n m a t r i c e s o f t h e l i n e a r i z e d m o d e l s o f b o t h t h e c l o s e d l o o p and t h e open l o o p s y s t e m a r e o b t a i n e d b y u s i n g t h e r e c u r s i v e maximum l i k e l i h o o d me thod . a