The DARPA Grand Challenge (DGC) was an opportunity to test autonomous vehicles in a competitive situation. In addition to intelligent behaviour, the participating vehicles must also exhibit ruggedness and endurance in order to survive the fast ride over rough terrain (.'win with the software -lose with the hardware". The SciAutonics teams decided to use compact and agile vehicles that employ proven mechanical designs v e v suitable for the desert environment. 4-wheel drive ensures robust controllability even in slippeiy ground, and a roll cage protects the vehicle components from damage in case of a collision. The control system relies primarily on a diferential GPS (Sta$re) and a set of inertial sensors for navigating between the given set of waypoints. A sensor suite using infrared laser (LIDAR) and ultrasound sensing provides the capability of obstacle avoidance and path following. This paper shows the components of the vehicle and results @om driving at the DGC.
Science C e n t e r , Rockwell I n t e r n a t i o n a l , Thousand Oaks, C a l i f o r n i a 91360 ABSTRACT. The n o n d e s t r u c t i v e measurement of t h e s t r e n g t h of a completed adhesive bond j o i n i n g two metal p l a t e s has been a major roadblock t o t h e use of adhesive bonding f o r s t r u c t u r a l a p p l i c a t i o n . Since t h e s t r e n g t h of adhesive bonds i s o f t e n c o n t r o l l e d by t h e nature of t h e i n t e r f a c e between t h e metal and t h e polymeric adhesive, any u l t r a s o n i c n o n d e s t r u c t i v e t e s t method must e x h i b i t a s e n s i t i v i t y t o t h i s t h i n region of space. W e have prepared a s e r i e s of bonded j o i n t s with v a r i o u s i n t e r f a c i a l s t r e n g t h s and have recorded t h e u l t r a s o n i c pulse wave forms r e f l e c t e d from t h e s e i n d i g i t a l format u s i n g a computer. By comparing these d a t a with p r e d i c t i o n s of t h e theory f o r wave propagation i n layered media, i t has been p o s s i b l e t o c o r r e l a t e c e r t a i n f e a t u r e s i n t h e frequency dependence of t h e r e f l e c t i v i t y with t h e mechanical s t r e n g t h of t h e completed bond. A model t o e x p l a i n t h e s e observations i m p l i e s t h a t t h e i n t e r f a c i a l r e g i o n a c t s i n some ways l i k e a low pass a c o u s t i c wave f i l t e r . I n t r o d u c t i o n The n o n d e s t r u c t i v e measurement of t h e s t r e n g t h of a completed adhesive bond between two p i e c e s of metal is a major problem which has s e r i o u s l y r e t a r d e d t h e f u l l u t i l i z a t i o n of t h i s very e f f i c i e n t method of j o i n i n g metal s t r u ct u r e s . Without a technique f o r v e r i f y i n g t h e s t r e n g t h of a f i n i s h e d j o i n t , t h e d e s i g n e r , t h e manufacturer and t h e user a r e r e l u c t a n t t o u t il i z e adhesive bonding f o r primary s t r u c t u r e s and, t h u s , heavy, complicated j o i n t s made with holes and b o l t s a r e s t i l l t h e dominant construct i o n method. Over the p a s t s e v e r a l y e a r s , vari o u s NDE techniques have been a p p l i e d t o t h i s problem and c o n s i d e r a b l e success has been achieved a t l o c a t i n g regions of disbands or f o r e i g n o b j e c t s whose dimensions a r e on a s c a l e l a r g e compared t o t h e bond l i n e t h i c k n e s s . What i s l a c k i n g a r e techniques which expose d e f ic i e n c i e s i n t h e i n t r i n s i c s t r e n g t h of t h e j o i n t which a r i s e from poor cohesive s t r e n g t h i n the bulk of t h e adhesive i t s e l f or from t h e lack of adhesion between the adhesive and t h e m e t a l l . The o b j e c t i v e of t h i s study i s t o f i n d u l t r as o n i c techniques t h a t can g i v e a q u a n t i t a t i v e measure of t h e s t a t u s of the metal t o adhesive i n t e r f a c e so t h a t t h e adhesion s t r e n g t h of an adhesive bond ...
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