Crane and crane control method

Abstract

The present invention provides a new crane and a crane control method capable of suppressing double pendulum load swing of a hoist and a hook. The crane has: a crane model calculation device that calculates a hoist speed of the hoist based on a double pendulum model constituted by the hook and the hoist, from a speed of a horizontal movement device; a first swing suppression control device that calculates a first speed command value of the horizontal movement device that suppresses a swing of a primary mode of the crane, from a target speed of the hoist and the hoist speed of the crane model calculation device; and a second swing suppression control device that calculates a second speed command value of the horizontal movement device that suppresses a swing of a secondary mode of the crane, from the first speed command value from the first swing suppression control device and the hoist speed of the crane model calculation device, the second speed command value from the second swing suppression control device being input to the crane model calculation device and the horizontal movement device.

Description

Technical Field

[0001] This invention relates to a crane for transporting suspended loads and a crane control method, and particularly to a crane and a crane control method having the function of suppressing the swaying of the suspended load. Background Technology

[0002] In recent years, with the aging of skilled crane operators and the increase in the number of cranes, leading to manpower shortages, there has been an increase in inexperienced operators taking over crane operations. These inexperienced operators are not adept at stopping the swaying of the load (load sway), resulting in high risks of collisions and trapping accidents caused by load swaying. Furthermore, stopping load swaying takes time, extending the operation period. Therefore, to improve safety and reduce operation time, technologies that automatically suppress load swaying are sought.

[0003] As a technique for automatically suppressing load sway, for example, there are known load sway suppression techniques as shown in Patent Document 1 (Japanese Patent Application Publication No. 2018-2391) and Non-Patent Document 1 (Zhang, et al., Control of Motion and Vibration of Crane System with Length Change Caused by IDCS, Proceedings of the 54th Joint Lecture on Automatic Control (2011)) (hereinafter referred to as Prior Art 1).

[0004] Patent Document 1 discloses a load sway suppression control. The crane includes a traction device that moves the load vertically by raising / lowering the rope suspending the load, a horizontal movement device that moves the load equipped with the traction device horizontally, and an operation input device for inputting the target speed of the load. In this crane, a model speed of the load is calculated based on the target horizontal speed of the load and the model of the crane. The speed command value of the horizontal movement device is then calculated and controlled to ensure that the target speed of the load matches or is close to the model speed. Additionally, Non-Patent Document 1 discloses a method for designing a controller using the DMM (Dual Model Matching) method.

[0005] Moreover, unlike this, in Patent Document 2 (Japanese Patent Application Publication No. 2021-75372 / hereinafter referred to as Prior Art 2), a method is shown that the load swing at the start of the stopping action of the horizontal moving device and the load swing caused by deceleration are offset by subsequent acceleration or deceleration, thereby suppressing the load swing at the stop.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2018-2391

[0009] Patent Document 2: Japanese Patent Application Publication No. 2021-75372

[0010] Non-Patent Literature 1: Zhang, two other authors, Control of Motion and Vibration of Crane System with Length Variation Caused by IDCS, Proceedings of the 54th Joint Lecture on Automatic Control (2011) Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] When using a crane to transport a load, a hook is installed at the end of the rope, and the load is suspended from the hook via a lifting device or lifting line, or directly from the hook for transport. Therefore, the crane becomes a double-pendulum load oscillation, applying the oscillation of the hook with the rotation center of the rope as the fulcrum and the oscillation of the load with the hook as the fulcrum.

[0013] If the hook swings, in addition to the instability of the load rotating around its center of gravity, there are also risks such as wear and tear on the lifting gear and cable, or the lifting gear or cable falling off the hook. Therefore, it is also necessary to suppress the swing of the hook.

[0014] In the aforementioned prior art 1 and prior art 2, a single pendulum is modeled as the hoisting object swinging around the rotation center of the rope as the fulcrum, thereby controlling the load swing. However, these techniques alone cannot suppress the load swing of a double pendulum.

[0015] The present invention was made in view of the following problems, and its object is to provide a crane and a crane control method capable of suppressing the oscillation of the double pendulum load between the hook and the load.

