Research On The Method Of Volume Metrology Of Irregular Tanks

Volume metrological method for irregular tanks is proposed by three dimensional scanning technology and volume comparison method.Based on the point cloud data,a model for calculating the volume of irregular tanks is designed to solve the problem that rapid measurement the volume for vertical tank bottom and horizontal tank.Based on the volume comparison method,automatic verification system is designed.Then the metrological characteristics of the two methods are compared through comparison experiment.The main research contents are as followed:(1)The point cloud data of irregular tanks were obtained by 3D scanning technology.Based on Delaunay triangulation,the topological structure of scattered point cloud was established.The projection algorithm that used point cloud for calculating irregular geometric volume was proposed.The point cloud projection algorithm is used to design the calculation model respectively that calculates the volume for vertical tank bottom and horizontal tank.(2)In order to verify the volumetric measurement method of irregular tanks based on 3D scanning principle.The automatic verification system of volumetric comparison method is designed.The selection of standard metal gauges and liquid level switches solve the problem that injected quantitative water to standard metal gauges and improve the degree of system automation.The verification system program and electrical control system are designed independent.The master computer and slave computer program are programmed to achieve automatic verification system of intelligent control.(3)The irregular geometric volume can be measured through volume measurement experiment for sand pile.The 3D laser scanning technology and point cloud projection algorithm are verified.The volume comparison method and the 3D laser scanning method are respectively used to measure the volume for vertical tank bottom and horizontal tank.According to the experimental results,the relative expansion uncertainty of the volumetric comparison system is 0.108%(k=2).The relative expansion uncertainty of the 3D laser scanning method is 0.37%(k=2)by the normalized deviation method.