INTEGRATED FIBER OPTIC COUPLED PROXIMITY SENSOR FOR ROBOTIC END EFFECTORS AND TOOLS

THERE IS A NEED FOR FIBER COUPLED PROXIMITY SENSORS WITH HIGH SPEED AND ACCURACY FOR APPLICATIONS TO ROBOTIC END EFFECTORS AND TO AUTOMATED INSPECTION AND QUALITY CONTROL. THE PROPOSED PHASE I EFFORT WILL DEMONSTRATE A NOVEL, ROBUST, INTEGRATED CONCEPT WITH MULTIPLE SENSOR CAPABILITY. FIBER OPTIC SENSORS HAVE BEEN DEMONSTRATED TO HAVE GEOMETRIC FLEXIBILITY. IN THE CASE OF PHASE MODULATED INTERFEROMETRIC TYPE SENSORS HIGH SENSITIVITY IS DEMONSTRATED AS WELL. HOWEVER, DUE TO THE SENSITIVITY OF MODE DIODE LASERS TO BACK-REFLECTED LIGHT AND TO THE SENSITIVITY OF CONVENTIONAL SINGLE MODE FIBERS TO ENVIRONMENTAL PERTURBATIONS, PROBLEMS SUCH AS CORRUPTION OF LASER FREQUENCY SPECTRUM AND FIBER POLARIZATION FADING ARE LIMITING FACTORS. THE PROPOSED PHASE I EFFORT IS TO DESIGN AND DEMONSTRATE A FIBER OPTIC SENSOR SYSTEM THAT UTILIZES MULTIMODE DIODE LASERS AS AN OPTICAL SOURCE IN A COHERENT DETECTION CONFIGURATION THAT ELIMINATES THE PROBLEM OF ENVIRONMENTAL PERTURBATIONS WHILE RETAINING THE SENSITIVITY OF PHASE MODULATED SENORS. THE PROPOSED DESIGN HAS THE FLEXIBILITY TO MULTIPLEX A NUMBER OF MINIATURE SENSORS MOUNTED ON ROBOTIC END EFFECTORS AND TOOLSTO MEASURE PROXIMITY, TACTILE PRESSURE (TOUCH), FORCE, TORQUE.