A laser-based yard crane lifting height checking method and device

Abstract

The application discloses a kind of yard bridge lifting height verification method and device based on laser, which comprises the first lifting height of yard bridge by encoder real-time acquisition, the point cloud data of reflector plate is obtained by laser radar, and point cloud calibration is carried out to point cloud data, the second lifting height of yard bridge is calculated, and the difference between the first lifting height and the second lifting height is determined, if the difference is less than or equal to preset safety threshold, it is judged that the first lifting height obtained by encoder is normal, and controller controls yard bridge to continue automatic operation;If the difference is greater than preset safety threshold, it is judged that the first lifting height obtained by encoder is abnormal, and controller controls yard bridge to stop automatic operation.The above technical scheme is used, and the actual height of yard bridge lifting device can be obtained in real time and accurately in the process of yard bridge automatic operation, and the lifting height obtained by encoder is verified, to enhance the accuracy and safety of automatic operation.

Description

Technical Field

[0001] This invention relates to the field of port automation equipment technology, and in particular to a laser-based method and apparatus for verifying the lifting height of a yard crane. Background Technology

[0002] Yard cranes are a common piece of equipment used in port transportation operations. In existing technologies, when yard cranes are used for automated operations, the operating height of the lifting mechanism is generally obtained through encoders. However, during the operation, there will be an error between the height value provided by the encoder and the actual value. This error may be an accumulated error generated during long-term operation, or it may be a sudden change caused by encoder damage. When this error exceeds a certain value, it will seriously affect the accuracy and safety of the automated operation of the yard crane. Summary of the Invention

[0003] In view of the technical problem that the operating height of the lifting mechanism obtained by the encoder may have a large error, the present invention proposes an embodiment of the present invention. The embodiment of the present invention designs a laser-based field bridge lifting height verification system, which can obtain the actual height of the field bridge lifting mechanism in real time and accurately during automatic operation, and verify it with the height value obtained by the encoder, thereby enhancing the safety of automated operation.

[0004] To address the aforementioned problems, this invention discloses, in one aspect, a laser-based method for verifying the lifting height of a field bridge. This method is applied to a field bridge lifting height verification system, which includes a trolley, a crane, a lifting device, and a scanning system. The lifting device is equipped with a reflector. The scanning system includes a controller, a laser radar, and an encoder electrically connected to the controller. The laser radar is located at the bottom of the crane, and the encoder is used to acquire the first lifting height of the field bridge in real time. The method includes:

[0005] The position data information of the lifting device is obtained by the lidar, and the position data information includes the point cloud data of the reflector;

[0006] The location data information is processed to extract the point cloud data of the reflector from the location data information, and the point cloud data is calibrated. The point cloud calibration includes coordinate system transformation, calibration angle error and calibration height error.

[0007] Calculate the second lifting height of the field bridge and determine the difference between the first lifting height and the second lifting height. The second lifting height of the field bridge is the average height of all point clouds in the point cloud data of the reflector after point cloud calibration.

[0008] If the difference is less than or equal to a preset safety threshold, it is determined that the first lifting height obtained by the encoder is normal, and the controller controls the field bridge to continue automated operation.

[0009] If the difference is greater than a preset safety threshold, the first lifting height obtained by the encoder is determined to be abnormal, and the controller controls the field bridge to stop automated operation.

[0010] Optionally, processing the location data information to extract the point cloud data of the reflector from the location data information includes:

[0011] Set the coordinate range and reflectivity range of the reflector;

[0012] The position data information is subjected to pass-through filtering based on the coordinate range and reflectivity range of the reflector to remove point clouds that do not belong to the scanning device and point clouds with reflectivity less than a preset threshold.

[0013] Determine the point cloud data belonging to the reflector.

[0014] Optionally, the coordinate system transformation process in point cloud calibration includes:

[0015] Establish a lidar coordinate system, which is a first Cartesian coordinate system with the right side of the lidar as the positive x-axis, the front of the lidar as the positive y-axis, the top of the lidar as the z-axis, and the center of the lidar as the origin.

