JP5194660B2 - Crane steady rest control apparatus and crane steady rest control method - Google Patents

Description

  The present invention relates to a crane steady-state control device and a crane steady-state control method, and in particular, is suitable for application to a steady-state control method for a suspended crane in which a trolley is traversed to perform a cargo handling operation.

In harbors, steelworks, and various factories, cargo handling operations are performed by traversing trolleys while holding suspended loads with cranes. In such a crane handling operation, if the target position can be reached within a short time and the swing angle of the suspended load can be reduced to zero when the target position is reached, the crane can be operated ideally. In order to realize an ideal crane operation, various crane steady-state control systems have been developed so far. Crane steady rest control systems can be broadly divided into two types: mechanical steady rest control systems and electrical steady rest control systems. In recent years, electrical steady rest control systems have become mainstream from the viewpoint of maintainability. ing.
In the electric steadying control method, a method of performing steadying control by calculating a speed pattern that can eliminate shaking at the end of acceleration / deceleration (Patent Document 1), and detecting a swinging angle of a suspended load and the detection result Is fed back to the drive system (Patent Document 2).

FIG. 5 is a block diagram illustrating an example of a schematic configuration of a conventional crane steady-state control device, and FIG. 6 is a diagram illustrating an ideal swing angle response by the crane steady-state control device of FIG.
In Figure 5, the speed controller 101, a difference circuit for calculating a deviation between the detected speed V _m of the corrected speed desired values V _d and the motor 101d, the deviation between the rotational speed V _m of the corrected speed desired values V _d and the motor 101d Is provided with a compensator 101b for compensating so that the value approaches zero, a main amplifier 101c for amplifying the output of the compensator 101b, an electric motor 101d for driving the crane 102, and a speed detector 101e for detecting the rotational speed Vm of the electric motor 101d. Yes.

In the preceding stage of the speed control device 101, an input device 103 for inputting traveling conditions such as a rope length l, a moving amount L, a maximum speed V _max which is a constraint condition of the crane system, a maximum acceleration a _{max, and the} like are input to the input device 103. An acceleration switching time calculation device 104 that calculates an acceleration switching time from the input running conditions and a speed pattern generation device 105 that generates a trolley speed pattern are provided.
Further, the crane 102 is provided with a trolley 102a that traverses the rails by wheels while suspending a suspended load 102c, and a gear mechanism 102b that transmits the power of the electric motor 101d to the trolley 102a.

Then, as shown in FIG. 6, the speed pattern generator 105 solves the equation of motion related to the trolley speed and the rope deflection angle while satisfying the conditions obtained from the boundary conditions and the constraint conditions at the start and end of acceleration. the speed pattern having an acceleration section in which speed interval is inserted to generate a command pattern x _r, by operating the trolley 102a based on this speed pattern, it is possible to suppress the deflection of the suspended load 102c.

FIG. 7 is a block diagram showing another example of a schematic configuration of a conventional crane steady-state control device, and FIG. 8 is a diagram showing an ideal swing angle response by the crane steady-state control device of FIG.
In FIG. 7, the crane steadying control device includes a speed command device 121 that generates a speed command signal, and a linear command device 122 that converts the speed command signal generated by the speed command device 121 into a ramp-shaped speed command N _RF0. By _adding the damping control speed command correction signal N _RFDF generated by feeding back the signal N _MFB passed through the filter 126 having the first-order lag element to the speed command N _RF0 output from the linear command unit 122, damping controller 130 for calculating a compensation velocity command signal N _RF2, generates a corrected speed command signal N _RF2 outputted from the damping controller 130, a speed command signal T _RF from the deviation between the signal N _MFB through the filter 126 speed controller 123, the motor torque controller 124 for generating a torque T _M from the velocity command signal T _RF, block 125, indicating the mechanical time constant tau _M of the electric motor primary A filter 126 having a moving element, a block 127 indicating a motion model of a swinging angle of a suspended load, a block 128 indicating a load model of a load torque of an electric motor, and a swinging angle detector 129 for detecting a swinging angle θ of the suspended load. Yes.

