US 11,981,403 B1Granted

Method and device for automatic detection of vessel draft depth

AssigneeWuhan University of Technology

InventorsWen Liu, Jingxiang Qu, Chenjie Zhao, Yang Zhang, Yu Guo

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Abstract

Disclosed is a method and device for automatic detection of vessel draft depth, which processes the image of a vessel's hull and extracts local area image blocks with vessel's water gauge scale separately to improve the pertinence of data processing and reduce the complexity of data processing; and based on a multi-task learning network model, performing data processing on local area image blocks to extract scale characters and waterline position, reducing the computational complexity of the model; finally, based on the relative positions of the scale and waterline, determining the vessel's draft depth, thus achieving automatic acquisition of the vessel's draft depth, this method greatly improves the efficiency of reading the vessel's draft depth.

Claims8

Dependent claims

A method for automatic detection of vessel draft depth, comprising:

obtaining a hull image of a vessel;
based on a target image recognition network model, performing image recognition on the hull image of the vessel to obtain local area image blocks, where the local area image blocks include the vessel's water gauge scale;
constructing a multi-task learning network model, the multi-task learning network model includes a multi-scale convolutional neural network, a target detection sub network, and a water surface and vessel hull segmentation sub network;
performing feature extraction of local area image blocks based on multi-scale convolutional neural networks to obtain image features of the local area image blocks;
based on the target detection sub network, performing target classification, target box position prediction, and background judgment on image features to determine scale characters;
based on a sub network of water surface and hull segmentation, performing target extraction on the image features to determine the position of the waterline;
determining whether only a first available scale is included in the available scales;
if so, determining the vessel's draft depth using a first draft depth calculation formula based on the first available scale, the distance between the first available scale and the water surface, and the character height;
if not, determining whether the available scales include a second available scale and a third available scale;
if the third available scale is not included in the available scales, then based on the first available scale, the second available scale, the distance between the available scale and the water surface, and the distance between the available scales, determining the vessel's draft depth by a second draft depth calculation formula;
if the available scales include the second available scale and the third available scale, then based on the first available scale, the second available scale, the third available scale, the distance between the available scale and the water surface, and the distance between the available scales, determining the vessel's draft depth using a third draft depth calculation formula;
wherein the first draft depth calculation formula is:
D
=
S
1
-
β
·
d
h
1
where, D is the vessel's draft depth, S1 is the first available scale, β is the character height, d is the distance between the first available scale and the water surface, and II is the height of the detection box corresponding to the scale;
the second draft depth calculation formula is:
D
=
d
d
1
⁢
(
S
1
-
S
2
)
where, d1 is the distance between the first available scale and the second available scale, and S2 is the second available scale;
the third draft depth calculation formula is:
D
=
d
2
·
d
·
(
S
2
-
S
1
)
d
1
·
d
1
·
(
S
3
-
S
2
)
where, d2 is the distance between the second available scale and the third available scale, S3 and is the third available scale.

64 more elements

A device for automatic detection of vessel draft depth, comprising:

a vessel hull image acquisition module, configured to obtain vessel hull image;
a local area image blocks acquisition module, configured to perform image recognition of a vessel hull image based on a target image recognition network model to obtain local area image blocks, wherein the local area image blocks include the vessel water gauge scale of the vessel hull image;
a multi-task learning network model construction module, configured to construct a multi-task learning network model, the multi-task learning network model includes a multi-scale convolutional neural network, a target detection sub network, and a water surface and vessel hull segmentation sub network;
an image feature extraction module, configured to extract features from the local area image block based on the multi-scale convolutional neural network, and obtain image features of the local area image blocks;
a scale character determination module, configured to perform target classification, target box position prediction, and background judgment of the image features based on the target detection sub network to determine scale characters, wherein the scale characters include available scale, distance between available scale and water surface, available scale spacing, and character height;
a waterline position determination module, configured to extract targets from the image features based on the water surface and ship hull segmentation sub network, and determine the waterline position;
a vessel draft depth determination module, configured to determine whether only a first available scale is included in the available scales;
if so, determine the vessel's draft depth using a first draft depth calculation formula based on the first available scale, the distance between the first available scale and the water surface, and the character height;
if not, determine whether the available scales include a second available scale and a third available scale;
if the third available scale is not included in the available scales, then based on the first available scale, the second available scale, the distance between the available scale and the water surface, and the distance between the available scales, determine the vessel's draft depth by a second draft depth calculation formula;
if the available scales include the second available scale and the third available scale, then based on the first available scale, the second available scale, the third available scale, the distance between the available scale and the water surface, and the distance between the available scales, determine the vessel's draft depth using a third draft depth calculation formula;
D
=
S
1
-
β
·
d
h
1
D
=
d
d
1
⁢
(
S
1
-
S
2
)
D
=
d
2
·
d
·
(
S
2
-
S
1
)
d
1
·
d
1
·
(
S
3
-
S
2
)
wherein the first draft depth calculation formula is:
D
=
S
1
-
β
·
d
h
1
where, D is the vessel's draft depth, S1 is the first available scale, β is the character height, d is the distance between the first available scale and the water surface, and h1 is the height of the detection box corresponding to the scale;
the second draft depth calculation formula is:
D
=
d
d
1
⁢
(
S
1
-
S
2
)
where, d1 is the distance between the first available scale and the second available scale, and S2 is the second available scale;
the third draft depth calculation formula is:
D
=
d
2
·
d
·
(
S
2
-
S
1
)
d
1
·
d
1
·
(
S
3
-
S
2
)
where, d2 is the distance between the second available scale and the third available scale, S3 and is the third available scale.

114 more elements

Dependencies are inferred from the claim text.