JP7477034B1 - CRANE CONTROL SYSTEM, CONTROL DEVICE, AND CONTROL METHOD - Google Patents

Abstract

[Problem] To improve work efficiency. [Solution] A crane control system according to one aspect of the present disclosure includes a crane having a boom that can be extended and hoisted, a support part to which the boom is connected and which can be rotated, and a control device for controlling the crane, the control device being configured to perform at least one of telescopic control and rotation control of the boom when a specific part of the boom is moved to a target point, and if the specific part cannot reach the target point, to update the height coordinate of the target point, and to perform hoisting control of the boom to reach the target point including the updated coordinate. [Selected Figure] Figure 1

Description

The present invention relates to a crane control system, a control device, and a control method.

Technologies have been proposed for setting transport routes when transporting suspended loads using a crane. For example, there is a technology for setting transport routes so as to avoid entering prohibited areas (for example, Patent Document 1).

JP 2021-147139 A

However, conventional technologies such as those disclosed in Patent Document 1 are technologies that set a transport route within a movable range so as to prevent the load from approaching a three-dimensional no-approach zone in which obstacles are set, but are not technologies that set a route taking into account the structure of the crane. For this reason, structural constraints of the crane boom can make it difficult to move the load along the route.

One aspect of the present invention is to improve work efficiency by performing control that takes into account the boom structure.

A crane control system according to one aspect of the present invention comprises a crane having a boom that can be extended and lowered, and a support part to which the boom is connected and which can be rotated, and a control device for controlling the crane, wherein the control device is configured to perform at least one of telescopic control and rotation control of the boom when moving a specific part of the boom to a target point, calculate a length of the boom for reaching the specific part to the target point, determine whether the specific part can reach the target point depending on whether the boom can be extended or lowered to the calculated length, and when the boom is at its shortest, move the specific part further toward the center of rotation, so that if it is determined that the specific part cannot reach the target point, update the height coordinate of the target point, and control raising the boom to reach the target point including the updated coordinate.

According to one aspect of the present invention, work efficiency is improved by controlling the vehicle to reach the target location.

FIG. 1 is a side view of a crane according to a first embodiment. FIG. 1 is a diagram illustrating an example of the configuration of a crane control system according to a first embodiment. FIG. 2 is a conceptual diagram showing a travel route generated by a route generating unit according to the first embodiment. 4 is a conceptual diagram illustrating a movement path generated by a path generating unit according to the first embodiment, in an XY plane. FIG. 6 is a diagram illustrating relay points set by a coordinate setting unit according to the first embodiment; FIG. 6 is a diagram illustrating relay points set by a coordinate setting unit according to the first embodiment; FIG. 11 is a diagram illustrating a relay point after being updated by a coordinate update unit according to the first embodiment; FIG. 4 is a flowchart showing a processing procedure by a calculation unit of the PLC according to the first embodiment.

The following describes an embodiment of the present invention with reference to the drawings. The embodiments described below are illustrative and do not limit the invention, and all features and combinations described in the embodiments are not necessarily essential to the invention. In addition, identical or corresponding components in each drawing are denoted by identical or corresponding reference numerals, and descriptions thereof may be omitted.

In the following embodiment of the present invention, an example is described in which a crane is used as an example of a work machine that lifts a load while moving the load. In this embodiment, an example is described in which a jib crane is used as an example of a crane, but this is not limited to a crane, and the crane may be, for example, a tower crane or a rotary crane.

First Embodiment
An overview of a crane included in a crane control system according to this embodiment will be described with reference to Fig. 1. Fig. 1 is a side view of a crane according to this embodiment.

As shown in FIG. 1, the crane 100 includes a post 1, a boom 2, a hoisting rope 31, a hoisting rope 32, a winch 4, and a hook 5. A PLC (Programmable Logic Controller) 200 is connected to the crane 100. The PLC 200 is provided to control the crane 100.

The winch 4 includes a first winch 41 and a second winch 42.

The first winch 41 supports the boom 2 via the hoisting rope 31. The first winch 41 changes the hoisting state (hoisting angle) of the boom 2 by winding up or down the hoisting rope 31.

The second winch 42 supports the hook 5 via a hoisting rope 32 hung on a sheave 24 (not shown) at the tip of the boom 2. The hoisting rope 32 extends downward from the tip Pc of the boom 2, and has a hook 5 attached to its lower end. For example, a load 6 may be suspended from the hook 5.

The second winch 42 raises and lowers the hook 5 by winding up or down the hanging rope 32. In other words, it can move the suspended load 6 in the height direction (Z-axis direction).

The post 1 is an example of a support member fixed to the ground (an example of a horizontal surface) S, and connects the boom 2 so that it can rotate up and down. The post 1 is composed of an upper body portion 11 and a lower body portion 12. The upper body portion 11 and the lower body portion 12 are connected by an actuator 13 (see Figure 2) so that they can rotate relative to the ground S. The actuator 13 rotates the upper body portion 11 relative to the lower body portion 12, thereby controlling the rotation of the boom 2.

