A method and system for alignment calibration of a shore crane

Abstract

The application discloses a kind of shore crane's alignment calibration method and alignment calibration system, and the alignment calibration method includes: control sling movement to calibration position, make the sling hover in the calibration position;Start laser scanner to scan the sling, obtain scanning data;The scanning data is calculated, and the new alignment reference information of the sling is obtained;With the new alignment reference information replaces original alignment reference information.The alignment calibration method and alignment calibration system can be automatically calibrated, without manual measurement, good safety, high accuracy.

Description

Technical Field

[0001] This invention relates to the field of shore cranes, and more specifically, to a method and system for calibrating a shore crane. Background Technology

[0002] To improve the operational efficiency of shore cranes, shore crane positioning and guidance systems have been widely used. The correction of the positioning reference position is generally done by manual measurement, which is carried out on-site by system maintenance personnel on a regular basis and manually set in the system.

[0003] Due to the busy operation of shore cranes and the complex working environment, manual measurement methods require a lot of on-site coordination work and cannot meet the requirements in terms of safety, real-time performance, and accuracy. Therefore, a practical and feasible alignment calibration method is urgently needed. Summary of the Invention

[0004] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a positioning calibration method for a shore crane, which can automatically complete the calibration without manual measurement and has good safety.

[0005] The alignment calibration method for a shore crane of the present invention includes: controlling the spreader to move to a calibration position and hovering at the calibration position; starting a laser scanner to scan the spreader and obtain scanning data; calculating the scanning data to obtain new alignment reference information for the spreader; and replacing the original alignment reference information with the new alignment reference information.

[0006] The alignment calibration method for the shore crane of the present invention uses a laser scanner to automatically obtain the alignment reference information of the spreader, eliminating the need for manual measurement, saving labor costs, ensuring good safety and high accuracy, and thus improving the operating efficiency of the shore crane.

[0007] Furthermore, the lifting device is an unloaded lifting device, and the ground clearance of the calibration position is 4.3 meters to 4.6 meters.

[0008] Furthermore, the lifting device swings back and forth when it is suspended at the calibration position, and the total scanning time of the laser scanner is greater than or equal to two swing cycles of the lifting device.

[0009] Furthermore, the scanned data is calculated to obtain new alignment reference information for the spreader, specifically including:

[0010] A. Obtain measurement data from a single measurement by the laser scanner, and extract the cross-sectional profile data of the lifting device from the measurement data from the single measurement;

[0011] B. Calculate the position information of one side elevation of the lifting device based on the cross-sectional profile data;

[0012] C. Calculate the central axis position information of the lifting device measured in one step based on the position information of one side elevation;

[0013] D. Repeat steps A, B and C above within one total scanning time of the laser scanner to obtain multiple central plane position information;

[0014] E. Calculate the new alignment reference information of the lifting device based on the position information of all the central planes within a total scanning time.

[0015] Furthermore, the aforementioned side elevation is the left side elevation.

[0016] Furthermore, the position information of the left side facade of the lifting device is calculated using the following formula:

[0017] LXhst(k)=minX(ΩZX(LD,k))

[0018] Where ΩZX(LD,k) is the cross-sectional profile data obtained by the laser scanner in the kth measurement, and k is a natural number.

[0019] Furthermore, the position information of the central axis plane of the lifting device measured in the first measurement is calculated using the following formula:

[0020] Xhst*(k)=LXhst(k)+CL20 / 2

[0021] Where LXhst(k) is the left elevation position of the spreader in the kth calculation, CL20 is the distance from the left elevation to the right elevation of the spreader, and k is a natural number.

[0022] Furthermore, the alignment reference position information of the spreader is calculated using the following formula:

[0023] Xhst*=(min(Xhst*(k))+max(Xhst*(k))) / 2

[0024] k is a natural number.

[0025] Furthermore, the laser scanner is a two-dimensional laser scanner.