Then, the swinging angle signal V _LE of the suspended load detected by the swinging angle detector 129 is fed back to the damping controller 130, and as shown in FIG. 8, a damping control speed command in consideration of this swinging angle signal _VLE is obtained. a correction signal N _RFDF, by adding the speed command N _RF0 outputted from the linear commander 122 generates a corrected speed command signal N _RF2 as command pattern x _r, operate the trolley on the basis of the command pattern x _r By doing so, the damping according to the damping coefficient δ can be applied to the vibration of the swing of the suspended load, and the swing of the suspended load can be suppressed.
JP 56-149987 A JP-A-8-2877

However, in the method disclosed in Patent Document 1, feedforward control is performed, the speed pattern condition depends on the natural frequency (swing period) that changes with the rope length l and the like, and the initial swing angle is zero. Conceivable. For this reason, when the trolley 102a is traversed, there is a problem that the control performance is deteriorated when there is a disturbance such as a mechanical disturbance applied to the trolley 102a or the suspended load 102c, a change in natural frequency, or a shake in an initial state. .
Further, in the method disclosed in Patent Document 2, feedback control using detection values such as a shake angle and a shake angular velocity is performed. Therefore, when there is an abnormality in a sensor that detects a shake angle, a shake angular velocity, or the like, When a disturbance is applied, there is a problem that control becomes impossible or control performance is deteriorated.

Further, when both the feedforward control and the feedback control are applied by combining the configuration of FIG. 5 and the configuration of FIG. 7, the influence of disturbance is reduced as compared to the configuration of FIG. 5, but FIG. Damping is also applied to the deflection angle during acceleration of the configuration of FIG. 5 by the feedback control of the configuration of FIG. For this reason, as shown in FIG. 9, when the acceleration / deceleration ends, the deflection angle does not converge to zero, and when there is no disturbance, there is a problem that the control performance is deteriorated as compared with the configuration of FIG.
Therefore, the object of the present invention is to achieve the target position within a short time while suppressing the swing of the suspended load when the target position is reached even when a disturbance is applied to the trolley, the suspended load or the sensor. The present invention is to provide a crane steady rest control device and a crane steady rest control method.

In order to solve the above-described problem, according to the crane steady-state control apparatus according to claim 1, the swing of the suspended load becomes zero when the acceleration / deceleration of the trolley having the suspended load suspended by the rope is zero. A position control means for generating a speed command value for moving the trolley to a predetermined distance while feeding back the current position of the trolley so as to follow the speed pattern, and the speed pattern and the suspension A suspended load motion model for obtaining a motion command of the suspended load based on a mathematical model of the load, a suspended load motion estimating means for estimating an amount of motion of the suspended load from a swing angle of the suspended load, and the suspended load motion estimating means by calculating the compensation amount to follow the estimated movement amount to the operation command at, and a trolley motion compensation means for compensating the speed command value, the trolley The compensation means is configured to damping an acceleration compensator that sets a compensation amount so that an acceleration of the suspended load follows the operation command, and a transmission characteristic from the speed of the trolley to the acceleration of the suspended load. And a compensation amount set by the acceleration compensator during acceleration / deceleration of the trolley, and set by the damping compensator after completion of acceleration / deceleration of the trolley. And a compensation switching device for selecting the compensated amount .

Further, according to the crane steady-state control method according to claim 2, in the crane steady-state control method provided with a trolley having a suspended load suspended by a rope and a trolley driving device for driving the trolley, the trolley When the trolley moves a predetermined distance, the speed pattern is such that the swing of the suspended load is zero when the acceleration / deceleration of the trolley is zero with respect to the rope swing caused by acceleration / deceleration, Generating a speed command value for moving the trolley to a predetermined distance while feeding back the position and following the speed pattern; and operating the suspended load based on the speed pattern and a mathematical model of the suspended load. And determining the amount of movement of the suspended load from the swing angle of the suspended load to cause the suspended load to follow the operation command. Calculating a compensation amount, and a step of compensating the speed command value by the compensation amount, operation instruction and the operation amount of the suspended load are each acceleration and speed, the compensation amount is acceleration or deceleration of the trolley Sometimes the acceleration of the suspended load is set to follow the operation command, and after the acceleration / deceleration of the trolley is completed, the transmission characteristic from the speed of the trolley to the acceleration of the suspended load is set to be damped. characterized in that that.

