Control arithmetic unit and crane

Abstract

To provide a novel crane capable of suppressing double pendulum load swing of a suspended load and a hook.SOLUTION: A crane has a crane model calculation unit that calculates the load speed from a speed of the horizontal movement device based on a double pendulum model consisting of a hook and a load, a first sway suppression control unit that calculates a first speed command value for the horizontal movement device that suppresses the crane's first-mode sway from the target speed of the load and the load speed of the crane model calculation unit, and a notch filter that calculates a second speed command value from the first speed command value, using the crane's second-mode sway frequency as the cutoff frequency, to suppress the crane's second-mode sway. The second speed command value from the notch filter is output to the crane model calculation unit and the horizontal movement control unit.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The present invention relates to a crane that suspends and transports a load, and a crane control method, and more particularly to a crane that has a function of suppressing swing of the load, and a crane control method. [Background technology]

[0002] In recent years, due to the aging of experienced crane operators and labor shortages caused by the increasing number of installed cranes, there has been an increase in cases where inexperienced operators who are unfamiliar with the operation are operating cranes. Unskilled operators are not adept at operating the anti-sway operation to stop the swing of the suspended load (load sway), which increases the risk of collision accidents with the suspended load or accidents involving being pinched by the suspended load. In addition, it takes time for the load sway to stop, which increases the work time. Therefore, there is a need for technology that automatically suppresses load sway to improve safety and shorten work time.

[0003] Known technologies for automatically suppressing load sway include the load sway suppression technology (hereinafter referred to as Prior Art 1) disclosed in Patent Document 1 (JP Patent Publication No. 2018-2391) and Non-Patent Document 1 (Zhang et al., "Control of Motion and Vibration of Crane Systems with Variable Length Using IDCS," Proceedings of the 54th Joint Conference on Automatic Control (2011)).

[0004] Patent Document 1 discloses load sway suppression control in a crane having a hoisting device that moves a load up and down by winding up and down a rope that suspends the load, a horizontal movement device that moves the load to which the hoisting device is attached in the horizontal direction, and an operation input device for inputting a target speed of the load, in which a model speed of the load is calculated based on the target horizontal speed of the load and a crane model, and a speed command value for the horizontal movement device is calculated and controlled so that the target speed of the load and the model speed match or approach each other. Non-Patent Document 1 also discloses a method for designing a controller using the DMM method (Dual Model Matching method).

[0005] Furthermore, separately from this, Patent Document 2 (JP 2021-75372 A / hereinafter referred to as Prior Art 2) discloses a method of suppressing load sway when the horizontal movement device is stopped by counteracting the load sway caused by deceleration and load sway when the device starts to stop, with subsequent acceleration or deceleration. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2018-2391 [Patent Document 2] Patent Publication No. 2021-75372 [Non-patent literature]

[0007] [Non-Patent Document 1] Zhang et al., Motion and Vibration Control of a Crane System with Variable Length Using IDCS, Proceedings of the 54th Joint Conference on Automatic Control (2011) Summary of the Invention [Problem to be solved by the invention]

[0008] When a crane transports a load, a hook is attached to the end of the rope, and the load is suspended from the hook via a sling or a sling wire, or directly from the hook. As a result, the crane experiences a double pendulum swing, with the hook swinging around the rope's center of rotation as the fulcrum, and the load swinging around the hook as the fulcrum.

[0009] If the hook sways, the load will rotate around its center of gravity, making it unstable, and there is also the risk of the sling and sling wire wearing out or coming off the hook. For this reason, it is also necessary to suppress hook sway.

[0010] In the above-mentioned prior art 1 and prior art 2, the suspended load is modeled as a simple pendulum that swings around the rotation center of the rope as a fulcrum, and control is performed to suppress the load swing. However, these technologies alone cannot suppress double pendulum load swing.

[0011] The present invention has been made in view of the above problems, and an object of the present invention is to provide a crane and a method for controlling a crane that can suppress double pendulum load swing between the hook and the suspended load. [Means for solving the problem]

