3D Laser Scanner Technology Appling In Vertical Metal Tank Capacity Measurement

The vertical metal tank (hereinafter called vertical tank) is the mainmeasuring instrument between the international petrochemical products tradesettlement. Whether the measurement is accurate or not is directly related to theeconomic interests of the trading parties and the measurement reputation of thecountry. However, there are so many problems that widespread in the vertical tankcapacity measurement, such as the measurement time is long, the work intensity islarge, the examination cost is high, and the measurement results accuracy is low, andso on. In view of the above, the paper introduces the3D laser scanning technique intothe capacity metrology, giving its specific application in the vertical metal tankcapacity measurement. The main research contents are as follow:First of all, study the working principle of the3D laser scanning technique, theworkflow of the scanning and modeling is given. Give the specific method to achievethe capacity measurement combining the particular of the capacity measurement field.Secondly, process the3D point cloud data of the tank acquired by scanning,including the point cloud data preprocessing and the capacity calculations. The pointcloud data preprocessing includes target coordinate information extracting, stitching,de-noising, vacuating, feature information extracting, segmenting etc. While thecapacity calculation can be achieved by Leica HDS tank measurement system orself-development software. Simultaneously, the ideas to achieve the capacitycalculation are given.Thirdly, the actual measurements are carried out. Complete the testingverification of the3D laser scanning measurement system, including the measurementrepeatability, reproducibility and the impact of the angle of incidence etc. Carry on theexternal testing experiment and the comparison experiment, and explore theapplication of the scanner in different type and nominal vertical tank at the same time.Finally, analysis and evaluate the measurement uncertainty of3D laser scanningmethod applied in vertical tank capacity measurement combining with the measuringexperiment. Analyze the source of the affecting factors and give the evaluation method of the various uncertainty components, then calculate the relative expandeduncertainty of the measurement result and give the measurement uncertainty report.The research demonstrates that: the application of3D laser scanning technique in thefield of capacity measurement is not only an expansion of itself but also a supplementof the original capacity examination method. It can reduce the cost of measurementwhile improving the measurement accuracy, having obvious advantages.