Spark plug size measurement system and method based on machine vision

The invention provides a spark plug size measurement system based on machine vision. The spark plug size measurement system comprises an image acquisition module, an image conversion module, a visionanalysis module and a PLC. The image acquisition module comprises an industrial camera, and the industrial camera is used for carrying out image acquisition on a spark plug and transmitting an acquired image to the image conversion module; the image conversion module converts the gray value of the acquired image into a digital signal and transmits the digital signal to the visual analysis module;the visual analysis module performs algorithm processing on the digital signal and outputs a processing result to the PLC; and the PLC judges the processing result. The invention further provides a measuring method based on the system. According to the invention, non-contact measurement is realized; the detection speed detection precision error is smaller than 0.0167 mm, the repeatability test error is smaller than 0.002 m