Ship unloading method based on portal crane automation

Abstract

The invention discloses a gantry crane automation-based ship unloading method, which comprises the following steps: S1, acquiring ship information through a scanning subsystem, and sending the ship information to a control subsystem, S2, manually setting an unloading point and an obstacle point by an operator, S3, controlling a gantry crane to run and a grab bucket anti-swing subsystem to start by the control subsystem according to a working path formed by point cloud data, and S4, carrying out ship unloading. And S4, the portal crane completes cyclic actions of grabbing, transferring, anti-swing, discharging and returning to a grabbing point, ship information is obtained through the scanning subsystem and sent to the control subsystem, the control subsystem generates an operation path according to point cloud data and controls the portal crane to operate, the grab bucket anti-swing subsystem is started in the process, and the grab bucket anti-swing subsystem is started in the process. The built-in acquisition module is used for correspondingly acquiring coordinate positions of all mechanisms of the grab bucket, so that the real-time spatial position of the grab bucket can be conveniently identified, and the running track and the speed curve of each mechanism can be accurately and quickly calculated through system modeling operation, so that the grab bucket can be controlled to stably run without swinging at any time.

Description

Technical Field

[0001] This invention relates to the field of gantry crane automation technology, specifically to a ship unloading method based on gantry crane automation. Background Technology

[0002] The construction of smart ports has been underway in China for many years, and the level of intelligence has become an important indicator of port competitiveness. Currently, there are 14 fully automated terminals completed in China, with more than 10 under construction. However, all of these automated terminals are container terminals; automated bulk cargo terminals are still unprecedented globally. To meet the current development needs of ports, it is necessary to improve the automation, intelligence, and information technology levels of gantry cranes, reduce the labor intensity of operators, improve their comfort, and enhance operational safety. On the other hand, advanced industrial technologies should be utilized to scientifically improve operational efficiency and increase the economic benefits for enterprises.

[0003] Currently, the automated operation technology of cranes is being rapidly adopted in container terminals in China. One of the most critical technologies in crane automation is anti-sway technology. For cranes using wire ropes, the handling of heavy objects involves three-dimensional movement, including not only the up-and-down movement of the hoisting mechanism but also the linear movement of the translation mechanism and the rotational movement of the slewing mechanism. When the load suspended by the wire rope undergoes translational or rotational movement, it will sway. This swaying can only be actively suppressed by skilled operators and cannot be controlled by automation. This is mainly because the swaying caused by linear motion is only in the direction of linear motion and can be easily suppressed by changing the acceleration and deceleration of the linear drive mechanism. However, the swaying caused by rotational motion exists not only in the direction of rotation but also in the direction of centrifugal force perpendicular to the direction of rotation. Suppressing these two types of swaying requires the combined action of the rotary drive mechanism and the luffing drive mechanism, which is more difficult to achieve. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing an automated gantry crane unloading method. The method involves acquiring ship information through a scanning subsystem and sending it to a control subsystem. The control subsystem generates an operation path based on point cloud data and controls the operation of the gantry crane. During the process, an anti-sway subsystem for the grab bucket is activated to ensure that the grab bucket does not sway during operation.

[0005] The technical solution of the present invention is as follows:

[0006] A method for unloading ships based on gantry crane automation includes a gantry crane automation system for the method. The gantry crane automation system includes a control subsystem, a scanning subsystem, a grab bucket anti-sway subsystem, and a positioning subsystem. The steps of the method are as follows:

[0007] S1: Obtain vessel information through the scanning subsystem and send it to the control subsystem;

[0008] S2: Operators manually set unloading points and obstacle points;

[0009] S3: The control subsystem controls the operation of the gantry crane based on the point cloud data to form the operation path, and the grab bucket anti-shake subsystem is activated;

[0010] S4: The gantry crane completes the cycle of grabbing, transferring, anti-shaking, discharging, and returning to the grabbing point. During the process, the positioning system determines the position of the gantry crane and the grab bucket in real time.

[0011] Preferably, the scanning subsystem applied in S1 includes an identification module and a data processing module, wherein the identification module includes material and ship type identification and obstacle identification, and the data processing module includes ship cabin data integration and operation path analysis.

[0012] Preferably, step S1 further includes the following step:

[0013] S1.1: The scanning subsystem quickly scans the ground operation area through material and ship type recognition and obstacle recognition in the recognition module, accurately identifies material and ship type information, divides and filters the operation grid, and then transmits the acquired information to the data processing module.

