Crystal Growth Detection System Based On The LabVIEW And IMAQ Vision

Visual detection is widely used in industrial detection field. With the development of computer technology, virtual instrument has become the important development direction of measurement and control field in the future. The combination of virtual instrument technology and visual detection technology has become the research hot spot in recent years. In this paper, the purpose of design is detecting the diameter of mono-crystalline silicon equal diameter growth. Under the machine vision detection technology, it uses image processing technology to design a crystal growth detection system by virtual instrument development platform and graphical language LabVIEW.According to the diameter detection of crystal equal diameter growth, this paper combines with the visual detection characteristics of virtual instrument, and uses image acquisition, processing and analysis technology to complete the detection system design of crystal growth diameter which includes the detection system overall mechanism design, hardware configuration, the selection of software and detection system software design. In the detection scheme setting, it makes full use of optical characteristics generated in crystal growth process. The reflector aperture diameter length generated by draft tube is used to be pixel equivalent calibration. The crystallization heat release halo in the crystal growth is used to be detection object. According to the least squares fitting characteristics, it makes arc fitting for the part of heat release halo to achieve the crystal diameter detection. The software program design of detection system takes full advantage of the function and image processing program provided by the IMAQ Vision to complete filtering, sharpening, segmentation and comparison of different algorithm effect in edge detection for target feature. It determines the best treatment option. Finally, it uses sub-pixel edge positioning technology and.fitting to complete the arc fitting, achieves the crystal diameter detection. The results of crystal diameter detection can meet the indicators of detection system. In order to improve the detection accuracy, the error correction is made for the system, and the causes of errors are analyzed. visual detection system of virtual instrument overcomes disadvantages of long development cycle and difficult system upgrade and maintenance in the traditional machine vision detection system. There are the advantages of high precision, low cost, easy maintenance.