A LOW COST INFRARED SENSOR BASED SYSTEM FOR ROBOTIC WELDING

NONDESTRUCTIVE TESTING, IDENTIFICATION, AND REPAIR OF WELD DEFECTS HAVE BEEN DOCUMENTED TO CONSUME AS MUCH AS 25% OF THE TOTAL WELD PRODUCTION COST IN PIPELINES, SHIP FABRICATION, AND POWER GENERATING SYSTEMS. INFRARED SENSOR CONTROLLED WELDING SYSTEMS HAVE BEEN DEMONSTRATED THAT WOULD GREATLY REDUCE OR ELIMINATE EXPENSIVE, AFTER-THE-FACT NONDESTRUCTIVE TESTING AND WELD REPAIR. HOWEVER, THE COST OF THESE SYSTEMS HAS BEEN WELL OVER $60,000, AND HENCE COMMERCIALIZATION OF THIS TECHNOLOGY HAS NOT OCCURRED. THIS PROJECT WILL DEVELOP AN INFRARED SENSOR-BASED SYSTEM FOR WELD PROCESS CONTROL THAT IS NEARLY AN ORDER OF MAGNITUDE CHEAPER THAN CURRENT SYSTEMS. THIS COST WOULD PLACE THIS NEW TECHNOLOGY WELL WITHIN THE REACH OF PIPELINE, SHIP, AND HEAT TRANSFER PIPING FABRICATORS. THE LARGE COST REDUCTION IS DUE TO DEVELOPMENT OF A NEW LOW COST INFRARED SENSOR HEAD. IN PHASE I, PROTOTYPE SENSOR HEADS WILL BE CONSTRUCTED AND TESTED TO DEMONSTRATE THE ABILITY OF THE NEW SYSTEM TO IDENTIFY WELD PERTURBATIONS WHICH OCCUR DURING COMMERCIAL, LARGE SCALE WELDING OPERATIONS. THE ABILITY OF THE INFRARED SENSORS TO IDENTIFY VARYING DEPTHS OF WELD PENETRATION AND WELD MICROSTRUCTURE (MECHANICAL PROPERTIES) WILL BE TESTED. SENSOR SYSTEM SENSITIVITY, RESPONSE, AND ROBUSTNESS WILL BE EXAMINED TO DETERMINE THE APPLICABILITY OF THE DEVICE TO CONTROLLING THE WELDING PROCESS IN A HARSH WELDING ENVIRONMENT. BASED UPON THE SUCCESSFUL TESTING OF THE SENSOR SYSTEM, PHASE II RESEARCH WILL LEAD TO THE DEVELOPMENT OF A PROTOTYPE INFRARED SENSOR-BASED CONTROL SYSTEM FOR ROBOTIC WELDING.