  As described above, according to the present invention, during the trolley acceleration / deceleration operation, the trolley can be operated so that the actual deflection angle follows the ideal deflection angle, and the trolley acceleration / deceleration can be performed. After completion, it is possible to move the trolley to the desired distance while converging the rope swing due to disturbance to zero by virtually increasing the damping, reaching the target position within a short time, and The swing of the suspended load when it reaches can be suppressed.

Hereinafter, a crane steadying control apparatus according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a schematic configuration of a crane steadying control apparatus according to an embodiment of the present invention, and FIG. 2 is a diagram showing a crane motion model according to an embodiment of the present invention.
1 and 2, the crane mechanical system 8 constitutes the crane 21 of FIG. 2, and the crane 21 is provided with a trolley 24 having a suspended load 23 suspended by a rope 22. The crane mechanical system 8 is connected to a trolley driving device 7 that drives the trolley 24 and a deflection angle detector 9 that detects a deflection angle θ of the suspended load 23. A crane steady-state control device 16 that controls the drive of the trolley 24 while suppressing the swing of the suspended load 23 when reaching the target position is connected.

This crane steady rest control device 16 includes an angular frequency setter 1, an acceleration condition calculator 2, a pattern generator 3, a subtracter 4, a position controller 5, an adder 6, a lifting motion model 10, and a speed estimator 11. , An acceleration estimator 12, an acceleration compensator 13, a damping compensator 14, and a compensation switching device 15 are provided.
Here, the angular frequency setter 1 can input the rope length l of the rope 22 and set the nominal specific frequency ω _n of the suspended load 23 that changes according to the rope length l of the rope 22.

The acceleration condition calculator 2 inputs operating conditions such as nominal specific frequencies ω _n , the movement amount L of the trolley 24, the maximum speed V _{max of} the trolley 24, the maximum acceleration a _max of the trolley 24, and defines the acceleration switching time. The minimum acceleration time t _acc to be output can be output.
The pattern generator 3 can generate an operation pattern of the trolley 24 from the operation conditions input to the acceleration condition calculator 2 and output a position command x _Mr of the trolley 24.
The subtractor 4 can output the position deviation x _e by subtracting the current position x _Ma of the trolley 24 fed back from the position detector from the position command x _Mr output from the pattern generator 3.

The position controller 5 can generate a speed command value n _Mr that causes the current position x _Ma of the trolley 24 to follow the position command x _Mr by performing proportional control so that the position deviation x _e decreases.
The adder 6 adds the trolley speed compensation amount n _coma or the trolley speed compensation amount n _comd selected by the compensation switching device 15 to the speed command value n _Mr , so that the speed command value n _Mr is compensated. The value n ′ _Mr can be generated.
The suspended load motion model 10 is based on the mathematical model of the suspended load 23 from the velocity pattern generated by the pattern generator 3 and the nominal specific frequencies ω _n set by the angular frequency setter 1. The suspended load speed command n _Lr and the suspended load acceleration command a _Lr can be obtained.

The speed estimator 11 can calculate the estimated speed n ^* _La of the suspended load 23 based on the trolley speed _nMa and the swing angle θ of the suspended load 23.
The acceleration estimator 12 can calculate the estimated acceleration a ^* _La of the suspended load 23 based on the swing angle θ of the suspended load 23.
The acceleration compensator 13 compensates the trolley speed so that the estimated acceleration a ^* _La of the suspended load 23 calculated by the acceleration estimator 12 follows the suspended load acceleration command a _Lr calculated by the suspended load motion model 10. The quantity n _coma can be set.

The damping compensator 14 can set the trolley speed compensation amount n _comd so that damping is applied to the transfer characteristic from the trolley speed n _Ma to the estimated acceleration a ^* _La of the suspended load 23.
The compensation switching unit 15 selects either the trolley speed compensation amount n _coma output from the acceleration compensator 13 or the trolley speed compensation amount n _comd output from the damping compensator 14 and outputs the selected one to the adder 6. Can do.
Then, the angular frequency setting device 1 sets the nominal specific frequency ω _n of the suspended load 23 based on the rope length l of the rope 22 and outputs it to the acceleration condition calculator 2, the suspended load motion model 10 and the damping compensator 14. To do.

