New method to measure piston skirt dimensions

The measurement of the middle-convex and varying ellipse profile of a piston skirt is a key technology because of its complex profile andhigh precision. Generally, a piston is measured on a special device after it is machined. High accuracy can be achieved through this off-line measurement, but the result diverges from the actual dimension. Therefore, a no-contact in-site measurement system is proposed. A laser displacement meter is used to measure the profile of the piston skirt. A computer connected to the meter is used to process the measured data. A regression analysis method is used to process the ellipsesection data. The method of moving average is used to process the middle-convex curve data.By using the given system, high measurementaccuracy