Three-dimensional Visual Measurement Method And Realization Of Copper Workpiece Based On Structured Light

The development of the mold industry and other manufacturing industries are interdependent,and its overall level of improvement is closely related to the strategic goals of China Smart 2025.Since 2002,China's mold industry has achieved more than 20% growth for many years in a row,and domestic mold industry products continue to inflict impact on the highest level in the world.Mold size and appearance shape defect detection is an important breakthrough to improve product quality and enterprise competitiveness.Therefore,developing a high-precision,high-efficiency,low-cost three-dimensional measurement system is of great significance and value.In this paper,a variety of non-contact three-dimensional vision measurement methods have been studied in depth.After comprehensive analysis of the advantages and disadvantages of all methods,a three-dimensional visual measurement method based on surface structured light copper workpieces is proposed.This method is based on surface scanning.The method has the advantages of greater data acquisition,faster measurement speed,high measurement accuracy,and low cost for a single measurement,and can effectively realize non-contact fullautomatic measurement of three-dimensional dimensions of the copper plate workpiece.The main work content and innovation of this article are as follows:Firstly,the method of surface-structured optical phase profilometry(PMP)was used to complete the three-dimensional measurement of copper workpieces.The measurement system was mainly composed of industrial cameras and projectors.The principle of the phase shift algorithm and the phase unwrapping algorithm in this method are introduced.The three-step phase-shifting method and the phase unwrapping algorithm based on the graph-cutting are used to solve the phase.The experiments show that the algorithm selected in this paper can accurately calculate the complexity.Continuous object surface phase information.In-depth study of the 3D reconstruction system of the classical model,analyzes the deficiency of it,a new three-dimensional system model is developed and the mapping relationship between phase and three-dimensional coordinates in the system model is deduced.A high-accuracy calibration algorithm based on the system model was completed,and the system parameters of the measurement system were calibrated through experiments.Systematic analysis of the error sources of the system.Through theoretical analysis,simulation experiment and actual measurement,analyzed the process of phase error,and on this basis,a method of correcting the system's non-linear gray-scale response and an absolute phase error compensation algorithm based on cubic spline interpolation are proposed.Experimental results show that both of the proposed algorithms can effectively reduce the phase error and improve the measurement accuracy of the system.A method is proposed to reduce the amount of data calculation of the measurement system by using prior knowledge and two-dimensional image algorithms,which improves the measurement efficiency of the system.Then,the appropriate hardware is selected around the above measurement scheme to complete the hardware construction of the measurement system.Finally,the measurement system built in this paper is used for experiments to obtain threedimensional point clouds and three-dimensional dimensional data of different specifications of copper plate workpieces.