Development of a model-based, integrated monitoring and control system for laser processing applications

On the basis of previous work, the development of a model-based monitoring and on-line automatic regulation system applicable to the real-time control of laser welding and surface heat treatment has been undertaken. In both kinds of applications, the main diagnosis system considered in the control loop is a thermal camera either used to provide a 2D temperature map or, more suitably according to typical response time parameters, used as a line scanner sweeping the appropriate diagnosis zone. From the automatic regulation point of view, the developed control system is defined to correct typical perturbations in incoming laser power, material thickness or piece motion speed within the appropriate time scale in order to assure a practical validity of the in-course weld seam or heat treatment track, respectively. The resulting control module, grounded on reasonably reliable calculations of the processes parameters performed with own-generated models provides a valuable tool for the practical implementation of the referred applications with special regard to quality assurance purposes.