Control of a spreader flap configured as a spreader for lifting a container

Abstract

This disclosure relates to the control of a flapper for lifting a container. The invention generally relates to a computer-implemented method for controlling at least one flapper (102) of a spreader (100) configured to lift a container (106), the method comprising: controlling (S102) at least one flapper arm to move from a lower position to an upper position, waiting (S104) for a predetermined duration, and after the predetermined duration has elapsed, controlling (S106) at least one flapper arm to move to a lower position.

Description

Technical Field

[0001] The present invention generally relates to a computer-implemented method for controlling at least one flap of a spreader configured to lift a container, a control unit, a spreader, and a computer program product. Background Technology

[0002] Container spreaders are used to lift containers at their four corners. To facilitate the lifting operation, the spreader's boom helps align the spreader's lifting mechanism with the lifting points on the container.

[0003] Traditional spreader rigs use flaps that remain in a fixed, lower position during the pickup process or can stop in an intermediate position to grip the container. The former method limits operational flexibility, while the latter requires a specialized flap that can stop in the middle, increasing complexity and cost. Summary of the Invention

[0004] In view of the above and other disadvantages of the prior art, the object of the present invention is to provide a method and lifting device that at least partially mitigates the disadvantages of the prior art.

[0005] According to a first aspect of the invention, a computer-implemented method is provided for controlling at least one flap of a spreader configured to lift a container, the method comprising: controlling at least one flap arm to move from a lower position toward an upper position, waiting for a predetermined duration, and after the predetermined duration has elapsed, controlling at least one flap arm to move to a lower position.

[0006] This invention is based, at least in part, on the understanding that upon approaching a container, an upward command is first given, followed by a brief waiting period during which the flapper arm moves upward, and then a downward command is given. This allows the flapper arm to be slightly "opened" to allow for better alignment with the container, after which the flapper arm is closed for final alignment.

[0007] Spreaders are lifting devices commonly used in port and terminal operations to handle intermodal containers. Spreaders are typically attached to cranes and are designed to adjust their width to fit various container sizes, ensuring a secure and balanced lift. Equipped with twist locks or other securing mechanisms at each corner, the spreader engages with the corner castings of the container, allowing for efficient lifting, moving, and placement of the container.

[0008] A flapper arm is a component of a spreader that helps position the spreader on a container to ensure lifting and handling operations. The flapper arm is mounted on the side of the spreader and can move between upper and lower positions. In the upper position, the flapper arm facilitates alignment of the spreader with the container, while in the lower position, it helps secure the container by engaging with its side. For example, the flapper arm contacts the container and guides the spreader to align the locking engagement between the spreader and the container.

[0009] In one embodiment, the method may include: determining a distance between at least one tilting arm and the container when the tilting arm approaches the container; determining that the distance is less than or equal to a threshold distance; and controlling at least one tilting arm in response to the distance being less than or equal to the threshold distance. This advantageously allows for timing of the tilting arm operation as the spreader approaches the container.

[0010] The distance between at least one flap and the container can be measured by a sensor on the spreader. This ensures accurate distance determination, thereby improving the timing of the flap movement. The sensor's accuracy is preferably 5 cm or less.

[0011] In this embodiment, the threshold distance can be based on the speed at which the flapper approaches the container. By basing the threshold distance on the flapper's speed, the timing of the flapper's movement can be dynamically adjusted. This ensures that the flapper engages with the container at the optimal moment, thereby improving the accuracy of the container gripping process.

[0012] In several embodiments, the method may include receiving user input and, in response to the received user input, initiating control of the at least one flapper arm. In other words, control of the flapper arm may be manually initiated by an operator who visually inspects the spreader using, for example, a camera and a display user interface.

[0013] In this embodiment, the predetermined duration can be fixed. A fixed predetermined duration simplifies the control algorithm and ensures that the flapper arm movement is consistent each time it is triggered. This consistency leads to predictable and repeatable operation, which helps maintain efficiency and reliability in the spreader. The predetermined duration is long enough to allow the flapper arm to open for the spreader to receive the container, and then close to the lower position once the container is in place in the spreader.

[0014] The predetermined duration can be selected in the range of 0.3 seconds to 1.5 seconds, preferably about 0.6 seconds.

[0015] Preferably, the method steps are automated once initiated. That is, the up-and-down movement of the flap is automatic, regardless of whether the operation is automated by using sensors or manually initiated by user input.

[0016] Preferably, at least four flaps of the spreader are controlled.

[0017] In one embodiment, the method may include providing an alert on the user interface regarding the imminent automatic control of the flapper arm. That is, the operator can be aware of the flapper's movement before it is triggered. This method can be implemented in an embedded control system. Embedded control systems, such as programmable logic controllers (PLCs), offer improved integration with existing systems and control within the lifting device.

