Gantry crane boom hoist cable drum cable control retraction and extension system and method

Abstract

The present invention discloses a cable control and retraction system for a gantry crane boom hoist cable drum, comprising: a cable drum mounted on one end of a boom hoist, the hoist being provided with a cable, one end of the cable mounted on the hoist cable drum, and the cable being retracted and released by rotating the cable drum; a lifting absolute value encoder for measuring the lifting height of the hoist; an amplitude measurement device for measuring the boom rotation angle; a drum controller for controlling the rotation direction of the cable drum, and obtaining adjustment data for the cable drum based on data from the lifting absolute value encoder and the amplitude measurement device. The drum controller comprises a retraction and release prediction module and a retraction and release control module, wherein the retraction and release prediction module is used to obtain prediction data based on the current motion state and control the retraction and release control module to control the cable reel. This effectively improves the operational safety and efficiency of the crane and reduces maintenance costs.

Description

Technical Field

[0001] The present invention belongs to the technical field of cable retraction and extension control, and in particular relates to a cable retraction and extension control system and method for a gantry crane boom hoist cable drum. Background Art

[0002] With the development of the logistics industry, there are more and more types of cargo in ports. A single terminal may have different types of cargo such as containers, general cargo, bulk cargo, etc. As the loading and unloading equipment at the forefront of the terminal, the gantry crane needs to take into account the loading and unloading functions of multiple types of cargo. Different types of cargo require different lifting equipment for loading and unloading.

[0003] When loading and unloading containers, gantry cranes utilize specialized container spreaders. A dedicated spreader cable is installed on the gantry crane to power and control the spreader. The container spreader's height changes during gantry crane operation, necessitating the retraction and deployment of the spreader cable. Currently, there are two methods for retracting and deploying the spreader cable. The first method involves securing one end of the spreader cable to the boom head and the other end to a cable storage frame mounted on the rotating hook. When the lifting height changes, the spreader cable falls into the cable storage frame, thereby controlling the spreader cable's length. However, since the spreader cable is in a free-hanging state, it can easily become entangled with adjacent wire ropes at high altitudes, potentially leading to safety accidents. The second method involves installing a spreader cable reel at the boom head, with the other end secured to the rotating hook. When the lifting height changes, the reel retracts and deploys the cable to control the spreader cable's length, keeping the cable straight at all times. This can easily cause the cable to break, leading to unexpected situations.

[0004] Due to the complex working conditions of gantry cranes, the length of the spreader cable will change when the load is lifted; when the luffing mechanism operates, it will also affect the change of the spreader cable. Therefore, we provide a spreader cable retraction and extension control system to avoid safety accidents caused by spreader cable problems during operation. Summary of the Invention

[0005] The purpose of the present invention is to provide a portal crane boom hoist cable reel cable control and release system to avoid safety accidents caused by problems with the hoist cable during operation.

[0006] The present invention discloses a portal crane boom hoist cable drum cable control and retraction system, comprising:

[0007] A cable drum is mounted on one end of a sling provided on the boom, the sling being provided with a cable, one end of the cable being mounted on a cable drum of the sling, and the cable being retracted and released by rotating the cable drum;

[0008] Lifting absolute value encoder, used to measure the lifting height of the spreader;

[0009] Luffing amplitude measuring device, used to measure the boom rotation angle;

[0010] The reel controller is used to control the rotation direction of the cable reel and obtain the adjustment data of the cable reel according to the data of the lifting absolute value encoder and the amplitude measurement device.

[0011] As a further improvement of the above technical solution:

[0012] The reel controller includes a retraction and extension prediction module and a retraction and extension control module. The retraction and extension prediction module is used to obtain prediction data based on the current motion state and control the retraction and extension control module to control the cable reel. The retraction and extension prediction module includes a current position parameter acquisition unit, a predicted position calculation unit, and a parameter correction unit.

[0013] The prediction here is mainly the working status prediction. The first step is to determine the current task. The current tasks include picking up goods, moving goods and releasing goods. The picking process includes amplitude change and sling lowering. Moving goods includes rotation. Only amplitude change occurs in this process. The releasing process involves amplitude change and sling lifting. According to the task, the cable reel work is planned. If the amplitude change is downward and the sling is lowered, the sling will pay out the line and the cable should also be paid out. The cable should be paid out in advance before the sling pays out the line to prevent the sling from breaking the cable. If the sling is lifted, the sling will reel in the line and the cable should also be reeled in. The cable should be paid out after reeling in to prevent the cable from being broken. Cable transition redundancy may occur in the process, so a parameter correction unit is set to prevent transition redundancy by adjusting the cable reel speed. The present invention can ensure that the cable is not excessively redundant and that the cable is not broken, thereby improving the safety of use.