The boom 2 is composed of a first-stage boom 21 and a second-stage boom 22. The first-stage boom 21 and the second-stage boom 22 are connected by a hydraulic cylinder 23 (see FIG. 2) so that they can be extended and retracted. In this embodiment, an example in which the boom 2 is composed of two stages will be described, but the boom 2 is not limited to two stages and may be, for example, three or more stages.

The length L of the boom 2 is the length from the center of the foot pin Pf to the tip Pc of the boom 2. In this embodiment, the length L of the boom 2 can be changed by hydraulic control of the hydraulic cylinder. In this embodiment, the shortest length of the boom 2 is the minimum boom length Lmin, and the longest length of the boom 2 is the maximum boom length Lmax.

The boom 2 is also arranged to be rotatable (raised and hoisted) in the vertical direction around the fulcrum of the foot pin Pf attached to the upper body 11. The vertical rotation (hoisting operation) of the boom 2 is performed by winding up or down the hoisting rope 31 with the first winch 41.

As described above, the crane 100 according to this embodiment is configured to be able to move three-dimensionally by rotating, raising and lowering, and extending the boom 2. Note that the crane 100 according to this embodiment is merely an example, and is not limited to the above-mentioned configuration. Any crane that can apply the control according to this embodiment is able to rotate, raise and lower, and extend the boom.

The PLC 200 according to this embodiment controls the crane 100 based on the position of the tip Pc of the boom 2. The Cartesian coordinate system used for calculations in this embodiment is a coordinate system in three-dimensional space with the crane 100 as the reference. The Cartesian coordinate system is, for example, an XYZ space with the origin O, which is the center of rotation, as the reference. In the XYZ space, the Z axis is the axis in the height direction, and the XY plane (an example of a two-dimensional coordinate plane including the X and Y axes) is a plane approximately parallel to the ground surface S (an example of a horizontal plane).

In this embodiment, the distance b is the distance between the fulcrum of the foot pin Pf and the origin O. In this embodiment, the distance b is a negative value.

Next, the control system for the crane 100 according to this embodiment will be described. Figure 2 is a diagram showing an example of the configuration of the crane control system SYS according to this embodiment.

As shown in FIG. 2, the crane control system SYS is composed of a crane 100, a PLC 200, and an input device 300.

The crane 100 has the external appearance shown in FIG. 1, and includes, as a control system, a rotation angle detector S11, a boom length measuring instrument S12, a boom angle measuring instrument S13, a hoisting rope length measuring instrument S14, an actuator 13, a hydraulic cylinder 23, a first winch 41, and a second winch 42.

The rotation angle detector S11 detects the rotation angle of the upper body part 11 relative to the lower body part 12 and transmits the detected rotation angle to the PLC 200.

The boom length measuring device S12 calculates the length L of the boom 2 based on the operation of the hydraulic cylinder 23, etc., and transmits the length L of the boom 2 to the PLC 200.

The boom angle measuring device S13 calculates the boom hoisting angle of the boom 2 based on the state of the first winch 41 (a detection value detected by an encoder, etc.) and transmits the boom hoisting angle to the PLC 200.

The hoisting rope length measuring device S14 calculates the length λ of the hoisting rope 32 to the suspended load 6 based on the state of the second winch 42 (a detection value detected by an encoder, etc.), and transmits the length λ of the hoisting rope 32 to the suspended load 6 to the PLC 200.

The input device 300 is a device that allows an operator to input information to the PLC 200. The input device 300 may include, for example, an operating lever for operating the crane 100. The input device 300 may also include a touch panel or the like that allows an operator to input information by touching a screen displayed on a display device (not shown).

For example, when the crane 100 performs autonomous control, the input device 300 accepts input of coordinates indicating a target point of the tip Pc of the boom 2 or the suspended load 6, and outputs coordinate information indicating the target point to the PLC 200. The coordinate information indicating the target point may be, for example, position coordinates in a coordinate system of a three-dimensional space based on the crane 100, as described above. The coordinate information indicating the target point may be coordinates on an XY plane. Furthermore, the coordinate information indicating the target point may be input as any point on the ground surface.

As another example, the input device 300 may be provided with an operating lever that can be tilted in a direction included in a two-dimensional coordinate plane, and the crane 100 may move the tip Pc of the boom 2 in the tilt direction of the operating lever. In this case, the input device 300 may output a signal indicating the tilt direction of the operating lever (a direction included in the two-dimensional coordinate plane) to the PLC 200.

PLC 200 is a control device for controlling crane 100. It includes an input interface 201, an output interface 202, and a calculation unit 203. In FIG. 2, PLC 200 is shown as being provided outside crane 100, but it may be provided inside crane 100.

The PLC 200 controls the crane to move the tip Pc (an example of a specified part) of the boom 2 to the target point. For example, the PLC 200 performs rotation control, extension control, and elevation control of the boom 2 when moving the tip Pc (an example of a specified part) of the boom 2 to the target point. In this embodiment, an example of performing rotation control, extension control, and elevation control of the boom 2 will be described. Note that this embodiment is not limited to a method of performing all of the rotation control, extension control, and elevation control simultaneously, but rather, it is sufficient if elevation control can be performed as necessary at least while the rotation control or extension control of the boom 2 is being performed.

