Ship construction inspection method

Abstract

The invention provides a ship construction inspection method, which comprises the following steps of: firstly, selecting a design model of a ship construction part, selecting path points according to internal space characteristics of the design model, and planning a shortest path penetrating through all the path points; and carrying out patrolling shooting on the ship building part according to the shortest path to obtain image data of the ship building part. And further performing three-dimensional model reconstruction according to the image data to obtain a reconstructed model of the ship building part. And then, removing accessories except the ship structure from the reconstruction model to obtain a pure reconstruction model of the building part. And then selecting a proper angle according to the path points, and respectively intercepting pictures in the pure reconstruction model and the design model at the same path point and the same angle so as to obtain a reconstruction picture and a design picture at the same position. And finally, comparing and checking the reconstructed picture and the design picture to obtain and output a checking report. According to the ship construction inspection method, the problems of wrong loading, neglected loading and sundries remaining in the ship construction process can be identified.

Description

Technical Field

[0001] The present invention relates to the technical field of shipbuilding, and in particular to a shipbuilding inspection method. Background Art

[0002] Economic development and the growth of shipping capacity demand are the main driving forces for the expansion of shipyard business. With the prosperity of global trade and the increase in demand for maritime transportation, shipyards have received an increasing number of ship orders. At the same time, in order to meet greater shipping needs, the size of ships is gradually increasing, and the internal structure and systems are becoming more complex. These changes have posed higher challenges to the shipbuilding process, requiring shipyards to ensure the quality of shipbuilding while improving construction efficiency. Before shipbuilding, 3D design modeling has become a standard practice in the industry. Through 3D design modeling, shipyards can have a more intuitive understanding of the structure and internal layout of the ship, thereby optimizing the design plan and improving construction efficiency. However, although 3D design modeling provides strong support for shipbuilding, there are still some problems in the actual construction process.

[0003] Among them, the uneven knowledge and construction skill levels of on-site workers is an important issue. Since the shipbuilding process involves multiple professional fields and complex process flows, workers are required to have high professional knowledge and skill levels. However, in actual operations, due to differences in workers' skill levels, it often leads to mis-installation and omissions during shipbuilding, as well as production waste and debris that are not taken away by construction workers in a timely manner. This not only affects the quality of shipbuilding, but also increases additional repair costs and time costs. Summary of the invention

[0004] In view of the problems existing in the prior art described above, the present application provides a ship construction inspection method, which can identify the problems of wrong installation, missing installation, and leftover debris and construction waste during the ship construction process.

[0005] To achieve the above-mentioned object and other related objects, the present invention provides a shipbuilding inspection method, comprising the following steps:

[0006] Select the design model of the shipbuilding part to be inspected, select path points according to the internal space characteristics of the design model, and plan the shortest path that runs through all path points;

[0007] Perform patrol photography of the ship construction department along the shortest path to obtain image data of the ship construction department;

[0008] Reconstructing a three-dimensional model according to the image data to obtain a reconstructed model of the ship construction department;

[0009] Eliminate the attachments other than the ship structure from the reconstructed model to obtain a pure reconstructed model of the ship construction part;

[0010] Select appropriate angles according to the path points, and capture images in the pure reconstruction model and the design model at the same path point and the same angle, respectively, to obtain the reconstruction image and the design image at the path point;

[0011] Perform a comparative test on the reconstructed image and the designed image to obtain and output a test report.

[0012] Optionally, a drone is used to patrol and photograph the ship construction department, and the drone has an RGB-D camera and a lighting lamp with adjustable brightness.

[0013] Optionally, selecting appropriate path points according to the internal space characteristics of the design model further includes the following steps:

[0014] If the design model is an open area without any obstructions, the path points are selected using the maximum interpolation method based on the spatial distance of the open area;

[0015] If the design model is a part where there is an obstruction, the path points are selected by fixing points on both the inner and outer sides of the obstruction.

[0016] Optionally, when determining points on both inner and outer sides of the obstruction, the first point is a point in front of the obstruction divided equally in space, and the second point is a point behind the obstruction at the same horizontal position.

