Port container shipping cabin position monitoring method and device

Abstract

The invention discloses a port container shipment cabin position monitoring method, and belongs to the technical field of container shipment automation, and the method comprises the following steps: outputting a stowage chart; coordinates of all points on the ship in the space rectangular coordinate system are obtained; the corresponding containers are clamped, and the containers are transferred according to the coordinates, obtained through last adjustment and updating, of the corresponding shipping spaces of the containers; through first position adjustment, the container corresponds to the position of the corresponding cabin; after the position of the container is stable, the height of the container is gradually reduced. Through laser radar multi-source scanning and three-dimensional digital twinborn body comparison, real-time mapping of a ship and port coordinate system is established, high-precision coincidence of a container projection position and a target shipping space is realized in combination with identification of a visual system on shipping space corners, accurate determination of a container placement position is realized, and high-precision positioning of the container is realized. Therefore, the positioning and position adjusting time in the container shipping process is shortened, and the shipping efficiency is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of automated port container loading, and in particular relates to a method and device for monitoring the position of a hold for port container loading. Background Art

[0002] With the development of the global container shipping industry, port loading and unloading efficiency and operational safety have become key challenges. In the traditional container loading process, cabin positioning mainly relies on manual experience or fixed sensors, which has significant defects:

[0003] Low positioning accuracy: Ships are affected by tides and load changes, which can cause draft fluctuations and position drift, resulting in deviations between pre-loaded coordinates and actual cargo space.

[0004] Adjustment relies on manual labor: After the container is hovering, it needs to be manually visually corrected, which is inefficient and easily affected by environmental interference;

[0005] Rough lowering control: The container lowering speed is fixed, which can easily cause collision accidents due to ship shaking or height misjudgment, especially in high-density stacking scenarios.

[0006] Existing technologies, such as laser scanning of ship profiles, can construct static models but are unable to correlate dynamic loading and unloading processes in real time, and lack a closed-loop control mechanism for container-to-space matching. Therefore, a loading monitoring method that integrates high-precision dynamic positioning, adaptive position correction, and intelligent drop control is urgently needed. Summary of the Invention

[0007] The purpose of the present invention is to provide a method and device for monitoring the position of a container loading hold at a port, so as to solve the problem in the prior art that the container loading mainly relies on the positioning by operators, which is inefficient and has poor safety.

[0008] The purpose of the present invention can be achieved through the following technical solutions:

[0009] The method for monitoring the position of a container loading hold at a port comprises the following steps:

[0010] Step 1. Output the loading diagram;

[0011] Step 2: When the ship enters the port to load the container, a spatial rectangular coordinate system is established to obtain the coordinates of each point on the ship in the spatial rectangular coordinate system;

[0012] Step 3: According to the loading diagram, the container loading and unloading bridge grabs the corresponding container and transfers the container to the preset height above the corresponding space according to the coordinates of the corresponding space obtained by the last adjustment and update;

[0013] At this time, the container is adjusted for the first time so that the projection position of the container on the horizontal plane corresponds to the projection position of its corresponding cabin on the horizontal plane;

[0014] Step 4: After completing the first position adjustment and stabilizing the container position, gradually lower the height of the container.

[0015] As a further solution of the present invention, the method for obtaining the coordinates of each point on the ship is:

[0016] A spatial coordinate system is established with the movement direction of the container loading and unloading bridge from the bow to the stern as the horizontal axis, the direction perpendicular to the horizontal axis as the vertical axis, and the vertical height direction as the vertical axis;

[0017] Obtain a 3D digital twin of a ship after it enters the port and before containers are loaded;

[0018] The local position of the ship is scanned by the laser radar installed on the port shore to obtain the digital twin of the local position on the ship;

[0019] There shall be at least two groups of laser radars installed on the port shore;

[0020] The digital twin of this local position is compared with the three-dimensional digital twin of the ship to obtain the relative position relationship between each point on the ship and the lidar, and then the coordinate position of each point on the ship in the spatial rectangular coordinate system is obtained based on the coordinate position of the lidar in the spatial rectangular coordinate system.

