KR102031140B1 - The crane and method for controlling the crane - Google Patents

Abstract

Disclosed is a control method for a crane transferring multiple hooks individually installed in multiple ropes by hanging the multiple hooks on a cargo. The control method for a crane includes: a step of arranging an inclination sensing unit for sensing an inclination of the cargo and setting an initial coordinate of each of the multiple hooks based on the inclination sensing unit; a step of receiving an inclination value of the cargo from the inclination sensing unit while the cargo is transported and obtaining a moving coordinate of each of the multiple hooks based on the inclination value; a step of obtaining the height of each of the multiple hooks by comparing the moving coordinate and initial coordinate of the multiple hooks; a step of obtaining the height difference of the different hooks in comparison with the height of a reference hook; and a step of compensating the speed of winding or unwinding the rope of the other hook in accordance with the height difference based on the speed of winding or unwinding the reference hook.

Description

Crane and crane control method {THE CRANE AND METHOD FOR CONTROLLING THE CRANE}

The present invention relates to a crane and a control method of the crane.

A crane is a machine that lifts and transports cargo. Generally, cranes include overhead cranes, jib cranes, unloaders, tower cranes, cable cranes and gantry cranes, depending on the purpose and shape. Gantry cranes are mainly used for loading or unloading containers in container ships. The gantry crane has a lower support coupled to the bogie moving along rails installed parallel to the land, a leg coupled to the lower support, an upper support coupled to the top of the leg, a boom coupled to the upper support, and a machine room installed on the boom. And a trolley moving along the rail fixed to the boom, a hoist installed on the trolley, a wire rope provided on the hoist, and a hook formed at the end of the hoist to hang on the cargo.

In offshore plant installations, very large Goliath gantry cranes are used to lift heavy loads and transport them to the correct location. Goliath gantry cranes need to load-balance the wire rope hooks of the 48 hoists of the trolley to the plate, for example, to carry more than 15,000 tons of cargo. In this case, the cargo may be inclined due to a difference in the center of gravity, acceleration due to horizontal movement of the cargo, and environmental factors such as wind. When such a heavy load is lifted or lowered in an inclined state, a load is concentrated on a specific wire rope, which causes a problem that the wire rope is broken or cannot be transported to an accurate position.

An object of the present invention is to provide a control method of a crane and a crane for lifting and unloading a cargo in real time to solve the above-mentioned conventional problems.

In order to achieve the above object, there is provided a control method of a crane for carrying the cargo by hooking a plurality of hooks respectively provided on a plurality of ropes to the cargo. In the crane control method, an inclination sensing unit for sensing the inclination of the cargo is disposed, and the initial coordinates of each of the plurality of hooks are set from the inclination sensing unit as an origin; Receiving a slope value, obtaining movement coordinates of each of the plurality of hooks based on the slope value, comparing the movement coordinates of the plurality of hooks with the initial coordinates, and obtaining a height of each of the plurality of hooks; Comprising the step of obtaining the height difference of the other hooks, and compensating the speed of winding or unwinding each of the rope of the other hook based on the speed of winding or unwinding the rope of the reference hook according to the height difference.

The crane control method includes obtaining an angle of each of the plurality of ropes in the vertical direction, obtaining an angle difference of each of the other ropes relative to the reference rope, and determining the angle based on the speed of winding or unwinding the rope of the reference hook. Compensating the winding or unwinding speed of each rope of the hook according to the angle difference.

Obtaining the height difference may reflect the initial height difference of the plurality of hooks.

According to an embodiment of the present invention there is provided a crane for carrying the cargo by hooking a plurality of hooks respectively provided on the plurality of ropes to the cargo. The crane is a hoist for hoisting or unwinding the plurality of ropes, an inclination sensing unit for sensing the inclination of the cargo, and the inclination sensing unit as starting points, and set initial coordinates of each of the plurality of hooks. Or receiving the inclination value of the cargo from the inclination detecting unit during the unloading, obtaining the moving coordinates of each of the plurality of hooks based on the inclination value, and comparing the moving coordinates and the initial coordinates of the plurality of hooks to determine the height of each of the multiple hooks The hoist to obtain a height difference of the other hooks relative to the height of the reference hook, and compensate the speed of winding or unwinding each of the ropes of the other hook based on the speed of winding or unwinding the rope of the reference hook according to the height difference. It includes a control unit for controlling.