[0026] The alignment calibration system for a shore crane of the present invention includes a lifting device, a laser scanner, a memory, and a processor. The memory stores a computer program, which, when executed by the processor, implements the alignment calibration method. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the various operational elements involved in the shore loading and unloading operations in an embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of the lifting device in an embodiment of the present invention. Detailed Implementation

[0029] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar units or units having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0030] In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the structure or unit referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In the description of this invention, unless otherwise stated, "a plurality of" means two or more. In the description of this specification, the terms "installation," "setting," "connection," etc., should be interpreted broadly, and can refer to direct installation, setting, or connection, or indirect installation, setting, or connection. "Connection" can be a mechanical connection, an electrical connection, or a transmission connection for realizing power transmission.

[0031] The following is for reference. Figure 1-2 The present invention describes a method and system for aligning and calibrating a shore crane according to an embodiment of the present invention.

[0032] This invention is applied to quayside loading and unloading operations at container terminals, specifically targeting the most common type of quayside gantry crane that employs a through-type, multi-lane operation mode. The operational elements are described below:

[0033] 1. Container: A rectangular metal box with different "box types". It has "lock holes" on the four corner posts on the top and bottom surfaces for lifting and securing to the trailer of a container truck. The main box types include 20-foot, 40-foot, and 45-foot containers. The length, width, height, and lock hole spacing of each type conform to international standards; the width is exactly the same, but the length and height vary.

[0034] 2. Shore crane (also known as shore gantry crane): such as Figure 1 The image shows a crane with a frame structure, whose structural elements include:

[0035] 1) Trolley: Composed of two sets of gantry legs and a pair of crossbeams mounted on top of the gantry legs, it is called "trolley". During container loading and unloading operations, the gantry legs closer to the quay (sea side) are called "front gantry legs", and the gantry legs farther away from the quay (land side) are called "rear gantry legs". Each set of gantry legs includes two gantry posts, and wheelsets are installed under the gantry posts. During operation, it travels along ground rails parallel to the quay.

[0036] 2) Connecting beam: The left and right doorposts of the front and rear door legs are connected by a connecting beam. The two connecting beams are parallel and perpendicular to the direction of travel of the vehicle. The height of the connecting beam from the ground is about 12 meters to 20 meters.

[0037] 3) Trolley: A set of rails is laid on another set of crossbeams perpendicular to the direction of travel of the main vehicle at the top of the gantry leg, and a wheel-rail mechanism is erected to travel along the crossbeams, called the "trolley"; a lifting device is hoisted on the trolley by wire rope. During landside loading and unloading operations, the trolley moves the lifting device to above the target lane, and the lifting device is raised and lowered by raising and lowering the wire rope to above the inner trailer in the lane, completing the operation.

[0038] 3. Lifting equipment: such as Figure 2 As shown, this is a container lifting device with a twist lock at the bottom. Its working method and structural features include:

[0039] 1) Operating Method: The spreader has two pairs of horizontally extendable booms below the main beam. The bottom of each boom has rotatable locking pins at both ends and the middle. The two pairs of locking pins at the ends are called outer locks, and the two pairs in the middle are called center locks. The spreader extends and retracts the booms according to the container type, aligning the locking pins with the locking holes on the top of the container. Inserting the locking pins into the locking holes and rotating them securely connects them to the container, allowing for lifting. The spreader can lift a single 20ft / 40ft / 45ft container at a time, or two 20ft containers simultaneously. When lifting a single 40ft, 45ft, or 20ft container, the center locks are retracted; when lifting two 20ft containers, the center locks are lowered. The spreader and wire ropes require regular replacement and maintenance to ensure the reliability and safety of loading and unloading operations.

[0040] 2) Left-right symmetry of the spreader structure: The main beam structure of the spreader is left-right symmetrical. The side elevations at both ends are symmetrical about the central axis of the spreader in the left-right direction and are parallel to the axis of symmetry. The center of mass of the spreader is located on the axis of symmetry. When lifting 20-foot and 40-foot containers, the distance between the left and right side elevations of the boom (boom span) is the same as that of the container. That is, the distance between the left and right side elevations of the boom and the axis of symmetry is half the length of the container.