[0012] In the present invention, A crane having a hoisting device that moves a suspended load attached to a hook at the end of a rope via a sling wire or directly to the hook in a vertical direction by hoisting / lowering the rope, a horizontal movement device to which the hoisting device is attached and that moves the suspended load in a horizontal direction, an operation input device for inputting a target speed of the suspended load, a speed command value calculation device that generates a speed command value for the horizontal movement device based on the input target speed, and a horizontal movement control device that controls the speed of the horizontal movement device in accordance with the speed command value, The speed command value calculation device a crane model calculation device that calculates the lifting speed of the load from a speed command value of the horizontal movement device based on a double pendulum model in which a double pendulum is formed by the swing of the hook with the rotation center of the rope as a fulcrum and the swing of the load with the hook as a fulcrum; a first sway suppression control device that calculates a first speed command value that suppresses sway of the first mode of the crane from a target speed of the load and the load speed of the crane model calculation device; a second sway suppression control device that calculates a second speed command value that suppresses second-order mode sway of the crane from a first speed command value from the first sway suppression control device and a lifting load speed from the crane model calculation device, The second speed command value from the second vibration suppression control device is input to the crane model calculation device and the horizontal movement device. This is a crane characterized by the following. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a crane and a method for controlling a crane that can suppress double pendulum load swing between a hook and a suspended load. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a configuration diagram showing the configuration of a crane to which the present invention is applied; [Figure 2] 1 is a block diagram showing the configuration of a crane control device to which the present invention is applied. [Figure 3] FIG. 1 is a model diagram illustrating a prior art crane model. [Figure 4] FIG. 1 is a block diagram showing the configuration of a speed command value calculation device when Prior Art 1 is applied. [Figure 5] 10 is an example of the calculation results of the time response of the load swing amount and the relative swing amount when Prior Art 1 is applied. [Figure 6] FIG. 10 is a block diagram showing the configuration of a speed command value calculation device when Prior Art 2 is applied. [Figure 7] FIG. 10 is a diagram showing the trolley speed when prior art 2 is applied. [Figure 8] 10 is an example of the calculation results of the time response of the load swing amount and relative swing amount when Prior Art 2 is applied. [Figure 9] FIG. 2 is a model diagram illustrating a crane model according to the present invention. [Figure 10] 1 is a block diagram showing a configuration of a speed command value calculation device according to a first embodiment of the present invention. [Figure 11] FIG. 10 is a block diagram showing the configuration of a speed command value calculation device when the second vibration suppression control device is configured with a notch filter. [Figure 12] 10 is an example of calculation results of the time response of the load swing amount and the relative swing amount, showing the effect of the present invention. [Figure 13] 10 is another example of the calculation results of the time response of the load swing amount and the relative swing amount, showing the effect of the present invention. [Figure 14] FIG. 10 is a block diagram showing the configuration of a speed command value calculation device according to a second embodiment of the present invention. [Figure 15] FIG. 10 is a block diagram showing the configuration of a speed command value calculation device according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiment, and various modifications and application examples within the technical concept of the present invention are also included within its scope.

[0016] Here, the present invention is effective for all cranes that can move a suspended load horizontally, and can be applied not only to cranes that traverse and travel a suspended load using a trolley and girder (for example, overhead cranes), but also to cranes that only traverse or travel (for example, unloaders). In other words, the term "crane" used below includes all types of cranes that can move a suspended load horizontally.

[0017] Furthermore, although the load (suspended load) transported by the crane is suspended by ropes, chains, etc., the present invention is not limited to any suspending device that can be used to suspend the load, and the type of material, shape, etc. is not important. Therefore, as mentioned above, the term "rope" is used as a general term for suspending devices used to suspend loads. In other words, the term "rope" includes not only so-called ropes, but also chains, belts, wires, cables, strings, cords, etc.

[0018] Next, the configuration and operation of a crane to which the present invention is applied will be described. Note that in each drawing, the same equipment (devices, parts) will be given the same reference numerals, and in the following explanation, explanations of equipment that has already been mentioned may be omitted.

[0019] [Crane Description] 1 shows a schematic configuration of an overhead crane. However, as mentioned above, the present invention is not limited to an overhead crane.

[0020] The crane 1 is composed of a runway 2 provided along the walls on both sides of a building (not shown) such as a factory, a girder 3 that moves on the top surface of this runway 2, and a trolley 4 that moves along the underside of the girder 3. The girder 3 and the trolley 4 are provided with wheels driven by electric motors, and these wheels allow the girder 3 to move in the Y direction (forward and backward) and the trolley 4 to move in the X direction (left and right).

[0021] In addition, a hoist 5 is provided below the trolley 4. The hoist 5 is composed of an electric motor and a drum that is rotated by the electric motor and winds up a rope 6. By using the hoist 5 to wind up or wind down the rope 6, a hook 7 at the end of the rope 6 is raised and lowered.