The PLC 200 has a program for controlling the crane 100 stored in the memory, and the calculation unit 203 reads the program to realize an acquisition unit 211, a path generation unit 212, a coordinate setting unit 213, a coordinate system calculation unit 214, and an output control unit 215. This allows the calculation unit 203 to perform rotation control, extension control, and elevation control of the boom 2.

The acquisition unit 211 acquires various information based on signals received from various detectors and measuring instruments provided on the crane 100 via the input interface 201.

For example, the acquisition unit 211 may acquire the current position of the tip Pc of the boom 2 based on the rotation angle received from the rotation angle detector S11, the length L of the boom 2 received from the boom length measuring instrument S12, and the elevation angle of the boom 2 received from the boom angle measuring instrument S13.

The acquisition unit 211 may also acquire the current position of the load 6 based on the length λ of the suspension rope 32 and the current position of the tip Pc of the boom 2 received from the suspension rope length measuring device S14.

For example, the acquisition unit 211 acquires coordinate information indicating the target point of the tip Pc of the boom 2 based on coordinate information input as the target position (of the tip Pc of the boom 2 or the load 6) from the input device 300 or a device capable of communicating with the PLC 200. As another example, when a signal indicating the tilt direction of the above-mentioned operating lever is input from the input device 300, the acquisition unit 211 acquires as the target point a point that is moved a predetermined distance from the current value of the tip Pc of the boom 2 in the input direction.

The path generating unit 212 generates a movement path from the current position (an example of a starting position) of the tip Pc of the boom 2 (an example of a specified part) to the target point. The movement path generated by the path generating unit 212 may have any shape, and may be, for example, a straight line connecting the current position to the target point. Note that in this embodiment, an example of generating a movement path for the tip Pc of the boom 2 is described, but the target for which the movement path is generated may be any specified part of the boom 2 and is not limited to the tip Pc.

Figure 3 is a conceptual diagram showing a movement path generated by the path generation unit 212 according to this embodiment. The example shown in Figure 3 shows a schematic diagram of the movement of the boom 2 in a three-dimensional space based on the origin O.

Specifically, it shows boom 2A at the current location before starting movement, and boom 2B after moving to the target location.

The current position of the tip Pc of the boom 2A at the current point is indicated as the initial coordinates Ps (Xs, Ys, Zs). The boom 2A is at a hoisting angle γs.

The target point of the tip Pc of the boom 2B at the target point is indicated by the coordinates Pe (Xe, Ye, Ze). The boom 2B is at a hoisting angle γe.

In the example shown in FIG. 3, the path generation unit 212 generates a movement path 1310 that shows a straight line from the initial coordinates Ps (Xs, Ys, Zs) of the current point to the coordinates Pe (Xe, Ye, Ze) of the target point. Note that the hoisting angle γs and the hoisting angle γe of the boom 2A may be the same or different.

Figure 4 is a conceptual diagram showing the movement path generated by the path generation unit 212 according to this embodiment on the XY plane. In the example shown in Figure 4, the movement of the boom 2 is shown generally on the XY plane based on the origin O.

The current position of the tip Pc of the boom 2A at the current point is indicated as the initial coordinates Ps (Xs, Ys, Zs). The rotation angle of the boom 2A based on the Y axis is θs.

The target point of the tip Pc of the boom 2B at the target point is indicated by the coordinates Pe (Xe, Ye, Ze). The rotation angle of the boom 2A based on the Y axis is θe.

The coordinate setting unit 213 sets multiple relay points along the movement path 1310 through which the tip Pc moves.

FIG. 5 is a diagram illustrating relay points set by the coordinate setting unit 213 according to this embodiment. In the example shown in FIG. 5, relay points P1 to P15 set by the coordinate setting unit 213 are shown between the initial coordinate Ps (Xs, Ys, Zs) and the coordinate Pe (Xe, Ye, Ze) of the target point on the movement path 1310 projected onto the XY plane based on the origin O. As shown in FIG. 5, relay points P1 to P15 are set to be equally spaced on the movement path 1310. Note that this embodiment describes an example in which relay points P1 to P15 are set at equal intervals, but is not limited to a method of setting them at equal intervals. For example, the intervals between relay points may be set taking into account the speed of the tip Pc.

The relay points P1 to P15 are used as the destination of the tip Pc. For example, when the tip Pc is at the initial coordinates Ps (Xs, Ys, Zs), the relay point P1 is used as the destination. Then, when the tip Pc has moved to the relay point P1, the relay point P2 is used as the destination. The calculation unit 203 according to this embodiment repeats this control. Finally, when the tip Pc has moved to the relay point P15, the coordinates Pe (Xe, Ye, Ze) of the target point are used as the destination.

In the example shown in FIG. 5, the number of relay points is 15, but the number of relay points is not limited to 15. The number of relay points may be determined, for example, according to the length of the travel route or the user's settings. Next, the control for moving to the destination will be described.

