Dynamic models relating processing parameters and melt track width during laser marking of clay tiles

This paper describes two dynamic models relating processing parameters and melt pool width during laser marking/engraving of clay tiles using a high-power diode laser. The models were determined by process identification techniques and were validated with a PI algorithm. The output variable considered for the laser clay tile marking process was melt pool width, measured by using a fast CCD recording system and analysed with an image-processing software. The input quantities investigated were laser power and traverse speed. Reasonable agreements between the measured data and the model outputs were achieved. Errors less than 1.3 μm of the melt pool width for the operating points were found. On the basis of these models a simple PI-controller was designed and tuned to guarantee zero steady-state error in case of an absorptivity disturbance.