[0016] Establish a field bridge coordinate system, which is a second Cartesian coordinate system with the positive x-axis for the trolley moving forward, the positive y-axis for moving to the left, the z-axis perpendicular to the ground and upward, and the projection of the center of the driver's cab onto the ground as the origin;

[0017] Based on the correspondence between the point cloud data of the reflector, the lidar coordinate system, and the field bridge coordinate system, the coordinates of the point cloud data of the reflector in the field bridge coordinate system are determined.

[0018] Optionally, the process of calibrating angle errors in point cloud calibration includes:

[0019] Determine the first deviation angle between the actual scanning line of the lidar and the direction of the vehicle's movement, and calibrate the actual scanning line of the lidar using a rotation matrix so that the actual scanning line of the lidar is parallel to the direction of the vehicle's movement;

[0020] Determine the second deviation angle between the actual scanning line of the lidar and the direction of travel of the vehicle, and calibrate the actual scanning line of the lidar using a rotation matrix so that the actual scanning line of the lidar is perpendicular to the direction of travel of the vehicle.

[0021] If the actual distance from the lidar to the ground is b, and the actual distance from the reflector to the ground is a, then the actual distance from the lidar to the reflector is d = ba. The distance from the lidar to the reflector obtained from the lidar scan can be determined as c using point cloud data. The formula for calculating the second deviation angle β is as follows:

[0022] cosβ=d / c=(ba) / c.

[0023] Optionally, the process of calibrating height error in point cloud calibration includes:

[0024] The lifting device is moved to the ground, and when the lifting device is located on the ground, the encoder reads the field bridge height value e.

[0025] The point cloud data of the lifting device when it is on the ground is obtained by the lidar, and the angle error of the point cloud data is calibrated.

[0026] Determine the position of the reflector in the point cloud data, and select the center of the point cloud with a reflectivity exceeding a preset threshold as the true coordinate position of the reflector, and calculate the height f of the true coordinate position of the reflector;

[0027] The height error is calibrated, where the height error g = ef.

[0028] Optionally, the trolley is also equipped with a bracket, and the lidar is rotatably connected to the bracket. Before obtaining the position data information of the lifting device through the lidar, the method for verifying the lifting height of the yard crane further includes:

[0029] The scanning angle of the lidar is adjusted by the bracket so that the scanning range of the lidar covers the vehicle and the reflector.

[0030] Optionally, the reflector is mounted on the upper surface of the lifting device, and the method for verifying the lifting height of the yard bridge further includes:

[0031] The laser scanning direction of the lidar is consistent with the running direction of the vehicle, and the laser scanning surface of the lidar faces the ground.

[0032] On the other hand, this invention discloses a laser-based field bridge lifting height verification device. The device is applied to a field bridge lifting height verification system, which includes a trolley, a crane, a lifting device, and a scanning system. The lifting device is equipped with a reflector. The scanning system includes a controller, a laser radar, and an encoder electrically connected to the controller. The laser radar is located at the bottom of the crane. The encoder is used to acquire the first lifting height of the field bridge in real time. The device includes:

[0033] The point cloud data acquisition module is used to acquire the position data information of the lifting device through the lidar, and the position data information includes the point cloud data of the reflector;

[0034] The point cloud data calibration module is used to process the location data information, extract the point cloud data of the reflector from the location data information, and perform point cloud calibration on the point cloud data. The point cloud calibration includes coordinate system transformation, calibration angle error and calibration height error.

[0035] The hoisting height calculation module of the yard bridge is used to calculate the second hoisting height of the yard bridge and determine the difference between the first hoisting height and the second hoisting height. The second hoisting height of the yard bridge is the average height of all point clouds in the point cloud data of the reflector after point cloud calibration.

[0036] The first execution module is used to determine that the first lifting height obtained by the encoder is normal if the difference is less than or equal to a preset safety threshold, and the controller controls the field bridge to continue automated operation.

[0037] The second execution module is used to determine that the first lifting height obtained by the encoder is abnormal if the difference is greater than a preset safety threshold, and the controller controls the field bridge to stop the automated operation.

[0038] On the other hand, embodiments of the present invention also provide an electronic device, which includes a processor, a memory, and a computer program stored in the memory and capable of running on the processor, wherein the computer program, when executed by the processor, implements the steps of the field bridge lifting height verification method.