[0016] Technical solutions for solving the problem

[0017] In this invention, a crane is provided, comprising: a traction device that moves a load in the vertical direction via a hoisting line or a hook directly suspended from the end of the rope by raising / lowering the rope; a horizontal movement device capable of mounting the traction device to move the load in the horizontal direction; an operation input device for inputting a target speed of the 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 according to the speed command value. The crane is characterized in that the speed command value calculation device comprises: a crane model calculation device, which is based on the hook as a fulcrum at the rotation center of the rope. A double-pendulum model consisting of a pendulum swing and the swing of the hoisted object with the hook as the fulcrum is used to calculate the hoisted object speed based on the speed command value of the horizontal moving device; a first pendulum suppression control device calculates a first speed command value to suppress the primary mode of the crane's swing based on the target speed of the hoisted object and the hoisted object speed of the crane model calculation device; and a second pendulum suppression control device calculates a second speed command value to suppress the secondary mode of the crane's swing based on the first speed command value from the first pendulum suppression control device and the hoisted object speed from the crane model calculation device. The second speed command value from the second pendulum suppression control device is input to the crane model calculation device and the horizontal moving device.

[0018] Invention Effects

[0019] According to the present invention, a crane and a control method for a crane capable of suppressing the oscillation of the hook and the load under a double pendulum load can be provided. Attached Figure Description

[0020] Figure 1 This is a structural diagram showing the structure of the crane that is the subject of this invention.

[0021] Figure 2 This is a block diagram illustrating the structure of the control device for a crane to which the present invention is applied.

[0022] Figure 3 This is a model diagram illustrating a crane model based on existing technology.

[0023] Figure 4 This is a block diagram showing the structure of the speed command value calculation device when applying prior art 1.

[0024] Figure 5 This is an example of the calculation results of the time response of the load swing and relative swing when applying existing technology 1.

[0025] Figure 6 This is a block diagram showing the structure of the speed command value calculation device when applying prior art 2.

[0026] Figure 7 This is a graph showing the speed of the crane when using existing technology 2.

[0027] Figure 8 This is an example of the calculation results of the time response of the load swing and relative swing when applying existing technology 2.

[0028] Figure 9 This is a model diagram illustrating the crane of the present invention.

[0029] Figure 10 This is a block diagram illustrating the structure of the speed command value calculation device according to the first embodiment of the present invention.

[0030] Figure 11 This is a block diagram showing the structure of the speed command value calculation device when the second oscillation suppression control device is composed of a notch filter.

[0031] Figure 12 This is an example of the calculation results of the time response of the load swing amount and the relative swing amount, which represent the effect of the present invention.

[0032] Figure 13 Other examples are calculation results of the load swing amount and the time response of the relative swing amount, which represent the effects of the present invention.

[0033] Figure 14 This is a block diagram illustrating the structure of the speed command value calculation device according to the second embodiment of the present invention.

[0034] Figure 15 This is a block diagram illustrating the structure of the speed command value calculation device according to the third embodiment of the present invention. Detailed Implementation

[0035] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the following embodiments, and various modifications and applications are also included within the scope of the technical concept of the present invention.

[0036] Here, the present invention is effective for all cranes capable of moving the load horizontally, and is applicable not only to cranes that move the load both horizontally and vertically via a hoisting vehicle and truss (e.g., roof cranes), but also to cranes that only move horizontally or vertically (e.g., unloaders). That is, the term "crane" as used below includes all types of cranes capable of moving the load horizontally.

[0037] Furthermore, goods (lifted objects) transported by cranes are suspended and transported via ropes or chains, but this is not limited in this invention; any lifting device capable of suspending goods is acceptable, and its material or shape is not limited. Therefore, as mentioned above, the term "rope" is used as a general term for lifting devices used to suspend goods. That is, "rope" includes not only ropes but also chains, belts, wires, cables, lines, cords, etc.

[0038] Next, the structure and operation of the crane to which the present invention is applied will be described. Furthermore, in the various figures, the same reference numerals are used to label the same equipment (devices, components), and descriptions of equipment that have already appeared may be omitted in the following description.

[0039] [Crane Description]

[0040] Figure 1 This illustrates a schematic structure of a roof-mounted crane. Furthermore, as mentioned above, the present invention is not limited to roof-mounted cranes.

[0041] Crane 1 includes a track 2 installed along the walls on both sides of a building (not shown), a truss 3 that moves along the upper surface of the track 2, and a hoisting carriage 4 that moves along the lower surface of the truss 3. The truss 3 and the hoisting carriage 4 are equipped with wheels driven by electric motors, which enable the truss 3 to move in the Y direction (forward and backward) and the hoisting carriage 4 to move in the X direction (left and right).

[0042] Additionally, a traction device (hoist) 5 is installed at the lower part of the hoisting vehicle 4. The traction device 5 consists of an electric motor and a drum that winds up the rope 6 by rotating the motor. By using the traction device 5 to raise or lower the rope 6, the hook 7 at the front end of the rope 6 is raised or lowered.

