Research On Measurement Method Of Key Dimensions Of Rotary Body Based On Vision Measurement

Rotary parts are widely used in industry.In the field of mechanical manufacturing,the processing and production of rotary parts occupy a great position.Its manufacturing accuracy has a great influence on its performance.Therefore,the advanced detection technology should be used for rapid and accurate measurement after processing to ensure the manufacturing accuracy.Binocular vision technology is becoming more mature.Compared with manual measurement,it is faster,more accurate and more real-time.In addition,the structured light is added to the binocular vision to extract the image information more conveniently.Therefore,it proposes a method of combining binocular vision and structured light to realize the rapid measurement of workpiece size in this paper.The main contents of this paper are as follows:1.The camera calibration method is studied.In order to meet the needs of the measurement system,the imaging principle and calibration method of the camera are analyzed.Finally,a calibration method based on checkerboard template is selected.The method is simple,convenient,high precision and easy to implement.Finally,the relevant parameters of the camera system are obtained.2.The image processing method of revolving workpiece is studied.Firstly,the image filtering algorithms are compared.The median filtering method with a 5×5 window is used to process the image.The global threshold method based on Gaussian distribution is used to segment the object from the image background.Then,the gray centroid method of adaptive gray extremum is used to extract the center coordinates of structured light.The linear equation of center is obtained by linear fitting coordinates.Finally,the corresponding intersection coordinates are obtained.3.The stereo matching method is studied;SIFT algorithm and SURF algorithm are studied and compared in this paper.It is found that there are mismatches by using them;Then,RANSAC algorithm is used to purify the feature points of the two algorithms.Finally,SURF+RANSAC stereo matching method is selected according to efficiency and accuracy.4.The binocular vision measurement system is completed.The hardware platform of binocular vision is built and the corresponding software interface is developed.The system is used to measure the size of the rotary workpiece.The measurement results are obtained and analyzed.The results show that when the measurement error is within 0.1 mm,the single measurement can meet the requirement;When the system error is within 0.01 mm,the average of 8～10 times of measurement can meet the demand.Finally,the reason of the error is analyzed.