A method for installing a positioning plate of a portal crane spreader

Abstract

The application discloses a portal crane sling positioning plate mounting method, belongs to the related technical field of the sling, and is characterized in that the upper surface of the sling is provided with front and rear positioning plates at both ends; a front scanner scanning surface intersects with the rear positioning plate, the rear positioning plate surface is inclined forward, namely, the rear is high and the front is low, and the vertex of the rear positioning plate scanned by the front scanner is a front scanner positioning plate detection point; a rear scanner scanning surface intersects with the front positioning plate, the front positioning plate surface is inclined backward, namely, the front is high and the rear is low, and the vertex of the front positioning plate scanned by the rear scanner is a rear scanner positioning plate detection point. The application is used for solving the technical problems of the prior art, such as water accumulation in the positioning plate, poor detection reliability of the positioning point and poor shielding performance.

Description

Technical Field

[0001] This invention belongs to the technical field of lifting devices, specifically a method for installing a positioning plate of a gantry crane lifting device. Background Technology

[0002] During gantry crane operations, the spreader is the fundamental component connecting the crane and the container. Its attitude (height / forward / backward position / rotation angle) data is crucial for achieving precise alignment with the container and avoiding collisions. Therefore, real-time measurement of the spreader's attitude is a key technology for automated control and safety protection in crane operations.

[0003] Typically, lifting slings are flexibly suspended by steel wire ropes (4 or 8 ropes). Uncontrolled swaying can occur due to speed changes and stress. Furthermore, operators may actively alter the sling's rotation angle by adjusting different wire ropes for operational needs. These swaying and rotations are critical for safety and automated control, but cannot be accurately measured by fixed sensors (such as wire rope absolute encoders) and require direct measurement by a laser scanner. Laser scanning positioning requires positioning plates mounted on the upper surface of the lifting sling. Existing lifting sling positioning and detection systems suffer from three key problems: water accumulation on the plates, low reliability of positioning point detection, and weak resistance to obstruction. Therefore, a gantry crane lifting sling scanning and positioning system is needed to solve these technical problems. Summary of the Invention

[0004] To address the above problems, this invention provides a method for installing a positioning plate on a gantry crane lifting device, which solves the technical problems of water accumulation on the positioning plate, poor reliability of positioning point detection, and weak obstruction in the prior art.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: a method for installing positioning plates of a gantry crane lifting device, wherein a front positioning plate and a rear positioning plate are provided at both ends of the upper surface of the lifting device;

[0006] The scanning surface of the front scanner intersects with the rear positioning plate. The rear positioning plate is tilted forward, i.e., the rear is higher than the front. The vertex of the rear positioning plate scanned by the front scanner is the detection point of the front scanner positioning plate.

[0007] The scanning surface of the rear scanner intersects with the front positioning plate. The front positioning plate is tilted backward, i.e., the front is higher than the back. The vertex of the front positioning plate scanned by the rear scanner is the detection point of the rear scanner positioning plate.

[0008] A trolley platform is installed above the spreader. A front scanner and a rear scanner are installed at the front and rear ends of the trolley platform, respectively. The front scanner is used to scan the surface scanned by the front scanner, and the rear scanner is used to scan the surface scanned by the rear scanner.

[0009] When the lifting device is in the zero position, the surfaces of the front and rear positioning plates are perpendicular to the scanning surfaces of the front and rear scanners, respectively, and their upper edges are parallel to the ground. The scanning surfaces of the front and rear scanners are perpendicular to the ground and parallel to the direction of travel of the trolley.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows: the rear positioning plate and the front positioning plate in the present invention are inclined, so water will not accumulate; and the inclination directions are opposite, providing more favorable scanning incident angle and field of view for the corresponding front scanner and rear scanner; the front scanner positioning plate is rearward and the rear scanner positioning plate is frontward, which can further improve the scanning incident angle and field of view, and has stronger anti-obstruction ability.

[0011] Compared with the commonly used horizontal positioning plates, the positioning plate layout of this invention will not cause laser measurement failure due to water accumulation, and can optimize the incident angle of laser scanning (closer to vertical incident), making the measurement more reliable; using the upper edge vertex of the scanning contour line of the positioning plate as the positioning feature point, the detection results are more robust and less likely to be interfered with by other surrounding structures; the positioning plate of the front scanner is placed at the rear and the positioning plate of the rear scanner is placed at the front, so it is not easily obstructed when the spreader is deep into the container well.

