Application research on digital image technology in the measurement of nozzle spray cone angle

Spray cone angle is one of the important performance indexes of motor nozzle. The size of spray cone angle affects the distribution characteristics of fuel in combustion space directly. This paper uses digital image technology to get the binary edge image of spray cone angle through enhancing, edge detecting, and thinning to the spray cone angle image acquired. Classical Hough Transform is used to get the image edge. As a result, the spray cone angle can be discerned automatically. The field test shows that the relative error between image processing data and experimental data is less than 2%, which indicates that digital image processing technology has a comparatively high measurement accuracy and good promotional value.