Research Of 3D Image Reconstruction Of Hollow Defects In Logs Based On LabVIEW

In recent years,with the continuous improvement of environmental protection in China and the severe situation of the ever-changing structure of timber resource,how to improve timber utilization becomes more and more important.Stress wave detection technology is a kind of non-destructive testing technology that can effectively reflect the internal characteristics of wood by using the propagation characteristics of stress waves in wood in case of destroying the original characteristics of the wood.Meanwhile the stress wave wood nondestructive testing technology is mostly limited to keep in a status of MATLAB simulation theory research.This article innovatively explores that how to achieve online nondestructive testing based on LabVIEW technology,and mainly revolves around 2D and 3D defect image reconstruction modeling algorithm.This paper is dedicated to explore how to embed a reconstructed image program on the LabVIEW platform to achieve online non-destructive testing.This paper combines the technical advantages of stress wave non-destructive testing and the strong compatibility and flexibility of LabVIEW virtual instrument platform in order to perform 2D image reconstruction and optimization of wood internal defects that 3D modeling of the reconstructed multilayer 2D images.The integration of stress wave non-destructive testing across platforms has been realized,and the two-dimensional graphical reconstruction of the void area of the logs which comes from the establishment of a three-dimensional model that have basically been completed through nondestructive testing of stress waves.Real-time stress wave detection,2D image,and 3D model feature display on the LabVIEW virtual instrument platform.Through stress wave non-destructive testing technology to reconstruct and display the outline image of wood internal defects,this process can clearly and real-time reflect the internal characteristics of the wood,and provide effective detection basis for future protection,prevention and protection of wood.This paper focuses on the reconstruction of three-dimensional images based on stress wave non-destructive testing.Firstly this paper focuses on how to ensure that the reconstruction accuracy of two-dimensional images can be improved based on the establishment of two-dimensional images.The time-domain processing of the collected stress wave signal is performed by a piezoelectric acceleration sensor,a charge amplifier,an NI data acquisition card,and a PC,and ray tracing and sensor test point interpolation are performed by using a cell back projection method and an improved Dijkstra shortest path planning.The basic algorithm of image processing and image processing improve the two-dimensional image reconstruction,optimization of defect areas and non-defect areas in the log on the LabVIEW virtual instrument platform.At the same time,the two-dimensional image fitting degree evaluation of the wood defect image is performed.The feasibility of image reconstruction methods and image optimization method improve the accuracy and resolution of the two-dimensional image.Because the reconstructed and optimized two-dimensional image is a necessary part of the three-dimensional image reconstruction,the accuracy of the three-dimensional image modeling is indirectly improved to some extent.Finally,a three-dimensional model reconstruction based on multi-dimensional 2D tomographic images.Using multi-dimensional 2D tomographic image data is so significant reference information for 3D model reconstruction.The 3D image reconstruction methods based on surface tomographic images and 3D image reconstruction methods based on volume data are used to establish 3D images,and ultimately on the LabVIEW virtual instrument platform.The three-dimensional graphical reconstruction of the real-time sampling data of the log supports a relatively clear display.