[0039] On the other hand, embodiments of the present invention also provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the field bridge lifting height verification method.

[0040] This invention discloses a laser-based method and apparatus for verifying the lifting height of a field bridge. The method includes acquiring a first lifting height of the field bridge in real time via an encoder, acquiring point cloud data of a reflector via a lidar, calibrating the point cloud data, calculating a second lifting height of the field bridge, and determining the difference between the first and second lifting heights. If the difference is less than or equal to a preset safety threshold, the first lifting height acquired by the encoder is determined to be normal, and the controller controls the field bridge to continue automated operation. If the difference is greater than the preset safety threshold, the first lifting height acquired by the encoder is determined to be abnormal, and the controller controls the field bridge to stop automated operation.

[0041] By adopting the above technical solution, the technical solution of the present invention has the following technical effects:

[0042] (1) The second lifting height of the yard bridge can be determined by lidar, so that the actual height of the yard bridge lifting device can be obtained in real time and accurately during the automatic operation, and verified with the first lifting height obtained by the encoder, thereby enhancing the accuracy and safety of the automated operation.

[0043] (2) A bracket is provided on the trolley to adjust the scanning angle of the lidar so that the scanning range of the lidar covers the trolley and the reflector, so that the lidar can scan the reflector under various extreme working conditions, thereby improving the applicability of the method. Attached Figure Description

[0044] Figure 1 A flowchart illustrating the steps of a laser-based field bridge lifting height verification method provided in this embodiment of the invention;

[0045] Figure 2 This is a schematic diagram of the installation of a lidar and a reflector in a field bridge lifting height verification system provided in an embodiment of the present invention;

[0046] Figure 3 This is a schematic diagram illustrating the relative relationship between the laser scanning direction, the trolley's running direction, and the large vehicle's running direction, provided in an embodiment of the present invention.

[0047] Figure 4 This is a schematic diagram illustrating a method for determining a first deviation angle according to an embodiment of the present invention.

[0048] Figure 5 This is a schematic diagram illustrating a method for determining a second deviation angle according to an embodiment of the present invention;

[0049] Figure 6 This is a structural block diagram of a laser-based field bridge lifting height verification device provided in an embodiment of the present invention. Detailed Implementation

[0050] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0051] Figure 1 A flowchart illustrating the steps of a laser-based field bridge lifting height verification method provided in this embodiment of the invention. Figure 2This is a schematic diagram of the installation of a lidar and a reflector in a yard crane lifting height calibration system provided by an embodiment of the present invention. The method is applied to a yard crane lifting height calibration system, which includes a trolley (not shown), a carriage 1, a lifting device 2, and a scanning system. A reflector 3 is installed on the lifting device 2. The scanning system includes a controller, a lidar 4 and an encoder electrically connected to the controller. The lidar 4 is located at the bottom of the carriage 1. The encoder is used to acquire the first lifting height of the yard crane in real time. The method includes:

[0052] Step 101: Obtain the position data information of the lifting device through the lidar, the position data information including the point cloud data of the reflector;

[0053] Figure 3 This is a schematic diagram illustrating the relative relationship between the laser scanning direction, the trolley's running direction, and the trolley's running direction, provided as an embodiment of the present invention. In the diagram, A represents the trolley's running direction, B represents the trolley's running direction, and C represents the laser scanning direction. A lidar 4 is installed at the bottom of the trolley 1, with its laser scanning surface facing the ground. Simultaneously, the laser scanning direction of the lidar 4 is consistent with the trolley's running direction and perpendicular to the trolley's running direction. A reflector 3 is installed on the upper surface of the lifting device 2 to ensure unobstructed laser scanning of the reflector.