[0017] Optionally, planning the shortest path through all path points includes the following steps:

[0018] Get all path point data, set the starting point A, the end point B, and the number of intermediate nodes to n;

[0019] A graph theory algorithm is used to pre-process n intermediate nodes to generate an intermediate node sequence of n*(n-1) rows. The starting point of the intermediate node sequence is recorded as M1, and the end point is recorded as Mn.

[0020] The A* algorithm is used to obtain the shortest path S1 from the starting point A of the path point data to the starting point M1 of the intermediate node sequence, the shortest path S2 from the end point Mn of the intermediate node sequence to the end point B of the path point data, and the shortest path S4 from the end point B of the path point data to the starting point A of the path point data;

[0021] The A* algorithm is used to calculate the paths between all adjacent intermediate nodes and connect the paths between all adjacent intermediate nodes to obtain the shortest path S3 between the intermediate nodes M1 to Mn;

[0022] Connect S1, S3, S2 and S4 in sequence to obtain the shortest path that runs through all path points.

[0023] Optionally, the patrol shooting of the ship construction department includes using a drone to perform patrol shooting, and using a dynamic culling algorithm during the shooting process to eliminate moving objects in the shot video.

[0024] Optionally, before capturing images of the pure reconstruction model and the design model at the same path point and the same angle, a vertical line is drawn from the path point to the plane where the hull of the ship construction part around the path point is located, and screenshots of the pure reconstruction model and the design model are taken according to the length of the vertical line and the difference between the lengths of the vertical lines.

[0025] Optionally, after reconstructing the three-dimensional model according to the image data to obtain the reconstructed model of the ship building part, the reconstructed model is rendered.

[0026] Optionally, after obtaining and outputting the inspection report, the inspection report is submitted to the quality assurance department.

[0027] Optionally, attachments other than the ship's structure are removed through image recognition technology.

[0028] As described above, the shipbuilding inspection method provided by the present invention has at least the following beneficial technical effects:

[0029] The shipbuilding inspection method of the present invention first selects the design model of the shipbuilding section to be inspected, selects the path points according to the internal space characteristics of the design model, and plans the shortest path that runs through all the path points. Next, the shipbuilding section is patrolled and photographed along the shortest path to obtain image data of the shipbuilding section. Further, a three-dimensional model is reconstructed according to the image data to obtain a reconstructed model of the shipbuilding section. Then, the accessories other than the structure of the ship itself are removed from the reconstructed model to obtain a pure reconstructed model of the shipbuilding section. Subsequently, appropriate angles are selected according to the path points, and pictures are captured in the pure reconstructed model and the design model at the same path point and the same angle, respectively, to obtain the reconstructed picture and the design picture at the path point. Finally, the reconstructed picture and the design picture are compared and inspected to obtain and output an inspection report. The shipbuilding inspection method of the present application can identify the problems of misinstallation and missing installation during shipbuilding, as well as the problems of leftover debris and construction waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Shown is a flow chart of a shipbuilding inspection method provided by an embodiment of the present invention.

[0031] Figure 2 Shown is a schematic diagram of the position of a perpendicular line drawn from a path point provided by an embodiment of the present invention to the plane where the hull is located.

[0032] Figure 3The diagram shows the positions of vertical lines when no three vertical lines are in the same plane when vertical lines are drawn from the path points provided by the embodiment of the present invention to the plane where the hull is located.

[0033] Reference numerals

[0034] 1. The shortest distance vertical line; 2. The second shortest distance vertical line; 3. The third shortest distance vertical line; 4. The fourth shortest distance vertical line. DETAILED DESCRIPTION

[0035] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0036] It should be noted that the illustrations provided in this embodiment only illustrate the basic concept of the present invention in a schematic manner. Although the illustrations only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation, the form, quantity, positional relationship and proportion of each component in actual implementation can be changed at will under the premise of realizing the technical solution of this party, and the component layout form may also be more complicated.