The height Zi of each of the plurality of hooks can be obtained from the following equation.

Here, θ _ix and θ _iy are the x-axis, y-axis rotation angles, x _i , y _i , z _i obtained from the tilt detection unit, respectively, and are initial coordinate values of the plurality of hooks.

According to the crane and the control method of the crane of the present invention has the following advantages.

First, accurate compensation rates can be calculated based on the mechanical model. Existing fuzzy logic calculation methods set the approximate value for the compensation speed directly, whereas the method of the present invention calculates the compensation speed based on a mechanical model, and thus accurate calculation is possible.

Second, it can be calculated regardless of the number of hooks. The existing fuzzy logic calculation method had to have a condition for all selectable hook cases, and when the number of hooks was added, a condition must be added as well. If a crane uses 24 hooks, the number of conditions required is 2 ^ 24, and setting a condition is difficult because a human must enter a value. On the other hand, the method of the present invention does not require individual conditions according to the hook, and even if the number of hooks is increased, it is possible to calculate only the initial coordinates of the hook used.

Third, the height of the hook can be calculated as a linear function of the initial position, making it easy to describe in any programming language. In this case, the code is organized in LabVIEW.

Fourth, there is little data to store basically. Existing fuzzy logic should store input, output belonging function, condition according to selected hook, etc., but the method of the present invention does not need these.

1 is a perspective view of a crane according to an embodiment of the present invention.
FIG. 2 is a perspective view illustrating the hoist disposed in the trolley of FIG. 1. FIG.
3 is a block diagram of a crane according to an embodiment of the present invention.
4 is a flowchart illustrating a crane control method according to an embodiment of the present invention.
5 is a schematic view showing a state in which a hook is attached to a load.
6 is a view showing a state in which the cargo rotated in FIG.
7 is a vector diagram for calculating the movement coordinates of the hook according to the rotation of the cargo in FIG.
FIG. 8 is a diagram illustrating an angle measured by the tilt sensor in FIG. 5.
9 is a view showing a change in height of each hook in FIG.
10 is a view showing the vertical angle of the rope.
FIG. 11 is a vector diagram for calculating a compensation speed of a rope according to the vertical angle of FIG. 10.
12 is a schematic diagram illustrating a case where the initial positions of the plurality of hooks are different.
13 is a diagram illustrating a labview program according to an exemplary embodiment of the present invention.

Hereinafter, a crane 1 and a control method thereof according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a perspective view showing a crane 1 according to an embodiment of the present invention. 1 illustrates a Goliath gantry crane as an example for description, and may be applied to various kinds of cranes.

The crane 1 includes a support 10, a girder 20 and a trolley 30. The crane 1 may further include a cab (not shown) for controlling the trolley 30 for the transportation of cargo.

The support 10 supports the girder 20 at the upper end. The support 10 is provided with a wheel 12 at the lower end can move in the transverse direction in the extension direction of the girder.

The girder 20 consists of a pair of parallel spaced apart. Of course, the girder 20 may be made of one or three or more depending on the design. The girder 20 includes a guide rail (not shown) provided in an extending direction.

The trolley 30 may move in the longitudinal direction of the girder 20 along a guide rail installed between the pair of girders 20. The trolley 30 is provided with a number of hoists (32 in FIG. 2). The trolley 30 may be provided with, for example, 42 hoists 32 for distributing and transporting ultra-high load cargo.

2 is a perspective view of the hoist 32. As shown, the hoist 32 includes a winch drum 324 that can wind and unwind the rope 322 and a motor 326 that can rotate the winch drum 324. Hoist 32 may wind up and unload cargo by winding and unwinding rope 323.

The rope 322 is provided with a hook 323 for hanging on the cargo. The ropes 322 of each of the plurality of hoists 32 may be individually provided with hooks 323 to hang individually on the load. The rope 322 of each of the plurality of hoists 32 may hang on a plate-shaped spreader (not shown). The spreader may include a cargo hold for securing the cargo and a hook for hanging a plurality of hooks 323.