[0041] 3) Left-right symmetry of the lifting device's swing: The lifting device's wire rope suspension method is flexible, and it will swing left-right and forward-backward when suspended. The suspension positions of the wire ropes on the left and right sides of the lifting device are also symmetrical about the left-right central axis of the lifting device to ensure load-bearing balance during lifting. Therefore, when the lifting device is unloaded, the swing in the left-right direction basically follows the principle of a simple pendulum, and the swing limit position of the left-right central axis is symmetrical about the static position in the stationary state.

[0042] 4. Interior trailer: such as Figure 1 As shown, this is a container truck with a trailer. The container is placed on the trailer, and loading and unloading operations are carried out using a spreader.

[0043] 5. Lane: such as Figure 1 As shown, the passageway for the inner trailer is located between the front and rear gantry legs of the quay crane. Each quay crane has multiple lanes beneath it, parallel to the direction of travel of the main trolley, with standard width and spacing. The inner trailer enters from the left and right sides of the crane along the lanes and parks under the spreader, cooperating with the crane operator to load and unload containers using the spreader.

[0044] The basic operations of quay cranes using the above-mentioned operating mode on the landside are as follows: using spreader to place containers lifted from container ships onto inner trailers (container dispatch), or to lift containers carried on inner trailers onto container ships (container return). A typical process is as follows:

[0045] 1. Container Launch: The inner trailer driver drives to the designated working lane of the quay crane according to the work instructions and stops, aligning the placement area of ​​the target container on the trailer with the vertical projection area of ​​the target container being lifted by the spreader; the crane operator operates the trolley to stop above the working lane, aligning the spreader with the trailer front and back, lowering the spreader, and placing the container on the trailer; unlocking the spreader; raising the spreader; after the spreader is raised to a safe height, the inner trailer driver drives away from the site.

[0046] 2. Container Retrieval: The inner trailer driver drives to the designated work lane of the shore crane according to the work instructions and stops, aligning the top of the target container to be lifted on the trailer with the vertical projection area of ​​the spreader boom; the crane driver operates the trolley to stop above the work lane, aligning the spreader with the target container, lowering the spreader onto the container, inserting the locking pin into the locking hole on the top of the container, and locking the spreader; the spreader is then raised; after the spreader is raised to a safe height, the inner trailer driver drives away from the site.

[0047] Since the quay crane needs to be aligned with the ship's container train and generally cannot be moved after it is in place, the inner trailer needs to be aligned with the quay crane's spreader, that is, parked in the correct position in the work lane, in order to complete the container receiving and dispatching operations.

[0048] The trailer of an inner trailer is generally quite long, allowing for a relatively large alignment error during loading and unloading without significantly impacting work efficiency. However, during unloading and unloading, it is crucial to ensure that the container and the spreader are aligned horizontally. Specifically, the left-right center plane of the container must be aligned as closely as possible with the left-right center plane of the spreader, with the error not exceeding the width of the spreader's twist lock. This error is called the basic alignment error, typically 8-10 centimeters. Otherwise, when the spreader is lowered to near the top of the container, braking is required, and the inner trailer driver must continue moving the vehicle to complete the alignment before the spreader can be lowered, thus prolonging the operation and significantly impacting work efficiency.

[0049] The positioning and guidance system of the quay crane should use the current position of the central plane of the spreader in the left-right direction when it is stationary as the reference position. This position is called the positioning reference position. If the error of the positioning reference position actually used by the system is too large, the inner trailer will not be able to complete the container loading operation smoothly after completing the positioning according to the instructions of the positioning and guidance system, thus failing to achieve the goal of improving work efficiency.

[0050] Ideally, the left-right central plane of the lifting device should coincide with the left-right central plane of the crane's main structure, and the alignment reference position can be obtained from the crane's structural drawings. However, due to the large size of the crane, there are inherent errors in its frame structure, trolley, and lifting device installation; therefore, the alignment reference position needs to be measured. Furthermore, during long-term use, the crane's structure will undergo slight deformation, and periodic maintenance requires the replacement of the lifting device and wire ropes. These factors can all cause changes in the alignment reference position, necessitating continuous correction.