[0018] A control unit is also provided, which is configured to perform the methods of any of the embodiments disclosed herein.

[0019] A lifting device is also provided, which includes at least one flap and a control unit.

[0020] A computer program product including program code is also provided, which, when executed by a control unit, is used to perform a method according to any of the embodiments disclosed herein.

[0021] Other features and advantages of the invention will become apparent when examined in light of the appended claims and the following description. Those skilled in the art will recognize that different features of the invention can be combined to produce embodiments other than those described below without departing from the scope of the invention. Attached Figure Description

[0022] These and other aspects of the invention will now be described in more detail with reference to the accompanying drawings, which illustrate exemplary embodiments of the invention, in which:

[0023] Figure 1 A crane with a lifting device according to an embodiment of the present invention is illustrated schematically;

[0024] Figure 2 The control of the flap arm of the spreader according to an embodiment of the present invention is illustrated schematically;

[0025] Figure 3 This is a flowchart of the method steps according to an embodiment of the present invention;

[0026] Figure 4 This is a flowchart of the method steps according to an embodiment of the present invention; and

[0027] Figure 5 This is a flowchart of the method steps according to an embodiment of the present invention. Detailed Implementation

[0028] In this detailed description, various embodiments of the invention are described with reference to specific implementations. Specific terminology is used in the described embodiments for clarity. However, the invention is not limited to the chosen specific terminology. While specific exemplary embodiments are discussed, it should be understood that this is merely for illustrative purposes. Those skilled in the art will recognize that other components and configurations can be used without departing from the scope of the invention.

[0029] Figure 1 A spreader 100 with multiple flap arms 102 is schematically shown. The spreader 100 is attached to a crane 104 via a lifting mechanism 105 configured to lift the spreader up and down to lift a container 106. The spreader 100 can adjust its width to accommodate containers of different sizes.

[0030] The spreader 100 includes a twist lock 108 adapted to lock into a corresponding receiving unit 110 of the container, which is typically in the form of a receiver hole 110. The geometry of the twist lock ensures that the engagement in the receiving hole 110 remains in the proper position once rotated.

[0031] Also referred to as flap arm 102, flaps 102 are mounted on the side of spreader 100 and can move between upper and lower positions. In the upper position, flap arms 102 facilitate alignment of spreader 100 with container 100, while in the lower position, they help secure container 106 by engaging with its side. Figure 1 In this configuration, when crane 104 lowers spreader 100 toward container 106, the boom is positioned below it. Crane 104 and spreader 100 can be operated by a crane operator.

[0032] Although the number of flap arms 102 varies depending on the type of spreader, in this example, the spreader 100 has at least four flap arms, and in this case, six flap arms, which are controlled according to embodiments of the present disclosure.

[0033] Combination Figure 3 The flowchart in the middle Figure 2 .

[0034] exist Figure 2 In position P1 of the spreader 100, the flap arm 102 is positioned below it. The spreader 100 moves downward toward the container 106.

[0035] The control unit 120 is configured to control the at least one flap arm 102 to move from a lower position to an upper position in step S102. As shown in position P2, where the spreader 100 is closer to the container than in position P1, the flap arms are now moved to the upper position. That is, they are "open" to facilitate the positioning of the container 106.

[0036] Once the movement of the flap arm 102 is triggered, in step S104, the control unit 120 waits for a predetermined duration, thereby allowing the flap arm 102 to move slightly upward as indicated by arrow 122, although it does not move to the fully upward position.

[0037] Once the predetermined duration has elapsed, the control unit 120 controls at least one flap arm 102 to move to the lower position as shown in position P3, in which the flap arm 102 has moved in the opposite direction indicated by arrow 124. The movement of the flap arm 102 is achieved by rotating it about a pivot axis at one end of the flap arm 102. Figure 2 Position P2 indicates a pivot axis 132.

[0038] The predetermined duration is long enough to allow the flap arm to open slightly for the spreader 100 to receive the container 106, and then closes once the container is in place, i.e., moves back to the lower position. The predetermined duration can be fixed and selected in the range of 0.3 seconds to 1.5 seconds. In a preferred embodiment, the predetermined duration is approximately 0.6 seconds.

[0039] Figure 4 Is Figure 3 The flowchart of the method steps preceding the steps.

[0040] In step S202, when the flapper 102 approaches the container 106, the control unit 120 determines the distance d between at least one flapper 102 and the container 106. The distance d between at least one flapper 102 and the container 106 is measured by a sensor 126 on the spreader 100. The sensor 126 may be, for example, an ultrasonic sensor or a laser-based sensor, such as a lidar.

[0041] In step S204, the control unit 120 determines that the distance is less than or equal to the threshold distance.

[0042] In response to the distance being less than or equal to a threshold distance, regarding Figure 2 and Figure 3 In step S102, the control unit 120 controls at least one flap arm to move toward an upward position.

