JP6838781B2 - Steering method for suspended loads and cranes - Google Patents

Description

The present invention relates to a method for restraining a suspended load in a crane and a crane.

In the cargo handling work by a crane for lifting a suspended load, for example, a container crane, the container is shaken when the container is lifted by a rope and when the lifted container is moved. If the container is swinging, when the target position is reached, the container cannot be lowered to the correct position until the swing is settled, and the work efficiency is reduced.
When the container is lifted with a rope, when the trolley that hangs the container moves from a stationary state without runout, the runout of the container that occurs due to the movement is suppressed by controlling the movement speed of the trolley, etc. However, if there is a runout in the container before moving by lifting the container with a rope, the runout of the container that occurs when the container moves overlaps with this runout, and the runout increases, making it difficult to suppress the runout. In some cases.
Therefore, when the container is lifted by a rope, it is important to detect the magnitude of the runout and determine whether or not to suppress the runout.

In order to suppress the runout of the container, it is necessary to accurately detect the runout angle of the container. In order to detect the runout angle, a technique is known in which a rod following the rope is attached near a fulcrum on the base side of the rope and the runout angle of the suspended load is detected as the angle of the rod (Patent Document 1).

Japanese Unexamined Patent Publication No. 2014-97893

However, since the above technique is a mechanical runout detection device, the maximum runout angle at which the runout angle of the container is maximized must wait until the runout angle of the container is maximized. Since the runout of the container has a period of several tens of seconds, waiting until the maximum runout angle is reached is not preferable because it reduces the work efficiency of cargo handling work.

Therefore, the present invention is a steady rest method and a crane for a suspended load, which can quickly predict the maximum runout angle of the runout generated when the suspended load is lifted by a rope and suppress the runout in a short time according to the prediction result. The purpose is to provide.

One aspect of the present invention is a method for restraining a suspended load in a crane. The steady rest method is
While the position of the suspended load fluctuates due to the swing of the suspended load generated when the trolley lifts the suspended load with a rope, the measurement information of the swing angle of the suspended load or the swing displacement of the suspended load and the rope length of the rope. Steps to get the information and
After acquiring the measurement information and the rope length information, the measurement information and the rope length of the suspended load are before the timing when the variable suspended load first reaches the position of the maximum swing angle of the suspended load. The step of predicting the maximum runout angle using the information of
According to the prediction result of the maximum runout angle, the necessity of the steady rest of the suspended load is determined, and when the determination is the steady rest, the step of performing the steady rest control to stop the runout, and
including.
In the steady rest control, the target speed of the trolley is generated based on the difference between the current position of the trolley and the command information of the target position of the trolley, and the difference between the generated target speed and the current speed of the trolley is used. The sum of the amount determined accordingly, the amount determined according to the runout displacement of the suspended load with respect to the trolley, and the amount determined according to the runout speed of the suspended load with respect to the trolley is used as a change amount for changing the generated target speed. The command information of the speed of the trolley given to the driving device for driving the trolley is changed.
At that time, the necessity of the steady rest of the suspended load is determined during the transfer of the suspended load.
In the steady rest control, it is preferable to set the sum of the target speed and the change amount as the command information of the speed of the trolley during the transfer of the suspended load in order to reduce the runout of the suspended load.

When the runout angle is φ, the runout angular velocity of the suspended load is φ', the rope length of the rope is l, and the gravitational acceleration is g, the maximum runout angle is cos ^-1 {cos φ- (l. It is preferably obtained as φ') ² / (2 g · l)}.

The time from the acquisition of the measurement information and the rope length information to the start of the steady rest control is preferably 1/100 or less of the runout cycle of the suspended load. For example, the time is preferably 100 msec or less, preferably 50 msec or less, and even more preferably 40 msec or less. The time is, for example, the same time length as the sampling time of the measurement information. The sampling time is preferably, for example, 40 msec or less, and is, for example, 20 msec.

It is preferable that the steady rest control is started before the timing.

It is preferable that the steady rest control is performed by controlling the position of the trolley so as to reduce the runout of the suspended load.