[0022] A load 9 is suspended from this hook 7 directly or via a sling wire 8, and the load 9 rises and falls as the hook 7 rises and falls. In other words, the crane 1 moves the load 9 horizontally by the horizontal movement (traveling) of the girder 3 and the horizontal movement (traverse) of the trolley 4, and can raise and lower the load 9 in the Z direction (up and down) by the hoisting device 5. In Figure 1, the trolley 4 and girder 3 correspond to the "horizontal movement device," but either the trolley 4 or the girder 3 can also be considered the "horizontal movement device."

[0023] [Explanation of crane control device] Figure 2 shows the configuration of the crane control device. For simplicity of explanation, Figure 2 shows the control of the traverse movement by the trolley 4 and the lifting movement by the hoisting device 5, but does not show the travel by the girder 3. Also, drive units such as electric motors are not shown.

[0024] The crane control device is composed of a control calculation device 100, a traverse motor control device 300 that controls the electric motor (traverse motor) of the trolley 4, a hoisting motor control device 310 that controls the electric motor (hoisting motor) of the hoisting device 5, an operation input device 200, and a display device 210.

[0025] The control calculation device 100 is equipped with a speed command value calculation device 110 that calculates speed command values ​​for the trolley 4, hoisting device 5, etc. based on operation input received from the operation input device 200, and performs calculation and output of speed command values ​​for the trolley 4, hoisting device 5, etc., and controls the output of display information to the display device 210.

[0026] The control and arithmetic device 100 is mainly a general-purpose computer and is composed of a microprocessing unit (MPU) 101 that executes control and arithmetic processing using built-in programs and data, a memory 102 that stores the programs and data, and an input / output control unit 103 that inputs data and signals from the outside and outputs signals processed by the MPU 101 to the outside. The MPU 101, memory 102, and input / output control unit 103 are connected by a bus line 104 for sending and receiving signals and data.

[0027] The operation input device 200 is equipped with an operation terminal device 201 operated by an operator, and the operation terminal device 201 is provided with operation buttons 202 corresponding to the directions of movement of the suspended load: forward, backward, rightward, leftward, upward, and downward. The display device 210 displays the operating status of the crane, etc.

[0028] The operation terminal device 201 may be connected to the control arithmetic device 100 by a wire such as a cable, or may be connected wirelessly. In addition, the display device 210 may be mounted in the same housing as the operation terminal device 201.

[0029] The traverse motor control device 300 and the hoisting motor control device 310 control the electric motors of the trolley 4 and the hoisting device 5 based on the speed command value output from the control arithmetic device 100. Although the specific configurations of the traverse motor control device 300 and the hoisting motor control device 310 are not shown, they are configured by well-known general-purpose computers, inverter circuits, etc., similar to the control arithmetic device 100. Furthermore, the traverse motor control device 300 and the hoisting motor control device 310 may be mounted in the same housing as the control arithmetic device 100.

[0030] Although omitted in Fig. 2, the control arithmetic device 100 outputs a speed command value not only for the trolley 4 and the hoisting device 5 but also for the girder 3. On the girder 3 side, an electric motor (travel motor) control device (not shown) controls the electric motor based on this speed command value.

[0031] [Description of prior art crane models] Figure 3 shows a model of a crane in the prior art. In Figure 3, the crane is modeled as a simple pendulum with a suspended load 9 swinging around the center of rotation of a rope 6 as a fulcrum. The distance from the center of rotation of the rope 6 to the hook 7 (rope length) is "L1," and the distance from the hook 7 to the center of gravity of the suspended load 9 (sling wire length) is "L2."

[0032] Based on the simple pendulum model in Figure 3, the transfer function (Px2s) from the trolley speed (v0), which is the speed command value, to the swing amount (x2) of the suspended load can be calculated as shown in the following equation (1). Note that the swing amount (x2) is the amount of load swing, and indicates the relative position of the suspended load with respect to the trolley.

[0033]

number

[0034] Here, ωr=sqrt(g / L), ζr=vl / (L*ωr), where "ωr" is the natural frequency, "L=L1+L2", "vl" is the hoisting speed, and "g" is the gravitational acceleration.

[0035] In addition, the transfer function (Pmodels) from the trolley speed (v0) of the trolley 4 to the load speed (vp) of the load 9 is given by the following equation (2).

[0036]

number

[0037] [Explanation of the problems of the prior art] Next, we will explain the problems with the prior art mentioned above. In all of the prior art, the crane is modeled as a simple pendulum, as shown in Figure 3, and a control system for suppressing load swing is designed based on this simple pendulum model.

