The Research Of Material Pile Volume Measurement Based On Multi-vision

In order to enhance the physical distribution informatization management of sizeable enterprise, the enterprise needs to seasonable control the stock of original material, and solve the efficient measurement problem of material pile of outdoor storage yard in taking inventory and storage. This paper first analyses several3D measurement methods of computer vision, and points at the problem of camera view field’s blind angle and setting up spot measuring system when using recent single camera vision and double camera vision detection system in measuring sizeable material pile, then it presents the volume measuring method of material pile which bases on tri-vision.The main research content of this paper are listed as follows:(1) Analyse the influence of tri-vision measuring system’s geometry structure on measurement, define the position and angle in putting up cameras, and set up optics projection system.(2) accomplish the single-point and global calibration of three cameras based on Tsai two steps calibration method; set up the transform relation and calibration model of four coordinate system in measurement system; appraise the calibration precision of camera.(3) preprocessed material pile image for using gray scale of color image and histogram equalization of gray scale image, enhance the contrast ratio of image; on the basis of researching several existing abstracted and matched method, because of the unobvious change of material pile image gray, choose the artificial assist method to abstract and match the tagged points of material pile.(4) On the basis of getting the inside and outside parameter of camera and accomplishing the tagged points’matching of material pile image, according to the inverse transformation principle of camera calibration model, calculate the space coordinate of material pile surface tagged points.(5) Calculate the angle of roll for using method of least squares, then correct the deflection of whole scattered points because of imbalance between camera platform and material pile platform.(6) Use the inverse distance weighted interpolation and RBF interpolation to solve the corrected scattered points, and accomplish the3D reconstruction and volume calculation of material pile.This research realizes the automatic goal of sizeable material pile volume measurement in a certain extent, after the modeling test in the lab, achieves the precision demand of material pile measurement. This method is simple, low cost and easy to popularize.