In-process optical measurement and data graphing of paper sheets using Sherlock32 and Visual Basic

Quality control through real-time process improvement and on-line inspection has become a key element in establishing efficient production lines. Machine vision solutions to these quality control issues are becoming increasingly popular as machine vision systems become more cost effective. This paper discusses how a machine vision system is incorporated into a paper product production line to provide 100 percent inspection and real-time, process control feedback. Seven dimensional measurements are performed on an 8.5 by 11 inch, 3 ring binder divider sheet, to an accuracy within 0.002 inches. The vision system hardware engine is comprised of a standard, multimedia personal computer that is enhanced with two frame grabber boards and Sherlock software from Imaging Technology. Two progressive scan CCD cameras are used to provide high speed image acquisition and adequate image resolution. Using Microsoft Visual Basic, the operator is provided with a single, graphical user interface with real-time graphing of the measurement data. Visual Basic runs in the foreground, controlling the user interface, while Sherlock operates in the background, performing all the machine vision tasks. By viewing the real-time graphs generated in Visual Basic, the operator is able to make process improvements, in real time, at line sped sin excess of 200 sheets per minute.