[0038] FIG. 4 shows the configuration of a speed command value calculation device 110 that calculates the trolley speed command value (v0) of the trolley 4, which is mounted on a control device 100 when load sway suppression is performed using Prior Art 1.

[0039] The speed command value calculation device 110 is composed of a crane model calculation device 111 that calculates the load speed (vp) of the suspended load from the trolley speed command value (v0) using equation (2), a sway suppression control device 112 that calculates the trolley speed command value (v0) that suppresses load sway from the target speed command value (vpref) of the suspended load and the load speed (vp) calculated by the crane model calculation device 111, and a limit processing device 113 that performs limit processing so that the output (speed / acceleration) from the sway suppression control device 112 does not exceed the speed / acceleration limit values.

[0040] The sway suppression control device 112 is composed of a feedforward control device 112a and a feedback control device 112b, and the output speed from the feedforward control device 112a, to which a target speed command value (vpref) is input, is corrected by feedback of the load speed (vp) from the crane model calculation device 111. These are designed by the method described in Non-Patent Document 1.

[0041] Figure 5 shows an example of the simulation results that calculate the time changes in the load sway amount (x2) and relative sway amount (x12) when using Prior Art 1. As described above, Prior Art 1 models the crane as a simple pendulum, so it can suppress the load sway amount (x2) due to acceleration and deceleration, but it cannot suppress the relative sway amount (x12).

[0042] 6 shows the configuration of a speed command value calculation device 110 equipped with a speed command value generation device 112c when load sway suppression is performed using Prior Art 2. A target speed command value (vpref) is input to the speed command value generation device 112c, and the output speed is given to a limit processing device 113, where limit processing is performed so that the speed and acceleration limit values ​​are not exceeded. Then, in Prior Art 2, the trolley 4 is decelerated and then driven at a trapezoidal wave speed, thereby suppressing load sway after the trolley 4 has stopped.

[0043] Figure 7 shows the speed command waveform of the trolley 4 in prior art 2, and the vibration suppression control device 112 is equipped with a speed command value generator 112c that generates the waveform of Figure 7. In Figure 7, deceleration (1) is performed at time intervals (T1), and then the trolley 4 is driven at trapezoidal wave speed (2) at time intervals (T2). Note that the time interval (TW) is the time from when the trolley 4 starts to decelerate until the trapezoidal wave speed (2) is achieved.

[0044] Figure 8 shows an example of the results of a simulation that calculates the time changes in the amount of load sway (x2) and the amount of relative sway (x12) when using Prior Art 2. In this case too, the crane is modeled as a simple pendulum, so the amount of load sway (x2) due to acceleration and deceleration can be suppressed, but the amount of relative sway (x12) cannot be suppressed. [Example]

[0045] [Description of the crane model in the present invention] Next, an embodiment of the present invention will be described. The present invention is characterized by regarding a crane as a double pendulum. Figure 9 shows a model of a crane as a double pendulum consisting of the swing of a hook 7 with the center of rotation of a rope 6 as the fulcrum, and the swing of a suspended load 9 with the hook 7 as the fulcrum.

[0046] In Figure 9, the mass of the hook is "M1" and the mass of the suspended load is "M2." Furthermore, the swing amount of the suspended load is (x2), and the relative swing amount of the hook with respect to the suspended load (x12) is defined as in the following equation (3). Note that L = L1 + L2, the swing amount (x2) is the amount of load swing and indicates the relative position of the suspended load with respect to the trolley, and the swing amount (x1) indicates the relative position of the hook 7 with respect to the trolley.

[0047]

number

[0048] Based on the model in Figure 9, the transfer function (Px1), transfer function (Px2), and transfer function (Px12) from the trolley speed command value (v0) to the swing amount (x1) of the hook 7, the swing amount (x2) of the suspended load 9, and the relative swing amount (x12) are calculated as shown in the following equations (4), (5), and (6).

[0049]

number

[0050]

number

[0051]

number

[0052] As is clear from equations (4) to (6), this double pendulum model has two modes (the primary mode due to the suspended load and the secondary mode due to the hook), and its natural frequency wri (i=1,2) is given by the following equation (7).

[0053]

number

[0054] Here, "D" in equation (7) can be calculated using the following equation (8).

[0055]

number

[0056] In addition, the transfer function (Pmodel) from the trolley speed command value (v0) to the load speed (vp) is expressed by the following equation (9).

[0057]

number

[0058] As can be seen from equation (9), the crane model calculation device 111 calculates the load speed (vp) by adding the swing amount and the speed (v0) of the trolley 4.