[0012] As a further improvement to the above solution, the front and rear scanners are connected to the system controller. The system controller calculates the real-time attitude of the spreader based on the detection points of the positioning plates of the front and rear scanners. The real-time attitude parameters of the spreader calculated by the system controller include the spreader height, forward and backward translation, roll angle, and yaw angle.

[0013] The technical benefits of the above improvements are: they facilitate the calculation of real-time attitude parameters of the spreader.

[0014] As a further improvement to the above solution, the front positioning plate and the rear positioning plate are ordinary painted metal plates, which are fixed to the upper surface of the lifting device by welding or bolt connection.

[0015] The aforementioned improvements have the following effects: they can increase the service life of the positioning system and improve its ease of maintenance.

[0016] As a further improvement to the above scheme, the front scanner can be set on the left side of the trolley platform and the rear scanner can be set on the right side of the trolley platform; then the rear positioning plate can be set on the left side of the lifting device and the front positioning plate can be set on the right side of the lifting device.

[0017] The aforementioned improvements enhance the compatibility of the positioning system with the original structure of the trolley and lifting device.

[0018] As a further improvement to the above scheme, the front scanner can also be set on the right side of the trolley platform and the rear scanner on the left side of the trolley platform; then the rear positioning plate is set on the right side of the lifting device and the front positioning plate is set on the left side of the lifting device.

[0019] The aforementioned improvements enhance the compatibility of the positioning system with the original structure of the trolley and lifting device. Attached Figure Description

[0020] Figure 1 This is a front view of the present invention.

[0021] Figure 2 This is a side view of the present invention.

[0022] In the diagram: 1. Car platform; 2. Front scanner; 3. Front scanner positioning plate detection point; 4. Rear positioning plate; 5. Front scanner scanning surface; 6. Rear scanner; 7. Rear scanner scanning surface; 8. Front positioning plate; 9. Rear scanner positioning plate detection point; 10. Lifting device. Detailed Implementation

[0023] To enable those skilled in the art to better understand the technical solution, the technical solution will be described in detail below with reference to the embodiments. The description in this part is only exemplary and explanatory, and should not be used to limit the scope of protection of the present invention in any way.

[0024] Please see Figures 1 to 2 In one specific embodiment, a method for installing a positioning plate of a gantry crane lifting device includes a lifting device 10, a trolley platform 1 is provided above the lifting device 10, and a front scanner 2 and a rear scanner 6 are respectively provided at the front and rear ends of the trolley platform 1. The front scanner 2 is used to scan the scanning surface 5 of the front scanner, and the rear scanner 6 is used to scan the scanning surface 7 of the rear scanner. A front positioning plate 8 and a rear positioning plate 4 are provided at the left and right ends of the upper surface of the lifting device 10.

[0025] The front scanner scanning surface 5 intersects with the rear positioning plate 4. The rear positioning plate 4 is tilted forward, that is, the rear is higher than the front. The vertex of the rear positioning plate 4 scanned by the front scanner 2 (that is, the intersection of the scanning surface of the front scanner 2 and the upper edge of the rear positioning plate 4) is the front scanner positioning plate detection point 3.

[0026] The scanning surface 7 of the rear scanner intersects with the front positioning plate 8. The front positioning plate 8 is tilted backward, that is, the front is higher than the back. The vertex of the front positioning plate 8 scanned by the rear scanner 6 (that is, the intersection of the scanning surface of the rear scanner 6 and the upper edge of the front positioning plate 8) is the detection point 9 of the rear scanner positioning plate.

[0027] When the lifting device 10 is in the zero position, the front positioning plate 8 and the rear positioning plate 4 are perpendicular to the front scanner scanning surface 5 and the rear scanner scanning surface 7, and their upper edges are parallel to the ground.

[0028] The front scanner scanning surface 5 and the rear scanner scanning surface 7 are perpendicular to the ground and parallel to the direction of travel of the vehicle.