[0043] Figure 5This is a flowchart of the method steps in an alternative embodiment, wherein in step S302, the control unit 120 receives user input to trigger the movement of the flap 102. In this embodiment, the sensor 126 is not required. Instead, the operator can visually inspect the descent of the spreader 100 toward the container 106 and trigger the movement of the flap arm 102 at the correct time.

[0044] In response to the received user input, as described above in conjunction with step S102, control of the at least one flap arm is initiated in step S102.

[0045] Optionally, an alarm indicating that the flip arm 102 will be automatically controlled can be provided on a user interface 130, such as a display or speaker.

[0046] Once the method is initiated, either automatically by detecting that the distance between at least one flap and the container is less than or equal to a threshold distance, or by receiving user input, the method steps involving the control of flap 102 are automated.

[0047] The control unit 120 can be implemented in an embedded control system such as a programmable logic controller (PLC).

[0048] The control unit may include a microprocessor, a microcontroller, a programmable digital signal processor, or another programmable device. The control unit may also, or alternatively, include an application-specific integrated circuit, a programmable gate array (FPGA), or a programmable array logic, a programmable logic device, or a digital signal processor. Where the control unit includes a programmable device such as a microprocessor, microcontroller, or programmable digital signal processor as described above, the processor may also include computer-executable code that controls the operation of the programmable device.

[0049] In one or more examples, the described functionality may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, these functions may be stored or transmitted as one or more instructions or code on a computer-readable medium and executed by a hardware-based processing unit. A computer-readable medium may include a computer-readable storage medium, which corresponds to a tangible medium such as a data storage medium, or a communication medium, which includes any medium that facilitates, for example, the transfer of a computer program from one place to another according to a communication protocol. In this way, a computer-readable medium may generally correspond to (1) a non-transitory tangible computer-readable storage medium or (2) a communication medium such as a signal or carrier wave. A data storage medium may be any available medium accessible by one or more computers or one or more processors to retrieve instructions, code, and / or data structures for implementing the techniques described herein. Computer program products may include computer-readable media.

[0050] By way of example and not limitation, such computer-readable storage media may include RAM, ROM, EEPROM, CD-ROM or other optical disc storage, disk storage or other magnetic storage devices, flash memory, or any other medium that can be used to store the required program code in the form of instructions or data structures and that can be accessed by a computer.

[0051] Although the invention has been described with reference to specific exemplary embodiments thereof, many different substitutions, modifications, etc., will become apparent to those skilled in the art.

[0052] Furthermore, by studying the accompanying drawings, the disclosure, and the appended claims, those skilled in the art can understand and implement variations of the disclosed embodiments in practicing the claimed invention. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude a plurality. The fact that certain measures are recited in mutually different dependent claims does not imply that combinations of these measures cannot be advantageously used.

Claims

1. A computer-implemented method for controlling at least one flap (102) of a spreader (100) configured for lifting a container (106), the method comprising: Control (S102) the at least one flap arm moves from the lower position to the upper position. The scheduled duration of waiting (S104), and After the predetermined duration has elapsed, the control (S106) moves the at least one flap arm to the lower position.

2. The method according to claim 1, comprising: When the flap approaches the container, determine (S202) the distance (d) between the at least one flap and the container. Determine (S204) that the distance is less than or equal to the threshold distance. In response to the distance being less than or equal to the threshold distance, control (S102) the at least one flap arm.

3. The method according to claim 2, wherein the distance between the at least one flap and the container is measured by a sensor (126) on the spreader.

4. The method according to any one of claims 2 and 3, wherein the threshold distance is based on the speed at which the flap approaches the container.

5. The method according to claim 1, comprising: Receive (S302) user input, and In response to the received user input, control of the at least one flap arm is initiated (S102).

6. The method according to any one of the preceding claims, wherein the predetermined duration is fixed.

7. The method of claim 6, wherein the predetermined duration is long enough to allow the flap arm to open for the spreader (100) to receive the container (106), and the flap arm closes to the lower position once the container is in place in the spreader.

8. The method according to any one of the preceding claims, wherein the predetermined duration is selected in the range of 0.3 seconds to 1.5 seconds, preferably about 0.6 seconds.

9. The method according to any one of the preceding claims, wherein the method steps are automated once started.

10. The method according to any one of the preceding claims, wherein at least four flap arms of the spreader are controlled.

11. The method according to any one of the preceding claims, comprising providing an alarm on the user interface indicating that the flip arm will be automatically controlled.

12. The method according to any one of the preceding claims is implemented in an embedded control system.

13. A control unit (120) configured to perform the method of any one of the preceding claims.

14. A lifting device comprising at least one flap and a control unit according to claim 13.

15. A computer program product comprising program code, which, when executed by a control unit, performs the method according to any one of claims 1 to 12.

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