Research On Key Techniques For Measurement System Of Inner Diameter Of Revolving Artifacts

Revolving artifacts are widely applied in agriculture,industry,military,and other fields.They are generally mass-produced using automatic production lines,which requires high-precision automatic measurement of the inner diameter of the revolving artifacts for the manufacturing precision.This dissertation reviews the literatures on the measurement of revolving artifacts and researches the key techniques for measurement system of inner diameter of revolving artifacts.The main work in this dissertation is as follows:The current measurement equipment was improved.Specifically,the X-axis was removed,while the two-axis contact measurement scheme for revolving artifacts consisting of the Z-axis and the C-axis was proposed.The measurement workflow was designed.Then,the measurement principle of the inner diameter of the revolving artifacts in a section was analyzed,and the two measurement methods of inner diameter were compared.The mechanical structure of the measurement host was designed,and selected the main components.Next,the measurement system was built.Besides,a pneumatic telescopic contact displacement sensor was adopted for inner diameter measurement;a special measurement software was developed.The machine vision-based artifact recognition system was proposed to identify whether the artifacts were placed in the measurement station,and the hardware of the artifact recognition system was designed and built.A recognition algorithm using the matching of circular projection templates was adopted,which was then improved by image pyramid and non-maximum suppression method.Then,the improved algorithm was compared with the original algorithm and demonstrated significantly higher recognition efficiency.Later,experiments of the revolving artifacts were carried out under different conditions,which verified the effectiveness of the method.The influence of the eccentricity error of the displacement sensor relative to the revolving center of the revolving table,the sensor inclination error,the artifact tilt error,the Z-axis error,and the revolving error of the revolving table on the inner diameter measurement of the revolving artifact was analyzed,and the realistic mathematical model of the measurement system was established.Then,the inner diameter measurement algorithm based on the least-square fitting method was optimized by eliminating coarse errors.Using the differential evolution algorithm,based on the standard inner diameter of the standard ring gauge,the realistic mathematical model of the measurement system was applied to derive the system parameters.Then,the verification experiment was carried out using another standard ring gauge.Experiments show that the repeatability,stability and anti-interference performance of the measurement system meet the measurement requirements.The method proposed in this dissertation can also be used in the measurement applications of revolving artifacts in other specifications and is of great significance for promoting the high precision and automation measurement of revolving artifacts.