Research On Vision Coordinate Measurement Method Of Small Parts

The application of vision coordinate measurement technology in industrial automation detection is currently one of the hot research subjects, which can substantially reduce the cost of measurement, improve productivity and rate, and it has been widely used in the field of the industrial automation measurement and control. Based on image processing technology, choosing small modulus gear and complex shape parts as examples, this thesis studies a combining method of vision and coordinate measurement, achieving non-contact measurement of the small parts, solving some problems in traditional measurement method. This thesis mainly discusses the following four parts.Analyzing geometrical features and optical information of small parts, the corresponding vision coordinate measurement methods and system composition scheme was investigated. The image acquisition and image processing was detailedly discussed, the image pretreatment, image segmentation and image filtering method was described. In order to solve the problem that the microscopic image can't obtain the panorama of observed objects, image mosaiking and image fusion technique were primarily introduced, so as to more fully and accurately reflect the feature information of the entire part and to provide basis for following measurements. In order to complete the relevant parameter measurement, combining with the existing geometric measurement methods, corresponding coordinate system and transform relation were established, and mathematical models for geometric measurement were set up. Finally, the hardware system was assembled, software was developed, the systems calibration, the typical parameter measurement and experimental data processing were implemented, meanwhile the causes of error and the main factors for affecting measurement accuracy were analysised.The experimental results show that with the camera instead of focusing visual aiming target, manually adjust the displacement of coordinates instead of using image mosaiking and size measurement using software algorithm, measuring small parts with visual coordinate measurement method can reduce the aiming error of instrument, the reading error of coordinate, subjective error of testers and the work intensity in general measurement. The discussion of vision coordinate measurement system and data processing method is significant to measure geometrical parameters of other small parts, and their application prospects are very broad.