Visual Measurement Methods for Gear Geometric Parameters in Automotive Transmission

A geometric parameter system based on the principle of vision was developed for automotive transmission gears aiming to improve detection efficiency and measurement automation to address low automation and efficiency of measurement of geometric parameters with traditional methods in automotive transmission gear manufacturing. First, the images of gears were obtained through an image acquisition platform, some of which were preprocessed to separate their background information. An improved caliper measurement method was developed to address the light interference of the gear surface in the measurement. By using this method, the Deriche algorithm was used to extract image edges at the subpixel level, and the edge point information was obtained with a caliper and input into the Huber algorithm for edge fitting, which calculated the pitch diameter, modules, and geometric parameters. Finally, a geometric parameter measurement system was built for automotive transmission gears, and the measurement results were displayed using C# programming. The proposed system, with an average detection time of 2.86 s, met the on-site accuracy requirements with a measurement precision of 0.02 mm compared to the image-measuring instrument used in the studies. Compared with manual inspection, this system improves the inspection efficiency and automation degree and can meet the actual production site of 5 s per piece of the beat demand, applicable to the production site of the rapid inspection.