NASREM: Robot Control System and Testbed

The prob lem o f robot c o n t r o l i s approached f r o m a systems standpoint where a complete cont ro l system m u s t include a l l o f t he aspects involved i n moving a robot, not j us t t h e algor i thms i n t h e c l a s s i c con t ro l s l i t e r a t u r e . The NASA/NBS S t a n d a r d Reference Model f o r T e l e r o b o t C o n t r o l S y s t e m A r c h i t e c t u r e (NASREM) provides t h e framework f o r a comple te m a n i p u l a t o r c o n t r o l system. It i s composed o f t h r e e h i e r a r c h i e s : t a s k decomposition, world modeling, and sensory processing. The task decomposition h ie rarchy divides tasks into smal le r and sma l le r subtasks. In order t o achieve the desi red decomposition, t h e task decomposition hierarchy m u s t o f t en access in fo rmat ion stored i n t h e wor ld model ing h i e r a r c h y , which con ta ins a workspace r e p r e s e n t a t i o n , o b j e c t descr ip t ions , r o b o t models , e t c . The sensory processing hierarchy constant ly fils the wor ld model w i t h processed sensor in format ion. I n the process o f building NASREM, a great deal o f e f f o r t has been spent i n the def in i t ion o f the i n t e r f a c e s between l e v e l s o f t h e h ie ra rchy so t h a t t h e m a j o r i t y o f robot contro l and sensory processing algorithms i n t h e l i t e r a t u r e can be implemented. Th is a l lows the r e a l i z a t i o n o f t h e NASREM arch i tec tu re t o serve the dual purpose o f a robot c o n t r o l l e r and a t e s t b e d f o r robo t c o n t r o l a l go r i t hms . T h i s paper describes the purpose and o v e r a l l o rgan iza t ion o f NASREM. Then, t w o examples o f NASREM t a s k decompos i t ion modules a r e discussed i n terms o f function as w e l l as i n t e r f a c e requi rements.