The winch drum 324 may be rotated and rotated by the motor 326 in order so as not to overlap the rope 322.

The motor 326 is controlled by the controller (40 of FIG. 3) to rotate the position drum 324 to adjust the length of the rope 322 caught in the load through the hook 323.

3 is a block diagram of a crane 1 according to an embodiment of the invention. The crane 1 is a trolley 30 having a plurality of hoists 32, a control unit 40 for controlling the trolley 30 and the hoist 32, a tilt detection unit 50 for detecting the inclination of the cargo, the inclination The first communication unit 62 transmits the inclination value detected by the sensing unit 50 and the second communication unit 64 receives the inclination value transmitted by the first communication unit 62 and transmits it to the control unit 40. .

The trolley 30 may move from one point to another by riding the guide rail along the longitudinal direction of the girder (20 in FIG. 1) by the controller 40. At this time, each of the plurality of hoists 32 is a state in which the lifting of the cargo by lifting the rope 322 or the release of the rope 322 to put down the cargo and wound up the rope 322 again.

The controller 40 may control the movement of the trolley 30 itself and a motor (326 of FIG. 2) for winding and unwinding the ropes of the plurality of hoists 32. The controller 40 controls the hoist 32 using, for example, inclination information of the cargo or the spreader received from the first communication unit 62 through the second communication unit 64.

The control unit 40 includes at least one general purpose processor which loads at least a part of the control program into the volatile memory from the nonvolatile memory in which the control program is installed, and executes the loaded control program, for example, a CPU (Central Processing) It may be implemented as a unit, an application processor (AP), or a microprocessor.

The controller 40 may include a single core, dual cores, triple cores, quad cores, and multiple cores thereof. The controller 40 may be provided in plural and, for example, may operate in a main processor and a sleep mode (for example, only standby power is supplied and does not operate as the first electronic device). It may include a sub processor. In addition, the processor, ROM and RAM are interconnected via an internal bus.

The controller 40 may be implemented as a form included in a main SoC mounted on a PCB.

The control program may include program (s) implemented in at least one of a BIOS, a device driver, an operating system, firmware, a platform, and an application (application). The control program may include, for example, a LabVIEW program used for data acquisition, instrument control, and industrial automation. The application may be installed or stored in advance at the time of manufacture, or may be installed based on the data received by receiving data of the application from the outside in future use. The data of the application may be downloaded from an external server such as, for example, an application market. Such an external server is an example of a computer program product, but is not limited thereto.

The tilt detection unit 50 may be formed of a PCB circuit module including a tilt sensor for measuring a tilt with respect to a reference plane. The tilt sensor may include a 2-axis digital tilt sensor, a tilt sensor with a gyroscope, and the like. Tilt detection unit 50 is disposed in the center of the cargo 100 to form the origin of the coordinates.

The first communication unit 62 is provided on the tilt detection unit 50 side to receive in real time the inclination value of the cargo or spreader 100 measured by the tilt detection unit 50 to the second communication unit 64 on the control unit 40 side. ). The first communication unit 62 may transmit the slope value to the controller 40 or a memory (not shown) by wire or wirelessly.

The first communication unit 62 includes data communication modules such as VDSL, Ethernet, token ring, high definition multimedia interface (HDMI), USB, component, LVDS, and HEC, 2G, 3G, 4G, and Long Term Evolution (LTE). Wireless Internet modules such as mobile communication, WLAN (Wireless LAN) (Wi-Fi), Wibro (Wireless broadband), World Interoperability for Microwave Access (Wimax), High Speed Downlink Packet Access (HSDPA), Bluetooth, RFID And a short range communication module such as radio frequency identification (IrDA), infrared data association (IrDA), ultra wideband (UWB), and ZigBee.

The second communication unit 64 may be provided at the control unit 40 to receive an inclination value from the first communication unit 62. The inclination value received by the second communication unit 64 may be transmitted to the control unit 40 or stored in a memory (not shown). At this time, the control unit 40 may adjust each rope 322 by controlling each of the plurality of hoists 32 based on the received or stored inclination value.

In another embodiment, the first and second communication units 62 and 64 may be omitted, and the inclination value may be transferred directly from the inclination detecting unit 50 to the control unit 40 or the memory through the signal line.