The acceleration condition calculator 2 calculates the acceleration switching time based on the operating conditions such as the nominal natural frequencies ω _n , the movement amount L of the trolley 24, the maximum speed V _{max of} the trolley 24, and the maximum acceleration a _max of the trolley 24. The minimum acceleration time t _acc to be defined is calculated and output to the pattern generator 3. Then, the pattern generator 3 generates an operation pattern of the trolley 24 based on the minimum acceleration time t _acc output from the acceleration condition calculator 2, and the position command x _Mr of the trolley 24 is subtracted from the subtractor 4 and the suspended load motion model. 10 is output. As an operation pattern of the trolley 24, for example, a speed pattern by two-stage acceleration can be used.

FIG. 3 is a diagram showing a speed pattern by two-stage acceleration according to an embodiment of the present invention.
In FIG. 3, the speed pattern by the two-stage acceleration can be expressed by acceleration switching times t ₁ , t ₂ , t ₃ , t ₄ ... The switching times t ₁ , t ₂ , t ₃ , t ₄ ... Can be defined by the minimum acceleration time t _acc .
2 (n−1) <ω _n t _acc <2nπ
t ₁ = (n−1) π / ω _n + t _acc / 2
t ₂ = (n−1) π / ω _n
t ₃ = nπ / ω _n + t _acc / 2
Here, n = 1, 2, 3,..., .Pi.
Alternatively, as an operation pattern of the trolley 24, as shown in FIG. 4, a speed pattern by one-stage acceleration may be used. In this case, the time t _a of the acceleration to the end can be expressed by the following equation.
t _a = ω _n / 2π

When the position command x _Mr trolley 24 is input to the subtractor 4, the subtractor 4 position by subtracting the current position x _Ma of the trolley 24 that is fed back from the position detector from a position command x _Mr deviation _xe is calculated and output to the position controller 5. Then, the position controller 5 performs a proportional control so that the position deviation x _e decreases, thereby generating a speed command value n _Mr that causes the current position x _Ma of the trolley 24 to follow the position command x _Mr. 6 is output. The position controller 5 may generate a speed command value n _Mr by positional deviation x _e performs other control such as proportional integral control to decrease.

On the other hand, when the position command x _Mr of the trolley 24 generated by the pattern generator 3 is input to the suspended load motion model 10, the suspended load motion model 10 is suspended from the position command x _Mr and the nominal natural frequencies ω _n. Based on the mathematical model of the load 23, the suspension load speed command n _Lr and the suspension acceleration command a _Lr of the suspension load 23 are obtained, and the suspension load acceleration command a _Lr is output to the acceleration compensator 13 and the suspension load speed command n _Lr. Is output to the damping compensator 14.

Here, the mathematical model of the suspended load 23 assumes that the movement of the rope 22 and the suspended load 23 with respect to the swing angle θ is a single pendulum and approximates the response of the position control system of the trolley 24 with a first order delay. The suspended load speed command n _Lr and the suspended load acceleration command a _Lr can be obtained by the following equations.
n _Lr (s) = ω _n ² / (s ² + ω _n ² ) · 1 / (T _p s + 1) · x ′ _Mr (s)
a _Lr (s) = sω _n ² / (s ² + ω _n ² ) · 1 / (T _p s + 1) · x ′ _Mr (s)
Here, s is a Laplace operator, and T _p is a time constant when the position control system of the trolley 24 is approximated by a first-order lag system. x ′ _Mr is the derivative of x _Mr.

The trolley speed n _Ma output from the trolley driving device 7 is input to the crane mechanical system 8 and also input to the speed estimator 11. Further, the swing angle θ of the suspended load 23 detected by the swing angle detector 9 is input to the speed estimator 11 and the acceleration estimator 12.
When the trolley speed n _Ma and the swing angle θ of the suspended load 23 are input to the speed estimator 11, the speed estimator 11 detects the rope length l of the rope 22, the trolley speed n _Ma and the swing angle θ of the suspended load 23. Based on the above, the estimated speed n ^* _La of the suspended load 23 is calculated and output to the damping compensator 14.