[0021] As a further solution of the present invention, the specific method of the first position adjustment is:

[0022] Identify the four corners of the container's corresponding cabin space;

[0023] A plurality of cameras are distributed on the manipulator that fixes the container on the container loading and unloading bridge, and the relative position relationship between the above-mentioned four corners and each camera is obtained through camera positioning, and then the relative position relationship between the manipulator and the above-mentioned four corners is obtained according to the distribution position of the cameras on the manipulator; the coordinates of the above-mentioned four corners in the spatial rectangular coordinate system are obtained according to the coordinates of the manipulator in the spatial rectangular coordinate system at this time, and the position of the manipulator is adjusted according to the relative position relationship.

[0024] As a further solution of the present invention, a method for adjusting and updating the coordinates of each point on the ship according to the coordinates of the four corners in the spatial rectangular coordinate system is as follows:

[0025] Taking one of the corners as an example, mark the coordinates of the corner obtained by the camera in step 3 as (x1, y1, z1), and mark the coordinates of the corner after the last adjustment and update as (x2, y2, z2);

[0026] when When the value is less than the preset threshold L and any of |x1-x2|, |y1-y2|, and |z1-z2| is less than the preset threshold L1, a corrected coordinate of the corner is obtained.

[0027] The position of the ship in the port is corrected according to the corrected coordinates corresponding to the four corners in the spatial rectangular coordinate system. After obtaining the correction, the updated coordinates of each point on the ship are adjusted in the spatial rectangular coordinate system.

[0028] As a further embodiment of the present invention, when the following conditions are not satisfied: When the value is less than the preset threshold L and any of |x1-x2|, |y1-y2|, and |z1-z2| are less than the preset threshold L1, the real-time coordinates of the corresponding corner are obtained again through the camera. If the above conditions are not met for two or more consecutive times, the collected real-time coordinates are used as the corrected coordinates of the corresponding corner.

[0029] As a further solution of the present invention, the collected real-time coordinates are the most recently collected real-time coordinates or the average value of the most recently collected real-time coordinates.

[0030] As a further solution of the present invention, the method of gradually lowering the height of the container is:

[0031] Obtain the height difference h1 between the bottom surface of the container to be loaded and the placement surface;

[0032] Get the height difference h2 between the bottom of the container to be loaded and the corresponding cabin entrance

[0033] First, the container is lowered at the set uniform speed v1, and the real-time height difference h2 satisfies h2-h3=v1t+at 2 / 2, the container loading and unloading bridge decelerates to a standstill according to the acceleration a, where h3 is the set height threshold;

[0034] Adjust the position of the container until it can safely enter the corresponding space;

[0035] After the container enters the cabin, it is first lowered at the set uniform speed v1, and the real-time height difference h1 satisfies h1-h4=v1t+at 2 / 2, the container loading and unloading bridge decelerates to v2 according to the acceleration a, and then descends at a constant speed of v2 until the placement action is completed. h4 is a set height threshold that is less than or equal to h3.

[0036] As a further solution of the present invention, a horizontal movement path of a container when the container is transferred by a container loading and unloading bridge is obtained;

[0037] After obtaining its horizontal path, obtain the highest point height Hmax within the range covered by the horizontal projection of the path. When actually transshipping the corresponding container, first raise the height of the container to Hmax+Hy before transshipping it horizontally.

[0038] Where Hy is the corresponding preset height value.

[0039] Beneficial effects of the present invention:

[0040] The present invention establishes a real-time mapping of the ship and port coordinate systems through multi-source scanning of laser radar + three-dimensional digital twin comparison, and combines the recognition of cabin corners by the visual system to achieve high-precision coincidence of the container projection position with the target cabin. While taking into account the position movement of the ship during cargo loading, the container placement position is accurately determined, thereby reducing the time for positioning and position adjustment during container loading and improving loading efficiency.

[0041] The present invention has an original dual-coordinate verification mechanism: it compares the real-time corner coordinates (x1, y1, z1) with the historical coordinates (x2, y2, z2). When the offset exceeds the threshold, it triggers a rescan or mean correction, effectively offsetting the hull posture drift caused by tides and loading, and ensuring the continuous reliability of the cabin coordinates.