[0043] The load 9 is suspended directly or via the lifting line 8 by the hook 7, and the load 9 rises and falls with the lifting of the hook 7. That is, the crane 1 can move the load 9 horizontally by the horizontal movement (longitudinal) of the truss 3 and the horizontal movement (lateral) of the hoisting vehicle 4, and raise and lower the load 9 in the Z-direction (vertical) by the traction device 5. Figure 1 In this context, the crane 4 and the truss 3 are equivalent to "horizontal moving devices," but either the crane 4 or the truss 3 can also be used as a "horizontal moving device."

[0044] [Description of the crane's control system]

[0045] Figure 2 This describes the structure of the crane's control device. Furthermore, in Figure 2 For the sake of simplicity, this diagram shows the control of the lateral movement of the crane 4 and the lifting movement of the traction device 5, while omitting the longitudinal movement of the truss 3. Additionally, drive units such as motors are omitted.

[0046] The crane's control device includes a control and calculation device 100, a horizontal motor control device 300 for controlling the motor (horizontal motor) of the hoisting vehicle 4, a traction motor control device 310 for controlling the motor (traction motor) of the traction device 5, an operation input device 200, and a display device 210.

[0047] The control calculation unit 100 is equipped with a speed command value calculation unit 110, etc., which calculates the speed command values ​​of the hoist 4, traction device 5, etc. based on the operation input input from the operation input device 200, and performs the calculation and output of the speed command values ​​of the hoist 4, traction device 5, etc., and controls the output of display information to the display device 210.

[0048] The control and arithmetic device 100 typically uses a general-purpose computer, including: a microprocessor unit (MPU) 101 that performs control and arithmetic processing using built-in programs and data; a memory 102 that stores previous programs and data; and an input / output control unit 103 for receiving data and signals from the outside and outputting 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 104 for transmitting and receiving signals and data.

[0049] The operation input device 200 includes an operation terminal device 201 for operator control, and the operation terminal device 201 is equipped with operation buttons 202 corresponding to the forward, backward, right, left, upward, and downward directions of the hoisted object. The display device 210 displays the crane's operating status, etc.

[0050] The operating terminal device 201 can be connected to the control and computing device 100 via a wired connection such as a cable, or it can be connected wirelessly. Additionally, the display device 210 can be mounted in the same enclosure as the operating terminal device 201.

[0051] The horizontal motor control device 300 and the traction motor control device 310 control the motors of the crane 4 and the traction device 5 based on the speed command values ​​output from the control computing device 100. The specific structures of the horizontal motor control device 300 and the traction motor control device 310 are not shown, but they are the same as those of the control computing device 100, consisting of a known general-purpose computer and an inverter circuit. Alternatively, the horizontal motor control device 300 and the traction motor control device 310 can also be mounted in the same housing as the control computing device 100.

[0052] In addition, although Figure 2The speed command values ​​are omitted, but the control and calculation unit 100 outputs not only the speed command values ​​of the hoist 4 and the traction device 5, but also the speed command value of the truss 3. The truss 3 side controls the motor (longitudinal motor) based on the speed command value through a motor control device (not shown).

[0053] [Description of existing crane models]

[0054] Figure 3 This represents a model of a crane in the prior art. Figure 3 In this model, the crane is represented as a simple pendulum oscillating around the rotation center of the rope 6, with the load 9 as the fulcrum. The distance from the rotation center of the rope 7 to the hook 7 (rope length) is set as "L1", and the distance from the hook 7 to the center of gravity of the load 9 (suspension line length) is set as "L2".

[0055] according to Figure 3 Using a simple pendulum model, the transfer function (Px2s) from the crane speed (v0), which is the speed command value, to the swing amount (x2) of the hoisted object is obtained, as shown in equation (1). Furthermore, the swing amount (x2) is the load swing amount, representing the relative position of the hoisted object with respect to the crane.

[0056] [Formula 1]

[0057]

[0058] Where ωr=sqrt(g / L) and ζr=vl / (L*ωr), "ωr" is the natural frequency, "L=L1+L2" and "vl" are the lifting speeds, and "g" is the gravitational acceleration.

[0059] In addition, the transfer function (Pmodels) from the hoisting vehicle speed (v0) of the hoisting vehicle 4 to the hoisting speed (vp) of the hoisting object 9 is as follows (2).

[0060] [Equation 2]

[0061]

[0062] [Explanation of the problems in the prior art]

[0063] Next, the issues of the prior art described earlier will be explained. In any prior art, there is such a... Figure 3 The crane is modeled as a pendulum, and a control system based on this pendulum model is designed to suppress load sway.

[0064] Figure 4 This describes the structure of a speed command value calculation device 110 that calculates the hoisting vehicle speed command value (v0) of the hoisting vehicle 4, which is mounted on a control device 100 used for load sway suppression in the prior art 1.