Here, the relationship between the trolley speed n _Ma and the position x _La of the suspended load 23 can be expressed by the following equation using the swing angle θ of the suspended load 23 and the rope length l of the rope 22.
lsin θ = n _Ma / s−x _La
Therefore, assuming that sin θ = θ, assuming that the change in the swing angle θ of the suspended load 23 is small, the estimated speed n ^* _La of the suspended load 23 can be expressed by the following equation.
^{_{n * La = n Ma -ldθ /}} dt

When the swing angle θ of the suspended load 23 is input to the acceleration estimator 12, the acceleration estimator 12 calculates the estimated acceleration a ^* _La of the suspended load 23 based on the swing angle θ of the suspended load 23, and accelerates the acceleration. It outputs to the compensator 13 and the damping compensator 14.
When the suspended load acceleration command a _Lr and the estimated acceleration a ^* _La of the suspended load 23 are input to the acceleration compensator 13, the acceleration compensator 13 determines that the estimated acceleration a ^* _La of the suspended load 23 is the suspended load acceleration command a. _The trolley speed compensation amount n _coma is set so as to follow _Lr, and is output to the compensation switch 15.

Here, when the mathematical model of the suspended load 23 in the suspended load motion model 10 and the characteristics of the crane mechanical system 8 substantially coincide, the estimated acceleration a ^* _La of the suspended load 23 is also the suspended load even during the acceleration / deceleration operation of the trolley 24. It almost coincides with the acceleration command a _Lr . When the disturbance is applied to the trolley 24, or when the nominal natural frequencies ω _n are different from the actual natural frequencies ω _p of the crane machine system 8, the estimated acceleration a ^* _La of the suspended load 23 is the suspended load acceleration command a. _When deviating from _Lr , the acceleration compensator 13 compensates the speed command value n _Mr with the trolley speed compensation amount n _coma so that the estimated acceleration a ^* _La of the suspended load 23 follows the suspended load acceleration command a _Lr. Unexpected shake during operation of the trolley 24 can be suppressed.

Further, when the suspended load speed command n _Lr , the estimated speed n ^* _La of the suspended load 23 and the estimated acceleration a ^* _La of the suspended load 23 are input to the damping compensator 14, the damping compensator 14 determines from the trolley speed n _Ma. The trolley speed compensation amount n _comd is set so that damping is applied to the transmission characteristic up to the estimated acceleration a ^* _La of the suspended load 23 and is output to the compensation switch 15.
Here, if the motion related to the swing angle θ of the rope 22 and the suspended load 23 is a single pendulum and a damping element σ _L is introduced and a damping element is added, the relationship between the trolley speed n _Ma and the speed n _La of the suspended load 23 is obtained. Can be calculated by the following equation.
n _La (s) = ω _p ² / (s ² + 2σ _L ω _p s + ω _p ² ) · n _Ma (s)

Then, when deforming the above equation, the relationship between the speed n _La of the load 23 hanging the trolley speed n _Ma is as the following equation, may be fed back as the acceleration a _La of the load 23 hanging sn _La.
n _La (s) = (n _Ma (s) −sn _La (s) 2σ _L / ω _p ) ω _p ² / (s ² + ω _p ² )
Therefore, the damping compensator 14 uses the estimated speed n ^* _La of the suspended load 23 and the estimated acceleration a ^* _La of the suspended load 23 in order to add a damping element to the transmission characteristic as described above. As shown, an ideal load speed n _Li is calculated when a damping element is added.
n _Li = n ^* _La -2σ _L / ω _p · a ^* _La

If the trolley speed n _Ma is controlled so as to follow the ideal load speed n _Li , the swing angle θ of the suspended load 23 converges to zero. Therefore, by using the damping compensation gain K _cd , the following formula As shown, the trolley speed compensation amount n _comd is calculated from the suspended load speed command n _Lr .
n _comd = K _cd (n _Li −n _Lr )
The damping compensator 14 compensates the speed command value n _Mr with the trolley speed compensation amount n _comd so that the trolley speed n _Ma follows the speed n _La of the suspended load 23 based on the transmission characteristic to which the damping element is added. Thus, it is possible to move the trolley 24 to a desired distance while converging the rope 22 due to disturbance to zero.

The compensation switch 15 selects the trolley speed compensation amount n _coma output from the acceleration compensator 13 and outputs it to the adder 6 during the acceleration / deceleration operation of the trolley 24. The trolley speed compensation amount n _comd output from the damping compensator 14 is selected and output to the adder 6.
As a result, the trolley 24 can be operated so that the actual deflection angle follows the ideal deflection angle during the acceleration / deceleration operation of the trolley 24. By increasing the damping, it becomes possible to move the trolley 24 to a desired distance while converging the vibration of the rope 22 due to disturbance to zero, and when the target position is reached within a short time, The swinging of the suspended load 23 can be suppressed.