4 is a flowchart illustrating a control method of the crane 1 according to the embodiment of the present invention, and FIG. 5 is a schematic diagram showing a state in which the hook 323 is fastened to the load 100.

First, as shown in FIG. 5, a hook 323 attached to the end of the rope 322 of each of the plurality of hoists (32 in FIG. 2) mounted to the trolley 30 to carry the cargo 100 is connected to the cargo 100. On the ring 102. FIG. 5 illustrates that four ropes 322 and four hooks 323 lift the cargo 100 as an example for convenience of description, and in practice, more ropes 322 increase as the load of the cargo 100 increases. This can be applied. In addition, the cargo 100 is shown as a flat steel sheet, but is not limited to the shape or size of the cargo. Here, the cargo 100 may be a spreader (not shown).

In step S11, the inclination detection unit 50 is installed in the center of the cargo 100, and the initial coordinates of each of the plurality of hooks 323 are set using the inclination detection unit 50 as the origin. Here, the tilt detection unit 50 does not necessarily need to be disposed in the center of the cargo 100.

Cargo 100 can obtain the initial coordinates of each hook (323-1 ~ 323-4) by hooking each hook (323-1 ~ 323-4) in the state placed on the ground before transport. For example, in FIG. 5, when the cargo 100 is in a horizontal state, initial coordinates of the hooks 323-1 to 323-4 are (-x, y, 0), (x, y, 0), ( x, -y, 0) and (x, y, 0). If the cargo 100 is inclined rather than horizontal in its initial state, the initial coordinates of the hooks 323-1 to 323-4 can be known by applying the rotation matrix described later.

 In operation S12, the tilt detection unit 50 may detect the predetermined angle θ when the cargo 100 rotates at a predetermined angle θ relative to the initial state while the cargo 100 is transported.

In operation S13, the controller 40 may receive a predetermined angle θ to obtain moving coordinates of the hooks 323-1 to 323-4.

Hereinafter, a method of obtaining moving coordinates of each hook 323-1 to 323-4 according to an embodiment of the present invention will be described with reference to FIGS. 6 to 8.

In FIG. 6, the cargo 100 in the initial state was rotated by the angle θ (0 ≦ θ <π) on the rotation axis u with the tilt detection unit 50 as the origin during transportation. The rotation axis u to (α, β, γ), (α 2 + β 2 + γ 2 = 1), the initial position of a rotation matrix rotated by an angle θ to the axis of rotation u R _rot, Hook _i r _i a rotation axis u When the position rotated by θ is (x _i , y _i , z _i ), the following equation is established.

The x, y, z axis rotation operator is as follows.

The rotation vector w is

The rotation transformation that rotates a specific coordinate by the rotation axis u by θ using the three-dimensional rotation matrix general formula (SO (3)) is as follows.

Therefore, the moving coordinates X _i , Y _i , Z _i of the multiple hooks can be obtained as follows using the three-dimensional rotation matrix general formula SO (3). α, β, and γ are slopes of the x, y, and z axes. Here, γ (z-axis rotation) is ignored (γ = 0).

Here, ignoring γ (z-axis rotation) (γ = 0) is as follows.

In step S14, the height difference of each hook can be obtained using the inclination value from the moving coordinates X _i , Y _i , Z _{i of} each hook.

Z _i = -βtanθ _x + αtanθ _y

Here, θ _Ix and θ _Iy are inclination values in the x-axis and y-axis directions obtained from the tilt detection unit 50 as shown in FIG. 8.

Therefore, the height Z _i of each hook can be determined by the following equation (1).

Ten thousand and one, θ«1 / 10 radians, that is, θ _{Ix, Iy} θ is «1 / 10 (radians) If, because tanθ θ ≒ _{Ix Ix, Iy} tanθ θ ≒ _Iy Equation 1 is simplified to the following equation (2) Can be.

In step S15, it is determined whether the angle difference of the plurality of ropes 322 is reflected in the vertical direction. If the angle difference with respect to the vertical direction of the plurality of ropes 322 is zero or negligible, step S16 is performed.