[0042] The present invention is based on dynamic speed regulation of height differences h1 and h2, and uses segmented deceleration through acceleration a (decelerating to a standstill from h2 to h3, and slowing down to v2 to place the container from h1 to h4). No human intervention is required throughout the process, thereby ensuring loading safety and improving container loading efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The present invention will be further described below with reference to the accompanying drawings.

[0044] Figure 1 It is a flow chart of the method for monitoring the position of a container loading hold at a port according to the present invention. DETAILED DESCRIPTION

[0045] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0046] Method for monitoring the position of container loading hold in port, such as Figure 1 As shown, the following steps are included:

[0047] Step 1. First, use ship stowage software such as Navis N4, MACS3, COSMOS, OCTOPUS, etc. to develop a detailed stowage plan and output the stowage diagram;

[0048] The stowage plan can fully represent the placement coordinates of each container, and the placement coordinates are (shell position, row position, layer position);

[0049] Step 2: When the ship enters the port to load containers, a spatial rectangular coordinate system is established based on the port ground, and the coordinates of each point on the ship in the spatial rectangular coordinate system are obtained, and the coordinates are marked as original coordinates;

[0050] Specifically:

[0051] A spatial coordinate system is established with the movement direction of the container loading and unloading bridge from the bow to the stern as the horizontal axis, the direction perpendicular to the horizontal axis as the vertical axis, and the vertical height direction as the vertical axis;

[0052] Building a 3D digital twin of a ship using LiDAR;

[0053] The ship's 3D digital twin can be established by the ship owner before the ship enters the port, and the obtained 3D digital twin data can be sent to the port. Alternatively, after the ship enters the port, the 3D digital twin can be established through the laser radar installed in the port.

[0054] Obtain a 3D digital twin of a ship after it enters the port and before containers are loaded;

[0055] The local position of the ship is scanned by the laser radar installed on the port shore to obtain the digital twin of the local position on the ship;

[0056] There are at least two groups of laser radars installed on the port shore, which means that at least two digital twins with locations are obtained;

[0057] The digital twin of this local position is compared with the three-dimensional digital twin of the ship to obtain the relative position relationship between each point on the ship and the lidar, and then the coordinate position of each point on the ship in the spatial rectangular coordinate system is obtained based on the coordinate position of the lidar in the spatial rectangular coordinate system.

[0058] Step 3: Adjust the exact position of the container loading and unloading bridge when transferring containers according to the docking position of the ship;

[0059] Specifically:

[0060] According to the loading plan, the container loading and unloading bridge will grab the corresponding container and transfer the container to a certain height above the corresponding space according to the coordinates of the corresponding space obtained by the last adjustment and update;

[0061] At this time, the container is adjusted for the first time so that the projection position of the container on the horizontal plane coincides with the projection position of its corresponding cabin on the horizontal plane as much as possible;

[0062] Specifically, the specific method for the first position adjustment is:

[0063] Identify the four corners of the container's corresponding cabin space;

[0064] Multiple cameras are distributed on the manipulator that fixes the container on the container loading and unloading bridge. The relative position relationship between the four corners and each camera is obtained through camera positioning. Then, the relative position relationship between the manipulator and the four corners is obtained based on the distribution position of the cameras on the manipulator, and the position of the manipulator is adjusted according to the relative position relationship;

[0065] Among them, when the container is transferred by the container loading and unloading bridge, for a container, after determining the corresponding placement space and the container placement point at the port, the horizontal movement path of the container when the container is transferred by the container loading and unloading bridge is obtained;

[0066] After obtaining its horizontal path, obtain the highest point height Hmax within the range covered by the horizontal projection of the path. When actually transshipping the corresponding container, first raise the height of the container to Hmax+Hy before transshipping it horizontally.

[0067] Where Hy is the corresponding preset height value.