[0037] This embodiment provides a ship construction inspection method, such as Figure 1 As shown, the method comprises the following steps:

[0038] S100: selecting a design model of a ship construction part to be inspected, selecting path points according to the internal space characteristics of the design model, and planning the shortest path that passes through all the path points;

[0039] Specifically, when selecting path points, it is necessary to classify them according to the spatial characteristics of the design model. If the design model is an open area such as a liquid tank or a hull where there are no obstructions. The maximum interpolation method is used according to the spatial distance of the open area, and new virtual points are inserted according to the maximum distance between the design models to ensure that the entire design model is evenly and effectively covered, and the path points are divided evenly according to equidistant. If the design model is a part with obstructions such as the engine room main engine and the ship's upper structure, it is necessary to fix the points on both sides of the inner and outer sides of the obstruction. The first point is the point in front of the obstruction divided equally in space. This point is selected to ensure that the drone can shoot the area in front of the obstruction; the second point is the point behind the obstruction at the same horizontal position. This point is selected to ensure that the drone can bypass the obstruction and shoot the area behind it. That is, when the number of path points selected is as small as possible, the situation of no obstruction during drone shooting can be met. In this embodiment, the shortest path running through all path points is planned by the A* algorithm and the graph theory algorithm, including the following steps:

[0040] Get all path point data, set the starting point A, the end point B, and the number of intermediate nodes to n;

[0041] A graph theory algorithm is used to pre-process n intermediate nodes according to their weights to generate an intermediate node sequence of n*(n-1) rows. The starting point of the intermediate node sequence is recorded as M1, and the end point is recorded as Mn.

[0042] The A* algorithm is used to obtain the shortest path S1 from the starting point A of the path point data to the starting point M1 of the intermediate node sequence, the shortest path S2 from the end point Mn of the intermediate node sequence to the end point B of the path point data, and the shortest path S4 from the end point B of the path point data to the starting point A of the path point data;

[0043] The A* algorithm is used to calculate the paths between all adjacent intermediate nodes and connect the paths between all adjacent intermediate nodes to obtain the shortest path S3 between the intermediate nodes M1 to Mn;

[0044] Connect S1, S3, S2 and S4 in sequence to obtain the shortest path that runs through all path points.

[0045] When using the A* algorithm and graph theory algorithm to calculate the shortest path, it is not a simple matter of selecting a few path points and finding the shortest path between them. Instead, it is necessary to traverse all path points, consider all possible access sequences, and find the one with the smallest total distance.

[0046] S200: performing a patrol flight to photograph the ship construction part according to the shortest path to obtain image data of the ship construction part;

[0047] Specifically, in order to provide a sufficient light environment, the brightness of the lighting is adjusted under different conditions, and a drone carrying an RGB-D camera and a high-intensity lighting lamp with adjustable brightness is used to patrol and inspect the construction department along the shortest path. The RGB-D camera is a camera that can capture color images and depth information at the same time. The depth information helps the drone to more accurately judge the distance to the object of shooting, so as to take more accurate photos. The drone is equipped with a lighting lamp, the brightness of which can be adjusted according to the shooting environment. This helps to ensure that the images taken under different lighting conditions can show good color and details. The images taken by the drone RGB-D camera show the following two situations. The first situation is to reflect the color and material of the ship hull of the construction department. In areas with sufficient ambient brightness such as superstructures and engine rooms, the lighting lamp chooses high-reflection and low-brightness lighting to avoid color distortion or reflection caused by excessive light. The second situation is that in closed and unlit areas such as liquid cargo, high-brightness lighting is selected to make the color difference inside the liquid cargo area shot obvious.

[0048] Preferably, in order to avoid interfering with the work of on-site workers, the drone should be used for patrol shooting during the workers' rest time and when it does not affect the work of on-site workers. The drone should also adopt a dynamic elimination algorithm to eliminate moving objects in the environment, such as working people, moving vehicles, and towers for lifting goods, based on the relative movement of objects in the video. This helps ensure that the images taken are clearer and more accurate, without being interfered with by external factors.