[0065] The speed command value calculation device 110 includes: a crane model calculation device 111 that calculates the hoisting speed (vp) of the hoisting object based on the hoisting vehicle speed command value (v0) according to formula (2); a sway suppression control device 112 that calculates the hoisting vehicle speed command value (v0) to suppress load sway based on the target speed command value (vpref) of the hoisting object and the hoisting speed (vp) calculated by the crane model calculation device 111; and a limit processing device 113 that performs limit processing in such a way that the output (speed / acceleration) from the sway suppression control device 112 does not exceed the speed·acceleration limit value.

[0066] The sway suppression control device 112 consists of a feedforward control device 112a and a feedback control device 112b. It corrects the speed of the hoisted object (vp) fed back from the crane model calculation device 111 by providing feedback to the output speed of the feedforward control device 112a, which is based on the input target speed command value (vpref). These are designed using the method described in Non-Patent Document 1.

[0067] Figure 5 This is an example of the simulation results for calculating the time variation of load sway (x2) and relative sway (x12) when using prior art 1. Thus, in prior art 1, because the crane is modeled as a pendulum, the load sway (x2) caused by acceleration and deceleration can be suppressed, but the relative sway (x12) cannot be suppressed.

[0068] in addition, Figure 6 This describes the structure of a speed command value calculation device 110 with a speed command value generation device 112c when using prior art 2 for load sway suppression. A target speed command value (vpref) is input to the speed command value generation device 112c, and its output speed is assigned to a limit processing device 113 for limit processing to ensure that the speed and acceleration limits are not exceeded. In prior art 2, after the crane 4 is decelerated, load sway after the crane 4 stops is suppressed by driving the crane 4 at a trapezoidal wave speed.

[0069] Figure 7 The speed command waveform of the crane 4 in prior art 2, and the swing suppression control device 112 has the function of generating Figure 7 The waveform speed command value generation device 112c. In Figure 7 In the process, deceleration (1) is performed at time interval (T1), and then the crane 4 is driven at time interval (T2) with trapezoidal wave velocity (2). Furthermore, the time interval (TW) is the time from when the crane 4 begins to decelerate to when it is given trapezoidal wave velocity (2).

[0070] Figure 8This is an example of the simulation results for calculating the time variation of load sway (x2) and relative sway (x12) when using prior art 2. Because the crane is also modeled as a pendulum in this case, the load sway (x2) caused by acceleration and deceleration can be suppressed, but the relative sway (x12) cannot be suppressed.

[0071] [Example 1]

[0072] [Description of the crane model in this invention]

[0073] Next, embodiments of the present invention will be described. A key feature of the present invention is that the crane is treated as a double pendulum. Figure 9 It is a diagram that models the crane as a double pendulum consisting of the swing of the hook 7 with the rotation center of the rope 6 as the fulcrum and the swing of the hoisted object 9 with the hook 7 as the fulcrum.

[0074] exist Figure 9 In this context, the mass of the hook is set to "M1", and the mass of the object being lifted is set to "M2". In addition, the swing amount (x2) of the object being lifted is set, and the relative swing amount (x12) of the hook relative to the object being lifted is defined as follows (3). Furthermore, L = L1 + L2, the swing amount (x2) is the load swing amount, which represents the relative position of the object being lifted relative to the crane, and the swing amount (x1) represents the relative position of the hook 7 relative to the crane.

[0075] [Formula 3]

[0076]

[0077] based on Figure 9 The model is used to obtain the transfer functions (Px1), (Px2), and (Px12) from the speed command value (v0) of the crane to the swing amount (x1) of the hook 7, the swing amount (x2) of the hoisted object 9 and the relative swing amount (x12), as shown in equations (4), (5) and (6).

[0078] [Formula 4]

[0079]

[0080] [Formula 5]

[0081]

[0082] [Formula 6]

[0083]

[0084] According to these equations (4) to (6), the double pendulum model has two modes (a primary mode based on the hoisting object and a secondary mode based on the hook), and its natural frequency wri (i = 1, 2) is as shown in equation (7).

[0085] [Formula 7]

[0086]

[0087] Here, “D” in equation (7) is obtained by equation (8).

[0088] [Formula 8]

[0089]

[0090] In addition, the transfer function (Pmodel) from the crane speed command value (v0) to the speed of the hoisted object (vp) is as follows (9).

[0091] [Formula 9]

[0092]

[0093] According to equation (9), the crane model calculation device 111 calculates the speed (vp) of the hoisted object by adding the swing amount to the speed (v0) of the hoisting vehicle 4.