The coordinate system calculation unit 214 includes a determination unit 221 and a coordinate update unit 222, and performs processing to convert the next destination of the tip Pc from an orthogonal coordinate system to a polar coordinate system in which the origin O is indicated on the axis about which the crane 100 rotates. This processing is performed to perform extension/retraction control, elevation control, and rotation control of the boom 2 based on the rotation center.

The coordinate system calculation unit 214 calculates the swing angle θt ^* , boom length Lt ^* , and boom hoisting angle γt ^* of the next destination of the tip Pc. The coordinates of the next destination in the orthogonal coordinate system are indicated as coordinate Pt ^* (Xt ^* , Yt ^* , Zt ^* ). The coordinate Pt ^* is the coordinate Pe of the relay points P1 to P15 or the target point described above. The coordinate system calculation unit 214 then calculates the swing angle θt ^* , boom length Lt ^* , and boom hoisting angle γt ^* of the destination from the destination coordinate Pt ^* (Xt ^* , Yt ^* , Zt ^* ).

As shown in Figures 4 and 5, in this embodiment, the rotation angle θ is based on the Y axis (in other words, it is offset by π/2 when the X axis is used as the reference), but this embodiment is merely an example, and the rotation angle may also be based on the X axis.

The coordinate system calculation unit 214 according to this embodiment calculates the turning angle θt ^* by the following equation (1).

The above-mentioned atan2 is a type of function used in a certain programming language, and means arctan that takes two arguments. In other words, the angle (radian) between the positive direction of the X-axis and the half line extended to (Xt ^* , Yt ^* ) is output from the formula (1).

The following formula (2) is established based on the case where the tip Pc is projected onto the XY plane: Note that, as described above, the distance b is a negative value.

From the formula (2), the following formula (3) can be derived. Therefore, cosγt ^* can be calculated.

Furthermore, sinγt ^* can be calculated from the following formula (4).

Equation (5) can be derived by substituting equation (3) and equation (4) into "cosγt ^*2 + sinγt ^*2 = 1" and transforming the equation.

Therefore, the coordinate system calculation unit 214 uses equation (5) to calculate the boom length Lt ^* required for the tip Pc to reach the next destination (the relay point or the target point). The calculated length Lt ^* must be equal to or greater than the minimum boom length Lmin and equal to or less than the maximum boom length Lmax in order to be matched by telescopic control.

Therefore, the determination unit 221 determines whether the calculated length Lt ^* is equal to or greater than the minimum boom length Lmin and equal to or less than the maximum boom length Lmax, in other words, whether it is within the extendable range of the boom 2 (whether it can be matched by extension/retraction control).

In this way, each time the tip Pc moves to a relay point, the determination unit 221 determines whether the tip Pc can reach the next destination (relay point or target point).

When the determination unit 221 determines that the calculated length Lt ^* is within the expandable range, in other words, that the coordinates of the tip Pc projected onto the XY plane can reach the coordinates of the relay point projected onto the XY plane, the coordinate system calculation unit 214 calculates γt ^* using the following equation (6).

However, if the calculated length Lt ^* is outside the extendable range, the tip Pc cannot move to the next destination point (the point indicated by the coordinates Pt ^* (Xt ^* , Yt ^* , Zt ^* )). Of the next destination points for the tip Pc of the boom 2, it is difficult to change the coordinates Xt ^* and Yt ^* . On the other hand, changing the coordinate Zt ^* can be done by winding up or down the hoisting rope 32, which maintains the vertical position of the load 6 and therefore maintains the destination of the load 6.

Therefore, in this embodiment, when the determination unit 221 determines that the condition is not satisfied, the coordinate update unit 222 updates the (height direction) coordinate Zt ^* of the next destination. In this embodiment, the updated coordinate is indicated as Zt ^** . In this manner, when the Z-axis coordinate of the next destination is updated, the calculation unit 203 performs hoisting control of the boom 2 to reach the next destination including the updated coordinate Zt ^** .

In other words, if the determination unit 221 determines that the coordinates of the tip Pc projected onto the XY plane are not within the extendable range, in other words, that the coordinates of the relay point projected onto the XY plane cannot be reached, the PLC 200 performs boom 2 raising and lowering control to allow the coordinates of the tip Pc projected onto the XY plane to reach the coordinates of the relay point projected onto the XY plane.

Specifically, equation (7) is used, which is a modified version of equation (5). The coordinate update unit 222 calculates the updated coordinate Zt ^** by substituting the minimum boom length Lmin or the maximum boom length Lmax for the length Lt ^* in equation (7). The coordinate update unit 222 then updates the coordinate Pt ^* (Xt ^* , Yt ^* , Zt ^** ) of the next destination.

Then, the coordinate system calculation unit 214 uses the following equation (8) to calculate the undulation angle γt ^* when the coordinate is updated to Zt ^** .

In other words, in this embodiment, if the calculated length Lt ^* cannot be achieved, the boom 2 is set to the minimum boom length Lmin or the maximum boom length Lmax and the coordinate Zt ^** is updated; in other words, by performing hoisting control of the boom 2, movement control of the boom 2 can be continued.

The coordinate system calculation unit 214 then calculates the swing angle θt ^* , boom length Lt ^* , and boom hoisting angle γt ^* of the next destination of the tip portion Pc through the above-mentioned calculations.