[0049] S300: reconstructing a three-dimensional model according to the image data to obtain a reconstructed model of the ship construction part;

[0050] Specifically, when the RGB-D camera is working, it continuously captures images of the scene and generates data streams containing depth information and color information. These data streams are updated in real time, providing a continuous and accurate source of information for three-dimensional reconstruction. In the three-dimensional reconstruction process, depth information plays a vital role. Depth information provides the precise geometry of the surface of the object and is the basis for reconstructing the model. Although color information also provides valuable visual clues for the reconstruction process, depth information is more critical in determining the three-dimensional position and shape of the object. Therefore, in this embodiment, the data stream is three-dimensionally reconstructed based on depth information. The three-dimensional reconstruction effect is also divided into two types, which are related to the two light brightness in S200. When the lighting lamp selects high-reflection and low-brightness lighting, the image captured by the RGB-D camera will more reflect the inherent characteristics of the ship construction material, such as color, gloss and texture. The three-dimensional reconstruction effect under this lighting condition will focus more on the material effect model of the ship construction, making the model visually closer to the real ship structure. When high-brightness lighting is selected, the RGB-D camera can capture more detailed information, including slight differences and material characteristics on the surface of the design model, which will be used to generate a more accurate reconstruction model. After the reconstructed model is generated, the material information of the design model is applied to the reconstructed model through material mapping rendering technology. This method can significantly improve the color difference effect of the reconstructed model, making the reconstructed model more in line with design requirements and actual usage scenarios.

[0051] S400: removing the accessories other than the ship structure itself from the reconstructed model to obtain a pure reconstructed model of the ship construction part;

[0052] Specifically, by performing image recognition on the reconstructed model, objects that do not belong to the hull construction are deleted from the reconstructed model to obtain a pure reconstructed model of the construction part. Accessories that do not belong to the ship itself include scaffolding, supports, debris and garbage during the ship construction process. By removing these accessories, it can be ensured that the reconstructed model more accurately reflects the structure and shape of the ship itself. By intelligently removing accessories that do not belong to the ship itself, the problem of inaccurate reconstruction of the hull part due to occlusion by foreign objects during the reconstruction process can be avoided. This helps to improve the accuracy and completeness of the reconstructed model and provide more valuable information for subsequent analysis and processing.

[0053] S500: selecting an appropriate angle according to the path point, and capturing images in the pure reconstruction model and the design model at the same path point and the same angle, respectively, to obtain the reconstruction image and the design image at the path point;

[0054] Specifically, refer to Figure 2 and Figure 3Before capturing the image, in order to determine the specific location of the captured image, vertical lines are drawn from the selected path point to the plane of the hull of the ship construction part except the bottom plate around the path point. By comparing the length of each vertical line, each vertical line is named the shortest distance vertical line 1, the second shortest distance vertical line 2, the third shortest distance vertical line 3 and the fourth shortest distance vertical line 4. These vertical lines are used to determine the viewing angle and distance when capturing the image. The capture of the image includes the following multiple methods.

[0055] If the length of all vertical lines is between 0 and 500 cm, a screenshot is taken on each vertical line.

[0056] If the difference between the length of the shortest distance vertical line 1 and the length of the second shortest distance vertical line 2 is between 100 cm and 500 cm, a screenshot is taken at the selected path point F1 along the direction of the shortest distance vertical line.

[0057] If the difference between the length of the shortest distance vertical line 1 and the length of the second shortest distance vertical line 2 is between 0 and 100 cm, and the angle between the shortest distance vertical line 1 and the second shortest distance vertical line 2 is less than or equal to 90 degrees, a screenshot is taken at the selected path point F1 along the direction of the angle bisector between the shortest distance vertical line 1 and the second shortest distance vertical line 2.

[0058] If the difference between the length of the shortest distance vertical line 1 and the length of the second shortest distance vertical line 2 is between 0 and 100 cm, and the angle between the shortest distance vertical line 1 and the second shortest distance vertical line 2 is greater than 90 degrees, a screenshot is taken every 45 degrees at the selected path point F1 toward the angle between the shortest distance vertical line 1 and the second shortest distance vertical line 2.

