A Study On3D Laser Scanner Data Processing Method In Large-capacity Measurement And Software Development

Vertical cylindrical metal tank and underground oil storage cavern are usedas main storage devices for crude oil, fuel oil and other liquid energy material.Vertical tank is also the main instruments for volume measurement in theinternational liquid energy trade, and it is involved in the measuring equipments ofnational compulsory verification. To measure the volume of these large sizecontainers quickly and accurately is the basic requirement in the huge energy storageand transportation engineering. In this work, algorithms for large capacitymeasurement using3D laser scanner are investigated. The corresponding software isdeveloped. The feasibility and accuracy of this large size volume measurementmethod is verified by practical tests. The thesis is composed of the following fourparts:Part1: The research status of large capacity measurement technology. Analysisis taken on the problems existing in the strapping method, radial deviation method,Electronic Total Station Method and other methods. The capacity measurementmethods of underground rock cavern oil storage are summarized. Large capacitymeasurement method based on the technology of3D laser scanning is introduced. Inthis method, we use a3D laser scanner to collect the point cloud data of the containersurface. Then the3D model of the container can be reconstructed. Based themetrological verification management system software for large capacitymeasurement, the total volume of the container can be calculated and the volumetable can be built.Part2: Investigation on the algorithm of volume measurement for3D laserscanning method. The capacity calculating model based on the point cloud analysis isstudied. The process and methods for the cross section point cloud datapreprocessing are elaborated, including gross error elimination, point cloud sorting,filtering, reduction. Three techniques are used to fit the tank surface point cloud dataand get the radius, i.e. the least square method, iterative method, and equivalent area method. Tank bottom capacity measurement method and tilt calculation methodbased on the point cloud analysis are also given out.Part3: Software development. Software for the large capacity measuringmanagement system was developed using c#and Access database based on Winformdesktop, which is ran on.Net platform. The software adopts the man-machineinteractive way, with beautiful and friendly interface, can rapidly and accuratelycalculate and print the volume form.Part4: Experimental measurement. Practical tests have been carried out toverify the method with a Leica HDS70003D laser scanner. A vertical tank with avolume of20000cubic meters was selected as the object being measured in terms ofrepeatability, reproducibility of the scanner and the corresponding data processingmethods. It is found that as the incidence angle being increased, data deviationincreases. It’s suggested that the incidence angle should not greater than60degree.Measurement has been made on vertical tank with a volume of5000cubic meters toverified the accuracy of the3D laser scanning method and the correspondingsoftware. Tests have also been carried out in a room experiment and a cave. Theresults indicate that is feasible to measure the volume of an underground rock cavernfor oil storage using3D laser scanning method.