Deviation and error compensation method for small module gears based on visual measurement

Abstract To solve the issues of locating and measurement errors that are presented in the visual inspection system for small module gears, an image sub-pixel location algorithm and gear measurement method were presented in this paper. Several methods have been developed to assess the accuracy level of small module gears, including a gear edge positioning algorithm based on the local area effect of the edge, a position error compensation algorithm, and a technique for calculating the number of gear teeth using Fourier transform. The effectiveness of these algorithms is verified by using virtual gears, and the result of the maximum profile deviation of 0.81 μm is achieved. Taking a plastic gear with a module of 0.5 mm and 14 teeth as a sample, the accuracy grade 8 is reached by using the aforementioned measurement system, aligning with the actual results. Experiment results have shown that this method provides a reference for the visual measurement of small module gears.