In step S16, the height difference of the other hooks relative to the reference hook is obtained from the height Z _i of each hook obtained in step S14, and the other difference is used based on the speed of winding or unwinding the rope of the reference hook using this height difference. The speed of winding or unwinding each of the ropes of the hook can be compensated for. The height difference ΔZ _i of each hook is a reference hook, which is obtained by subtracting the height Z _i of another hook from the height Z _I of the highest hook.

9 is a view showing the height difference of the other hook relative to the height of the reference hook. As shown, the height difference Zi of the other hooks Z ₁ , Z ₃ , Z ₄ relative to the highest hook position Z ₂ is ΔZ ₁ , ΔZ ₃ , ΔZ _4, respectively. It is then set relative to the highest hook position (Z ₂₎ hooks another hook _{(Z 1, Z 3, Z} 4) the height difference _{(ΔZ 1, ΔZ 3, ΔZ} 4) in proportion to the other hook (Z _1, Z of ₃ , Z ₄ to compensate for the faster winding or loosening of the rope 322. That is, the compensation speed (RV _i ) of each hook can be determined by the following equation (3).

Here, RV _MAX is the maximum compensation speed with respect to the rope of the hook having the largest height difference ΔZ _MAX , and may be arbitrarily set in consideration of the motor 326 specification of the hoist (32 in FIG. 2).

It is not necessary to set the reference hook as the hook of the highest position, and may be set arbitrarily. For example, a hook higher than the reference hook should slow down the winding or unwinding of the rope, depending on the height difference.

As described above, the control unit 40 receives the inclination value from the inclination detection unit 50 in real time while carrying the cargo 100 to obtain the height difference of each hook in real time, and then wound or unwinds the rope of each hook. By compensating for speed it is possible to carry the balance of cargo 100 simply and conveniently.

In step S15, the controller 40 determines whether the angle difference in the vertical direction of the plurality of ropes 322 is reflected, and proceeds to step S17 when the angle in the vertical direction of the plurality of ropes 322 is not negligible.

In step S17, the angle θ _i relative to the vertical direction of the rope of the plurality of hooks is measured.

In step S18, the vertical angle difference of the other hook rope with respect to the vertical direction of the reference hook is calculated.

In step S19, the controller 40 may compensate for the speed of winding or unwinding the rope of each hook (Hook ₁ to Hook ₄ ) according to the angle difference with respect to the vertical direction of the reference hook rope. Hereinafter, a method of determining the rope compensation speed of each hook (Hook ₁ to Hook ₄ ) according to the angle difference will be described in detail with reference to FIGS. 10 and 11.

10 and 11 are diagrams illustrating a case where the ropes 322-1 to 322-4 of the hooks ₁ to ₄ have a predetermined angle θ _{i with} respect to the vertical direction.

Referring to FIG. 11, the vertical compensation speed RV _i of the hook ₁ is RV _pi · cosθ _i . Here, RV _pi is the compensation speed in the pivot direction, and the vertical component of RV _pi coincides with the vertical compensation speed RV _i .

)는 다음과 같다.Hoist La (x _i, y _i, z _i), the coordinates r _i of the coordinates R _pi of the rope 322, the starting point of pivot _i (xp _i, yp _i, zp _i), Hook _i (Fig. 32 in Fig. 2) The pivot direction vector r _pi is obtained by subtracting the coordinate r _i of Hook _i from the coordinate R _pi of pivot _i . In addition, the pivot direction unit vector (

) Is as follows.

)를 곱한 값이다. 여기서, 연직방향 단위벡터(

)는 (0,0,1)이다.cosθ _i is the pivot unit vector r _pi and the vertical unit vector (

Multiplied by). Where the vertical unit vector (

) Is (0,0,1).

Therefore, the pivot direction compensation speed RV _pi can be determined by the following equation (4).

12 is a view illustrating a state in which a hook is lifted to a cargo 100 formed of a ship. As shown in the drawing, the first hook 323-1 and the second hook 323-2 do not have the same horizontality but have a height difference. Therefore, when the cargo rotates during transportation of the cargo 100, the height difference of each hook based on the inclination value of the tilt detection unit 50 should reflect the height difference of the initial state to obtain the height difference generated by the rotation substantially. Can be. That is, as shown in FIG. 9, when the initial state of the cargo 100 is horizontal, the height difference of the initial state should be considered to the height difference obtained by simply comparing the height of the reference hook.