The command information of velocity of the trolley and u _T, the target speed determined based on the difference between the current position and the target position of the trolley v and _Tref, the current speed of the trolley and v _T, wherein the suspended load When the runout displacement with respect to the trolley is x and the runout velocity of the suspended load with respect to the trolley is v, f ₁ , f ₂ , and f ₃ are set as gain coefficients.
It is preferable that the command information u _T is calculated according to _{v Tref} + f ₁ · (v _Tref −v _T ) −f ₂ · x−f ₃ · v.

One aspect of the present invention is a crane. The crane is
A crane main body including a trolley, a rope extending from the trolley for lifting a suspended load, and a rail forming a transfer path for the trolley.
A control device for controlling the lifting of the suspended load and the transfer of the trolley is provided.
The control device is
An information acquisition unit that acquires measurement information of the swing angle of the suspended load or the swing displacement of the suspended load during fluctuation and information on the rope length of the rope.
After acquiring the measurement information and the rope length information, and before the timing when the suspended load first reaches the position of the maximum swing angle of the suspended load, the maximum is used by using the measurement information and the rope length information. A predictor that predicts the runout angle and
A determination unit that determines the necessity of steady rest of the suspended load according to the prediction result of the maximum runout angle, and a determination unit.
When the determination requires steady rest, a steady rest control unit that performs steady rest control to stop the steady run and
including.
In the steady rest control, the target speed of the trolley is generated based on the difference between the current position of the trolley and the command information of the target position of the trolley, and the difference between the generated target speed and the current speed of the trolley is used. The sum of the amount determined accordingly, the amount determined according to the runout displacement of the suspended load with respect to the trolley, and the amount determined according to the runout speed of the suspended load with respect to the trolley is used as a change amount for changing the generated target speed. The command information of the speed of the trolley given to the driving device for driving the trolley is changed.
At that time, the determination unit determines the necessity of the steady rest of the suspended load during the transfer of the suspended load.
When the determination is that the steady rest is required, the steady rest control unit sets the sum of the target speed and the change amount as a command of the speed of the trolley during the transfer of the suspended load in order to reduce the runout of the suspended load. It is preferable to perform the steady rest control by setting it as information.

It is preferable that the steady rest control unit controls to change the position of the trolley so that the runout of the suspended load is reduced.

The command information of the speed of the trolley is u _T Then, the target speed determined based on the difference between the current position and the target position of the trolley is v. _Tref And the current speed of the trolley is v _T When the runout displacement of the suspended load with respect to the trolley is x and the runout speed of the suspended load with respect to the trolley is v, f. ₁ , F ₂ , And f ₃ As a gain coefficient
The command information u _T Is v _Tref + F ₁ ・ (V _Tref −v _T ) -F ₂ ・ X-f ₃ -It is preferable that it is calculated according to v.

According to the suspension method and the crane of the above-described embodiment, the maximum deflection angle of the runout generated when the suspended load is lifted by a rope can be quickly predicted, and the runout can be suppressed in a short time according to the prediction result. it can.

It is a figure which shows an example of the structure of the container crane of this embodiment. It is a figure which shows typically the swing angle φ of the suspended load, the runout displacement x of the suspended load, and the position x _{T of the trolley in the container crane of this embodiment.} It is a figure explaining an example of the structure of the control device of the container crane of this embodiment. It is a figure explaining an example of the structure of the steady rest control part of the control device shown in FIG. It is a figure explaining an example of the control of the steady rest control part of this embodiment. It is a figure which shows an example of the result of simulating the suppression of the steady rest of a container using the control simulation model which reproduced the feedback control system of the steady rest of a container used in this embodiment. It is a figure which schematically explains the behavior of the runout by the control of the steady rest of the suspended load performed in this embodiment.

Hereinafter, the steady rest control method and the control device for the container of the present embodiment will be described in detail.
In the present embodiment, the container is a suspended load, but the suspended load is not limited to the container. The suspended load and the crane are not limited to the container and the container crane as long as the suspended load is lifted by a rope and the lifted load is moved by using a trolley.