[0014] The present invention discloses a method for controlling the retraction and extension of a cable drum of a gantry crane boom spreader. The method is based on the aforementioned method for controlling the retraction and extension of a cable drum of a gantry crane boom spreader, and comprises the following steps:

[0015] S1. A current position parameter acquisition unit acquires current position parameters, where the position parameters include the lifting height of the spreader and the angle of the boom;

[0016] S2. Predicting the working state at the next time. The working state includes: the working state of the spreader and the working state of the boom. The working state of the spreader includes the state of lifting, lowering, and constant height. The working state of the boom includes the state of increasing, decreasing, and constant position of the rotation angle.

[0017] S3. Outputting an adjustment value to the reel controller through the predicted position calculation unit according to the next working state, so that the reel controller moves;

[0018] S4. After the next time working state is completed, the latest position parameter is obtained, and the correction adjustment value is output through the parameter correction unit to control the movement of the reel controller.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] Improved safety: By real-time monitoring of the spreader's lifting height and boom rotation angle, combined with a retraction and extension prediction module, it can effectively prevent cable breakage during crane operation, reducing the risk of accidents.

[0021] Improve work efficiency: The system can automatically adjust the retraction and extension of the cable reel according to the movement status of the spreader and boom, ensuring that the cable is always in a suitable state and reducing downtime caused by cable problems.

[0022] Extend cable life: By precisely controlling the retraction and extension of the cable, cable damage caused by excessive stretching or entanglement is avoided, thereby extending the cable life.

[0023] Optimized operating experience: The automated cable retraction and release control system reduces the operator's labor intensity and makes the operation more convenient and comfortable.

[0024] Energy saving and consumption reduction: The system can adjust the operation of the cable reel according to actual work needs to avoid unnecessary energy consumption.

[0025] Improved space utilization: By precisely controlling the cable length, redundant stacking of cables during operation is avoided, thus improving the space utilization at the work site.

[0026] Easy maintenance: The system has a simple structure, which is convenient for daily inspection and maintenance, reducing maintenance costs.

[0027] Improve operation accuracy: By adjusting the cable length in real time, the spreader can be ensured to operate stably during operation, thus improving operation accuracy.

[0028] In summary, the portal crane boom hoist cable reel cable control and retraction system provided in this embodiment effectively improves the crane's operating safety and efficiency, reduces maintenance costs, and has high practical value and market prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] 1. Lifting absolute value encoder; 2. Cable reel; 3. Cable; 5. Spreader; 7. Luffing amplitude measuring device. DETAILED DESCRIPTION

[0030] To make the technical means, creative features, objectives, and effects of the present invention easily understood, the following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without creative work are within the scope of protection of the present invention.

[0031] like Figure 1 As shown, the portal crane boom hoist cable reel cable control and retraction system of this embodiment includes:

[0032] The cable drum 2 is mounted on one end of the boom sling 5, on which the cable 3 is mounted. One end of the cable 3 is mounted on the cable drum 2, and the cable is retracted and released by rotating the cable drum.

[0033] Lifting absolute value encoder 1, used to measure the lifting height of the spreader;

[0034] Amplitude measurement device 7, used to measure the boom rotation angle;

[0035] The reel controller is used to control the rotation direction of the cable reel 2 and obtain the adjustment data of the cable reel 2 according to the data of the lifting absolute value encoder 1 and the amplitude measurement device 7.

[0036] The reel controller includes a retraction and extension prediction module and a retraction and extension control module. The retraction and extension prediction module is used to obtain prediction data according to the current motion state and control the retraction and extension control module to control the cable reel.

[0037] The retraction and extension prediction module includes a current position parameter acquisition unit, a predicted position calculation unit and a parameter correction unit.

[0038] Relationship between height change and amplitude:

[0039] like Figure 2 As shown, the definition is: boom length: L meters; the pitch angle between the boom and the horizontal plane is α; the track surface is the reference plane,

[0040] The height below the track surface is H1 meter; the height from the track surface to the center of the boom root shaft is H2 meters; the distance from the center of the boom root shaft to the boom head is H3 meters; the total length of the vertical cable: Htotal = H1+H2+H3.