[0094] [Description of the speed command value calculation device in this embodiment]

[0095] In this embodiment, a load swing suppression control device is proposed for using the double pendulum model to suppress the swing of the hook.

[0096] Figure 10 This describes the structure of the speed command value calculation device 110 in this embodiment. Figure 10 The speed command value calculation device 110 shown is for suppressing Figure 4 Based on the structure of the primary mode of oscillation (caused by the hoisting object), a device has been added to suppress the secondary mode of oscillation (caused by the hook).

[0097] In the crane model calculation device 111, using formula (9), the speed of the hoisted object (vp) including the swing of the hook 7 is calculated based on the hoisting vehicle speed command value (v0), and the hoisted object speed (vp) is fed back to the first swing suppression control device 112 and the second swing suppression control device 114.

[0098] exist Figure 10In this system, the first swing suppression control device 112 consists of a first feedforward control device 112a and a first feedback control device 112b. The first feedforward control device 112a is input with a target speed command value (vpref), and the speed of the hoisted object (vp) is fed back to it for correction. The first hoisting vehicle speed command value is then output.

[0099] In addition, the second swing suppression control device 114 is composed of a second feedforward control device 114a and a second feedback control device 114b. The second feedforward control device 114a receives the first hoist speed command value from the first swing suppression control device 112, outputs the hoist speed (vp) of the hoisted object to it for correction, and outputs the second hoist speed command value.

[0100] The second crane speed command value becomes the crane speed command value (v0) input to the crane model calculation device 111, and also becomes the crane speed command value (v0) input to the horizontal motor control device that controls the horizontal motor constituting the crane 4.

[0101] Thus, in the first swing suppression control device 112, the first crane speed command value for the primary mode (i.e., the first-mode swing) that suppresses the swing of the hoisted object 9 is calculated. Then, in the second swing suppression control device 114, the second crane speed command value for the secondary mode (i.e., the second-mode swing) that suppresses the swing of the hook 8 is calculated. Therefore, not only the swing of the hoisted object 9 can be suppressed, but also the swing of the hook 7 can be suppressed.

[0102] exist Figure 10 In the structure, if the transmission characteristics from the input of the second sway suppression control device 114 to the output of the crane model calculation device 111 are considered, the sway component of the second mode contained in the hoisting speed (vp) is suppressed by the second sway suppression control device 114 and becomes the sway component of only the first mode.

[0103] Therefore, from the perspective of the first swing suppression control device 112, the swing of a pendulum in a single-mode can be regarded as the object of suppression, and the knowledge of load swing suppression control based on the existing pendulum model can be flexibly applied to design the first load swing suppression control device.

[0104] Thus, in the present embodiment, the speed command value calculation device 110 includes: a crane model calculation device 111 that calculates a hoisted load speed (vp) of a hoisted load 9 based on a double pendulum model configured by the swing of a hook 7 pivoted on the rotation center of a rope and the swing of the hoisted load 9 pivoted on the hook, according to a speed command value (v0) of a trolley 4; a first swing suppression control device 112 that calculates a first speed command value of the trolley 4 for suppressing the swing of the primary mode of the crane, according to a target speed command value (vpref) of the hoisted load 9 and the hoisted load speed (vp) from the crane model calculation device; and a second swing suppression control device 114 that calculates a second speed command value (v0) of the trolley 4 for suppressing the swing of the secondary mode of the crane, according to the first speed command value from the first swing suppression control device and the hoisted load speed (vp) from the crane model calculation device.

[0105] The second speed command value (v0) from the second swing suppression control device 114 is configured to be input to the crane model calculation device 111 and the traversing motor control device 300 of the trolley 4. Thereby, the double pendulum load swing of the hook and the hoisted load can be suppressed.

[0106] Next, a modified example of the second swing suppression control device 114 will be described. The second swing suppression control device 114 only needs to be designed to suppress the swing of the secondary mode, which is the main mode of the swing of the hook 7. For this purpose, for example, a notch filter having the natural frequency of the secondary mode swing as the cutoff frequency may be used. Figure 11 shows its configuration.

[0107] In Figure 11 , instead of constituting Figure 10 the second feedforward control device 114a and the second feedback control device 114b of the second swing suppression control device 114 shown therein, a notch filter 114c is connected to the first swing suppression control device 112. This notch filter 114c is determined to have a frequency that cuts off the natural frequency of the secondary mode swing.

[0108] In this case, since the main frequency component of the output of the second swing suppression control device 114 is only the primary mode, the crane model calculation device 111 may also calculate the hoisted load speed (vp) from the trolley speed command value (v0) using the following formula (10), based on a single pendulum model having the natural vibration frequency of the primary mode.