FIG. 1 is a diagram showing an example of the configuration of the container crane 4 used in the present embodiment. The container crane 4 is a device provided on the quay for loading and unloading containers between the container ship and the container yard. FIG. 1 shows a container crane 4 for loading and unloading a container 3 between a container yard of a quay 2 mooring a container ship 1 and the like and a container ship 1. The container crane 4 has a front leg 5 and a rear leg 6 movably provided on the quay 2 along the quay. A girder 9a is horizontally provided on the tops of the front legs 5 and the rear legs 6. A boom 9b is undulatingly attached to the sea side end of the girder 9a so as not to interfere with the berthing of the container ship 1. The horizontal beam 9 composed of the girder 9a and the boom 9b is reinforced by the backstay 10.

The container crane 4 mainly includes a crane main body 12, a control device 20, and a drive device 40.
The crane main body 12 includes a trolley 7, a rope 8 connected to the trolley 7 that lifts the container 3, and a rail 11 that forms a transfer path for the trolley 7. The rope 8 extends from the trolley 7.
The trolley 7 moves on the rail 11 provided on the horizontal beam 9. The trolley 7 is provided with a rope 8 for suspending the container 3, a spreader (not shown) for expanding and contracting the grip portion according to the size of the container, and a moving mechanism for the trolley 7. The trolley 7 lifts the container 3 and moves between the container ship 1 and the container yard. At this time, the steady rest feedback control of the container 3 including the position control with respect to _{the target position x Tref of the trolley 7 is performed.} When the container 3 is lifted or transferred, the container 3 causes a pendulum vibration, that is, a runout, according to the rope length of the rope 8 that suspends the container 3 due to a misalignment between the container 3 and the trolley 7. It may occur. In the present embodiment, it is determined whether or not the runout is within the permissible range, and if the runout is not within the permissible range as a result of the determination, the runout is stopped.

FIG. 2 is a diagram schematically illustrating a runout angle φ of the container 3 in the container crane 4 of the present embodiment, a runout displacement x of the container 3, and a position x _{T of the} trolley 7.
The runout angle φ is an angle based on a straight line in the vertical downward direction in which the rope 8 of the trolley 7 hangs down in the vertical direction. The runout displacement x of the container 3 is a relative position (position in the transfer direction of the container 3) with respect to the position where the rope 8 extends from the trolley 7, and assuming that the rope length l of the rope 8, x = l · φ It is expressed as. The position x _{T of the} trolley 7 represents the distance in the direction along the rail 11 from the predetermined reference position. The rope length l changes with time because the container 3 is lifted. The runout angle φ also changes with time. The runout speed of the container 3 is expressed as φ'. When the trolley 7 controls the steady rest of the container 3, the steady rest of the container 3 is suppressed by the position x _T fluctuating slightly or the speed of the trolley 7 fluctuating.

The trolley 7 of the container crane 4 of the present embodiment is provided with an image pickup device 7a (see FIG. 2) that captures an image of the container 3 from the trolley 7. The image pickup device 7a is configured to obtain the runout displacement x of the container 3 from the captured image and send it to the control device 20. Further, the container crane 4 is provided with a sensor 7b for measuring the transfer speed of the trolley 7. Sensor 7b outputs a velocity _{v T} of the trolley 7 to the control device 20.

The control device 20 controls the lifting of the container 3 and the transfer of the trolley 7. Specifically, the control device 20 sends a control signal for lifting the container 3 by the rope 8 to the drive device 40. When the container 3 is lifted, the control device 20 determines whether or not there is runout of the container 3, and sends a control signal for controlling the steady rest of the container 3 to the drive device 40 according to the determination result. Further, the control device 20 sends a control signal to the drive device 40 for performing the transfer controlled so that the runout does not occur during the transfer to the container 3 in which the runout is suppressed.
The drive device 40 is a device that winds up the rope 8 and transfers the container 3, and these operations are performed based on the control signal sent from the control device 20.