[0068] In step 3, after obtaining the relative position relationship between the manipulator and the four corners through the distribution of cameras on the manipulator, the coordinates of the four corners in the spatial rectangular coordinate system are obtained according to the coordinates of the manipulator in the spatial rectangular coordinate system at this time;

[0069] Then, the coordinates of each point on the ship are adjusted and updated according to the coordinates of these four corners in the spatial rectangular coordinate system;

[0070] Taking one of the corners as an example, mark the coordinates of the corner obtained by the camera in step 3 as (x1, y1, z1), and mark the coordinates of the corner after the last adjustment and update as (x2, y2, z2);

[0071] when When the value is less than the preset threshold L and any of |x1-x2|, |y1-y2|, and |z1-z2| is less than the preset threshold L1, a corrected coordinate of the corner is obtained.

[0072] When the above conditions are not met (i.e. When the value is less than the preset threshold L and any of |x1-x2|, |y1-y2|, and |z1-z2| are less than the preset threshold L1), it is considered that the position offset range of the ship is large between the two container loading actions. In order to avoid the influence of errors, the real-time coordinates of the corresponding corners can be obtained again through the camera. If the above conditions are not met for two or more consecutive times, the collected real-time coordinates (which can be the most recently collected real-time coordinates or the average of the most recent real-time coordinates) will be used as the corrected coordinates of the corresponding corners.

[0073] In addition, the position of the ship in the port is corrected according to the corrected coordinates corresponding to the four corners in the spatial rectangular coordinate system. After obtaining the correction, the updated coordinates of each point on the ship are adjusted in the spatial rectangular coordinate system.

[0074] When the container loading and unloading bridge transfers the container to the corresponding cabin space, the corresponding corrected coordinates shall prevail.

[0075] Step 4: After completing the first position adjustment and the container is in a stable position, gradually lower the height of the container;

[0076] Specifically:

[0077] Get the z-axis coordinates of each point on the bottom surface of the container currently being transferred by the container loading and unloading bridge;

[0078] According to the container loading record of the ship, the number of containers loaded at the same bay and row as the container currently required to be placed is obtained, thereby calculating the total height of these loaded containers;

[0079] Obtain the z-axis coordinates of each point on the ship's deck, thereby obtaining the height difference h1 between the bottom surface of the container to be loaded and the placement surface in the corresponding cabin (when there is no container in the cabin, the placement surface is the bottom surface of the corresponding cabin; when there is a container in the cabin, the placement surface is the top surface of the top container in the corresponding cabin);

[0080] Get the height difference h2 between the bottom of the container to be loaded and the corresponding cabin entrance

[0081] The lowering speed of the container loading and unloading bridge is adjusted according to the height difference h1 and the height difference h2.

[0082] Specifically:

[0083] First, the container is lowered at the set uniform speed v1, and the real-time height difference h2 satisfies h2-h3=v1t+at 2 / 2, the container loading and unloading bridge decelerates to a standstill according to the acceleration a, where h3 is the set height threshold;

[0084] Further adjust the position of the container according to the position relationship between the container to be loaded and the corresponding space until the container can safely enter the corresponding space;

[0085] After the container enters the cabin, it is lowered at the same speed v1, and the real-time height difference h1 satisfies h1-h4=v1t+at 2 / 2, the container loading and unloading bridge decelerates to v2 according to the acceleration a, and then descends at a constant speed of v2 until the placement action is completed. h4 is a set height threshold that is less than or equal to h3.

[0086] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in similar ways. As long as they do not deviate from the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present invention.

Claims

1. A method for monitoring the position of a container loading hold at a port, characterized in that: The steps include: Step 1. Output the loading diagram; Step 2: When the ship enters the port to load the container, a spatial rectangular coordinate system is established to obtain the coordinates of each point on the ship in the spatial rectangular coordinate system; Step 3: According to the loading diagram, the container loading and unloading bridge grabs the corresponding container and transfers the container to the preset height above the corresponding space according to the coordinates of the corresponding space obtained by the last adjustment and update; At this time, the container is adjusted for the first time so that the projection position of the container on the horizontal plane corresponds to the projection position of its corresponding cabin on the horizontal plane; Step 4: After completing the first position adjustment and stabilizing the container position, gradually lower the height of the container.

