Research On Key Technologies Of 3D Scanning Measurement

Three-dimensional measurement has been applied in many scenes,and the three-dimensional measurement system based on structured light has the characteristics of high precision,high speed and simple structure.This article describes the correlation and technical principles of 3D scanning.Aiming at the key steps in the structured light method:the phase analysis is analyzed in detail,and the corresponding solution for the phase jump in the phase dissolving process is proposed.The error effect caused by the shadow is analyzed and the corresponding phase error correction scheme is proposed.Parallel acceleration calculations are proposed for real-time requirements.The work done in this paper is as follows.(1)The structure of three-dimensional scanning system based on structured light is introduced in detail:projection equipment,shooting equipment and computing equipment.The influence of each part on the measurement results is analyzed,and the influence factors and different schemes of the different processes on the final result are intr~oduced.Focus on the analysis of the advantages and disadvantages of the physical grating which based projection method and digital raster projection method.(2)A sliding window filtering method is proposed for the shortcomings of the original backward judgment method.The backward decision method may cause a selection error of the standard phase in some cases and lead to the spread of the error.In this paper,a sliding window which based filtering method is proposed for this problem.The filtering method of the sliding window is different from the general filtering window.The purpose of the sliding window used in this paper is to find out that the standard phase is not filtering for all data.By comparison,it can be found that the sliding window filtering method can effectively solve the problem of error diffusion caused by standard phase selection error.(3)In the process of 3D scanning,it is inevitable that it will be affected by the shadow of the object.Since the data processing is processed for the gray image,the shadow part is detrimental to the data and will cause errors in the phase analysis of other non-shaded parts.influences.Aiming at this situation,this paper proposes a progressive-based correction scheme,which performs phase analysis through multiple progressive processing.A shadow error phase fill based on the fitting method is proposed for the data pin with shadow loss.(4)In many cases,3D scanning has real-time requirements,Such as industrial production and in autonomous driving.For the accelerated computing scheme of 3D scanning,a multi-process multi-core acceleration scheme based on CPU structure is proposed.For the parallel acceleration calculation scheme of GPU,comparing the processing speed of different schemes,it can be seen that the GPU can significantly accelerate the calculation process of 3D scanning.