Research On Application Of Lidar Technology In Ship Tank Capacity Measurement

Tank capacity measurement is an important guarantee for ship endurance,ship performance and trade handover.Ship owners and cargo owners pay more and more attention to the capacity of ship’s liquid tank.Vessel tank capacity measurement has become an indispensable part of modern ship construction and operation.The traditional methods of tank volume measurement mainly adopt the method of volume comparison and geometric measurement.The capacity comparison method is to transfer the standard capacity in the standard metal gauge to the tank to obtain the tank capacity table.The geometric measurement method uses total station,handheld rangefinder and steel tape measure to measure the length,width and height of discrete points.Calculate the cabin capacity according to the measurement data.With the increasing tonnage of ships,the traditional capacity measurement method is restricted by the factors of ship construction period and data processing.It is increasingly difficult to adapt to the modern production and operation of ships.This thesis studies the method of lidar technology to collect the shape data of the inner wall of the tank and internal structural members on the site of the cabin,so as to obtain the detailed geometry of the space inside the tank and calculate the tank capacity characteristics.Firstly,The 3d spatial point cloud data is obtained by lidar scanning and preprocessed.UG modeling software was used to fit the boundary of three-dimensional point cloud data according to plane or surface.Then,The internal components of the tank are modeled according to the size of point cloud data to obtain a detailed three-dimensional solid model of the effective space inside the tank.And then,the complex three-dimensional model is analyzed and the tank capacity is calculated,the calculation program is developed and the capacity table is generated.Finally,the measurement method and the capacity comparison method are used to measure a complex tank respectively.The difference between the two measurement methods is less than 0.3%,which verifies the feasibility and accuracy of the measurement method in this paper.Then the factors influencing the measurement and its uncertainty are analyzed.This study lays a good foundation for the follow-up research and application of accurate measurement and integration of ship capacity in different floating states into ship loading management system.