[0059] [Description of the Speed ​​Command Value Calculation Device of the Present Embodiment] In this embodiment, a load sway suppression control device for suppressing the swing of the hook using this double pendulum model is proposed.

[0060] Fig. 10 shows the configuration of the speed command value calculation device 110 of this embodiment. The speed command value calculation device 110 shown in Fig. 10 is based on the configuration for suppressing the first-order mode vibration (caused by the suspended load) shown in Fig. 4, and is configured to newly add a configuration for suppressing the second-order mode vibration (caused by the hook).

[0061] Then, the crane model calculation device 111 uses equation (9) to calculate the load speed (vp) including the swing of the hook 7 from the trolley speed command value (v0), and this load speed (vp) is fed back to the first swing suppression control device 112 and the second swing suppression control device 114.

[0062] In Figure 10, the first sway suppression control device 112 is composed of a first feedforward control device 112a and a first feedback control device 112b, and a target speed command value (vpref) is input to the first feedforward control device 112a, and the load speed (vp) is feedback corrected to the output speed to output a first trolley speed command value.

[0063] In addition, the second sway suppression control device 114 is composed of a second feedforward control device 114a and a second feedback control device 114b, and the first trolley speed command value from the first sway suppression control device 112 is input to the second feedforward control device 114a, and the load speed (vp) is feedback corrected to the output speed to output the second trolley speed command value.

[0064] This second trolley speed command value becomes the trolley speed command value (v0) input to the crane model calculation device 111, and also becomes the trolley speed command value (v0) input to the traverse motor control device that controls the traverse motor that constitutes the trolley 4.

[0065] In this way, the first sway suppression control device 112 calculates a first trolley speed command value that suppresses the sway of the first mode, which is the main mode of sway of the suspended load 9. Furthermore, the second sway suppression control device 114 calculates a second trolley speed command value that suppresses the sway of the second mode, which is the main mode of sway of the hook 8. This makes it possible to suppress not only the sway of the suspended load 9 but also the sway of the hook 7.

[0066] In the configuration of Figure 10, when considering the transfer characteristics from the input of the second sway suppression control device 114 to the output of the crane model calculation device 111, the second-mode sway component contained in the load speed (vp) is suppressed by the second sway suppression control device 114, leaving only the first-mode sway component.

[0067] Therefore, from the perspective of the first sway suppression control device 112, it can be considered as if only the swing of the simple pendulum in the first mode is to be suppressed, and the first load sway suppression control device can be designed by utilizing knowledge of load sway suppression control that has been designed based on the simple pendulum model up to now.

[0068] As described above, in this embodiment, the speed command value calculation device 110 has a crane model calculation device 111 that calculates the load speed (vp) of the load 9 from the speed command value (v0) of the trolley 4 based on a double pendulum model consisting of a double pendulum consisting of the swing of the hook 7 with the rope's center of rotation as the fulcrum and the swing of the load 9 with the hook as the fulcrum, a first sway suppression control device 112 that calculates a first speed command value of the trolley 4 that suppresses the swing of the first mode of the crane from the target speed command value (vpref) of the load 9 and the load speed (vp) of the crane model calculation device, and a second sway suppression control device 114 that calculates a second speed command value (v0) of the trolley 4 that suppresses the swing of the crane in the second mode from the first speed command value from the first sway suppression control device and the load speed (vp) of the crane model calculation device.

[0069] The second speed command value (v0) from the second sway suppression controller 114 is configured to be input to the crane model calculation device 111 and the traverse motor controller 300 of the trolley 4. This makes it possible to suppress double pendulum load sway of the hook and the suspended load.

[0070] Next, a description will be given of a modified example of the second vibration suppression control device 114. The second vibration suppression control device 114 may be designed to suppress vibration in the secondary mode, which is the main mode of vibration of the hook 7. This can be achieved by using, for example, a notch filter whose cutoff frequency is the natural frequency of the second-order mode vibration. The configuration of this filter is shown in FIG.

[0071] 11, instead of the second feedforward control device 114a and the second feedback control device 114b that constitute the second vibration suppression control device 114 shown in Fig. 10, a notch filter 114c is connected to the first vibration suppression control device 112. The frequency of this notch filter 114c is determined to be such that it cuts off the natural frequency of the second-order mode vibration.

[0072] In this case, the main frequency component of the output of the second vibration suppression control device 114 is only the first mode, so the crane model calculation device 111 may calculate the load speed (vp) from the trolley speed command value (v0) using the following equation (10) based on a simple pendulum model having a natural frequency of the first mode.