[0054] In practical applications, factors such as lifting device sway and installation errors can cause the lidar 4 to fail to scan the reflector 3. Therefore, before obtaining the position data of the lifting device 2 through the lidar 4, it is necessary to verify the positions of the lidar 4 and the reflector 3 to ensure that the scanning range of the lidar 4 can completely cover the reflector 3. To ensure that the scanning range of the lidar 4 can completely cover the reflector 3, in this embodiment of the invention, a bracket is also provided on the trolley 1 when designing the scanning range of the lidar 4, and the lidar 4 is mounted on the bracket. By fine-tuning the bracket angle, the lidar 4 can be rotated in the direction of the trolley 1, that is, the position of the lidar scanning line in the direction of the trolley can be translated. Under various extreme conditions of lifting device micro-movement, the point cloud visualization software is opened, and the reflectivity is used to check whether the reflector 3 is scanned. If it is not scanned, the bracket angle is adjusted so that the lidar 4 can scan the reflector 3 under various extreme conditions, thereby improving the applicability of the laser scanning method.

[0055] Step 102: Process the location data information, extract the point cloud data of the reflector from the location data information, and perform point cloud calibration on the point cloud data. The point cloud calibration includes coordinate system transformation, calibration angle error and calibration height error.

[0056] The location data information is processed to extract the point cloud data of the reflector, including: setting the coordinate range and reflectivity range of the reflector; performing pass-through filtering on the location data information according to the coordinate range and reflectivity range to remove point clouds that do not belong to the scanning fixture and point clouds with reflectivity less than a preset threshold, thereby determining the point cloud data belonging to the reflector. It should be noted that those skilled in the art can set the reflector coordinate range, reflectivity range, and reflectivity threshold according to actual conditions to obtain the corresponding point cloud data of the reflector.

[0057] The coordinate system transformation process in point cloud calibration includes: establishing a lidar coordinate system, which is a first Cartesian coordinate system with the right side of the lidar as the positive x-axis, the front of the lidar as the positive y-axis, the top of the lidar as the z-axis, and the center of the lidar as the origin; establishing a field bridge coordinate system, which is a second Cartesian coordinate system with the trolley moving forward as the positive x-axis, moving to the left as the positive y-axis, and the vertical upward direction from the ground as the z-axis, with the projection of the driver's cab center onto the ground as the origin; and determining the coordinates of the reflector's point cloud data in the field bridge coordinate system based on the correspondence between the reflector's point cloud data, the lidar coordinate system, and the field bridge coordinate system. It should be noted that after establishing the lidar and field bridge coordinate systems, since both are Cartesian coordinate systems, the corresponding coordinate transformation relationship can be determined based on their origin positions, thereby determining the coordinates of the point cloud data in the field bridge coordinate system based on the coordinate information acquired by the lidar in the lidar coordinate system.

[0058] The process of calibrating the angle error in point cloud calibration includes: determining the first deviation angle between the actual scanning line of the lidar and the direction of the vehicle's movement, and calibrating the actual scanning line of the lidar using a rotation matrix to make the actual scanning line of the lidar parallel to the direction of the vehicle's movement; determining the second deviation angle between the actual scanning line of the lidar and the direction of the vehicle's movement, and calibrating the actual scanning line of the lidar using a rotation matrix to make the actual scanning line of the lidar perpendicular to the direction of the vehicle's movement.

[0059] Figure 4 This is a schematic diagram of a method for determining a first deviation angle provided in an embodiment of the present invention. In the direction of the vehicle, due to the LiDAR itself and installation errors, it can be seen from the point cloud data that the actual radar scan line will have a certain angle with the ground. The angle between the radar scan line and the straight line perpendicular to the ground is α. After determining the specific value of the angle α, those skilled in the art can use a rotation matrix to calibrate it to be parallel to the ground.

[0060] Figure 5This is a schematic diagram of a method for determining a second deviation angle provided in an embodiment of the present invention. If the actual distance from the laser radar to the ground is b, and the actual distance from the reflector to the ground is a, then the actual distance from the laser radar to the reflector is d = ba. The distance from the laser radar to the reflector obtained by the laser radar scan can be determined as c using point cloud data. The formula for calculating the second deviation angle β is as follows:

[0061] cosβ=d / c=(ba) / c.