Furthermore, the coordinate system calculation unit 214 calculates the difference between the updated coordinate Zt ^** and the coordinate Zt ^** before the update as the adjustment amount λdef of the suspending rope 32. Then, the output control unit 215 described later generates and outputs a control signal for winding up or lowering the suspending rope 32 by the adjustment amount λdef. That is, in the crane 100 according to this embodiment, the height of the suspended load 6 is maintained by winding up or lowering the suspending rope 32 based on the updated coordinate of the height direction of the destination (relay point or target point). Note that this embodiment describes an example of adjusting the height of the suspended load 6 when the coordinate Zt ^** is updated, but is not limited to a method of adjusting the height of the suspended load 6 when the coordinate Zt ^** is updated. That is, the height of the suspended load 6 does not need to be changed in response to the update to the coordinate Zt ^** .

Thereafter, the output control unit 215 generates a command signal for the actuator 13 to set the swing angle θt ^* , a control signal for the hydraulic cylinder 23 to set the length Lt ^* of the boom 2, a control signal for the first winch 41 to set the hoisting angle γt ^* , and a control signal for the second winch 42 to wind up or wind down the hoisting rope 32 corresponding to the adjustment amount λdef. The output control unit 215 then outputs the generated control signals to the crane 100 via the output interface 202.

In this way, the output control unit 215 in this embodiment outputs various control signals to the crane 100 to perform one or more of the following: boom 2 extension/retraction control, boom 2 rotation control, boom 2 raising/lowering control, and lifting/lowering control of the suspension rope 32.

Next, changes in the destination of the tip Pc of the boom 2 will be described. Figure 6 is a diagram illustrating relay points set by the coordinate setting unit 213 according to this embodiment. In Figure 6, the tip Pc is set to an initial coordinate Ps1 and a target point coordinate Pe1. The coordinate setting unit 213 then sets relay points P51 to P69 between the initial coordinate Ps1 and the target point coordinate Pe1. Figure 6 shows an example in which 19 relay points are set. Note that the Z-axis coordinate between the initial coordinate Ps1 and the target point coordinate Pe1 is set to "0". Therefore, the coordinate setting unit 213 sets the Z-axis coordinate of relay points P51 to P69 to "0".

Then, each time the tip Pc of the boom 2 moves to each of the relay points P51 to P69, the determination unit 221 determines whether or not the length Lt ^* required to reach the next relay point satisfies the condition that it is equal to or greater than the minimum boom length Lmin and equal to or less than the maximum boom length Lmax. In other words, it determines whether or not the next relay point P51 to P69 can be reached. If it is determined that the length Lt ^* is smaller than the minimum boom length Lmin or larger than the maximum boom length Lmax, the Z-axis coordinate of the next relay point is updated. The update method is as described above, so a description thereof will be omitted.

Figure 7 is a diagram illustrating relay points after being updated by the coordinate update unit 222 according to this embodiment. In the example shown in Figure 7, a movement path is generated to move the tip Pc from the initial coordinate Ps1 to the coordinate Pe1 of the target point.

7, the determination unit 221 has determined that the length Lt* of the tip Pc from the initial coordinate Ps1 to the relay points P51 to P60 satisfies the condition that the length Lt ^* required to reach the next relay point is equal to or greater than the minimum boom length Lmin and equal to or less than the maximum boom length Lmax. Therefore, the Z-axis coordinates of the relay points were not updated.

The determination unit 221 then determines that the relay points P61 to P69 and the coordinate Pe1 of the target point do not satisfy the above conditions. As a result, the coordinate update unit 222 updates the Z-axis coordinates of the relay points P60 to P69 and the coordinate Pe1 of the target point, and the relay points are updated to P60 ^* to P69 ^* and the coordinate Pe1 ^* of the target point.

As shown in Figure 7, the relay points P60 ^* to P69 ^* and the coordinate Pe1 ^* of the target point are updated so that the Z-axis coordinate becomes higher as the coordinate Pe1 ^* of the target point is approached. In other words, since the boom 2 cannot be shortened any further, control is performed to raise the boom 2 as the coordinate Pe1 ^* of the target point is approached. This control allows the coordinate of the tip Pc projected onto the XY plane to reach the coordinate of the preset target point projected onto the XY plane.

In other words, the PLC 200 according to this embodiment controls the boom 2 to be raised when the tip Pc is moved further in the direction of the origin O (center of rotation) toward the target point when the boom 2 is at its shortest.

In the above-mentioned control example, an example of raising the boom 2 has been described. However, the PLC 200 according to this embodiment is not limited to the example of raising the boom 2. For example, the PLC 200 may control the boom 2 to extend in order to make the tip Pc of the boom 2 reach the target point. Then, when the boom 2 reaches the maximum boom length Lmax, the PLC 200 controls the boom 2 to be lowered in order to further move the tip Pc in the opposite direction of the origin O (center of rotation) toward the target point.