[0073]

number

[0074] Here, ζr1 is the equivalent damping ratio of the first mode, and is found from L1, L2, M1, and M2. When the winding speed is 0, ζr1 becomes 0. Approximately, it can be found as ζr1=vl / (L1*ωr1).

[0075] Fig. 12 shows an example of the results of a simulation that calculates the time changes in the load swing amount (x2) and the relative swing amount (x12) in the configuration of Fig. 11. From this result, it can be confirmed that the relative swing amount (x12) can be suppressed by this embodiment, as shown by the solid line, compared to the prior art, as shown by the dashed line.

[0076] The present invention is also effective when prior art 2 is applied to the first sway suppression control device 112, that is, when sway suppression is performed by decelerating the trolley 4 and then driving it at a trapezoidal wave speed as shown in Figure 7. In other words, the first sway suppression control device 112 can calculate the speed of the trolley 4 that suppresses the sway of the crane in the first mode by decelerating the trolley 4 and the subsequent trapezoidal wave speed.

[0077] Figure 13 shows an example of the results of a simulation that calculates the time changes in the load swing amount (x2) and the relative swing amount (x12) in this case. From this result, it can be confirmed that the relative swing amount (x12) can be suppressed by this embodiment as shown by the solid line, compared to the prior art shown by the dashed line.

[0078] As described above, this embodiment makes it possible to suppress double pendulum load sway between the hook and the suspended load. Furthermore, it is possible to design a control system for suppressing double pendulum load sway by utilizing knowledge of load sway suppression control designed based on the previous single pendulum model. [Example]

[0079] Next, the configuration of a crane control device according to a second embodiment of the present invention will be described. The second embodiment is characterized in that a crane model calculation device 111 is configured for a first mode and a second mode.

[0080] In other words, when the load speed (vp) is derived from the trolley speed command value (v0) based on the double pendulum model itself, the denominator polynomial becomes a quartic expression with "s" as shown in equation (9). Therefore, if the calculation accuracy of the control device 100 is single precision, it is thought that calculation errors will become large if equation (9) is implemented as is.

[0081] Therefore, this embodiment proposes a configuration as shown in Fig. 14. Note that duplicated explanations of components common to the above-described embodiment will be omitted.

[0082] Fig. 14 shows the configuration of a speed command value calculation device 110 according to a second embodiment of the present invention. Compared to the configuration in Fig. 10, it differs in that the crane model calculation device 111 includes a first crane model state quantity calculation device 111a that calculates the suspended load speed (vp) from the trolley speed command value (v0) based on a simple pendulum model having a natural frequency of the first mode using equation (10), and a second crane model state quantity calculation device 111b that calculates the suspended load speed (vp) from the trolley speed command value (v0) based on the simple pendulum model having a natural frequency of the second mode using the following equation (11):

[0083]

number

[0084] Here, ζr2 is the equivalent damping ratio of the second mode, and is found from L1, L2, M1, and M2. When the winding speed is 0, ζr2 is 0. Approximately, it can be found as ζr2=vl / (L*ωr2).

[0085] The load speed (vp) determined by the first crane model state quantity calculation device 111a is fed back and corrected to the first feedforward control device 112a by the first feedback control device 112b. Similarly, the load speed (vp) determined by the second crane model state quantity calculation device 111b is fed back and corrected to the second feedforward control device 114a by the second feedback control device 114b.

[0086] If the load speed is calculated based on the simple pendulum models of the first and second modes as in this embodiment, the polynomial in the denominator of the calculation formula will be a quadratic expression in "s", and sufficient calculation precision can be ensured even with a single-precision control device.

[0087] By doing so, double pendulum load swing can be suppressed even in a control device with single-precision calculation accuracy. [Example]

[0088] Next, the configuration of a crane control device according to a third embodiment of the present invention will be described. The third embodiment is characterized in that a crane model state calculation device for the primary mode is added to the second sway suppression control device 114, based on the embodiment shown in Fig. 10.

[0089] Fig. 15 shows the configuration of a speed command value calculation device 110 according to a third embodiment of the present invention. A feature of this configuration, compared to the configuration of Fig. 10, is that the second vibration suppression control device 114 includes a crane model state calculation device 111a that calculates the load speed (vp) from the trolley speed command value (v0) using equation (10) based on a simple pendulum model having a primary mode natural frequency.

[0090] In other words, the difference between the value of the crane model calculation device 111, which calculates the load speed (vp) based on the double pendulum model, and the value of the crane model state quantity calculation device 111a is used as an input to the feedback control device 114b of the second sway suppression control device.