[0062] The process of calibrating height error in point cloud calibration includes: moving the lifting device to the ground and determining the field bridge height value e read by the encoder when the lifting device is on the ground; acquiring point cloud data when the lifting device is on the ground using lidar and calibrating the angle error of the point cloud data; determining the position of the reflector in the point cloud data and selecting the center of the point cloud with reflectivity exceeding a preset threshold as the true coordinate position of the reflector, and calculating the height f of the true coordinate position of the reflector; calibrating the height error, wherein the height error g = ef. For example, if the lifting device is moved to the ground, the encoder reads the field bridge height value e as 210cm. In the acquired effective point cloud data, the coordinates in the Z-axis direction are 208, 209, 212, 209, 210, 211, 209 and 209 respectively. The height f of the corresponding reflector's true coordinate position is: f = (208 + 209 + 212 + 209 + 210 + 211 + 209 + 209) / 8 = 209.75.

[0063] The height error g = ef = 210 - 209.75 = 0.25. This 0.25cm height error is a fixed value that can be used in subsequent point cloud calibration. It should be noted that those skilled in the art can set indicators such as reflectivity range and reflectivity threshold according to actual conditions to determine the point cloud center of the reflector and its true coordinate position.

[0064] Step 103: Calculate the second lifting height of the field bridge and determine the difference between the first lifting height and the second lifting height. The second lifting height of the field bridge is the average height of all point clouds in the point cloud data of the reflector after point cloud calibration.

[0065] Step 104: If the difference is less than or equal to the preset safety threshold, it is determined that the first lifting height obtained by the encoder is normal, and the controller controls the field bridge to continue automated operation.

[0066] Step 105: If the difference is greater than the preset safety threshold, it is determined that the first lifting height obtained by the encoder is abnormal, and the controller controls the field bridge to stop the automated operation.

[0067] It should be noted that those skilled in the art can set the preset safety threshold according to the accuracy and requirements of use. For example, the safety threshold can be 0.2-0.5cm, and this height difference will not affect the automated operation process of the yard bridge.

[0068] This invention discloses a laser-based method for verifying the lifting height of a field bridge. The method includes acquiring a first lifting height of the field bridge in real time via an encoder, acquiring point cloud data of a reflector via a lidar, performing point cloud calibration on the point cloud data, calculating a second lifting height of the field bridge, and determining the difference between the first and second lifting heights. If the difference is less than or equal to a preset safety threshold, the first lifting height acquired by the encoder is determined to be normal, and the controller controls the field bridge to continue automated operation. If the difference is greater than the preset safety threshold, the first lifting height acquired by the encoder is determined to be abnormal, and the controller controls the field bridge to stop automated operation.

[0069] By adopting the above technical solution, the technical solution of the present invention has the following technical effects:

[0070] (1) The second lifting height of the yard bridge can be determined by lidar, so that the actual height of the yard bridge lifting device can be obtained in real time and accurately during the automatic operation, and verified with the first lifting height obtained by the encoder, thereby enhancing the accuracy and safety of the automated operation.

[0071] (2) A bracket is provided on the trolley to adjust the scanning angle of the lidar so that the scanning range of the lidar covers the trolley and the reflector, so that the lidar can scan the reflector under various extreme working conditions, thereby improving the applicability of the method.

[0072] It should be noted that, for the sake of simplicity, the method embodiments are all described as a series of actions. However, those skilled in the art should understand that the embodiments of the present invention are not limited to the described order of actions, because according to the embodiments of the present invention, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions involved are not necessarily essential to the embodiments of the present invention.

[0073] To implement the above-mentioned method for verifying the lifting height of the yard crane Figure 6This invention provides a structural block diagram of a laser-based field bridge lifting height verification device. This device is applied to a field bridge lifting height verification system, which includes a trolley, a crane, a lifting device, and a scanning system. The lifting device is equipped with a reflector. The scanning system includes a controller, a laser radar, and an encoder electrically connected to the controller. The laser radar is located at the bottom of the crane. The encoder is used to acquire the first lifting height of the field bridge in real time. The device includes:

[0074] The point cloud data acquisition module 601 is used to acquire the position data information of the lifting device through the lidar, and the position data information includes the point cloud data of the reflector;

[0075] The point cloud data calibration module 602 is used to process the location data information, extract the point cloud data of the reflector in the location data information, and perform point cloud calibration on the point cloud data. The point cloud calibration includes coordinate system transformation, calibration angle error and calibration height error.