[0029] The front scanner 2 and the rear scanner 6 are connected to the system controller. The system controller calculates the real-time attitude of the spreader 10 based on the detection points 3 and 9 of the front scanner positioning plate and the rear scanner positioning plate. The real-time attitude parameters of the spreader calculated by the system controller include the spreader height, forward and backward translation, roll angle, and yaw angle.

[0030] As a preferred embodiment of the above, the front positioning plate 8 and the rear positioning plate 4 are ordinary painted metal plates, which are fixed to the upper surface of the lifting device 10 by welding or bolt connection.

[0031] As a preferred embodiment of the above, the front scanner 2 can be located on the left side of the trolley platform 1, and the rear scanner 6 can be located on the right side of the trolley platform 1; then the rear positioning plate 4 can be located on the left side of the lifting device 10, and the front positioning plate 8 can be located on the right side of the lifting device 10.

[0032] As a preferred embodiment of the above, the front scanner 2 can also be located on the right side of the trolley platform 1 and the rear scanner 6 can be located on the left side of the trolley platform 1; then the rear positioning plate 4 can be located on the right side of the lifting device 10 and the front positioning plate 8 can be located on the left side of the lifting device 10.

[0033] The approximate calculation method for the real-time attitude parameters of the lifting device of the present invention is as follows:

[0034] I. Datum Surface and Measurement Coordinate System:

[0035] 1) The reference surface of the lifting device is the bottom surface of the lifting device, that is, the locking surface of the four lock heads;

[0036] 2) The reference point So of the lifting device is the center point of the rectangle on the reference surface of the lifting device with the center points of the four lock holes as its vertices;

[0037] 3) The positive X direction of the detection coordinate system is to the right, the positive Y direction is forward, and the positive Z direction is upward;

[0038] 4) The XY plane of the detection coordinate system is the ground;

[0039] 5) The origin O of the detection coordinate system is the projection point of the lifting device So on the ground when it is in the zero position (no swing / no rotation);

[0040] 6) The scanning surface of the laser scanner is parallel to the YZ plane of the detection coordinate system.

[0041] II. Basic Parameters:

[0042] 1) The front scanner measures the coordinates of the origin (xa,ya,za);

[0043] The scanning area of ​​the front scanner is x = xa;

[0044] The distance wa in the Y direction and the distance ha in the Z direction from the upper edge of the rear positioning plate to So;

[0045] The detection point A of the rear positioning plate is the intersection of the upper edge of the rear positioning plate and the scanning surface of the front scanner;

[0046] 2) The rear scanner measures the coordinates of the origin (xb, yb, zb);

[0047] The scanning area of ​​the rear scanner is x = xb;

[0048] The distance wb in the Y direction and the distance hb in the Z direction between the position on the front positioning plate and So;

[0049] The detection point B of the front positioning plate is the intersection of the upper edge of the front positioning plate and the scanning surface of the rear scanner.

[0050] III. Measurement Data:

[0051] 1) Point A: Distance wsa in the Y direction and distance hsa in the Z direction from the front scanner;

[0052] 2) Point B: Distance wsb in the Y direction and distance hsb in the Z direction from the rear scanner;

[0053] IV. Real-time attitude parameters of the lifting device:

[0054] 1) The translation of the spreader, i.e., yso and zso in the real-time coordinates (xso, yso, zso) of So;

[0055] 2) The rotation angle β (roll angle) of the spreader around the Y-axis and the rotation angle γ (yaw angle) around the Z-axis.

[0056] V. Approximate Calculation Method for Real-Time Attitude Parameters of Lifting Gear:

[0057] When approximating the real-time attitude parameters of the spreader based on the suspension and operation methods of the gantry crane, the following premises apply:

[0058] 1) The lifting device has no translation or rotation angle (pitch angle) in the X-axis direction;

[0059] 2) β and γ are very small, not exceeding 5°;

[0060] At this point, the coupling between β and γ is very low, and yso, zso, β, and γ can be calculated independently.