In other words, in the PLC 200, in order to make the tip Pc of the boom 2 reach the target point, if the determination unit 221 determines that the tip Pc cannot reach the target point through the extension and rotation control, the coordinate update unit 222 updates the height coordinate of the target point, and the output control unit 215 outputs a control signal to perform the raising and lowering control of the boom 2 to make the tip Pc reach the target point including the updated coordinate.

Then, the PLC 200 controls the winding up or winding down of the hoisting rope 32 based on the distance that the tip Pc position moves in the Z-axis direction (height direction) during the hoisting control of the boom 2. Specifically, the output control unit 215 outputs a control signal to the second winch 42 to control the winding up or winding down of the hoisting rope 32.

Next, the processing procedure in the calculation unit 203 of the PLC 200 will be described. FIG. 8 is a flowchart showing the processing procedure by the calculation unit 203 according to this embodiment.

First, the acquisition unit 211 acquires the initial coordinates (Xs, Ys, Zs) indicating the current position of the tip Pc of the boom 2 from signals from various sensors (detectors, measuring instruments) of the crane 100 (S1801).

Next, the acquisition unit 211 acquires the coordinates (Xe, Ye, Ze) of the target point of the tip Pc based on the information received from the input device 300 (S1802).

The route generation unit 212 generates a travel route for moving from the initial coordinates indicating the current position to the coordinates of the destination point (S1803).

The coordinate setting unit 213 sets each point that the tip Pc passes through as it moves along the generated movement path as a relay point (S1804).

Then, the calculation unit 203 starts controlling the movement of the boom 2 (S1805).

The coordinate system calculation unit 214 calculates the turning angle θt ^* of the next point (relay point or target point) based on the coordinates of the next point (S1806).

Next, the coordinate system calculation unit 214 calculates the length Lt ^* of the boom 2 at the next point based on the coordinates of the next point (relay point or target point) (S1807).

The determination unit 221 determines whether or not the calculated length Lt ^* of the boom 2 is within the extendable and contractible range of the boom 2 (S1808).

If the determination unit 221 determines that the calculated length Lt ^* of the boom 2 is within the extendable range of the boom 2 (S1808: YES), the coordinate system calculation unit 214 calculates the hoisting angle γt ^* based on the coordinates of the next point (relay point or target point) and the length Lt ^* of the boom 2 (S1809).

On the other hand, when the determination unit 221 determines that the calculated length Lt ^* of the boom 2 is not within the extendable range of the boom 2 (S1808: NO), the coordinate update unit 222 updates the length Lt ^* of the boom 2 to the minimum boom length Lmin or the maximum boom length Lmax (S1810). For example, the length Lt* is updated to the minimum boom length Lmin or the maximum boom length Lmax, whichever is closer to the current length of the boom 2.

Thereafter, the coordinate update unit 222 updates the Z-axis coordinate Zt ^** of the next point based on the updated length Lt ^* of the boom 2 (minimum boom length Lmin or maximum boom length Lmax) (S1811).

Thereafter, the coordinate system calculation unit 214 calculates the hoisting angle γt ^* based on the updated Z-axis coordinate Zt ^** and the length Lt ^* of the boom 2 (S1812).

Furthermore, the coordinate system calculation unit 214 calculates the adjustment amount λdef of the suspension rope 32 based on the updated Z-axis coordinate Zt ^** and the Z-axis coordinate Zt before the update (S1813).

Then, the output control unit 215 generates a control signal for moving to the next location and outputs it to the crane 100 (S1814). Therefore, a control signal for performing one or more of the rotation control, extension control, and elevation control for moving to the next location is generated and output.

Then, the calculation unit 203 judges whether the tip Pc of the boom 2 has reached the target point (S1815). If it is judged that the tip Pc has not reached the target point (S1815: NO), control is performed again from 1806.

On the other hand, if the calculation unit 203 determines that the tip Pc of the boom 2 has reached the target point (S1815: YES), it ends the processing.

As described above, in this embodiment, an example has been described in which the route generation unit 212 generates a travel route that connects the current location to the destination location in a straight line.

In addition, in this embodiment, the load 6 is moved in a straight line, so the operator can intuitively grasp the route of the load 6 to the target location at the work site, etc. Therefore, the operator can move the load 6 after recognizing objects, etc. that exist on the route to the target location, thereby improving safety. Furthermore, because the rotational movement of the load 6 is suppressed, centrifugal force, in other words, load, on the load 6 can be suppressed.

Conventionally, in order to move the load 6 along a travel path, the operator had to use the operating lever to perform a combination of telescopic control, swivel control, and elevation control. In contrast, in this embodiment, the load 6 can be moved in a straight line by performing the above-mentioned controls. As a result, when the operator wants to move the load 6 in a straight line, this can be achieved by simple operations or by setting a target point, regardless of the limitations imposed by the structure of the boom 2. In addition, by combining linear paths using the above-mentioned controls, it becomes easy to move the load 6 to the target point even when there are obstacles or only limited routes.

In this embodiment, an example has been described in which the path generation unit 212 generates a linear travel path to the target point. However, the path generation unit 212 is not limited to generating a linear travel path, and may generate a travel path using, for example, a combination of multiple ellipses, circles, free curves, or line segments.