[0109] [Equation 10]

[0110]

[0111] Here, ζr1 is the equivalent attenuation ratio of the primary mode, which is obtained from L1, L2, M1, and M2. When the rise rate is 0, ζr1 is 0. Approximately, it can be obtained by ζr1 = vl / (L1 * ωr1).

[0112] Figure 12 It is a calculation Figure 11 An example of the simulation results of the time variation of load swing (x2) and relative swing (x12) in the structure. According to the results, it can be confirmed that, compared with the prior art indicated by dashed lines, as shown by solid lines, the relative swing (x12) can be suppressed by this embodiment.

[0113] Furthermore, the existing technology 2 is applied in the first swing suppression control device 112, that is, in the... Figure 7 The present invention is also effective when the crane 4, after deceleration, is driven at a trapezoidal wave speed to suppress sway. That is, the first sway suppression control device 112 can calculate the speed of the crane 4 to suppress the sway of the crane in a single mode based on the deceleration of the crane 4 and the subsequent trapezoidal wave speed.

[0114] Figure 13 This is an example of the simulation results calculating the time variation of the load swing (x2) and the relative swing (x12) under this condition. Based on these results, it can be confirmed that, compared to the prior art indicated by dashed lines, as shown by solid lines, this embodiment can suppress the relative swing (x12).

[0115] As described above, this embodiment can suppress the oscillation of a double-pendulum load on the hook and the load. Furthermore, it allows for the flexible application of knowledge gained from load oscillation suppression control based on the traditional single-pendulum model, enabling the design of a control system to suppress the oscillation of a double-pendulum load.

[0116] [Example 2]

[0117] Next, the structure of the crane control device according to the second embodiment of the present invention will be described. In the second embodiment, the crane model calculation device 111 is characterized by being configured for both primary and secondary modes.

[0118] That is, if the hoisting speed (vp) is derived from the double pendulum model itself and the hoisting vehicle speed command value (v0), then as shown in equation (9), the polynomial in the denominator becomes a fourth-degree expression of "s". Therefore, considering that the calculation accuracy of the control device 100 is single precision, if equation (9) is used directly, the calculation error will increase.

[0119] Therefore, in this embodiment, it is proposed that... Figure 14 The structure shown is as described. Furthermore, repeated descriptions of structural elements common to the embodiments described above are omitted.

[0120] Figure 14 This illustrates the structure of the speed command value calculation device 110 according to the second embodiment of the present invention. (and...) Figure 10 Compared with the structure, the difference is that the crane model calculation device 111 has: a first crane model state quantity calculation device 111a, which calculates the hoisting speed (vp) based on the hoisting vehicle speed command value (v0) according to the simple pendulum model with a natural vibration frequency of a first mode by formula (10); and a second crane model state quantity calculation device 111b, which calculates the hoisting speed (vp) based on the hoisting vehicle speed command value (v0) according to the simple pendulum model with a natural vibration frequency of a second mode by formula (11).

[0121] [Equation 11]

[0122]

[0123] Here, ζr2 is the equivalent attenuation ratio of the quadratic mode, which is obtained from L1, L2, M1, and M2. When the rise rate is 0, ζr2 is 0. Approximately, it can be obtained by ζr2 = vl / (L * ωr2).

[0124] The hoisting speed (vp) calculated by the first crane model state variable calculation device 111a is fed back to the first feedforward control device 112a for correction via the first feedback control device 112b. Similarly, the hoisting speed (vp) calculated by the second crane model state variable calculation device 111b is fed back to the second feedforward control device 114a for correction via the second feedback control device 114b.

[0125] As in this embodiment, if the speed of the hoisted object is calculated based on the pendulum model of the first and second modes respectively, the polynomial in the denominator of the calculation formula becomes a quadratic expression of "s", and even a single-precision control device can ensure sufficient calculation accuracy.

[0126] As mentioned above, even a control device with a single-precision calculation accuracy can suppress the oscillation of a double pendulum load.

[0127] [Example 3]

[0128] Next, the structure of the crane control device according to the third embodiment of the present invention will be described. In the third embodiment, it is characterized by... Figure 10 Based on the embodiment shown, a crane model state calculation device for a primary mode is added to the second swing suppression control device 114.

[0129] Figure 15 This describes the structure of the speed command value calculation device 110 according to the third embodiment of the present invention. The features of this structure are similar to... Figure 10 Compared to the previous structure, the second swing suppression control device 114 has a crane model state calculation device 111a, which calculates the speed of the hoisted object (vp) based on the hoisting vehicle speed command value (v0) according to the formula (10) based on the pendulum model with a natural frequency of a single mode.

