MULTI-ROBOT CONTROL FOR FLEXIBLE MANUFACTURING SYSTEMS

THE PROPOSED WORK WOULD RESULT IN THE DEVELOPMENT OF A SUPERVISORY CONTROL SYSTEM FOR FLEXIBLE MANUFACTURING SYSTEMS (FMS) IN GENERAL, AND COOPERATING MULTI-ROBOT SYSTEMS IN PARTICULAR. THIS SYSTEM, TO BE REFERRED TO AS ANACTIVITY CONTROLLER (AC), WILL BE ORGANIZED IN A HIERARCHICAL STRUCTURE WHERE THE LEVELS OF THE HIERARCHY CORRESPOND TO THE DIFFERENT DECISION TYPES NECESSARY TO CONTROL A FMS. AS THE DECISIONS NARROW FROM PLANT-LEVEL TO MACHINE-LEVEL, BOTH DECISION DETAIL AND COMMUNICATION RATE INCREASE, THE LATTER FROM HOURS TO MILLISECONDS. IN THE AC HIERARCHY, THE REALTIME STATUS OF THE FMS IS TAKEN INTO ACCOUNT AT EACH LEVEL. THE HIGHEST LEVEL ORGANIZES FMS COMPONENTS TO MEET SHORT-TERM PRODUCTION REQUIREMENTS AND THE LOWEST LEVEL ISSUES COMMANDS TO A ROBOT CONTROLLER. THE WORK FOR PHASE I FOCUSES ON THE LOWER LEVEL OF THE AC, WHERE THE TASK IS TO ASSURE CONFLICT-FREE OPERATION OF THE SYSTEM. WE EMPHASIZE THE LOWER LEVEL IN THIS WORK AS IT IS THE FUNDAMENTAL BUILDING BLOCK (BEYOND COMMUNICATION) FOR SYSTEM INTEGRATION. CURRENT SOLUTIONS FOR CONFLICT AVOIDANCE ARE AD HOC AND DEMAND PROLONGED DEVELOPMENT TIME. IN PHASE I, A GENERAL METHODOLOGY FOR CONFLICT DETECTION ANDAVOIDANCE WILL BE DEVELOPED, AND AN EFFICIENT AC WILL BE GENERATED. INTERFACES TO BOTH LOWER (ROBOT) AND UPPER (PRODUCTION) LEVELS WILL BE CONSIDERED.