Machine Vision Technology for Measurement of Miniature Parts in Narrow Space Using Borescope

To achieve precise measurement for miniature parts in narrow space, a decouple measurement method using bore scope was proposed. A rigid bore scope was inserted into narrow space to acquire image, and image processing and image information obtaining was achieved based on IMAQ Vision module built in LabVIEW, the measuring position information of the bore scope was obtained by the driving linear stage, the position and attitude information of the object to be measured was gained by combining image and measuring position information eventually. A bore scope measurement system based on machine vision, which was composed of a bore scope, a CCD camera, an industrial computer, and a precision linear stage mounted with an optical linear encoder, was developed by adopting the above measurement method. The image processing algorithm was developed based on IMAQ Vision. The developed measurement system was used to measure the space of circular rings, and comparison with the results measured by universal tool microscope shows the maximum absolute measurement error of this system was below 8μm.