FIG. 3 is a diagram illustrating an example of the configuration of the control device 20.
The control device 20 is composed of a computer. The control device 20 includes an information acquisition unit 22, a prediction unit 24, a determination unit 26, and a steady rest control unit 28. Each part of the information acquisition unit 22, the prediction unit 24, the determination unit 26, and the steady rest control unit 28 is a software module formed by the computer calling and activating the program recorded in the memory of the computer. Therefore, the function of each part is substantially controlled by the central processing unit (CPU) of the computer according to the program.

The information acquisition unit 22 has the runout displacement x of the container 3 due to the runout of the container 3 generated when the trolley 7 lifts the container 3 with the rope 8, the runout velocity x'(= v) obtained from this runout displacement x, and Obtain the rope length l. The rope length l is sent to the control device 20 from a sensor provided in a mechanism for feeding and winding the rope 8. The runout velocity v is the time change Δx of the runout displacement x (the difference between the adjacent runout displacement data x1 and x2 of the runout displacement x sent at a constant sampling time interval Δt) at the sampling time interval Δt of the runout displacement x. Obtained by dividing.
The runout angle φ is obtained by calculating x / l, and the runout angular velocity φ'is the time change Δφ of the runout angle φ (the runout angles φ1 and φ2 of the runout angles φ for each constant sampling time interval Δt). Difference) is obtained by dividing by the sampling time interval Δt of the runout angle φ.

The prediction unit 24 uses the runout displacement x, the runout angular velocity φ', and the rope length l of the container 3 obtained by the information acquisition unit 22, and the maximum runout angle φ _{max, which is the maximum angle of the runout angle φ in the runout of the container 3.} Predict. Specifically, when the gravitational acceleration is g, the prediction unit 24 calculates the maximum runout angle φ _max as cos ^-1 {cos φ − (l · φ') ² / (2 g · l)}.
The above calculation formula can be obtained because the total energy of the runout of the container 3 is constant because the total amount of the kinetic energy of the container 3 and the potential energy with respect to gravity is constant.

The determination unit 26 determines the necessity of the steady rest of the container 3 according to the maximum runout angle φ _{max calculated by the prediction unit 24.} Specifically, if the maximum runout angle φ _max is within the permissible range, it is not necessary to stop the runout. If the maximum runout angle φ _max exceeds the permissible range, runout is stopped.

The steady rest control unit 28 performs steady rest control to stop the steady rest of the container 3 when the determination result of the determination unit 26 does not require the steady rest of the container 3. Specifically, the steady rest control unit 28 generates a control signal for transferring the container 3 by the trolley 7 based on _{the target position x Tref of the trolley 7 input from the operator.} This control signal is a signal for transferring the container 3, and is a control signal for steady rest control that stops the runout of the container 3 during the transfer of the container 3.
When a steady rest of the container 3 is required, a target position x _Tref is set so as to stand still at the current position of the trolley 7, and the container 3 generated by lifting by the rope 8 based on the _{set target position x Tref.} Generates a steady rest control signal that suppresses runout.
The information acquisition unit 22, the prediction unit 24, and the determination unit 26 continue to perform each of the above processes until the steady rest is no longer required.
The control of the steady rest generated when the container 3 is lifted by the rope 8 and the control of the steady rest during the transfer of the container 3 are performed by the same steady rest control method described later.

In the present embodiment, the prediction unit 24, as long as shake angle phi of the container 3 measured is not the maximum deflection angle phi _max, after the acquisition of the vibration displacement x rope length l, the position of the maximum deflection angle phi _max container 3 is first The maximum runout angle φ _max is predicted before the timing of reaching. Information on the runout displacement x and the rope length l is sent to the control device 20 every 20 msec, for example, but the control device 20 performs all the processing of the information acquisition unit 22, the prediction unit 24, and the determination unit 26 in, for example, 20 msec. It can be carried out. Therefore, before the timing at which the container 3 reaches the position of the first maximum deflection angle phi _max, it is possible to predict the maximum deflection angle phi _max.
In this way, the control device 20 can quickly predict _{the maximum runout angle φ max of the container 3.} Therefore, the control for suppressing the runout can be started in a short time according to the prediction result, and the runout can be suppressed in a short time.
In the present embodiment, the runout displacement x of the container 3 is measured, and the control device 20 acquires the runout displacement x. However, since there is a relationship of x = l · φ, the runout angle φ is used instead of the runout displacement x. You may get it.

