Real-Time Measurement of Thread Number of Rail Fastener

Abstract

A real-time measurement method for the thread number of rail fastener is proposed. The measurement is achieved by the processing of thread images. After analysis, the fastener thread has the elliptical feature, so two parameters‐‐‐elliptical similarity and elliptical integrity are proposed. Based on the two parameters, the thread region is located. Combining with the light intensity distribution of thread region and thread positions, the thread number is measured. 200 samples are chosen to verify the validity of this method. Experimental data show that the limitation error of this method can reach 0.1985 threads.