[0014] S1.2: The integration of ship cabin data in the data processing module includes ship point data, unloading point data and obstacle data. Among them, the ship point data contains information on the location of the ship hatch and the height of the ship's side. All of the aforementioned data are obtained by the identification module and sent to the data processing module.

[0015] S1.3: After the ship's cabin data is integrated, the data processing module, in conjunction with relevant algorithms, can analyze the operation path and obtain the coordinates of each time period of the gantry crane and grab bucket operation.

[0016] Preferably, the control subsystem applied in S3 includes a communication module, an Ethernet module, a PLC control module, an industrial computer, and an absolute encoder, while the grab bucket anti-shake subsystem includes a coordinate acquisition module, a model building module, a calculation module, and a positioning module.

[0017] Preferably, step S3 further includes the following step:

[0018] S3.1: The control subsystem uses communication modules and Ethernet modules to realize information interaction with the PLC control module and industrial computer;

[0019] S3.2: The position of each mechanism in the gantry crane and grab bucket is determined by an absolute encoder, and the corresponding positioning and anti-collision algorithms in the industrial control computer and PLC control module are used to avoid the grab bucket from colliding with obstacles during operation;

[0020] S3.3: During the grab bucket's material grabbing and unloading process, the coordinate acquisition module in the grab bucket anti-shake system collects and sends the grab bucket coordinate information in real time;

[0021] S3.4: The model building module uses the coordinate acquisition module to collect the position coordinates of the grab bucket to build a corresponding spatial model, which can accurately and quickly calculate its running trajectory and speed curve, thereby controlling the grab bucket to run smoothly and without swaying at any time.

[0022] Preferably, the positioning system applied in S4 includes a vehicle positioning module, a network transmission module, a Beidou module, and an RFID module.

[0023] Preferably, step S4 further includes the following step:

[0024] S4.1: The encoder in the trolley module can read the position of the trolley in real time. At the same time, the RFID module can read the position information of the trolley at a fixed point by reading the magnetic nails embedded near the trolley track.

[0025] S4.2: The Beidou module reads the current latitude and longitude information of the gantry crane in real time, calculates the distance difference between the current position of the gantry crane and the fixed point, calculates the position of the gantry crane, and thus obtains the position of the gantry crane on the track.

[0026] S4.3: Once the positions of the gantry crane and the trolley are determined, the control subsystem and the grab bucket anti-sway subsystem control the grab bucket operation. During the process, the control subsystem and the grab bucket anti-sway subsystem exchange information through the network transmission module in the positioning subsystem to ensure that the grab bucket is operating normally.

[0027] The beneficial effects of this invention are:

[0028] The scanning subsystem acquires ship information and sends it to the control subsystem. This information mainly includes the location of the ship's hatches and the material information within those hatches. Once this information is obtained, the control subsystem can perform corresponding control operations to prevent misalignment between the gantry crane and the grab bucket during operation. The control subsystem generates the operation path based on point cloud data and controls the gantry crane's operation. During this process, the grab bucket anti-sway subsystem is activated to ensure that the grab bucket does not sway during operation. The acquisition module within the grab bucket anti-sway subsystem collects the coordinate positions of each mechanism within the grab bucket to identify its real-time spatial position. Through system modeling and calculation, the operating trajectory and speed curve of each mechanism can be accurately and quickly calculated, enabling the grab bucket to operate smoothly and without swaying at all times. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of steps S1-S4 of the present invention;

[0031] Figure 2 This is a schematic diagram of the door operator automation system of the present invention;

[0032] Figure 3 This is a schematic diagram of the scanning subsystem of the present invention;

[0033] Figure 4 This is a schematic diagram of the ship cabin data integration of the present invention;

[0034] Figure 5 This is a schematic diagram of steps S1.1-S1.3 in step S1 of the present invention;

[0035] Figure 6 This is a schematic diagram of the control subsystem of the present invention;

[0036] Figure 7 This is a schematic diagram of the grab bucket anti-shake system of the present invention;

[0037] Figure 8 This is a schematic diagram of steps S3.1-S3.4 in step S3 of the present invention;

[0038] Figure 9 This is a schematic diagram of the positioning subsystem of the present invention;

[0039] Figure 10 This is a schematic diagram of steps S4.1-S4.3 in step S4 of the present invention;

[0040] Figure 11 This is a schematic diagram of the filtering calculation formula within the data processing module of the present invention. Detailed Implementation

[0041] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0042] To further understand this utility model, a detailed description of it will be provided below with reference to the accompanying drawings.

