Laser system for controlling glass drawing speed
The system is designed for control of glass drawing processes.
The system is based on the correlation method of measuring motion speed. The first photodetector of a CCD-camera reads image of a glass-sheet edge at fixed time intervals. The images acquired are digitized and compared to each other. The distance passed by the glass edge in a time interval between frames and, hence, the glass movement speed, is calculated from the position of the maximum of the correlation function in the selected image zones. Simultaneously, by processing of the image from the second photodetector the transverse displacement of the glass tape is calculated.
The system consists of
a TV camera with two CCD-linear arrays and image processor;
a semiconductor laser illuminator;
a control and display panel equipped with a graphic display, a numeric speed value indicator and a linear indicator of the glass displacement value. The control panel forms input signals for the automatics which controls the glass drawing process line and transmits information to workshop supervisorís PC;
an optical extender and a blind which reduce effects of extraneous light sources.
The system installation diagram
Glass drawing speed
Size of defects in the glass edge,
not less than 1 mm
Motion speed measurement error,
not more that 5%
Transverse displacement of glass sheet,
not more than 5mm
|Image formation arrangement
Water-cooled TV camera
overall dimensions 180x100x80 mm
Control and display panel
overall dimensions 200x100x65 mm