In the container crane 4 of this embodiment,
(1) While the position of the container 3 is fluctuating due to the runout of the container 3 that occurs when the trolley 7 lifts the container 3 with the rope 8, the information acquisition unit 22 measures the runout angle φ or the runout displacement x of the container 3. And get the information of the rope length l,
(2) After acquiring the above measurement information and the rope length l information, the prediction unit 24 sets the measurement information and before the timing when the _{fluctuating container 3 first reaches the position of the maximum swing angle φ max of the container 3.} Predict the _{maximum runout angle φ max} using the information of the rope length l,
(3) The determination unit 26 determines _{the necessity of the steady rest of the container 3 according to the prediction result of the maximum runout angle φ max} , and when the determination is the steady rest required, the steady rest control unit 28 of the container 3 Run-stop Control is performed to stop run-out.

_{In this case, the control device 20 sets the maximum runout angle φ max} with respect to the runout angle φ of the container 3, the rope length l, the runout speed v of the container 3, and the gravitational acceleration g, cos ^-1 {cos φ- (l). -V) ^{It is preferable to calculate as 2} / (2 g · l)}.

In the present embodiment, since the deflection angle phi of the container 3 is calculated quickly maximum deflection angle phi _max Before maximum deflection angle phi _max, to quickly suppress the vibration of the container 3, stopping deflection in a short time It is preferable to start the control of.
Therefore, in the present embodiment, the time from the acquisition of the measurement information of the runout displacement x and the information of the rope length l to the start of the control of the steady rest is 1/100 or less of the runout cycle of the container 3. preferable. This time is, for example, preferably 100 msec or less, more preferably 50 msec or less, and even more preferably 40 msec or less. For example, 20 ms. Further, this time is the same time as the sampling time for, for example, the measurement of the runout displacement x. Further, it is preferable that the steady rest control is started before the timing when the runout angle φ of the container 3 becomes the maximum runout angle φ _max.

(Sway stop control)
The method of controlling the steady rest of the container 3 used in the present embodiment will be described below.
FIG. 4 is a diagram illustrating an example of the configuration of the steady rest control unit 28 of the control device 20. FIG. 5 is a diagram illustrating an example of control of the steady rest control unit 28 of the present embodiment.

As shown in FIG. 4, the steady rest control unit 28 includes a position control compensation unit 28a and a speed command value generation unit 28b. When the steady rest control unit 28 _{receives the input of the target position x Tref} of the trolley 7 from the operator _{, the steady rest control unit 28 receives information on the position x T of} the trolley 7, the speed v _{T of the} trolley 7, the runout displacement x of the container 3, and the runout speed v thereof. and outputs a speed command value u _T of the trolley 7 to the drive unit 40 as a feedback control signal using. In this case, a steady rest control parameter is given in advance so that the runout overshoot of the container 3 is small and is rapidly attenuated.
Incidentally, the speed v _T of the trolley 7 are sent continuously from the sensor 7b provided on the trolley 7 to the control device 20, vibration displacement x of the container 3, the control unit 20 from the imaging device 7a provided on the trolley 7 Will be sent continuously. The control device 20 obtains and acquires _{the position x T} of the trolley 7 by integrating (accumulating) _{the velocity v T of the} trolley 7 from the time when the trolley 7 is located at the reference position. The control device 20 obtains and acquires the runout velocity v of the container 3 by dividing the time change of the runout displacement x of the container 3 by the sampling time interval Δt of the runout displacement x.