[0041] First, consider the case where the hoisting mechanism does not change but the luffing mechanism changes:

[0042] Due to the particularity of the crane, when the luffing mechanism changes, its lifting point position tends to be horizontally balanced, that is, it moves on a horizontal straight line. Therefore, the total height change of the vertical cable is calibrated at the H3 position to determine the initial position. The spreader is placed on the track surface to keep the wire rope and vertical cable in a vertical state. The initial position height is:

[0043] H11=0;

[0044] H21=H2;

[0045] H31 = Lsanα;

[0046] When the boom is stepped down, the angle between the boom and the horizontal plane is β, and the height is:

[0047] H32 = Lsanβ;

[0048] The cable drum at the boom head needs to be retracted H3:

[0049] H3=H31-H32=Lsanα-Lsanβ=L*(sanα-sanβ);

[0050] When the boom is reduced upward, the angle between the boom and the horizontal plane is β, and the height is:

[0051] H32 = Lsanβ;

[0052] The cable drum at the boom head needs to release the cable H3:

[0053] H3=H32-H31-=Lsanβ-Lsanα=L*(sanβ-sanα);

[0054] Luffing does not work, single lifting works:

[0055] The initial lifting height is set to H;

[0056] If the hoist rises, the hoisting height can be calculated through the hoisting encoder and defined as H5;

[0057] If lifting or lowering, the lifting or lowering height can be calculated through the lifting encoder and defined as H6;

[0058] At this time, you only need to control the lifting H5 or lowering H6 of the spreader cable drum.

[0059] Through combination, if the hoisting mechanism and luffing mechanism are linked:

[0060] 1. The boom of the luffing mechanism amplifies downward and the hoisting mechanism descends. At this time, the cable drum of the spreader is: total change Htotal = H3-H6. If Htotal ≥ 0, the cable drum of the spreader releases the cable downward; if Htotal < 0, the cable drum of the spreader reels the cable upward.

[0061] 2. The boom of the luffing mechanism moves downward and the hoisting mechanism rises. At this time, the cable drum of the spreader is:

[0062] The total change Htotal = H3 + H6, and the cable is reeled in on the cable drum of the spreader.

[0063] 3. The boom of the luffing mechanism decreases upwards, and the lifting mechanism decreases. The same calculation can be applied.

[0064] 4. The boom of the luffing mechanism decreases upwards, and the lifting mechanism rises. The same calculation can be applied.

[0065] This embodiment discloses a method for controlling the retraction and extension of a cable drum of a gantry crane boom hoist, comprising the following steps:

[0066] S1. A current position parameter acquisition unit acquires current position parameters, where the position parameters include a hoisting height of the spreader and an angle of the boom.

[0067] S2. Predict the next working state. The working state includes the spreader working state and the boom working state. The spreader working state includes lifting, lowering, and constant height. The boom working state includes increasing and decreasing rotation angles and constant position. The prediction is made based on preset parameters. The main purpose is to complete the cable laying in advance before the spreader changes position to avoid cable breakage.

[0068] S3. Based on the next working state, the predicted position calculation unit outputs an adjustment value to the reel controller, causing the reel controller to move; in this case, the cable is released in advance and reeled in later;

[0069] S4. After the next working state is completed, the latest position parameters are obtained and the parameter correction unit outputs the correction adjustment value to control the movement of the drum controller. Here, when the difference between the cable and the spreader is too large, the correction is made to ensure that the cable is not broken and the cable is not tangled.

[0070] The portal crane boom hoist cable drum cable control and retraction system provided in this embodiment effectively improves the operation safety and efficiency of the crane and reduces maintenance costs.

[0071] The above is only an embodiment of the present invention, and common sense such as the specific structure and characteristics disclosed in the scheme are not described in detail here. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes that fall within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claim involved.

Claims

1. A method for controlling the retraction and extension of a cable drum of a gantry crane boom hoist, characterized in that: The cable reel control and retraction system based on the gantry crane boom spreader cable drum includes the following steps: S1. A current position parameter acquisition unit acquires current position parameters, where the position parameters include the lifting height of the spreader and the angle of the boom; S2. Predicting the working state at the next time. The working state includes: the working state of the spreader and the working state of the boom. The working state of the spreader includes lifting, lowering, and constant height. The working state of the boom includes increasing, decreasing, and constant position of the rotation angle. S3. Outputting an adjustment value to the reel controller through the predicted position calculation unit according to the next working state, so that the reel controller moves; S4. After the next working state is completed, the latest position parameter is obtained, and the correction adjustment value is output through the parameter correction unit to control the movement of the drum controller; wherein the gantry crane boom hoist cable drum cable control retraction and extension system includes: a cable reel, which is installed at one end of the boom setting hoist, and the hoist is provided with a cable, and one end of the cable is installed on the cable reel, and the cable is retracted and extended by rotating the cable reel; a lifting absolute value encoder for measuring the lifting height of the hoist; an amplitude measurement device for measuring the rotation angle of the boom; a drum controller for controlling the rotation direction of the cable reel, and obtaining the adjustment data of the cable reel according to the data of the lifting absolute value encoder and the amplitude measurement device; the drum controller includes a retraction and extension prediction module and a retraction and extension control module, the retraction and extension prediction module is used to obtain prediction data according to the current motion state, and control the retraction and extension control module to control the cable reel; the retraction and extension prediction module includes a current position parameter acquisition unit, a predicted position calculation unit and a parameter correction unit.

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