[0051] In this embodiment of the invention, the direction of travel of the shore crane is taken as the left-right direction, and the direction perpendicular to the direction of travel of the shore crane is taken as the front-back direction.

[0052] An embodiment of the present invention provides a positioning and calibration method for a shore crane, comprising the following steps:

[0053] Control the spreader 12 to move to the calibration position and make the spreader 12 hover in the calibration position; start the laser scanner 10 to scan the spreader 12 and obtain scan data; calculate the scan data to obtain the new alignment reference information of the spreader 12; replace the original alignment reference information with the new alignment reference information.

[0054] By scanning the spreader 12 with a laser scanner 10 and calculating the scan data, the alignment reference position information of the spreader 12 is obtained. For example, the scan data from the laser scanner 10 can be input into the control system of the quay crane. The control system of the quay crane calculates the scan data to obtain new alignment reference information for the spreader 12, and replaces the original alignment reference information in the control system with the new alignment reference information, thus completing the alignment calibration of the quay crane. This alignment calibration method has a high degree of automation, high accuracy, and good safety. Specifically, the laser scanner 10 can be a two-dimensional laser scanner, and the scanning plane 11 of the two-dimensional laser scanner is as follows: Figure 1 As shown, the scanning plane 11 passes through the hanger 12, allowing the laser scanner 10 to scan the hanger 12. The scanning plane 11 is a vertical plane that extends in the left-right direction.

[0055] In one specific embodiment, the spreader 12 is an unloaded spreader, which allows for more accurate calculation results. Furthermore, the calibration position is 4.3 to 4.6 meters above the ground. For example, the spreader 12 is controlled to move downwards to a height of 4.3 to 4.6 meters above the ground and hover at this position. It should be noted that the spreader 12 is not completely stationary, but rather swings back and forth at the calibration position, with a swing period between 20 and 40 seconds.

[0056] In one specific embodiment, calculating the alignment reference position of the lifting device 12 based on the scanned data includes the following steps:

[0057] A. Acquire measurement data from a single measurement by the laser scanner 10, and extract the cross-sectional profile data of the lifting device 12 from the measurement data of a single measurement. A single measurement refers to one scanning cycle of the laser scanner 10. The measurement data of a single measurement is the scanning data of the laser scanner 10 within one scanning cycle, which can also be called one scan of the laser scanner 10. One scanning cycle is approximately between 10 milliseconds and 100 milliseconds. Within one scanning cycle, the laser scanner 10 performs one complete scan of the lifting device 12. The laser scanner 10 can rotate and perform scanning. One scanning cycle can be one rotation of the laser scanner 10.

[0058] B. Calculate the position information of one side elevation (left elevation 121 or right elevation 122) of the lifting device 12 during a single measurement based on the cross-sectional profile data. One type of position information for the left elevation 121 (LX) hst The calculation method for (k) is as follows: take the minimum value in the cross-sectional profile data as the position information of the left elevation 121, and the calculation formula is as follows:

[0059] LX hst (k)=min X (Ω ZX (LD,k))

[0060] Among them, Ω ZX (LD,k) represents the cross-sectional profile data obtained from the kth measurement by the laser scanner (i.e., the cross-sectional profile data from a single measurement), where k is a natural number.

[0061] C. Calculate the center plane position information (X) of the lifting device 12 in this measurement based on the left elevation position information of the lifting device 12 measured in the first measurement. hst * (k)). One type of central axis position information (X) hst * The calculation method for (k) is as follows: add half the distance from the left facade 121 to the right facade 122 of the measuring device 12 to the left facade position information of the device 12. The calculation formula is as follows:

[0062] X hst * (k)=LX hst (k)+C L20 / 2

[0063] Among them, LX hst (k) is the left elevation position information data of the lifting device 12 measured in the kth time, C L20 It is the distance from the left facade 121 to the right facade 122 of the lifting device 12, where k is a natural number.

[0064] D. Repeat steps A, B, and C above within one total scanning time of the laser scanner to obtain the position information of multiple central planes 123.