[0076] The hoisting height calculation module 603 is used to calculate the second hoisting height of the hoisting bridge and determine the difference between the first hoisting height and the second hoisting height. The second hoisting height of the hoisting bridge is the average height of all point clouds in the point cloud data of the reflector after point cloud calibration.

[0077] The first execution module 604 is used to determine that the first lifting height obtained by the encoder is normal if the difference is less than or equal to a preset safety threshold, and the controller controls the field bridge to continue automated operation.

[0078] The second execution module 605 is used to determine that the first lifting height obtained by the encoder is abnormal if the difference is greater than a preset safety threshold, and the controller controls the field bridge to stop the automated operation.

[0079] In an optional embodiment, the point cloud data calibration module 602 may include:

[0080] The first point cloud data calibration submodule is used to set the coordinate range and reflectivity range of the reflector;

[0081] The second point cloud data calibration submodule is used to perform pass-through filtering on the position data information according to the coordinate range and reflectivity range of the reflector, and remove point clouds that do not belong to the scanning device and point clouds with reflectivity less than a preset threshold.

[0082] The third point cloud data calibration submodule is used to determine the point cloud data belonging to the reflector.

[0083] In an optional embodiment, the point cloud data calibration module 602 may include:

[0084] The fourth point cloud data calibration submodule is used to establish a lidar coordinate system. The lidar coordinate system is a first Cartesian coordinate system with the right side of the lidar as the positive x-axis, the front of the lidar as the positive y-axis, the top of the lidar as the z-axis, and the center of the lidar as the origin.

[0085] The fifth point cloud data calibration submodule is used to establish the field bridge coordinate system. The field bridge coordinate system is a second Cartesian coordinate system with the positive x-axis for the trolley moving forward, the positive y-axis for moving to the left, the z-axis perpendicular to the ground and upward, and the projection of the center of the driver's cab onto the ground as the origin.

[0086] The sixth point cloud data calibration submodule is used to determine the coordinates of the point cloud data of the reflector in the field bridge coordinate system based on the correspondence between the point cloud data of the reflector, the lidar coordinate system and the field bridge coordinate system.

[0087] In an optional embodiment, the point cloud data calibration module 602 may include:

[0088] The seventh point cloud data calibration submodule is used to determine the first deviation angle between the actual scanning line of the lidar and the running direction of the vehicle, and to calibrate the actual scanning line of the lidar through a rotation matrix so that the actual scanning line of the lidar is parallel to the running direction of the vehicle.

[0089] The eighth point cloud data calibration submodule is used to determine the second deviation angle between the actual scanning line of the lidar and the running direction of the vehicle, and to calibrate the actual scanning line of the lidar through a rotation matrix so that the actual scanning line of the lidar is perpendicular to the running direction of the vehicle.

[0090] If the actual distance from the lidar to the ground is b, and the actual distance from the reflector to the ground is a, then the actual distance from the lidar to the reflector is d = ba. The distance from the lidar to the reflector obtained from the lidar scan can be determined as c using point cloud data. The formula for calculating the second deviation angle β is as follows:

[0091] cosβ=d / c=(ba) / c.

[0092] In an optional embodiment, the point cloud data calibration module 602 may include:

[0093] The ninth point cloud data calibration submodule is used to move the lifting device to the ground and determine the field bridge height value e read by the encoder when the lifting device is on the ground.

[0094] The tenth point cloud data calibration submodule is used to acquire point cloud data of the lifting device when it is on the ground through the lidar, and to calibrate the angle error of the point cloud data.

[0095] The eleventh point cloud data calibration submodule is used to determine the position of the reflector in the point cloud data, and select the center of the point cloud with reflectivity exceeding a preset threshold as the true coordinate position of the reflector, and calculate the height f of the true coordinate position of the reflector;

[0096] The twelfth point is the cloud data calibration submodule, which is used to calibrate the altitude error, where the altitude error is g = ef.

[0097] In an optional embodiment, the trolley is further provided with a bracket, the lidar is rotatably connected to the bracket, and the yard crane lifting height verification device further includes:

[0098] The laser scanning angle adjustment module is used to adjust the scanning angle of the laser radar via the bracket, so that the scanning range of the laser radar covers the vehicle and the reflector.

