The Automation Division of Tata Steel Limited has developed a Vision Based Width Measurment System using state of the art image processing techniques.
TrueSpan has been developed for online width measurement of strip in Hot and Cold Rolling Mills. TrueSpan can be configured for stereoscopic measurement of strip with varying HOP and TILT on the roller table. TrueSpan is developed to provide a very high-speed width output maintaining high precision measurement accuracy under all mill conditions.
TrueSpan senses the strip edges with two very high-resolution linear array CCD cameras used to snap at about 20 MHz placed on the top of the rolling table. For width measurement at same point with respect to the strip, a common clock controller synchronizes the cameras. TrueSpan uses sophisticated image processing algorithms for noise filtering and edge detection. Triangulation principles are used to estimate the width incase of HOP or TILT of the strip on the roll table. For measuring width of cold strip same principle is applied with appropriate back light arrangement.