[0065] E. Calculate the new alignment reference information of the lifting device based on the position information of all central planes 123 within a total scan duration.

[0066] Specifically, to obtain accurate calculation results, the total scanning time of the laser scanner 10 is not less than one swing cycle of the lifting device 12. Typically, the total scanning time of the laser scanner 10 is set to two swing cycles of the lifting device 12. Since one scanning cycle of the laser scanner 10 is very short, the laser scanner 10 needs to perform multiple scans (i.e., multiple measurements) within one total scanning time. After calculation, multiple central axis surface position information can be obtained, and then the alignment reference position of the lifting device 12 is calculated based on all the obtained central axis surface position information.

[0067] One type of lifting device 12 has an alignment reference position (X). hst * The calculation method is as follows: Select the minimum and maximum values ​​from all the central plane position information data, and calculate the average of the minimum and maximum values. The formula is as follows:

[0068] X hst* =(min(X) hst * (k))+max(X hst * (k))) / 2

[0069] Through the above measurement and calculation steps, the control system of the quay crane can obtain the latest alignment reference information of the spreader 12, and replace the original alignment reference information with the latest alignment reference information, thus completing the alignment calibration of the quay crane.

[0070] An embodiment of the present invention provides a positioning calibration system for a quay crane, comprising a spreader 12, a laser scanner 10, a memory, and a processor. The memory stores a computer program, which, when executed by the processor, implements the aforementioned positioning calibration method. The memory and processor can be borrowed from the memory and processor of the quay crane's control system, or they can be separately configured.

[0071] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A method for aligning and calibrating a shore crane, characterized in that, include: Control the spreader to move to the calibration position and hover at the calibration position; Start the laser scanner to scan the lifting device and obtain scan data; The scanned data is used to calculate and obtain new alignment reference information for the lifting device; Replace the original alignment reference information with the new alignment reference information; The step of calculating the scanned data to obtain new alignment reference information for the lifting device specifically includes: A. Obtain measurement data from a single measurement by the laser scanner, and extract the cross-sectional profile data of the lifting device from the measurement data from the single measurement; B. Calculate the position information of one side elevation of the lifting device based on the cross-sectional profile data; C. Calculate the central axis position information of the lifting device measured in one step based on the position information of one side elevation; D. Repeat steps A, B and C above within one total scanning time of the laser scanner to obtain multiple central plane position information; E. Calculate the new alignment reference information of the lifting device based on the position information of all the central planes within a total scanning time; The aforementioned side elevation is the left side elevation; The left-side elevation position information of the lifting device is calculated using the following formula: LX hst ( k ) = min X (Oh ZX ( LD , k )) Among them, Ω ZX ( LD, k ) is the first laser scanner k The cross-sectional profile data obtained from this measurement, where k is a natural number; The position information of the central axis of the lifting device measured in one step is calculated using the following formula: X hst * ( k ) = LX hst ( k ) + C L20 / 2 in, LX hst ( k () represents the left elevation position of the lifting device in the k-th calculation. C L20 It is the distance from the left facade to the right facade of the spreading device, where k is a natural number; The alignment reference position information of the lifting device is calculated using the following formula: X hst * =( min ( X hst * ( k ))+ max ( X hst * ( k ))) / 2 k is a natural number.

2. The alignment calibration method as described in claim 1, characterized in that, The lifting device is an unloaded lifting device, and the calibration position is 4.3 meters to 4.6 meters above the ground.

3. The alignment calibration method as described in claim 1, characterized in that, The lifting device swings back and forth when it is suspended at the calibration position, and the total scanning time of the laser scanner is greater than or equal to two swing cycles of the lifting device.

4. The alignment calibration method as described in claim 1, characterized in that, The laser scanner is a two-dimensional laser scanner.

5. A positioning and calibration system for a shore crane, characterized in that, It includes a lifting device, a laser scanner, a memory, and a processor, wherein the memory stores a computer program that, when executed by the processor, implements the alignment calibration method according to any one of claims 1-4.

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