Since the trolley speed _nMa is substantially proportional to the rotation speed of the electric motor that drives the trolley 24, the rotation speed of the electric motor may be used instead of the trolley speed _nMa . Further, when the acceleration of the trolley 24 is suddenly changed due to switching of acceleration in the operation pattern of the trolley 24, the operation pattern of the trolley 24 may be continuously changed by inserting a filter or the like.

It is a block diagram which shows schematic structure of the crane steadying control apparatus which concerns on one Embodiment of this invention. It is a figure which shows the movement model of the crane which concerns on one Embodiment of this invention. It is a figure which shows the speed pattern by the two-step acceleration which concerns on one Embodiment of this invention. It is a figure which shows the speed pattern by 1 step | paragraph acceleration based on one Embodiment of this invention. It is a block diagram which shows an example of schematic structure of the conventional crane steadying control apparatus. It is a figure which shows the response of the ideal deflection angle by the crane steadying control apparatus of FIG. It is a block diagram which shows the other example of schematic structure of the conventional crane steadying control apparatus. It is a figure which shows the response of the ideal deflection angle by the crane steadying control apparatus of FIG. It is a figure which shows the response of the deflection angle when combining the crane steady-state control apparatus of FIG. 5 and FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Angular frequency setter 2 Acceleration condition calculator 3 Pattern generator 4 Subtractor 5 Position controller 6 Adder 7 Trolley drive device 8 Crane mechanical system 9 Deflection angle detector 10 Suspension motion model 11 Speed estimator 12 Accelerator estimator DESCRIPTION OF SYMBOLS 13 Acceleration compensator 14 Damping compensator 15 Compensation switching device 16 Crane steadying control device 21 Crane 22 Rope 23 Suspended load 24 Trolley

Claims (2)

When the speed pattern is such that the swing of the suspended load is zero when the acceleration / deceleration of the trolley with the suspended load suspended by the rope is zero, the current position of the trolley is fed back to follow the speed pattern. Position control means for generating a speed command value for moving the trolley to a predetermined distance,
A suspended load motion model for obtaining an operation command of the suspended load based on the speed pattern and a mathematical model of the suspended load;
Suspended load motion estimation means for estimating the amount of motion of the suspended load from the swing angle of the suspended load;
Trolley motion compensation means for compensating the speed command value by calculating a compensation amount for causing the motion amount estimated by the suspended load motion estimation means to follow the motion command ;
The trolley operation compensation means is
An acceleration compensator that sets a compensation amount so that the acceleration of the suspended load follows the operation command;
A damping compensator for setting a compensation amount so that damping is applied to a transmission characteristic from the speed of the trolley to the acceleration of the suspended load;
A compensation switching unit for selecting a compensation amount set by the acceleration compensator at the time of acceleration / deceleration of the trolley, and a compensation amount set by the damping compensator after completion of the acceleration / deceleration of the trolley; A crane steady rest control device comprising: In a steadying control method of a crane provided with a trolley having a suspended load suspended by a rope and a trolley driving device for driving the trolley,
When the trolley moves a predetermined distance, a speed pattern is set such that the swing of the suspended load is zero when the acceleration / deceleration of the trolley is zero with respect to the rope swing caused by acceleration / deceleration, and the trolley Generating a speed command value for moving the trolley to a predetermined distance while feeding back the current position and following the speed pattern;
Based on the speed pattern and a mathematical model of the suspended load, an operation command for the suspended load is obtained, and the suspended load is caused to follow the operation command by estimating an operation amount of the suspended load from a swing angle of the suspended load. Calculating a compensation amount, and compensating the speed command value with the compensation amount ,
The operation command and operation amount of the suspended load are acceleration and speed, respectively.
The compensation amount is set so that the acceleration of the suspended load follows an operation command during acceleration / deceleration of the trolley, and a transfer characteristic from the speed of the trolley to the acceleration of the suspended load after the acceleration / deceleration of the trolley is completed. A crane steady-state control method, wherein the crane is set so as to be damped.

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