[0091] In this configuration, swings other than the swing of the first mode calculated by the crane model state quantity calculation device 111a are suppressed by the feedback control device 114b. As a result, the transfer characteristics from the input of the second swing suppression control device 114 to the output of the crane model calculation device 111 can be made to more accurately approximate the characteristics of the single pendulum model of the first mode, and the swing suppression performance of the suspended load 9 in double pendulum load swing suppression can be improved. [Example]

[0092] The crane model calculation device 111 in the embodiments described above performs calculations using equations (9), (10), and (11). In addition, the first vibration suppression control device 112 determines the coefficients used in its calculations based on the natural frequency of the first mode calculated using equations (7) and (8), and similarly, the second vibration suppression control device 114 determines the coefficients used in its calculations based on the natural frequency of the second mode.

[0093] Looking at equations (9), (10), and (11), the coefficient of "s" includes the rope length (L1), sling wire length (L2), hook mass (M1), and suspended load mass (M2). Additionally, the first and second modes and natural frequencies calculated by equations (7) and (8) change depending on the rope length (L1), sling wire length (L2), hook mass (M1), and suspended load mass (M2).

[0094] Therefore, if the rope length (L1), sling wire length (L2), hook mass (M1), and suspended load mass (M2) are automatically obtained, the coefficients of equation (9) and the natural frequencies of the first and second modes are sequentially calculated, and the calculation coefficients used in the crane model calculation device 111, first sway suppression control device 112, and second sway suppression control device 114 are sequentially updated, it will be possible to suppress the sway of the load and hook even when there is a hoisting operation that changes the rope length (L1), or a change or setup of the suspended load that changes the sling wire length (L2), hook mass (M1), and suspended load mass (M2).

[0095] The following method can be used to automatically obtain the parameters required for double pendulum load sway suppression control: rope length (L1), sling wire length (L2), hook mass (M1), and suspended load mass (M2).

[0096] The rope length L1 can be obtained, for example, by measuring it with an encoder attached to the hoisting motor.

[0097] The sling wire length (L2) can be obtained, for example, by estimating it from the relationship between the position of the trolley 4 and the rope length (L1) when it is wound up to a taut state without slack, or by attaching a tag to the sling wire 8 and automatically reading the information, or by setting the information on the sling wire length (L2) from an external system such as a production management system.

[0098] In addition, the hook mass (M1) can be obtained by, for example, estimating it from the motor operation information when the rope is wound up without the load 9 attached, or by setting information on the hook mass (M1) from an external system such as a production management system.

[0099] In addition, the suspended load mass (M2) can be obtained by the operator inputting the mass, or by estimating it from motor operation information when the rope is wound up, or by setting information on the suspended load mass (M2) from an external system such as a production management system.

[0100] By providing a function to automatically obtain the rope length (L1), sling wire length (L2), hook mass (M1), and suspended load mass (M2) as described above, the parameters required for load sway suppression control can be easily set, making operation easier. Note that these parameters may also be manually input by the operator.

[0101] Although the present invention is targeted at cranes, it can also be applied to vibration suppression of devices with multiple vibration modes, such as elastically deforming long arms. In this case, the first vibration suppression control device suppresses the dominant low-order vibration mode, and the second vibration suppression control device suppresses the other higher-order vibration modes.

[0102] The present invention is not limited to the above-described embodiments, but includes various modifications. The above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. It is also possible to add, delete, or replace other configurations with respect to the configuration of each embodiment. [Explanation of symbols]

[0103] 1...crane, 2...runway, 3...girder, 4...trolley, 5...hoisting device, 6...rope, 7...hook, 8...sling wire, 9...suspended load, 100...control device, 110...speed command value calculation device, 111...crane model calculation device, 112...first sway suppression control device, 113...limit processing device, 114...second load sway suppression control device, 200...operation input device, 300...traversing motor control device

