Study On Three-dimension Digital Reconstruction Of Agricultural Materials Based On Laser Contour Scanning

With the vigorous development of modern agricultural engineering technology.The three-dimensional reconstruction of the pose and color of the surface topography of the agricultural materials has broad application prospect.Based on the surface texture of agricultural materials(cactus model and soya)as the research object,Component a set of laser scanning experiment device in order to get the whole surface of the three-dimensional coordinates of agricultural materials point cloud,based on the triangles in the farm material and color rendering three-dimensional reconstruction of the whole surface.Specific studies content are as follows:The scanner and laser contour electric translational platform and its controller assemble 3d laser contour scanning experiment device and write control software.Among them,the outline of the laser scanner by cable 192.168.0.x are connected to the PC network IP address;Electric translational platform and its controller PC via RS485 serial port turn USB connection,set the working parameters and operation parameters,control the translation along the Y axis displacement of single step;In the three-dimensional laser contour scanning control software,set the intensity of the laser and exposure time,and the X and Z axis coordinate interval.In order to eliminate the systematic error of the experiment device,for the length,width,and high dimensions of 30mm,9mm.4mm and the three-dimensional contour scanning calibration in three-dimensional coordinate axis,method is that(1)in the scanner comes with RF620 Setup Program repeated adjust Angle parameters to determine the X axis offset Angle,realize the X axis and the translational parallel calibration;(2)along the X axis for standard block,the flat line point cloud mutations on the Z axis,the other side of the point cloud X coordinate values for the difference between the standard piece of scanning width AX,the calculation of the Y axis offset Angle for arccos(9/AX).Y axis and the X axis vertical alignment.(3)in the Z axis mutations to remove noise near a number of point cloud,respectively based on the standard block,the plane Z axis coordinates mean and standard deviation of the point cloud computing standard block highly AZ scan,the calculation of Z axis offset Angle for arccos(4/AZ),Z axis and translation units of vertical alignment.Finally,the agricultural material is fixed on the frame of the cube for three-dimensional contour scanning multiple points of view,based on rotating match,coordinate transformation and splicing technology for agricultural three-dimensional coordinates of point cloud surface material.Agricultural material surface point cloud at any point as a starting point,based on triangular growth algorithm to form a Delaunay triangle,the triangle is empty circumcircle,convex polygon shell and maximum angle of nature and of every point and near point cloud topology connection,until all points connected into a triangle.Iterate through each point there must be repeated connection and connection error phenomenon,a small amount of the large size triangular noise does not belong to agricultural material surface,to all triangle circumradius mean for threshold to remove false connection,accurate access to agricultural material surface point cloud of triangular facets.And the sum of agricultural materials triangular surface area,access to agricultural material surface area;the triangle along the Z axis projection forming a plurality of prism,triangle plane equation is obtained,and the sum of the prismatic volume,access to agricultural material volume;quadratic polynomial fitting of agricultural material outer contour x,Z axis points cloud,with line point cloud of the Z axis of the average error of the forms of agricultural materials classification.With the camera of 5 mm focal length,gathers the two-dimensional color images of agricultural materials,binary image processing,under the background of agricultural materials for two-dimensional color images.The three-dimensional coordinates of the agricultural material point cloud surface along the X axis direction projection for two-dimensional point cloud,for the boundary of the two-dimensional point cloud image and color image rotation change,color image rotation transform to the relevance of the highest point of view.The two-dimensional world coordinates of the point cloud with two-dimensional color images in pixel coordinates mapping,looking for the two-dimensional point cloud with two-dimensional image pixels corresponding relation,triangle vertex color information,and further,to triangle vertex color mean for triangles in the color rendering,realizes the the surface of the whole color rendering of agricultural material.The color of agricultural material is classified by gray scale.