[0059] If the difference in length between the shortest distance vertical line 1 and the third shortest distance vertical line 3 is between 0 and 200 cm, and the angle between any two perpendicular lines between the shortest distance vertical line 1, the second shortest distance vertical line 2 and the third shortest distance vertical line 3 is less than or equal to 90 degrees, then a screenshot is taken at the selected path point F1 in the direction of the bisector of the angle formed by each two perpendicular lines.

[0060] If the difference between the length of the shortest distance vertical line 1 and the length of the third shortest distance vertical line 3 is between 0 and 200 cm, and the angle between any two vertical lines between the shortest distance vertical line 1, the second shortest distance vertical line 2 and the third shortest distance vertical line 3 is greater than 90 degrees, then a screenshot is taken between the second plane where the smallest angle formed by any two vertical lines is located and another vertical line that is not in the second plane. Figure 2, the shortest distance vertical line 1 and the second shortest distance vertical line 2 are in the same plane, the third shortest distance vertical line 3 forms an angle with the plane where the shortest distance vertical line 1 and the second shortest distance vertical line 2 are located, and a screenshot is taken every 45 degrees at the path point F1 toward the angle formed by the third shortest distance vertical line 3 and the plane where the shortest distance vertical line 1 and the second shortest distance vertical line 2 are located.

[0061] If the difference in length between the shortest distance vertical line 1 and the fourth shortest distance vertical line 4 is between 0 and 400 cm, and the angles formed by the shortest distance vertical line 1, the second shortest distance vertical line 2, the third shortest distance vertical line 3 and the fourth shortest distance vertical line 4 are all less than or equal to 90 degrees, then a screenshot is taken at the selected path point F1 in the direction of the angle bisector of each angle formed by the shortest distance vertical line 1, the second shortest distance vertical line 2, the third shortest distance vertical line 3 and the fourth shortest distance vertical line 4.

[0062] If the difference between the length of the shortest distance vertical line 1 and the length of the fourth shortest distance vertical line 4 is between 0 and 400 cm, and two of the shortest distance vertical line 1, the second shortest distance vertical line 2, the third shortest distance vertical line 3, and the fourth shortest distance vertical line 4 have an angle greater than 90 degrees with each other, and three of the vertical lines are in the same plane, then a screenshot is taken between the vertical line that is not in the plane and the plane. Specifically, if Figure 2 As shown, the shortest distance vertical line 1, the second shortest distance vertical line 2 and the fourth shortest distance vertical line 4 are in the same plane, and an angle is formed between the third shortest distance vertical line 3 and the plane where the shortest distance vertical line 1, the second shortest distance vertical line 2 and the fourth shortest distance vertical line 4 are located. At the path point F1, a screenshot is taken every 45 degrees toward the angle formed by the third shortest distance vertical line 3 and the plane where the shortest distance vertical line 1, the second shortest distance vertical line 2 and the fourth shortest distance vertical line 4 are located.

[0063] If the difference between the length of the shortest distance vertical line 1 and the length of the fourth shortest distance vertical line 4 is between 0 and 400 cm, and there are two perpendicular lines of the shortest distance vertical line 1, the second shortest distance vertical line 2, the third shortest distance vertical line 3 and the fourth shortest distance vertical line 4 that have an angle greater than 90 degrees with each other and none of the three perpendicular lines are in the same plane, then a screenshot is taken between the first plane where the smallest angle formed by any two perpendicular lines is located and the other two perpendicular lines. Specifically, if Figure 3 As shown, the shortest distance vertical line 1 and the second short distance vertical line 2 are in the same plane, and the plane is defined as the first plane. The third short distance vertical line 3 and the fourth short distance vertical line 4 form an angle with the first plane, and a screenshot is taken every 45 degrees at the path point F1 in the direction of the angle formed by the third short distance vertical line 3 and the fourth short distance vertical line 4 and the first plane.

[0064] S600: Compare and test the reconstructed image and the designed image to obtain and output a test report.