[0099] The technical solution of the present invention has the following technical effects: (1) The second lifting height of the yard bridge can be determined by the laser radar, so that the actual height of the yard bridge lifting device can be obtained in real time and accurately during the automatic operation, and verified with the first lifting height obtained by the encoder, thereby enhancing the accuracy and safety of the automated operation; (2) A bracket is provided on the trolley to adjust the scanning angle of the laser radar so that the scanning range of the laser radar covers the trolley and the reflector, so that the laser radar can scan the reflector under various extreme working conditions, thereby improving the applicability of the method.

[0100] On the other hand, embodiments of the present invention also provide an electronic device, which includes a processor, a memory, and a computer program stored in the memory and capable of running on the processor, wherein the computer program, when executed by the processor, implements the steps of the field bridge lifting height verification method.

[0101] On the other hand, embodiments of the present invention also provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the field bridge lifting height verification method.

[0102] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0103] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, apparatus, or computer program products. Therefore, embodiments of the present invention can take the form of entirely hardware embodiments, entirely software embodiments, or embodiments combining software and hardware aspects. Furthermore, embodiments of the present invention can take the form of computer program products implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0104] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, terminal devices (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing terminal device to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing terminal device, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0105] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing terminal device to operate in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0106] These computer program instructions can also be loaded onto a computer or other programmable data processing terminal equipment, causing a series of operational steps to be performed on the computer or other programmable terminal equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable terminal equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0107] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present invention.

[0108] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0109] The above provides a detailed description of a laser-based field bridge lifting height verification method and a laser-based field bridge lifting height verification device provided by the present invention. Specific examples have been used to illustrate the principle and implementation of the present invention. For those skilled in the art, based on the idea of ​​the present invention, there will be changes in the specific implementation and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for checking the lifting height of a laser-based yard bridge, characterized in that The method is applied to a yard bridge lifting height verification system, the yard bridge lifting height verification system comprising a cart, a trolley, a lifting device and a scanning system, a reflector plate being arranged on the lifting device, the scanning system comprising a controller, and a laser radar and an encoder electrically connected with the controller respectively, the laser radar being arranged at the bottom of the trolley, the encoder being used to acquire a first lifting height of the yard bridge in real time, the method comprising: acquiring position data information of the lifting device by the laser radar, the position data information comprising point cloud data of the reflector plate; processing the position data information, extracting the point cloud data of the reflector plate in the position data information, and performing point cloud calibration on the point cloud data, the point cloud calibration comprising coordinate system conversion, calibration of angle error and calibration of height error; calculating a second lifting height of the yard bridge, and determining a difference between the first lifting height and the second lifting height, the second lifting height of the yard bridge being an average height of all point clouds in the point cloud data of the reflector plate after the point cloud calibration; if the difference is less than or equal to a preset safety threshold, judging that the first lifting height acquired by the encoder is normal, and controlling the controller to control the yard bridge to continue automatic operation; if the difference is greater than the preset safety threshold, judging that the first lifting height acquired by the encoder is abnormal, and controlling the controller to control the yard bridge to stop automatic operation; the process of calibration of angle error in the point cloud calibration comprising: determining a first deviation angle between an actual scanning line of the laser radar and a running direction of the trolley, and performing calibration on the actual scanning line of the laser radar by a rotation matrix, so that the actual scanning line of the laser radar is parallel to the running direction of the trolley; determining a second deviation angle between the actual scanning line of the laser radar and a running direction of the cart, and performing calibration on the actual scanning line of the laser radar by a rotation matrix, so that the actual scanning line of the laser radar is perpendicular to the running direction of the cart; wherein, if an actual distance of the laser radar to the ground is b, and an actual distance of the reflector plate to the ground is a, then an actual distance d of the laser radar to the reflector plate is d = b - a, the distance c of the laser radar to the reflector plate scanned by the point cloud data can be determined, and a calculation formula of the second deviation angle β is as follows: cos β = d / c = (b-a) / c; the process of calibration of height error in the point cloud calibration comprising: moving the lifting device to the ground, determining a yard bridge height value e read by the encoder when the lifting device is on the ground; acquiring point cloud data of the lifting device on the ground by the laser radar, and performing calibration of angle error on the point cloud data; determining a position of the reflector plate in the point cloud data, and selecting a point cloud center with reflectivity exceeding a preset threshold as a real coordinate position of the reflector plate, and calculating a height f of the real coordinate position of the reflector plate; calibrating a height error g = e - f.