As shown in FIG. 5, when the target position x _Tref of the trolley 7 is input to the steady rest control unit 28, the position control compensation unit 28a of the steady rest control unit 28 sets the current position x _T of the trolley 7 and the target position. The position control correction function H (s is a complex number in control engineering) is calculated on the difference from _{x Tref. The position control compensation unit 28a calculates the target speed v Tref} of the trolley 7 by calculating the position control correction function H (s). The position correction function H (s) is, for example, a function in which the denominator and the numerator are represented by a polynomial of s.
The speed command value generation unit 28b adds f ₁ · (v _Tref −v _{T ) to the target speed v Tref} calculated by the position control compensation unit 28a, _{and f 2} · x and f ₃ · v from the target speed v _Tref. by subtracting the calculated velocity command value u _T of the trolley 7. That is, the speed command value generation unit 28b _{calculates the speed command value u T according} to the following equation (1).

u _T = v _Tref + f ₁ · (v _Tref −v _T ) −f ₂ · x−f ₃ · v ・ ・ ・ Equation (1)
Note that v _Tref is v _Tref = H (s) · (x _Tref −x _T ).

Here, f ₁ , f ₂ , and f ₃ are gain coefficients in the feedback control. This gain coefficient can be obtained by obtaining a control simulation model that reproduces steady rest control with a mathematical model. Specifically, the control simulation model is a model in which a system model of a state equation representing the movements of the container 3 and the trolley 7 and a feedback control equation expressed by the above equation (1) of the crane main body 12 are coupled. Is. In the above equation of state _{, four state variables are used: the position x T of} the trolley 7 in the crane body 12, the speed v _{T of the} trolley 7, the runout displacement x of the container 3, and the runout speed v thereof.

Specifically, in the system model of the above state equation, when the velocity v _{T of} the trolley 7, the position x _{T of the} trolley 7, the runout velocity v of the container 3, and the runout displacement x of the container 3 are represented by the state vector X, It can be expressed by the following equation (2).
dX / dt = A ・ X + bu _T・ ・ ・ Equation (2)
Here, dX / dt represents the time derivative of the state vector X. A is a matrix representing the system model of the crane body 12, b is a vector representing the coefficients according to the speed command value u _T which is input to the system model. Therefore, the control simulation model is a model in which the above equations (1) and (2) are combined.
The simultaneous control simulation model is represented by the following equation (3).
dX / dt = A'・ X + b'v _Tref・ ・ ・ Equation (3)
Here, A'is a matrix of a control simulation model including feedback control, and _b'is a vector representing a coefficient related to the target velocity v Tref of the trolley 7 input to this control simulation. _{F 1} , f ₂ , and f ₃ in the formula (1) are included in the matrix A'. By performing the simulation using this control simulation model, it can be determined based on the control parameters defined so that the runout overshoot of the container 3 is small and is rapidly attenuated. The control parameter can include, for example, a parameter that determines the natural angular frequency of the pole in the control simulation model and a parameter (attenuation ratio) that indicates the degree of attenuation at the natural angular frequency. Using this control parameter _can represent f 1, _{f 2,} and _{f 3.} Therefore, f ₁ , f ₂ , and f _{3 are the values of f 1} , f ₂ , and f ₃ such that the overshoot of the runout of the container 3 is small and is rapidly attenuated by setting the value of the control parameter. Can be sought.

_{In such steady rest} control, if 0 is input to the target position x Tref, the steady rest 7 can perform the steady rest control without transferring the container 3. That is, the steady rest control of the container 3 can be performed before the transfer of the container 3.
Further, if a value larger than 0 is input to the target position x _Tref , the trolley 7 can be transferred, and the transfer speed of the trolley 7 can be controlled so that the container 3 does not swing during the transfer of the container 3. ..

FIG. 6 is a diagram showing an example of the result of simulating the suppression of the steady rest of the container 3 in the crane main body 12 using the control simulation model. In this example, 0 is input to _{the target position x Tref.} Shake the container 3 occurs at time _{T 1,} has started _f 1, _{f 2,} and steadying control using _{f 3} at time _{T 2.} At times T _{1 to} T ₂ , the runout of the container 3 is freely attenuated. In FIG. 6, the waveform of the runout is folded back and forth and overwritten. As can be seen from FIG. 6, the time T _2, after the shake angle φ is decreasing rapidly. Further, this simulation result is substantially in agreement with the behavior in the steady rest control of the container 3 in the actual container crane. From this, it can be seen that the steady rest control of the container used in the present embodiment is appropriate.