[0130] That is, the difference between the crane model calculation device 111, which calculates the hoisting speed (vp) based on the double pendulum model, and the crane model state quantity calculation device 111a is used as the input to the feedback control device 114b of the second swing suppression control device.

[0131] In this structure, swaying other than the swaying of the primary mode calculated by the crane model state quantity calculation device 111a is suppressed by the feedback control device 114b. Therefore, the transmission characteristics from the input of the second sway suppression control device 114 to the output of the crane model calculation device 111 can be made closer to the characteristics of the primary mode single pendulum model with higher precision, thereby improving the sway suppression performance of the hoisted object 9 in double pendulum load sway suppression.

[0132] [Example 4]

[0133] The crane model calculation device 111 in the previous embodiment was calculated by equation (9) or equation (10) and equation (11). In addition, the first swing suppression control device 112 determined the coefficients used in its calculation based on the natural frequency of the primary mode obtained by equation (7) and equation (8), and the second swing suppression control device 114 also determined the coefficients used in its calculation based on the natural frequency of the secondary mode.

[0134] Observing equations (9), (10), and (11), it can be seen that the coefficient of “s” includes the rope length (L1), the suspension line length (L2), the hook mass (M1), and the mass of the hoisted object (M2). In addition, the natural frequencies of the primary and secondary modes obtained from equations (7) and (8) also vary according to the rope length (L1), suspension line length (L2), hook mass (M1), and the mass of the hoisted object (M2).

[0135] Therefore, if the rope length (L1), suspension line length (L2), hook mass (M1), and hoisting mass (M2) are automatically obtained, and the coefficients of Equation (9), the natural frequencies of the primary mode and the secondary mode are calculated in sequence, and the calculation coefficients used in the crane model calculation device 111, the first swing suppression control device 112, and the second swing suppression control device 114 are updated in sequence, then even if there is a lifting operation with a change in rope length (L1), or a change or replacement of the hoisting object with a change in suspension line length (L2), hook mass (M1), or hoisting mass (M2), the swing of the hoisting object and the hook can be suppressed.

[0136] To automatically obtain the parameters required for the double pendulum load sway suppression control, namely rope length (L1), suspension line length (L2), hook mass (M1), and load mass (M2), the following method can be used.

[0137] One method to obtain the rope length L1 is, for example, simply by measuring it using an encoder installed on the traction motor.

[0138] The hoisting line length (L2) can be obtained, for example, by estimating based on the relationship between the position of the hoisting vehicle 4 and the rope length (L1) when it is wound up to a tensioned state without slack, or by automatically reading the information by installing a tag on the hoisting line 8, or by setting the hoisting line length (L2) information through an external system such as a production management system.

[0139] In addition, the hook mass (M1) can be obtained, for example, by estimating based on motor operation information when the rope is wound up without the load 9 being applied, or by setting the hook mass (M1) information through an external system such as a production management system.

[0140] In addition to the operator inputting the mass of the hoisted object (M2), the mass can also be obtained through methods such as estimating it based on the motor operation information when the hoisting rope is wound, or setting the mass of the hoisted object (M2) information based on external systems such as the production management system.

[0141] With the function of automatically acquiring rope length (L1), suspension line length (L2), hook mass (M1), and load mass (M2) as described above, the parameters required for load sway suppression control can be easily set, making operation easy. Alternatively, these parameters can also be manually entered by the operator.

[0142] This invention is designed for cranes, but it can also be applied to vibration reduction of devices with multiple vibration modes, such as elastically deformable booms. In this case, it is sufficient to suppress the dominant low-order vibration modes in the first oscillation suppression control device and suppress the other high-order vibration modes in the second oscillation suppression control device.

[0143] Furthermore, the present invention is not limited to the above-described embodiments, but includes various modifications. The embodiments described above have been detailed for ease of understanding of the present invention and are not limited to having all the described structures. Additionally, a portion of the structure of one embodiment can be replaced with the structure of another embodiment, and structures of other embodiments can be added to the structure of one embodiment. For the structures of each embodiment, other structures can also be added, deleted, or replaced.

[0144] Explanation of reference numerals in the attached figures

[0145] 1…Crane; 2…Rail; 3…Truss; 4…Lifting vehicle; 5…Traction device; 6…Rope; 7…Hook; 8…Lifting line; 9…Lifted object; 100…Control device; 110…Speed ​​command value calculation device; 111…Crane model calculation device; 112…First swing suppression control device; 113…Limit processing device; 114…Second load swing suppression control device; 200…Operation input device; 300…Horizontal motor control device.

