Research On 3D Contour Imaging Technology Of Objects Based On Ultrasonic Synthetic Aperture

Ultrasonic waves have strong penetrating power,good propagation direction,and no clear diffraction,fast and efficient features.And the most important thing was that it is harmless to the human body.In terms of industry,the main research focus of ultrasonic imaging lies in the field of non-destructive testing,detecting internal defects of objects.However,there is little research on the reconstruction of the surface contour and the reconstruction of the 3D point cloud data model.In this paper,the surface contour of the object was imaged by ultrasonic synthetic aperture focusing imaging,the acquired matrix data was converted into point cloud data,the coordinate system was determined according to the moving trajectory of the probe,and all the point cloud data was used to restore the entire model.Firstly,this paper introduces the basic four kinds of ultrasonic synthesis focusing methods and their respective characteristics.The synthetic focus imaging method is selected for imaging.And,the detection method of cube trajectory is proposed.The detection method of cube trajectory is used to record the moving distance of the probe.the ultrasonic image of the surface contour obtained by the ultrasonic synthetic aperture focusing imaging method is introduced in detail to extract the surface contour of the detected object,and the matrix data of the surface contour is converted into point cloud data.The coordinate system of the surface contour is established by the movement trajectory of the probe,and the spatial coordinate system of the restoration model is also positioned by the coordinates of the surface contour and the movement trajectory of the probe.The amount of point cloud data is used to determine the size of the reduction model.The surface contour line after edge detection of the ultrasound image has a clear demarcation point,and the data retained after the point cloud data is converted determines the size of the restoration model.A computer simulation standard cube model and a model with a stepped convex structure were used,a 128-aperture probe was used for data acquisition,and a synthetic focused imaging method was used for ultrasound imaging,and the three-dimensional point was restored.Cloud data model,For the standard cube model,the reduced 3D point clouddata model has a certain overall expansion,and its surface contour has a length error of 1.83 mm compared to the detection model,and in contrast to the model with a stepped convex structure,in the step The surface contour line on the convex structure has a length error of2.01 mm.On the surface contour line of the stepped convex structure,there is an error of 0.2mm,and the error on the stepped convex structure is shorter than that of the detection model.In this paper,the Multi2000 system was used to build an experimental platform and the actual data was collected.The detection model was a rectangular parallelepiped model.Since there is noise in the actual detection,the threshold value is increased in order to eliminate the noise when the point cloud data is converted,the detection model is restored by the positioning of the probe's moving trajectory and the processing of the point cloud data.Compared with the actual model,the surface contour has only a length error of 1.15 mm,1.20 mm,and 1.10 mm,which is shorter than the overall model because the threshold is increased.In this paper,the surface contour of the object is imaged by using the ultrasonic synthetic aperture to obtain the data and the data is processed to restore the entire object model.The use of simulation software and experiments continued the theoretical validation.Lays the foundation for 3D point cloud surface contour imaging technology based on ultrasonic synthetic aperture.