Research On Measuring Method Of Rotary Workpieces Based On Stereo Vision

In the automatic production process of modern manufacturing industry,it involves lots of inspection,measurement and identification of workpieces.Among them,the application of monocular vision technology is more,though monocular measurement requires many priori parameters than binocular measurement.In order to explore the practicability of the binocular vision system,this thesis proposes to use binocular vision technology to measure the position and size of the rotating parts in complex environment.It can be used for classification,grasping and inspection of workpieces with round surfaces,which helps to improve production efficiency.The main tasks are as follows:Investigate and analyze the development status of machine vision technology,clarify the research background,research objectives and content.Clarified the key technology of digital image processing used in the experiment and completed some theoretical derivations.Set up the hardware part of the vision system,establish a pinhole imaging model and complete the mathematical derivation of the mutual conversion relationship between the various coordinate systems in the model,then solve the camera calibration,then determine a more reasonable camera calibration method and finally get the camera internal and external parameters and correction Parameters required for lens distortion.Complete the software part of the vision system based on OpenCV,determine the overall flow of the measurement,choose a variety of filters and compare the performance of each filter,respectively choose a filter suitable for different environments to complete image smoothing and an ellipse selecting method is designed according to characteristics of the workpiece.Among ellipses obtained by the filter,the ellipse corresponding to the target workpiece is successfully identified and its position,size and posture are obtained.Based on the stereo vision directly grabbing the center of the part,then obtain the posture and size of the measurement example.And complete the error analysis,correct the measurement method on this basis,improve the accuracy,prove that the method has good stability,pertinence and practical value.