Claims

1. A crane comprising: a traction device that moves a load, via a suspension line or a hook directly suspended from the end of the rope, in a vertical direction by raising / lowering a rope; a horizontal movement device capable of mounting the traction device to move the load in a horizontal direction; an operation input device for inputting a target speed command value for the load; a speed command value calculation device for generating a speed command value for the horizontal movement device based on the target speed command value; and a horizontal movement device control device for controlling the speed of the horizontal movement device according to the speed command value, the crane being characterized in that: The speed command value calculation device has: A crane model calculation device, based on a double pendulum model consisting of the swing of the hook with the rotation center of the rope as the fulcrum and the swing of the hoisted object with the hook as the fulcrum, calculates the hoisted object speed according to the speed command value of the horizontal moving device. A first sway suppression control device calculates a first speed command value to suppress the sway of the crane in a single mode based on the target speed command value and the speed of the hoisted object from the crane model calculation device; and The second sway suppression control device calculates a second speed command value to suppress the sway of the crane in a secondary mode based on the first speed command value from the first sway suppression control device and the speed of the hoisted object from the crane model calculation device. The second speed command value from the second sway suppression control device is input to the crane model calculation device and the horizontal movement device control device.

2. The crane according to claim 1, characterized in that: The crane model calculation device calculates the speed of the hoisted object by adding the swing amount of the crane in one mode to the speed of the horizontal moving device.

3. The crane according to claim 1, characterized in that: The crane model computing device has the following features: The first crane model state quantity calculation device calculates the speed of the hoisted object by adding the swing amount of the crane's primary mode to the speed command value of the horizontal movement device; and The second crane model state quantity calculation device calculates the speed of the hoisted object by adding the swing amount of the crane's secondary mode to the speed command value of the horizontal movement device. The first sway suppression control device calculates the first speed command value to suppress the sway of the crane in the first mode based on the target speed command value and the speed of the hoisted object calculated by the first crane model state quantity calculation device. The second sway suppression control device calculates the second speed command value to suppress the sway of the crane in the secondary mode based on the first speed command value of the first sway suppression control device and the speed of the hoisted object of the second crane model state quantity calculation device.

4. The crane according to claim 1, characterized in that: The crane model computing device has the following features: A first crane model state quantity calculation device calculates the speed of the hoisted object; and The second crane model state quantity calculation device calculates the speed of the hoisted object by adding the swing amount of the crane in the first mode to the speed command value of the horizontal moving device. The first sway suppression control device calculates the first speed command value to suppress the sway of the crane in the first mode based on the target speed command value and the speed of the hoisted object calculated by 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 based on the first speed command value of the first sway suppression control device and the difference between the hoisting speed of the first crane model state quantity calculation device and the hoisting speed of the second crane model state quantity calculation device.

5. The crane according to any one of claims 1 to 4, characterized in that: The parameters of the crane model calculation device, the first swing suppression control device, and the second swing suppression control device are updated sequentially based on any one of the length of the rope, the length of the hoisting line, the mass of the hook, and the mass of the hoisted object.

6. The crane according to claim 5, characterized in that: The length of the rope, the length of the suspension line, the mass of the hook, and the mass of the hoisted object are obtained by measurement or estimation, or from external sources.

7. The crane according to any one of claims 1 to 4, characterized in that: The first sway suppression control device uses the deceleration of the horizontal moving device and its subsequent trapezoidal wave velocity to determine the speed command value for suppressing the sway of the crane in the first mode.

8. The crane according to claim 7, characterized in that: The parameters of the crane model calculation device, the first swing suppression control device, and the second swing suppression control device are updated sequentially based on any one of the length of the rope, the length of the hoisting line, the mass of the hook, and the mass of the hoisted object.

9. The crane according to claim 8, characterized in that: The length of the rope, the length of the suspension line, the mass of the hook, and the mass of the hoisted object are obtained by measurement or estimation, or from external sources.

10. A method for controlling a crane, the crane comprising: a traction device that moves a load, via a suspension line or a hook directly suspended from the end of the rope, in a vertical direction by raising / lowering a rope; a horizontal movement device capable of mounting the traction device to move the load in a horizontal direction; an operation input device for inputting 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 according to the speed command value, the crane control method being characterized in that: The speed command value calculation device performs the following operations: Based on a double pendulum model consisting of the swing of the hook with the rotation center of the rope as the fulcrum and the swing of the hoisted object with the hook as the fulcrum, the hoisted object speed is calculated according to the speed command value of the horizontal moving device. A first speed command value is calculated to suppress the oscillation of the crane in a single mode based on the target speed command value and the speed of the hoisted object; A second speed command value is calculated based on the first speed command value and the speed of the hoisted object to suppress the secondary mode oscillation of the crane; and The second speed command value is input into the control device of the double pendulum model and the horizontal movement device.

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