[0065] Specifically, when performing image recognition inspection, first select the optimal angle at the path point to capture the reconstructed image and the design image multiple times, and perform image recognition inspection on the reconstructed image and the design image. Through image recognition technology, anomalies and defects in the image can be automatically identified, such as problems of missing installation, leftover debris and construction waste during ship construction. After identifying these problems, an inspection report with pictures is generated and output. After outputting the inspection report with pictures, the inspection results are summarized and uploaded to the factory LAN cloud to ensure that the ship construction inspection process can be checked and adjusted at any time. And submit the inspection problems to the quality assurance department through the cloud, so that the quality assurance department can supervise the departments with problems in ship construction to make timely rectifications.

[0066] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A shipbuilding inspection method, characterized in that: The following steps are involved: Selecting a design model of a ship construction part to be inspected, selecting path points according to the internal space characteristics of the design model, and planning the shortest path that passes through all the path points; Performing patrol photography of the ship construction department along the shortest path to obtain image data of the ship construction department; Reconstructing a three-dimensional model according to the image data to obtain a reconstructed model of the ship construction part; Eliminate the accessories other than the ship structure from the reconstructed model to obtain a pure reconstructed model of the ship construction part; Selecting an appropriate angle according to the path point, capturing images in the pure reconstruction model and the design model at the same path point and the same angle, respectively, to obtain a reconstruction image and a design image at the path point; The reconstructed image and the designed image are compared and tested to obtain and output a test report.

2. The shipbuilding inspection method according to claim 1, characterized in that: A drone is used to patrol and photograph the ship construction department. The drone is equipped with an RGB-D camera and a lighting lamp with adjustable brightness.

3. The shipbuilding inspection method according to claim 1, characterized in that: Selecting appropriate path points according to the internal space characteristics of the design model also includes the following steps: If the design model is an open area without any obstruction, the path point is selected by using a maximum interpolation method according to the spatial distance of the open area; If the design model is a location where an obstruction exists, fixed points are performed on both inner and outer sides of the obstruction to select the path point.

4. The shipbuilding inspection method according to claim 3, characterized in that: When determining points on both inner and outer sides of the shielding object, the first point is a point in front of the shielding object divided equally in space, and the second point is a point behind the shielding object at the same horizontal position.

5. The shipbuilding inspection method according to claim 1, characterized in that: Planning the shortest path that runs through all the path points includes the following steps: Get all the path point data, set the starting point A, the end point B, and the number of intermediate nodes to n; A graph theory algorithm is used to pre-process n intermediate nodes to generate an intermediate node sequence of n*(n-1) rows, where the starting point of the intermediate node sequence is recorded as M1 and the end point is recorded as Mn; A* algorithm is used to obtain the shortest path S1 from the starting point A of the path point data to the starting point M1 of the intermediate node sequence, the shortest path S2 from the end point Mn of the intermediate node sequence to the end point B of the path point data, and the shortest path S4 from the end point B of the path point data to the starting point A of the path point data; The A* algorithm is used to calculate the paths between all adjacent intermediate nodes and the paths between all the adjacent intermediate nodes are connected to obtain the shortest path S3 between the intermediate nodes M1 to Mn; Connect S1, S3, S2 and S4 in sequence to obtain the shortest path that runs through all the path points.

6. The shipbuilding inspection method according to claim 1, characterized in that: The patrol shooting of the ship construction department includes using the drone to perform patrol shooting, and using a dynamic elimination algorithm during the shooting process to eliminate moving objects in the shot video.

7. The shipbuilding inspection method according to claim 1, characterized in that: Before capturing images of the pure reconstruction model and the design model at the same path point and at the same angle, a vertical line is drawn from the path point as a starting point to the plane where the hull of the ship construction part around the path point is located, and screenshots of the pure reconstruction model and the design model are taken according to the length of the vertical line and the difference between the lengths of the vertical lines.

8. The shipbuilding inspection method according to claim 1, characterized in that: After reconstructing the three-dimensional model according to the image data to obtain the reconstructed model of the ship construction part, rendering processing is performed on the reconstructed model.

9. The shipbuilding inspection method according to claim 1, characterized in that: After obtaining and outputting the inspection report, the inspection report is submitted to the quality assurance department.

10. The shipbuilding inspection method according to claim 1, characterized in that: Image recognition technology is used to remove accessories other than the ship's own structure.

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