[0043] Combination Figures 1-5 This utility model provides a ship unloading method based on gantry crane automation, including a gantry crane automation system for the method. The gantry crane automation system includes a control subsystem, a scanning subsystem, a grab bucket anti-sway subsystem, and a positioning subsystem. The steps of the method are as follows:

[0044] S1: The scanning subsystem acquires ship information and sends it to the control subsystem. The ship information mainly includes the location of the ship's hatches and the material information in the hatches. After acquiring this information, the control subsystem can perform corresponding control operations to prevent the gantry crane and grab bucket from being misaligned during operation.

[0045] S2: Operators manually set unloading points and obstacle points. Unloading points, obstacle points, and material collection points are all regionalized. This allows for the setting and filtering of work grids, enhancing the accuracy of the operation process.

[0046] S3: The control subsystem controls the operation of the gantry crane based on the point cloud data to form the operation path, and the grab bucket anti-shake subsystem is activated;

[0047] S4: The gantry crane completes the cycle of grabbing, transferring, anti-swaying, discharging, and returning to the grabbing point. During the process, the positioning system determines the position of the gantry crane and the grab bucket in real time.

[0048] The scanning subsystem applied in S1 includes an identification module and a data processing module. The identification module includes material and ship type identification and obstacle identification, and the data processing module includes ship cabin data integration and operation path analysis.

[0049] S1 also includes the following sub-steps:

[0050] S1.1: The scanning subsystem quickly scans the ground operation area through material and ship type recognition and obstacle recognition in the recognition module, accurately identifies material and ship type information, divides and filters the operation grid, and then transmits the acquired information to the data processing module.

[0051] S1.2: The integration of ship cabin data in the data processing module includes ship point data, unloading point data and obstacle data. Among them, the ship point data contains information on the location of the ship hatch and the height of the ship's side. All of the aforementioned data are obtained by the identification module and sent to the data processing module.

[0052] S1.3: After the ship's cabin data is integrated, the data processing module, in conjunction with relevant algorithms, can analyze the operation path and obtain the coordinates of each part of the gantry crane and grab bucket operation period;

[0053] In this embodiment, the identification module is equipped with two sets of 3D laser gimbal scanning devices (LiDAR) and three 2D laser scanners to identify the required targets. The data obtained by the two scanning devices are combined by an algorithm to calculate the required targets, including: ship hatch location, ship hull height, materials, and loading / unloading location identification.

[0054] The lidar at the boom hinge point collects data from the target area by carrying a gimbal. Combined with relevant algorithms, the original data is denoised. Based on the feature structure of the target to be identified, feature points are matched in the denoised data. The position of the target object in the space in the laser view is determined by the feature points. The lidar at the elephant's trunk head plays an auxiliary role.

[0055] The data acquired by two lidar sensors is combined with spatial coordinate transformation to convert the spatial coordinate system under the laser viewpoint into the actual ground material coordinate system, thereby accurately locating the actual physical coordinates of characteristic targets, including hatches, ship decks, and material areas. This enables the PLC to precisely position and control the actions of various electrical and actuator mechanisms, successfully completing the automated process control of the gantry crane.

[0056] Three 2D laser scanners are used for obstacle recognition. The targets to be recognized include obstacles on both sides of the gantry crane boom and in the direction of the elephant trunk beam. During the operation of the gantry crane, the pan-tilt head drives the scanner scanning surface to rotate according to the movement direction of the gantry crane slewing mechanism, keeping the scanning surface at a certain angle with the vertical plane of the boom mechanism, and performing advance detection on the area to be covered by the gantry crane boom mechanism and the grab bucket movement.

[0057] The data processing module comprehensively analyzes and calculates ship point cloud data, unloading point data, obstacle data, etc., and uses optimization methods to plan a trajectory from the material grabbing point to the material unloading point for automated operation, so as to achieve the goal of safe and efficient automated unloading operation.

[0058] The gantry crane automation system obtains obstacle information and material unloading location information through the human-machine interface, and obtains ship point cloud data through the scanning system. It then analyzes this data to determine information such as ship hatch location, hull height, and material composition. Adhering to the principles of safety and efficiency, the system plans the operation path, grabbing points, and unloading points based on actual conditions. This data is then controlled by the automated PLC system, which in turn controls the drive unit, enabling the gantry crane to operate according to the planned operation, achieving automatic unloading. The system also enables the gantry crane to perform closed-bucket grabbing, transfer, and open-bucket unloading actions according to the planned operation.

[0059] Combination Figures 6-8 The control subsystem applied in S3 includes a communication module, an Ethernet module, a PLC control module, an industrial computer, and an absolute encoder. The grab bucket anti-shake subsystem includes a coordinate acquisition module, a model building module, a calculation module, and a positioning module.

