Image measurement method of gear involute error of small module gear

In order to measure the gear involute error of small module gear, a new non-touch measurement method, which is difficult to measure by traditional measurement method, is proposed. By establishing the reasonable world coordinate, workpiece coordinate and image coordinate as well as the mutual coordinate transform relations corresponding to the gear profile, the each gear profile is scanned and imaged by the CCD camera and the mathematical, model is established; the gear profile feature is extracted through digital image processing technique; According to the measurement definition of the gear involute error, gear parameter measurements and error analyses are implemented automatically and more completely through the computer. Experimental results indicate that the use of image measurement method enables the absolute error of measurement to be less than 2mu m, and the method proposed is an effective approach to measure the gear involute error of small module gear. Not only the adjustment part for gaining corresponding information of gear generating angle in traditional measurement but also the personnel errors are reduced, and the measurement efficiency is improved.