Conventionally, operators have been requesting to move a suspended load along an arbitrary route. However, there are limitations to moving a suspended load along an arbitrary route due to the boom structure. In contrast, in this embodiment, when the tip of the boom cannot reach the target point, the above-mentioned control is performed, making it possible to make the suspended load reach the target point regardless of the limitations of the boom structure. In other words, the area in which the suspended load can be moved can be expanded. In the above-mentioned embodiment, the boom hoisting control is performed when the tip of the boom cannot reach the target point by the boom extension and contraction control. However, the above-mentioned embodiment is not limited to the case where the tip of the boom cannot reach the target point by the boom extension and contraction control. For example, when the tip of the boom cannot reach the target point due to the relationship between an obstacle and the boom structure, the height coordinate of the target point may be updated, and the boom hoisting control may be performed to reach the updated target point.

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In the above-described embodiment, the target point can be reached by updating the height coordinates of points included in the movement path in consideration of the boom structure. In other words, in the above-described embodiment, it is possible to make the load reach the target point, thereby improving workability.

In the above-described embodiment, the PLC can combine two or more of the rotation control, extension control, and elevation control to generate a movement path for moving the tip of the boom to a target location. This eliminates the need for the operator to perform complex operations, reducing the burden on the operator.

In addition, in the above-described embodiment, the calculation unit calculates the rotation angle, boom length, and elevation angle for the tip to reach the next point (relay point or target point) using the calculation method using the above-described trigonometric functions. The calculation unit can make the tip reach the target point by repeating this calculation. In other words, in the above-described embodiment, the movement of the crane can be controlled using a calculation method such as trigonometric functions, which has a low calculation load and is easy to implement, in a PLC or the like. Therefore, the PLC according to the above-described embodiment can move the tip to the target point while performing calculations in real time. In other words, there is no need to use a control device with high calculation performance, which can reduce costs.

Although the above describes the embodiments of the crane control system, control device, and control method according to the present invention, the present invention is not limited to the above-mentioned embodiments. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. Naturally, these also fall within the technical scope of the present invention.

REFERENCE SIGNS LIST 100 Crane 1 Post 11 Upper body 12 Lower body 13 Actuator 2 Boom 21 First boom stage 22 Second boom stage 23 Hydraulic cylinder 31 Hoisting rope 32 Suspension rope 41 First winch 42 Second winch 5 Hook Pc Boom tip 200 PLC
211 Acquisition unit 212 Path generation unit 213 Coordinate setting unit 214 Coordinate system calculation unit 215 Output control unit 221 Determination unit 222 Coordinate update unit 300 Input device S11 Swing angle detector S12 Boom length measuring device S13 Boom angle measuring device S14 Suspension rope length measuring device

Claims (11)