[0060] S3 also includes the following sub-steps:

[0061] S3.1: The control subsystem uses communication modules and Ethernet modules to realize information interaction with the PLC control module and industrial computer;

[0062] S3.2: The position of each mechanism in the gantry crane and grab bucket is determined by an absolute encoder, and the corresponding positioning and anti-collision algorithms in the industrial control computer and PLC control module are used to avoid the grab bucket from colliding with obstacles during operation;

[0063] S3.3: During the grab bucket's material grabbing and unloading process, the coordinate acquisition module in the grab bucket anti-shake system collects and sends the grab bucket coordinate information in real time;

[0064] S3.4: The model building module uses the coordinate acquisition module to collect the position coordinates of the grab bucket to build a corresponding spatial model, which can accurately and quickly calculate its running trajectory and speed curve, thereby controlling the grab bucket to run smoothly and without swaying at any time.

[0065] In this embodiment, the PLC control module is equipped with a Siemens S7-1500 PLC, while the industrial computer is selected from Advantech industrial computers. It is used for the application of the grab bucket anti-shake system and the implementation of the anti-collision algorithm. The PLC control module communicates with the host control system PLC through the Ethernet module to realize data interaction and realize the signals sent by the absolute encoder that detects the position of each mechanism of the gantry crane and grab bucket.

[0066] The communication module adopts DP communication. In the PLC control module, the laser scanner is connected to the industrial computer via an Ethernet module, so that the PLC control module can be used for the automatic control of the door machine. When the system fails, it can be switched to non-automatic mode without affecting the operation of the original host control system.

[0067] When the gantry crane is performing automated operations, it is also necessary to use the grab bucket anti-shake system to ensure that the grab bucket does not shake during operation. The acquisition module collects the coordinate position of each mechanism of the grab bucket to identify the real-time spatial position of the grab bucket. Then, through system modeling and calculation, the running trajectory and speed curve of each mechanism can be calculated accurately and quickly, so as to control the grab bucket to operate smoothly and without swaying at any time.

[0068] Based on the actual working conditions, a suitable lidar is selected and installed in the acquisition module to perform 3D scanning of the environment where the grab bucket is located, and generate the corresponding coordinate point cloud map. The acquired coordinates are then input into the modeling software to generate a scene model. The data processing module performs noise reduction to avoid some noise points in the coordinate point cloud map from affecting the modeling. OpenCV can be used for filtering and noise reduction during this noise reduction process.

[0069] The process is as follows:

[0070] First, we obtain the mean filter. The mean filter smooths the image by calculating the average value of all pixel values ​​within the filter window. It is a linear filter that can effectively reduce noise, but it can also blur the edges of the image.

[0071] A Gaussian filter is then applied, which uses the weights of a Gaussian function to calculate a weighted average of the pixels within the filtering window. Compared to mean filtering, it preserves edge information better. A Gaussian filter is a linear filter, and the weights are distributed in a centrally symmetric Gaussian distribution.

[0072] Finally, median filtering is used to smooth the image by selecting the median value of all pixels within the filtering window. Median filtering is a non-linear filter that is particularly suitable for removing salt-and-pepper noise and can preserve image edges well.

[0073] It should be noted that the pixel calculation formulas and Gaussian weight calculation formulas for mean filtering, Gaussian filtering, and median filtering can be used as a reference. Figure 11 The specific code implementations of the three OpenCV filtering methods are as follows:

[0074] Mean filtering: Implemented using cv2.blur(image,(5,5));

[0075] Gaussian filtering: Implemented using cv2.GaussianBlur(image,(5,5),1.0), where 1.0 is the standard deviation;

[0076] Median filtering: Implemented using cv2.medianBlur(image, 5)

[0077] Combination Figure 6 , Figure 7 , Figure 9 and Figure 10 The positioning system applied in S4 includes a vehicle positioning module, a network transmission module, a Beidou module, and an RFID module.

[0078] S4 also includes the following sub-steps:

[0079] S4.1: The encoder in the trolley module can read the position of the trolley in real time. At the same time, the RFID module can read the position information of the trolley at a fixed point by reading the magnetic nails embedded near the trolley track.

[0080] S4.2: The Beidou module reads the current latitude and longitude information of the gantry crane in real time, calculates the distance difference between the current position of the gantry crane and the fixed point, calculates the position of the gantry crane, and thus obtains the position of the gantry crane on the track.