As described above, the steady rest control of the present embodiment is _{controlled by giving the speed command value u T} of the trolley 7 to the drive device 40 so that the runout of the container 3 becomes small, that is, the position x _{T of the} trolley 7 is set. It is preferably performed by fluctuating control.
Further, the control of the steady rest of the container 3 of the present embodiment is controlled by the velocity v _T of the trolley 7, the runout displacement x of the container 3 with respect to the trolley 7, the position x _T of the trolley 7, and the runout speed v of the container 3 with respect to the trolley 7. Correspondingly, be done by changing the speed command value u _T of the trolley 7 to be applied to the driving device 40 for driving the trolley 7 is preferable in terms of accurate deflection suppression.
At that time, the speed command value u _{T of the trolley 7 is generated based on the difference between the position x T} of the trolley 7 and _{the command information of the target position x Tref} of the trolley 7, which accurately controls the position of the trolley 7. Preferred in terms of points.

FIG. 7 is a diagram schematically illustrating the behavior of runout by controlling the steady rest of the container 3 performed in the present embodiment.
In FIG. 7, the waveform A shows the runout angle φ, and the waveform B shows the prediction result of the _{maximum runout angle φ max.} In the waveform A, at time T _1, the deflection of the container 3 has occurred. After that, _{before reaching the time T 2} , the prediction unit 24 predicts the maximum runout angle φ _max , and the steady rest control is started at the time T _2. However, since the container 3 at time T _2, it is in a state where shake angle φ increases, immediately shake unattenuated, has a maximum deflection angle at time T _3. Then, at time T _4, the shake is set to substantially zero. The waveform B is a time-series waveform having a _{maximum runout angle φ max} predicted by the prediction unit 24. As described above, in the present embodiment, the prediction unit 24 can quickly predict the maximum runout angle φ _max before the runout angle φ of the container 3 reaches the maximum runout angle φ _max , and responds to this prediction result. Therefore, the runout of the container 3 can be suppressed in a short time.

Although the method for restraining the suspended load and the crane of the present invention have been described in detail above, the present invention is not limited to the above-described embodiment, and various improvements and changes may be made without departing from the gist of the present invention. Of course it is good.

1 Container ship 2 Quay 3 Container 4 Container crane 5 Front leg 6 Rear leg 7 Trolley 9 Horizontal beam 9a Girder 9b Boom 10 Backstay 11 Rail 20 Control device 22 Information acquisition unit 24 Prediction unit 26 Judgment unit 28 Steering control unit 28a Position control Compensation unit 28b Speed command value generation unit 40 Drive device

Claims (11)