[0061] The calculation formula is as follows:

[0062] 1) The coordinates of point A are: (xa,ya-wsa,za-hsa);

[0063] 2) The coordinates of point B are: (xb, yb+wsb, zb-hsb);

[0064] 3)yso=((yb+wsb-wb)*xa-(ya-wsa+wa)*xb) / (xa-xb);

[0065] 4)zso=((zb-hsb-hb)*xa-(za-hsa-ha)*xb) / (xa-xb);

[0066] 5)β=atan(((zb-hsb-hb)-(za-hsa-ha)) / (xa-xb));

[0067] 6)γ=atan(((ya-wsa+wa)-(yb+wsb-wb)) / (xa-xb)).

[0068] Error estimation:

[0069] Considering the rigid structure of the lifting device and its basic structure being symmetric about So, the systematic error in calculating yso and zso in the above manner originates from the coupling between yso and γ, and the coupling between zso and β. The relative error of the coupling does not exceed [a certain value].

[0070] 1 / cos(γ)-1

[0071] and

[0072] 1 / cos(β)-1

[0073] When β and γ do not exceed 5°, the upper limit of the above relative error is 0.38%, which meets the application requirements.

[0074] The systematic error in the calculation of β and γ originates from the coupling between β and γ, and the relative error of the coupling does not exceed [the specified value].

[0075] atan(sin(β) / (cos2(β)cos(γ))) / β-1

[0076] and

[0077] atan(sin(γ) / (cos2(γ)cos(β))) / γ-1

[0078] When β and γ do not exceed 5°, the upper limit of the above relative error is 0.76%, which meets the application requirements.

[0079] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus 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 apparatus. Specific examples have been used in this document to illustrate the principles and implementation methods of the present invention. These examples are merely for the purpose of helping to understand the method and core ideas of the present invention. The above are only preferred embodiments of the present invention. It should be pointed out that, due to the limitations of written expression and the objective existence of infinite specific structures, those skilled in the art can make several improvements, modifications, or variations without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner. These improvements, modifications, variations, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of the present invention.

Claims

1. A method for installing a positioning plate on a gantry crane lifting device, characterized in that, The upper surface of the lifting device (10) is provided with a front positioning plate (8) and a rear positioning plate (4) at both ends respectively. The front scanner scanning surface (5) intersects with the rear positioning plate (4). The rear positioning plate (4) is tilted forward, i.e., the rear is higher than the front. The vertex of the rear positioning plate (4) scanned by the front scanner (2) is the front scanner positioning plate detection point (3). The scanning surface (7) of the rear scanner intersects with the front positioning plate (8). The front positioning plate (8) is tilted backward, that is, the front is high and the back is low. The vertex of the front positioning plate (8) scanned by the rear scanner (6) is the detection point (9) of the rear scanner positioning plate. A trolley platform (1) is provided above the lifting device (10). A front scanner (2) and a rear scanner (6) are respectively provided on the upper edges of the two ends of the trolley platform (1). The front scanner (2) is used to scan the scanning surface (5) of the front scanner, and the rear scanner (6) is used to scan the scanning surface (7) of the rear scanner. The front scanner (2) and the rear scanner (6) are connected to the system controller, which calculates the real-time attitude of the lifting device (10) based on the detection points (3) of the positioning plate of the front scanner and the detection points (9) of the positioning plate of the rear scanner. The real-time attitude parameters of the spreader calculated by the system controller include spreader height, forward and backward translation, roll angle, and yaw angle.

2. A method for installing a gantry crane lifting device positioning plate according to claim 1, characterized in that, The front positioning plate (8) and the rear positioning plate (4) are ordinary painted metal plates, which are fixed to the upper surface of the lifting device (10) by welding or bolt connection.

3. A method for installing a gantry crane lifting device positioning plate according to claim 1, characterized in that, The front scanner (2) is located on the left side of the trolley platform (1), and the rear scanner (6) is located on the right side of the trolley platform (1); the rear positioning plate (4) is located on the right side of the lifting device (10), and the front positioning plate (8) is located on the left side of the lifting device (10).

4. A method for installing a gantry crane lifting device positioning plate according to claim 1, characterized in that, The front scanner (2) is located on the right side of the trolley platform (1), and the rear scanner (6) is located on the left side of the trolley platform (1); the rear positioning plate (4) is located on the left side of the lifting device (10), and the front positioning plate (8) is located on the right side of the lifting device (10).

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