[0081] S4.3: Once the positions of the gantry crane and the trolley are determined, the control subsystem and the grab bucket anti-sway subsystem control the grab bucket operation. During the process, the control subsystem and the grab bucket anti-sway subsystem exchange information through the network transmission module in the positioning subsystem to ensure that the grab bucket is operating normally.

[0082] In this embodiment, the Beidou module is specifically the Beidou satellite positioning system. After the position calculation of the trolley module is combined with the Beidou positioning system, it makes up for the cumulative error that occurs when the trolley positioning is based on the walking absolute encoder, and the two situations that occur when the RFID module (RFID is radio frequency identification technology) is limited by the flatness of the track and the life of the magnetic nail, resulting in the omission of detection points. This improves the positioning accuracy and stability of the trolley.

Claims

1. A method for unloading a ship based on gantry automation, characterized by, The method comprises a portal crane automation system, the portal crane automation system comprises a control subsystem, a scanning subsystem, a grab bucket anti-swing subsystem and a positioning subsystem, and the method comprises the following steps: S1: obtaining ship information through the scanning subsystem and sending the ship information to the control subsystem; S2: manually setting a discharge point and an obstacle point by an operator; S3: controlling the portal crane to run according to a work path formed according to point cloud data by the control subsystem, and starting the grab bucket anti-swing subsystem; S4: the portal crane completes a cycle of grabbing material, transferring, anti-swinging, discharging and returning to the material grabbing point, and the positioning system determines the positions of the portal crane and the grab bucket in real time during the cycle.

2. The automated unloading method based on the door machine according to claim 1, characterized in that: The scanning subsystem applied to S1 comprises an identification module and a data processing module, wherein the identification module comprises material and ship type identification and obstacle identification, and the data processing module comprises ship cabin data integration and work path analysis.

3. The automated unloading method based on the door machine according to claim 1, characterized in that: S1.1: the scanning subsystem quickly scans a ground work area through the material and ship type identification and the obstacle identification in the identification module, accurately identifies material and ship type information, divides and selects a work grid, and then transmits the obtained information to the data processing module; S1.2: the ship cabin data integration in the data processing module comprises ship point data, discharge point data and obstacle data, wherein the ship point data comprises ship hatch position and ship side height information, and the foregoing data are obtained by the identification module and sent to the data processing module; S1.3: after the ship cabin data integration is completed, the data processing module cooperates with a related algorithm to analyze the work path and obtain coordinates of the portal crane and the grab bucket during work. The control subsystem applied to S3 comprises a communication module, an Ethernet module, a PLC control module, an industrial computer and an absolute value encoder, and the grab bucket anti-swing subsystem comprises a coordinate acquisition module, a model building module, an operation module and a positioning module.

4. The automated unloading method based on the door machine according to claim 1, characterized in that: S3.1: the control subsystem realizes information interaction between the PLC control module and the industrial computer by using the communication module and the Ethernet module; 5. The automated unloading method based on the door machine according to claim 1, characterized in that: S3.2: the positions of mechanisms in the portal crane and the grab bucket are determined by using the absolute value encoder, and corresponding positioning and anti-collision algorithms in the industrial computer and the PLC control module are matched to avoid collision between the grab bucket and an obstacle during work of the grab bucket; S3.3: the coordinate acquisition module in the grab bucket anti-swing subsystem collects and sends grab bucket coordinate information in real time during grabbing and discharging of the grab bucket; S3.4: the model building module establishes a corresponding space model by using the grab bucket position coordinates collected by the coordinate acquisition module, and can accurately and quickly calculate a running track and a speed curve of the grab bucket, so that the grab bucket can run stably and without swinging at any time. The positioning system applied to S4 comprises a cart positioning module, a network transmission module, a Beidou module and an RFID module. S4.1: the encoder in the cart module can read the position of the cart in real time, and the RFID module can read the position information of the cart at a fixed point by reading magnetic nails pre-embedded near a cart track; 6. The automated unloading method based on the door machine according to claim 1, characterized in that: ​ 7. The automated unloading method based on the door machine according to claim 1, characterized in that: ​ ​ S4.2: The Beidou module calculates the distance difference between the current position of the trolley and the fixed point by reading the current latitude and longitude information of the portal machine in real time, calculates the moving position of the trolley, and thus obtains the position of the trolley on the track; S4.3: After the positions of the portal machine and the trolley are determined, the control subsystem and the grab bucket anti-shake subsystem control the grab bucket operation. During the process, the control subsystem and the grab bucket anti-shake subsystem interact information through the network transmission module in the positioning subsystem to ensure whether the grab bucket operation is normal.

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