It is a steady rest method for suspended loads in a crane.
While the position of the suspended load fluctuates due to the swing of the suspended load generated when the trolley lifts the suspended load with a rope, the measurement information of the swing angle of the suspended load or the swing displacement of the suspended load and the rope length of the rope. Steps to get the information and
After acquiring the measurement information and the rope length information, the measurement information and the rope length of the suspended load are before the timing when the variable suspended load first reaches the position of the maximum swing angle of the suspended load. The step of predicting the maximum runout angle using the information of
According to the prediction result of the maximum runout angle, the necessity of the steady rest of the suspended load is determined, and when the determination is the steady rest, the step of performing the steady rest control to stop the runout, and
Including
In the steady rest control, the target speed of the trolley is generated based on the difference between the current position of the trolley and the command information of the target position of the trolley, and the difference between the generated target speed and the current speed of the trolley is used. The sum of the amount determined accordingly, the amount determined according to the runout displacement of the suspended load with respect to the trolley, and the amount determined according to the runout speed of the suspended load with respect to the trolley is used as a change amount for changing the generated target speed. A method for restraining a suspended load, which comprises changing the command information of the speed of the trolley, which is determined and given to a driving device for driving the trolley. Judgment as to whether or not the suspension of the suspended load is necessary is performed during the transfer of the suspended load.
Wherein in steadying control, in order to reduce the deflection of the suspended load, it sets the sum of the change amount and the target speed as the command information of velocity of the trolley in the transfer of the suspended load, to claim 1 The method of restraining the suspended load described. When the runout angle is φ, the runout angular velocity of the suspended load is φ', the rope length of the rope is l, and the gravitational acceleration is g, the maximum runout angle is cos ^-1 {cos φ- (l. The method for preventing a suspended load according to claim 1 or 2, which is obtained as φ') ^{2 / (2 g · l)}.} The time from the acquisition of the measurement information and the rope length information to the start of the steady rest control is
The method for preventing the suspension of the suspended load according to any one of claims 1 to 3, which is 1/100 or less of the swing cycle of the suspended load. The steady rest method according to any one of claims 1 to 4, wherein the steady rest control is started before the timing. The steady rest method according to claim 1, wherein the steady rest control is performed by controlling the position of the trolley so as to reduce the runout of the suspended load. The command information of the speed of the trolley is u _T , the target speed determined based on the difference between the current position and the target position of the _{trolley is v Tref} , the current speed of the trolley is v _T , and the suspended load is When the runout displacement with respect to the trolley is x and the runout velocity of the suspended load with respect to the trolley is v, f ₁ , f ₂ , and f ₃ are set as gain coefficients.
The suspended load according to any one of claims 1 to 6, wherein the command information u _T is _{calculated according to v Tref} + f ₁ · (v _Tref −v _T ) −f ₂ · x−f _{3 · v.} How to stop the steady rest. A crane main body including a trolley, a rope extending from the trolley for lifting a suspended load, and a rail forming a transfer path for the trolley.
A control device for controlling the lifting of the suspended load and the transfer of the trolley is provided.
The control device is
An information acquisition unit that acquires measurement information of the swing angle of the suspended load or the swing displacement of the suspended load during fluctuation and information on the rope length of the rope.
After acquiring the measurement information and the rope length information, and before the timing when the suspended load first reaches the position of the maximum swing angle of the suspended load, the maximum is used by using the measurement information and the rope length information. A predictor that predicts the runout angle and
A determination unit that determines the necessity of steady rest of the suspended load according to the prediction result of the maximum runout angle, and a determination unit.
When the determination requires steady rest, a steady rest control unit that performs steady rest control to stop the steady run and
Including
In the steady rest control, the target speed of the trolley is generated based on the difference between the current position of the trolley and the command information of the target position of the trolley, and the difference between the generated target speed and the current speed of the trolley is used. The sum of the amount determined accordingly, the amount determined according to the runout displacement of the suspended load with respect to the trolley, and the amount determined according to the runout speed of the suspended load with respect to the trolley is used as a change amount for changing the generated target speed. A crane characterized in that the command information of the speed of the trolley is determined and given to a driving device for driving the trolley. The determination unit determines the necessity of steady rest of the suspended load during the transfer of the suspended load .
When the determination is necessary to stop the steady load, the steady rest control unit sets the sum of the target speed and the change amount as a command of the speed of the trolley during the transfer of the suspended load in order to reduce the runout of the suspended load. The crane according to claim 8 , wherein the steady rest control is performed by setting it as information. The crane according to claim 8, wherein the steady rest control unit controls to change the position of the trolley so that the runout of the suspended load is reduced. The command information of the speed of the trolley is u _T , the target speed determined based on the difference between the current position and the target position of the _{trolley is v Tref} , the current speed of the trolley is v _T , and the suspended load is When the runout displacement with respect to the trolley is x and the runout velocity of the suspended load with respect to the trolley is v, f ₁ , f ₂ , and f ₃ are set as gain coefficients.
The crane according to any one of claims 8 to 10, wherein the command information u _T is _{calculated according to v Tref} + f ₁ · (v _Tref −v _T ) −f ₂ · x−f _{3 · v.}

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