Research Of 3D Dimensional Omnidirectional Measurement Technology Based On Machine Vision

Many modern industrial productions require a full range of 3D measurements of parts.Some need to measure specific points on the part,while others need to measure the overall three-dimensional shape of the part,and then obtain other data of the part.In order to carry out high-precision three-dimensional measurement of parts,an all-dimensional three-dimensional measuring platform for parts was designed.The specific research work of the subject can be divided into the following parts:(1)Analyze the status quo of visual measurement technology at home and abroad,design a comprehensive high-precision measurement method and platform for parts based on machine vision,and adopt the method of visual measurement plus 5D high-precision mechanical motion to realize all-round high-precision measurement of parts.The platform includes mainly visual measurement modules,two-dimensional turntables and three-dimensional platforms.The two-dimensional turntable is used to adjust the pose of the vision measurement module,and the three-dimensional platform is used to adjust the position of the part.(2)According to the principle of structured light measurement,combined with the experimental platform design feature point measurement method to complete the high-precision three-dimensional measurement of the surface point of the part.The traditional structural light measurement method is used to complete the three-dimensional shape measurement of the part.The analytical geometry of the structured light measurement and the measurement accuracy of the perspective projection model on the experimental platform are compared.The accuracy of the analytical geometry is better than the perspective projection model.One of the main factors in the introduction of uncertainty in analytical geometric models is the uncertainty of calibration coefficients.(3)There are non-orthogonal and different-surface conditions on the rotating shaft of the experimental platform,and the uncertainty introduced in the two cases and the comprehensive situation is simulated and analyzed.The uncertainty introduced by the two cases will change with the rotation angle around the axis.The maximum uncertainty introduced by the single axis in the case of different faces is twice the distance of the different faces.The uncertainty introduced in the case of non-orthogonality is not The orthogonal yaw angle and the rotation angle are transformed.In general,the uncertainty is mainly affected by the distance of the different planes in the range of non-orthogonal declination of 100 arc seconds.