SIX-COMPONENT ROBOTIC FORCE-TORQUE SENSOR

BECAUSE OF THE EXPENSE AND COMPLEXITY OF MANNED FLIGHTS IT IS DESIRABLE TO PERFORM MANY OF THE NASA SPACE MISSIONS BY TELEOPERATOR CONTROL OF SPACE-BASED ROBOTIC SYSTEMS. THE REMOTE ORBITAL SERVICING SYSTEM (ROSS) IS BEING DEVELOPED TO ENABLE AN UNMANNED SPACE VEHICLE TO PERFORM MAINTENANCE AND REPAIR DUTIES. UNLIKE INDUSTRIAL ROBOTS, THE ROBOTIC SERVICER KIT PORTION OF ROSS WILL NEED TO OPERATE IN A RELATIVELY UNSTRUCTURED ENVIRONMENT. ALTHOUGH VISION SYSTEMS PROVIDE CRUCIAL INFORMATION FOR SERVICER KIT OPERATION, BOTH TACTILE INFORMATION AND REACTION FORCE- TORQUE MEASUREMENTS ARE MANDATORY FOR FULL CAPABILITY. CURRENT-MULTI-AXIS FORCE-TORQUE SENSORS ARE EXPENSIVE, BULKYDEVICES. THIS PROJECT ADDRESSES A NEW APPROACH TO THE DESIGNOF A SMALL, LIGHT-WEIGHT SIX-COMPONENT FORCE-TORQUE SENSORS BASED UPON ULTRASONIC PULSE-ECHO RANGING TO MEASURE THE DISPLACEMENT OF A CONSTRAINED ELASTROMERIC PAD THAT IS DEFORMED BY LOADING FORCES AND TORQUES. BY USING A THIN- FILM POLYMER MATERIAL AS THE ULTRASONIC TRANSDUCER, THE SENSOR HAS THE POTENTIAL OF BEING EXTREMELY RUGGED, SIMPLE, AND INEXPENSIVE. THE OVERALL OBJECTIVE OF THIS STUDY IS TO DETERMINE THE FEASIBILITY OF THE FORCE-TORQUE SENSOR CONCEPT BY DETERMINING THE SUITABILITY OF THE PROPOSED MEASUREMENT SCHEME, THE SUITABILITY OF ELASTOMERS AS LINEAR SPRINGS, AND SENSOR PERFORMANCE UNDER DIFFERENT LOADINGS.