INSTRUMENT TO MEASURE CONTACT VELOCITY IN SIDE IMPACT TESTS

OCCUPANT PROTECTION IN VEHICULAR SIDE IMPACT CRASHES IS AN IMPORTANT THEME OF THE '90S FOR THE DEPARTMENT OF TRANSPORTATION, FOR AUTOMAKERS, AND FOR INDEPENDENT RESEARCHERS. DEVELOPMENT OF OCCUPANT PROTECTION METHODS REQUIRES ACCURATE MEASUREMENT OF CONTACT VELOCITY IN SIDE IMPACT TESTS. MICROWAVE INTERFEROMETRY (MI) IS PROPOSED AS A MEANS TO MEASURE DOOR/OCCUPANT VELOCITIES IN SIDE IMPACT TESTS. MI IS EXTREMELY ACCURATE, AND MI-BASED SENSORS CAN BE CONFIGURED IN SMALL PACKAGES THAT ARE NEARLY IMMUNE TO HOSTILE ENVIRONMENTS. IN ADDITION, UNLIKE ITS OPTICAL ANALOGUE, MI DOES NOT NEED CUBE CORNER REFLECTOR DEVICES AND ACCURATE ALIGNMENT. THE APPLICABILITY OF MI WILL BE STUDIED AND COMPARED TO CONVENTIONAL MEASUREMENT METHODOLOGIES. A SIMPLE MI INSTRUMENT WILL BE USED TO MAKE ACTUAL MEASUREMENTS IN SEVERAL CRASH TESTS. HIGH SPEED FILM AND OTHER CONVENTIONALDISPLACEMENT INSTRUMENTATION WILL PROVIDE DATA FOR EVALUATION OF THE MI PERFORMANCE. MI IS IDEALLY SUITED TO CRASH TEST MEASUREMENTS. BECAUSE THIS MEASUREMENT METHODOLOGY WILL GIVE EXTREMELY ACCURATE RESULTS FOR A WIDE RANGE OF SPEEDS, AND BECAUSE IT IS NEARLYIMMUNE TO VERY HOSTILE ENVIRONMENTS, IT CAN BE USED IN MANY OTHER APPLICATIONS. IN ADDITION, MI IS INEXPENSIVE ENOUGH TO BE USED IN DESTRUCTIVE APPLICATIONS.