Patent ID: 11970246
Assignee: ZHOUSHAN INSTITUTE OF CALIBRATION AND TESTING FOR QUALITY AND TECHNOLOGY SUPERVISION
Field: Transport (Mechanical engineering)
Classification: CPC B  G | IPC B  G

Claim 0:
1. A method of automatically measuring a loading capacity of a ship cabin, the method comprising:
a) floating a ship comprising the ship cabin in water;
b) receiving, at a processor, a set of three-dimensional (3D) point clouds of a plurality of regions of the ship cabin of the floating ship from a lidar, wherein the set of 3D point clouds of the plurality of regions of the ship cabin includes a first 3D point cloud and a 3D second point cloud;
c) generating, by the processor, a 3D point cloud of the ship cabin by:
i) applying, by the processor, transformations including rotation and translation to the first 3D point cloud to create a modified first 3D point cloud;
ii) checking, by the processor, whether the modified first 3D point cloud satisfies a termination condition; and
iii) if not, turning to step i) to apply transformations including rotation and translation to the modified first 3D point cloud; and if yes, aligning and registering the modified first 3D point cloud and the second 3D point cloud to create the 3D point cloud of the ship cabin;

d) de-noising, by the processor, the 3D point cloud of the ship cabin with a K-dimensional tree algorithm to create a de-noised 3D point cloud of the ship cabin;
e) compressing, by the processor, the de-noised 3D point cloud of the ship cabin with a predetermined sharp feature culling algorithm to create a compressed 3D point cloud of the ship cabin;
f) modifying, by the processor, the compressed 3D point cloud of the ship cabin for longitudinal and transverse inclinations, and generating a modified 3D point cloud of the ship cabin;
wherein step f) comprises:
obtaining a longitudinal inclining angle and a transverse inclining angle of the ship cabin when the ship cabin is floating on an even keel and an inclined keel, respectively;
generating modification matrices according to the longitudinal inclining angle and the transverse inclining angle of the ship cabin; and
modifying the compressed 3D point cloud of the ship cabin for longitudinal and transverse inclinations according to the modification matrices;

g) extracting, by the processor, a plurality of 3D frustums from the modified 3D point cloud of the ship cabin according to a predetermined step-length; and
h) automatically generating, by the processor, a measurement result for the loading capacity of the ship cabin based on the plurality of 3D frustums.