2. The field bridge lift height verification method of claim 1, wherein, the processing of the position data information, and the extraction of the point cloud data of the reflector plate in the position data information comprising: setting a coordinate range and a reflectivity range of the reflector plate; The position data information is directly filtered according to the coordinate range and reflectivity range of the reflector plate, and point clouds not belonging to the scanning spreader and point clouds with reflectivity less than a preset threshold are removed; Point cloud data belonging to the reflector plate is determined.

3. The field bridge lift height verification method of claim 1, wherein, The coordinate system conversion process in the point cloud calibration includes: A laser radar coordinate system is established, which is a first Cartesian rectangular coordinate system with the right direction of the laser radar as the x-axis positive direction, the front direction of the laser radar as the y-axis positive direction, the upward direction of the laser radar as the z-axis, and the center of the laser radar as the origin; A field bridge coordinate system is established, which is a second Cartesian rectangular coordinate system with the forward movement of the trolley as the x-axis positive direction, the left movement as the y-axis positive direction, the upward direction perpendicular to the ground as the z-axis, and the projection of the driver's cabin center on the ground as the origin; According to the correspondence between the point cloud data of the reflector plate, the laser radar coordinate system and the field bridge coordinate system, the coordinates of the point cloud data of the reflector plate in the field bridge coordinate system are determined.

4. The field bridge lift height verification method of claim 1, wherein, The trolley is further provided with a bracket, and the laser radar is rotationally connected with the bracket. Before the position data information of the lifting device is acquired by the laser radar, the field bridge lifting height verification method further includes: The scanning angle of the laser radar is adjusted through the bracket, so that the scanning range of the laser radar covers the movable carrier and the reflector plate.

5. The field bridge lift height verification method of claim 1, wherein, The reflector plate is installed on the upper surface of the lifting device, and the field bridge lifting height verification method further includes: The laser scanning direction of the laser radar is consistent with the running direction of the trolley, and the laser scanning surface of the laser radar faces the ground.

6. A laser-based yard bridge lift height verification device, characterized by, The device is applied to a field bridge lifting height verification system, the field bridge lifting height verification system includes a movable carrier, a trolley, a lifting device and a scanning system, the lifting device is provided with a reflector plate, the scanning system includes a controller, and a laser radar and an encoder electrically connected with the controller, the laser radar is arranged at the bottom of the trolley, and the encoder is used to acquire a first lifting height of the field bridge in real time, and the device includes: A point cloud data acquisition module is configured to acquire position data information of the lifting device by the laser radar, and the position data information includes point cloud data of the reflector plate; A point cloud data calibration module is configured to process the position data information, extract the point cloud data of the reflector plate in the position data information, and calibrate the point cloud data, the point cloud calibration including coordinate system conversion, calibration angle error and calibration height error; A field bridge lifting height calculation module is configured to calculate a second lifting height of the field bridge, and determine a difference between the first lifting height and the second lifting height, the second lifting height of the field bridge being an average height of all point clouds in the point cloud data of the reflector plate after the point cloud calibration; A first execution module is configured to determine that the first lifting height acquired by the encoder is normal if the difference is less than or equal to a preset safety threshold, and control the controller to control the field bridge to continue automatic operation. The second execution module is configured to determine that the first lifting height is abnormal if the difference is greater than a preset safety threshold, and control the controller to control the yard crane to stop the automatic operation.

7. An electronic device, comprising: The computer program is stored on the computer readable storage medium and is executed by the processor to implement the steps of the method according to any one of claims 1-5. The computer program is stored on the computer readable storage medium and is executed by the processor to implement the steps of the method according to any one of claims 1-5.

8. A computer-readable storage medium, characterized in that, ​

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