In FIG. 12, when the first hook 323-1 is set as a reference hook, and the inclination detection unit 50 is disposed on the same plane, the position of the first hook is (x ₁ , y ₁ , 0), The position of the second hook 323-2 is (x ₂ , y ₂ , z ₂ ) and the initial height difference is Z ₂ . Then, after calculating the height difference according to the rotation during the transport of the cargo 100, the compensation speed is determined by subtracting the initial height difference (Z ₂ ).

FIG. 13 is a diagram illustrating a Labview program for determining a speed of winding or unwinding a rope according to the height of each hook in real time during transportation of cargo 100 according to an embodiment of the present invention. As shown, after setting and storing the initial position (coordinate) of the n hooks, and receives the inclination value in real time. Real-time gradient values are converted into tan_ix and tan_iy. The height of each hook is measured by applying tan_ix and tan_iy and initial coordinates (x _i , y _i , z _i ) to Equation 1. The hook with the largest height among the plurality of hooks is selected and set as the reference hook, and then the reference hook height site is obtained as the height difference between the other hooks. Finally, the compensation speeds (RV1, RV2, RV3, RV4) of winding or unwinding the rope of each hook are determined by Equation 3.

In FIG. 13, when the tilt value is smaller than 1/10 radians, the height of each hook may be measured by applying the tilt values θ _Ix , θ _Iy and the initial coordinates (x _i , y _i , z _i ) to Equation 2. have.

As described above, the present invention has been described through limited exemplary embodiments and drawings, but the present invention is not limited to the exemplary embodiments described above, and those skilled in the art to which the present invention pertains can various Modifications and variations are possible.

Therefore, the scope of the present invention should not be limited to the described exemplary embodiments, but should be defined not only by the claims below, but also by the equivalents of the claims.

1: crane
20: girder
30: trolley
32: hoist
322: rope
323: hook
324: winch drum
326: motor
40: control unit
50: tilt detection unit
100: cargo (spreader)

Claims (5)

In the control method of a crane for carrying a plurality of hooks each provided on a plurality of ropes on a cargo,
Arranging an inclination detection unit for detecting an inclination of the cargo and setting initial coordinates of each of the plurality of hooks;
Receiving an inclination value of the cargo from the inclination detection unit during transportation of the cargo, and obtaining moving coordinates of each of the plurality of hooks based on the inclination value;
Comparing the moving coordinates and the initial coordinates of the plurality of hooks to obtain a height of each of the plurality of hooks;
Obtaining a height difference of the other hooks from the height of the reference hook;
Compensating for the winding or unwinding speed of each of the ropes of the other hook according to the height difference based on the speed of winding or unwinding the rope of the reference hook,
The step of obtaining the height difference crane control method that reflects the initial height difference of the plurality of hooks. The method of claim 1,
Obtaining an angle of each of said plurality of ropes in a vertical direction;
Obtaining an angle difference of each of the other ropes relative to the reference rope;
Compensating for the winding or unwinding speed of each of the ropes of the other hook according to the angle difference based on the speed of winding or unwinding the rope of the reference hook. delete In the crane for carrying the cargo by hooking a plurality of hooks each provided on a plurality of ropes,
A hoist for winding or unwinding the plurality of ropes;
A tilt detection unit for detecting a tilt of the cargo;
Set initial coordinates of each of the plurality of hooks,
Receiving the inclination value of the cargo from the inclination detection unit while winding or unwinding the rope, to obtain the moving coordinates of each of the plurality of hooks based on the inclination value,
Comparing the moving coordinates and the initial coordinates of the plurality of hooks to obtain the height of each of the plurality of hooks,
Get the height difference of the other hooks relative to the height of the reference hook,
And a controller configured to control the hoist to compensate for the winding or unwinding speed of each of the ropes of the other hook according to the height difference based on the speed of winding or unwinding the rope of the reference hook. The method of claim 4, wherein
The height Zi of each of the plurality of hooks is obtained from the following equation.

Here, θ _ix and θ _iy are the x-axis, y-axis rotation angles, x _i , y _i , z _i obtained from the tilt detection unit, respectively, and are initial coordinate values of the plurality of hooks.

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