A crane having a boom that can be extended and lowered, and a support part that connects the boom and is rotatable;
A control device for controlling the crane,
The control device performs at least one of telescopic control and rotation control of the boom when moving the predetermined portion of the boom to a target point,
calculating a length of the boom for causing the predetermined portion to reach the target point, and determining whether the predetermined portion can reach the target point depending on whether the boom can be extended or retracted to the calculated length;
When the boom is at its shortest, the specific part is further moved toward the center of rotation. Therefore, if it is determined that the specific part cannot reach the target point, the coordinate of the target point in the height direction is updated, and control is performed to raise the boom to reach the target point including the updated coordinate.
Crane control system. A crane having a boom that can be extended and lowered, and a support part that connects the boom and is rotatable;
A control device for controlling the crane,
The control device performs at least one of telescopic control and rotation control of the boom when moving the predetermined portion of the boom to a target point,
calculating a length of the boom for causing the predetermined portion to reach the target point, and determining whether the predetermined portion can reach the target point depending on whether the boom can be extended or retracted to the calculated length;
When the boom is at its longest, the specific part is further moved in the direction opposite to the center of rotation. Therefore, if it is determined that the specific part cannot reach the target point, the coordinate of the target point in the height direction is updated, and control is performed to lower the boom to reach the target point including the updated coordinate .
Crane control system. A crane having a boom that can be extended and lowered, and a support part that connects the boom and is rotatable;
A control device for controlling the crane,
the control device performs at least one of telescopic control and rotation control of the boom to move a predetermined portion of the boom to a target point, generates a route along which the predetermined portion will move to the target point, and sets a plurality of relay points along the route;
Each time the predetermined part moves to the relay point, it is determined whether or not the predetermined part can reach the relay point of the next destination , and if it is determined that the predetermined part cannot reach the relay point , the height coordinate of the relay point of the next destination is updated, and control of raising and lowering the boom is performed to reach the relay point of the next destination including the updated coordinate;
When moving to the target point, it is determined whether or not the predetermined part can reach the target point, and if it is determined that the predetermined part cannot reach the target point, a coordinate in a height direction of the target point is updated, and control of raising and lowering the boom is performed to reach the target point including the updated coordinate.
Crane control system. The control device generates the path for moving the predetermined portion in a straight line from a start position to the target point.
The crane control system of claim 3 . the control device calculates a length of the boom for causing the predetermined part to reach the relay point of the next destination every time the control device moves to the relay point, and determines whether the predetermined part can reach the relay point of the next destination depending on whether the boom can be extended or retracted to the calculated length.
The crane control system of claim 3 . A control device for controlling a crane including a boom that can be extended and lowered, and a support part to which the boom is connected and which can be rotated,
an output control unit that outputs a control signal to the crane to perform at least one of telescopic control and rotation control of the boom when a predetermined portion of the boom is moved to a target point;
A calculation unit that calculates a length of the boom for reaching the predetermined portion to the target point;
a determination unit that determines whether the predetermined portion can reach the target point depending on whether the boom can be extended or retracted to the calculated length;
an update unit that updates a coordinate of the target point in a height direction when it is determined that the specific part cannot reach the target point because the specific part is further moved toward the center of rotation when the boom is at its shortest position,
The output control unit outputs a control signal to the crane for controlling the raising of the boom so as to reach the target point including the updated coordinates.
Crane control device. A control device for controlling a crane having a boom that can be extended and lowered, and a support part to which the boom is connected and which can be rotated, comprising:
an output control unit that outputs a control signal to the crane to perform at least one of telescopic control and rotation control of the boom when a predetermined portion of the boom is moved to a target point;
A calculation unit that calculates a length of the boom for reaching the predetermined portion to the target point;
a determination unit that determines whether the predetermined portion can reach the target point depending on whether the boom can be extended or retracted to the calculated length;
and an update unit that updates a coordinate of the target point in a height direction when it is determined that the specific part cannot reach the target point because the specific part is further moved in a direction opposite to the center of rotation when the boom is at its longest,
The output control unit outputs a control signal to the crane for controlling the lowering of the boom in order to reach the target point including the updated coordinates.
Crane control device. A control device for controlling a crane having a boom that can be extended and lowered, and a support part to which the boom is connected and which can be rotated, comprising:
an output control unit that outputs a control signal to the crane to perform at least one of telescopic control and rotation control of the boom when a predetermined portion of the boom is moved to a target point;
a route generating unit that generates a route for the specific unit to travel to the target point;
A setting unit that sets a plurality of relay points along the route;
a determination unit that determines whether the predetermined unit can reach the relay point of a next destination every time the predetermined unit moves to the relay point;
an update unit that updates a coordinate in a height direction of the relay point of the next destination when it is determined that the relay point is not reachable;
the output control unit outputs a control signal for controlling the boom to be raised and lowered to the crane so that the crane reaches the relay point, which is a next destination, including the updated coordinates;
The determination unit further determines whether or not the predetermined unit can reach the destination point when moving to the destination point,
The update unit further updates a coordinate of the target point in a height direction when it is determined that the predetermined unit cannot reach the target point;
The output control unit is further configured to perform boom hoisting control to reach the target point including the updated coordinates when it is determined that the target point cannot be reached.
Crane control device. A control method for controlling a crane including a boom that can be extended and extended and a support part that can be rotated and is connected to the boom, the method comprising the steps of:
When moving a predetermined portion of the boom to a target point, at least one of telescopic control and rotation control of the boom is performed;
Calculating a length of the boom for causing the predetermined portion to reach the target point;
determining whether the predetermined portion can reach the target point depending on whether the boom can be extended or retracted to the calculated length;
When the boom is at its shortest, the specific part is further moved toward the center of rotation. Therefore, if it is determined that the specific part cannot reach the target point, the coordinate of the target point in the height direction is updated.
controlling the boom to reach the target point including the updated coordinates;
How to control a crane. A control method for controlling a crane including a boom that can be extended and extended and a support part that can be rotated and is connected to the boom, the method comprising the steps of:
When moving a predetermined portion of the boom to a target point, at least one of telescopic control and rotation control of the boom is performed;
calculating a length of the boom for causing the predetermined portion to reach the target point, and determining whether the predetermined portion can reach the target point depending on whether the boom can be extended or retracted to the calculated length;
When the boom is at its longest, the specific part is further moved in the direction opposite to the center of rotation. If it is determined that the specific part cannot reach the target point, the coordinate of the target point in the height direction is updated.
performing control to lower the boom so as to reach the target point including the updated coordinates;
How to control a crane. A control method for controlling a crane including a boom that can be extended and extended and a support part that can be rotated and is connected to the boom, the method comprising the steps of:
When moving a predetermined portion of the boom to a target point, at least one of telescopic control and rotation control of the boom is performed;
generating a route for the predetermined portion to travel to the target point;
Setting a plurality of waypoints along the route;
Each time the predetermined part moves to the relay point, it is determined whether or not the predetermined part can reach the relay point of the next destination, and if it is determined that the predetermined part cannot reach the relay point, the height coordinate of the relay point of the next destination is updated, and control of raising and lowering the boom is performed to reach the relay point of the next destination including the updated coordinate;
When moving to the target point, it is determined whether or not the predetermined part can reach the target point, and if it is determined that the predetermined part cannot reach the target point, a coordinate in a height direction of the target point is updated, and control of raising and lowering the boom is performed to reach the target point including the updated coordinate.
How to control a crane.

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