Research On Comprehensive Measurement Method Of External Thread Parameters Based On Image

With the development of modern industry.The demand for high quality mechanical parts is increasing rapidly.Threaded parts is a widely used mechanical connection.Threaded parts are used in almost all industrial products.There are already a large number of thread measurement methods.Among them,image-based detection methods have received extensive attention and in-depth research due to their high detection accuracy and speed.Based on the research of existing measurement methods,The paper proposes a new comprehensive measurement method for external thread parameters.Theoretically make up for the shortcomings of the existing methods.At present,most image-based thread measurement methods determine the qualification of the thread based on the parameters extracted from a section.There is a problem with the detection results of such methods.The detection method proposed in this paper is no longer to detect single section.But a comprehensive measurement of the external thread.The paper improves the measurement platform so that the threaded parts can rotate continuously.Obtain the video of the threaded parts by the CCD camera.And then the video is processed and extracted the parameters of the threaded parts.Then use the sampling method designed in this paper to select the section from the video.Based on feature points on the section.Then reconstruct the 3D model of threaded parts.Finally,the comprehensive measurement will measure the threaded parts from two aspects,axial and radial.In addition,the paper research on the distortion of the thread profile curve and the thread distortion mathematical model.In the experimental part,the paper demonstrates the correctness of the model and the influence of various parameters on measurement results.In addition,demonstrates the model can reduce the results error.Finally.the comprehensive measurement methods proposed in this paper is verified.