Claims

1. A crane comprising: a hoisting device that moves a load suspended from a hook at the end of a rope via a sling wire or directly by winding up / down the rope; a horizontal movement device to which the hoisting device is attached and that moves the load horizontally; an operation input device that inputs a target speed command value for the load; a speed command value calculation device that generates a speed command value for the horizontal movement device based on the target speed command value; and a horizontal movement device control device that controls the speed of the horizontal movement device in accordance with the speed command value, The speed command value calculation device a crane model calculation device that calculates a lifting speed of the load from the speed command value of the horizontal movement device based on a double pendulum model in which a double pendulum is formed by the swing of the hook with the rotation center of the rope as a fulcrum and the swing of the load with the hook as a fulcrum; a first sway suppression control device that calculates a first speed command value that suppresses sway of the crane in a first mode from the target speed command value and the lifting load speed of the crane model calculation device; a second sway suppression control device that calculates a second speed command value that suppresses sway of the crane in a secondary mode from the first speed command value from the first sway suppression control device and the lifting load speed of the crane model calculation device, The second speed command value from the second vibration suppression control device is input to the crane model calculation device and the horizontal movement device. A crane characterized by:

2. 2. The crane of claim 1, The second vibration suppression control device is a notch filter having a cutoff frequency equal to the vibration frequency of the second mode of the crane. A crane characterized by:

3. The crane according to claim 2, The crane model calculation device calculates the lifting speed of the load by adding the swing amount of the first mode of the crane and the speed of the horizontal movement device. A crane characterized by:

4. 2. The crane of claim 1, The crane model calculation device a first crane model state quantity calculation device that calculates the load speed by adding the swing amount of the first mode of the crane and the speed command value of the horizontal movement device; a second crane model state quantity calculation device that calculates the load speed by adding the swing amount of the second mode of the crane and the speed command value of the horizontal movement device, the first sway suppression control device calculates the first speed command value for suppressing the sway of the crane in the first mode from the target speed command value and the lifting load speed of the first crane model state quantity calculation device, The second sway suppression control device calculates the second speed command value for suppressing the sway of the crane in the secondary mode from the first speed command value of the first sway suppression control device and the lifting load speed of the second crane model state quantity calculation device. A crane characterized by:

5. 2. The crane of claim 1, The crane model calculation device a first crane model state quantity calculation device that calculates the lifting speed of the load of the crane; a second crane model state quantity calculation device that calculates the load speed by adding the swing amount of the first mode of the crane and the speed command value of the horizontal movement device, the first sway suppression control device calculates the first speed command value that suppresses the sway of the crane in the first mode from the target speed command value and the lifting load speed of the first crane model state quantity calculation device, The second sway suppression control device determines the second speed command value for suppressing the sway of the crane in the secondary mode from the first speed command value of the first sway suppression control device and a difference between the load speed of the first crane model state quantity calculation device and the load speed of the second crane model state quantity calculation device. A crane characterized by:

6. A crane according to any one of claims 1 to 5, The parameters of the crane model calculation device, the first sway suppression control device, and the second sway suppression control device are sequentially updated based on any one of the length of the rope, the length of the sling wire, the mass of the hook, and the mass of the suspended load. A crane characterized by:

7. 7. The crane of claim 6, The length of the rope, the length of the sling wire, the mass of the hook, and the mass of the suspended load are measured, estimated, or obtained from an external source. A crane characterized by:

8. A crane according to any one of claims 1 to 5, The first sway suppression control device determines the speed command value that suppresses the sway of the crane in the first mode by decelerating the horizontal movement device and the subsequent trapezoidal wave speed. A crane characterized by:

9. 9. The crane of claim 8, The parameters of the crane model calculation device, the first sway suppression control device, and the second sway suppression control device are sequentially updated based on any one of the length of the rope, the length of the sling wire, the mass of the hook, and the mass of the suspended load. A crane characterized by:

10. 10. The crane of claim 9, The length of the rope, the length of the sling wire, the mass of the hook, and the mass of the suspended load are measured, estimated, or obtained from an external source. A crane characterized by:

11. A crane control method comprising: a hoisting device that moves a load suspended from a hook at the end of a rope via a sling wire or directly by winding up / down the rope; a horizontal movement device to which the hoisting device is attached and that moves the load horizontally; an operation input device that inputs a target speed command value for the load; a speed command value calculation device that generates a speed command value for the horizontal movement device based on the target speed command value; and a horizontal movement device control device that controls the speed of the horizontal movement device in accordance with the speed command value, The speed command value calculation device calculating a lifting speed of the load from the speed command value of the horizontal movement device based on a double pendulum model in which a double pendulum is formed by a swing of the hook with the rotation center of the rope as a fulcrum and a swing of the load with the hook as a fulcrum; calculating a first speed command value that suppresses a first mode swing of the crane from the target speed command value and the lifting load speed; calculating a second speed command value that suppresses second-order mode swing of the crane from the first speed command value and the lifting load speed; The second velocity command value is input to the double pendulum model and the horizontal movement device. A crane control method comprising:

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