2. The method for monitoring the position of a container loading hold at a port according to claim 1, characterized in that: The method to obtain the coordinates of each point on the ship is: A spatial coordinate system is established with the movement direction of the container loading and unloading bridge from the bow to the stern as the horizontal axis, the direction perpendicular to the horizontal axis as the vertical axis, and the vertical height direction as the vertical axis; Obtain a 3D digital twin of a ship after it enters the port and before containers are loaded; The local position of the ship is scanned by the laser radar installed on the port shore to obtain the digital twin of the local position on the ship; There shall be at least two groups of laser radars installed on the port shore; The digital twin of this local position is compared with the three-dimensional digital twin of the ship to obtain the relative position relationship between each point on the ship and the lidar, and then the coordinate position of each point on the ship in the spatial rectangular coordinate system is obtained based on the coordinate position of the lidar in the spatial rectangular coordinate system.

3. The method for monitoring the position of a container loading hold at a port according to claim 1, characterized in that: The specific method of the first position adjustment is: Identify the four corners of the container's corresponding cabin space; A plurality of cameras are distributed on the manipulator that fixes the container on the container loading and unloading bridge, and the relative position relationship between the above-mentioned four corners and each camera is obtained through camera positioning, and then the relative position relationship between the manipulator and the above-mentioned four corners is obtained according to the distribution position of the cameras on the manipulator; the coordinates of the above-mentioned four corners in the spatial rectangular coordinate system are obtained according to the coordinates of the manipulator in the spatial rectangular coordinate system at this time, and the position of the manipulator is adjusted according to the relative position relationship.

4. The method for monitoring the position of a container loading hold at a port according to claim 3, characterized in that: The method for adjusting and updating the coordinates of each point on the ship according to the coordinates of the four corners in the spatial rectangular coordinate system is: Taking one of the corners as an example, mark the coordinates of the corner obtained by the camera in step 3 as (x1, y1, z1), and mark the coordinates of the corner after the last adjustment and update as (x2, y2, z2); when When the value is less than the preset threshold L and any of |x1-x2|, |y1-y2|, and |z1-z2| is less than the preset threshold L1, a corrected coordinate of the corner is obtained. The position of the ship in the port is corrected according to the corrected coordinates corresponding to the four corners in the spatial rectangular coordinate system. After obtaining the correction, the updated coordinates of each point on the ship are adjusted in the spatial rectangular coordinate system.

5. The method for monitoring the position of a container loading hold at a port according to claim 4, characterized in that: When not satisfied: When the value is less than the preset threshold L and any of |x1-x2|, |y1-y2|, and |z1-z2| are less than the preset threshold L1, the real-time coordinates of the corresponding corner are obtained again through the camera. If the above conditions are not met for two or more consecutive times, the collected real-time coordinates are used as the corrected coordinates of the corresponding corner.

6. The method for monitoring the position of a container loading hold at a port according to claim 5, characterized in that: The collected real-time coordinates are the most recently collected real-time coordinates or the average of the most recently collected real-time coordinates.

7. The method for monitoring the position of a container loading hold at a port according to claim 1, characterized in that: The method of gradually lowering the height of the container is: Obtain the height difference h1 between the bottom surface of the container to be loaded and the placement surface; Get the height difference h2 between the bottom of the container to be loaded and the corresponding cabin entrance First, the container is lowered at the set uniform speed v1, and the real-time height difference h2 satisfies h2-h3=v1t+at 2 / 2, the container loading and unloading bridge decelerates to a standstill according to the acceleration a, where h3 is the set height threshold; Adjust the position of the container until it can safely enter the corresponding space; After the container enters the cabin, it is first lowered at the set uniform speed v1, and the real-time height difference h1 satisfies h1-h4=v1t+at 2 / 2, the container loading and unloading bridge decelerates to v2 according to the acceleration a, and then descends at a constant speed of v2 until the placement action is completed. h4 is a set height threshold that is less than or equal to h3.

8. The method for monitoring the position of a container loading hold at a port according to claim 1, characterized in that: Obtain the horizontal movement path of the container when the container is transferred by the container loading and unloading bridge; After obtaining its horizontal path, obtain the highest point height Hmax within the range covered by the horizontal projection of the path. When actually transshipping the corresponding container, first raise the height of the container to Hmax+Hy before transshipping it horizontally. Where Hy is the corresponding preset height value.

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