JP2000289978A - Method for controlling overhead traveling crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make swing stopping control and positioning control compatible and to improve swing stopping accuracy and positioning accuracy. SOLUTION: A basic speed pattern of a traveling body is prepared based on from/to data and rope length. Initial swing of a hoisting tool is measured after winding up is started, and acceleration is corrected to a value corresponding to the initial swing to perform acceleration operation. Transient swing of the hoisting tool is measured during uniform operation to correct a deceleration pattern and a deceleration point based on control data obtained at the time of transient swing and acceleration. Operation is shifted to deceleration operation at the deceleration point, residual swing of the hoisting tool is measured here, and deceleration is corrected to a value corresponding to residual swing. Operation is shifted to low speed operation at a creep speed, a stop point is corrected based on control data at the time of deceleration, and a stop command is outputted at the stop point.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for controlling an overhead crane.

[0002]

2. Description of the Related Art In an overhead crane that transports coils, containers, and the like, control for suppressing the periodic swing of a hanging tool and control for accurately positioning a suspended load at a target position are required. You. As an overhead crane control method,
Conventionally, Bang-Bang control, fuzzy control, model reference adaptive control, and the like are known, but it is difficult to achieve both the steady rest control and the positioning control by any method. There has been a problem that the positioning accuracy is reduced, and if the positioning accuracy is increased, the steadying accuracy is reduced.

[0003]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a method of controlling an overhead crane which can achieve both the steadying control and the positioning control, thereby improving both the steadying accuracy and the positioning accuracy.

[0004]

In order to solve the above-mentioned problems, a control method according to the present invention comprises installing a hoist on a moving body,
In an overhead crane in which a hoist is supported by a hoist via a rope, a basic speed pattern of the moving object is created based on the from / to data and the rope length, and the initial run-out of the hoist is measured after the start of hoisting. Is corrected to a value corresponding to the initial runout, perform acceleration operation at that acceleration, shift to constant speed operation at the target speed, measure the transient runout of the lifting gear during the constant speed operation, and Correct the deceleration pattern and deceleration point based on the control data of the above, shift to deceleration operation at the deceleration point, measure the residual vibration of the lifting gear during deceleration operation, and set the deceleration of the deceleration pattern to a value according to the residual vibration. The operation is corrected, the operation is shifted to the low speed operation at the creep speed, the stop point is corrected based on the control data at the time of deceleration during the low speed operation, and a stop command is output at the stop point.

[0005]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the overhead crane according to this embodiment places a trolley 2 as a traveling moving body on two rails 1 laid on the ceiling of a coil yard, and traverses the moving body on the trolley 2. , A hoisting machine 4 is installed on the club 3, and the hoisting machine 4 is supported with a hanging tool 6 via a rope 5. The trolley 2 is provided with an operator's cab 7 on which an operator rides, and the hanger 6 has a pair of arms 9 for holding a coil 8.
Is provided.

As shown in FIG. 2, in the operation control room of the coil yard, a host computer 11 for setting and controlling the operation system of the entire crane equipment and a ground control panel 12 are installed. The ground control panel 12 stores a ground sequencer 13 and an optical space transmission device 14. The ground sequencer 13 controls the ground operation panel 15, the emergency stop device 16, and the safety fence 17.
And other ground equipment.

On the side of the overhead crane, a traveling laser distance meter 19 for measuring the current position of the trolley 2, a traversing laser distance meter 20 for measuring the current position of the club 3, and a TV camera for detecting the swing angle of the hanging tool 6. 21 are provided. The cab 7 has a steady rest positioning device 22 and an on-board control panel 23.
The on-board control panel 23 has an on-board sequencer 2
4, the optical space transmission device 25, the traveling inverter 26, the traverse inverter 27, the hoisting inverter 28, the turning control unit 29, and the lifting gear control unit 30 are stored.

The on-board sequencer 24 outputs a position command and an automatic control command from the host computer 11 to the steady rest positioning device 22, and also inputs a speed command and control status information from the device 22, , 27, 28 and the control units 29, 30, the traveling motor 31 of the trolley 2 and the traversing motor 3 of the club 3.
2, hoisting motor 33 of hoisting machine 4, turning motor 3 of hoisting tool 6
4 and the arm opening / closing motor 35 of the hanging tool 6 are configured to be controlled. Pulse generators 36, 37, and 38 are attached to the motor shafts of the traveling motor 31, the traverse motor 32, and the hoist motor 33, respectively.
A signal corresponding to the number of rotations of 1, 32, and 33 is fed back to the steady rest positioning device 22.

As shown in FIG. 3, the steady rest positioning device 22 includes a speed pattern creating section 41 for creating a trapezoidal basic speed pattern corresponding to the moving distance of the trolley 2 and the club 3, and laser rangefinders 19 and 20. And pulse generator 3
A position data correction unit 42 that corrects the position data of the trolley 2 and the club 3 based on the output of the ropes 6, 37, and 38, and a rope length detection unit 43 that detects the extension length of the rope 5.
And a shake angle detection unit 44 for detecting a shake angle of the hanging tool 6 from a signal from the TV camera 21, and a steady rest positioning control unit 45 for performing both steady rest control and positioning control. In the correction unit 42, data processing is performed so that the correction value is not suddenly changed so as not to disturb the steadying control.

According to the overhead crane of this embodiment, the position data correction unit 42 uses the laser distance meters 19, 20.
Is obtained from the position data obtained by integrating the signals of the pulse generators 36, 37, and 38, and by multiplying this by a proportional gain, the trolley 2 and the club 3 are obtained.
Is corrected. Therefore, even when the wheels of the trolley 2 and the club 3 slip or float at the joints of the rails, their current positions can be accurately detected, and highly accurate steady rest data and positioning data can be obtained. . In addition, because the laser rangefinders 19 and 20 have excellent resolution and responsiveness, compared with position detectors such as induction radios and encoders, the influence of errors due to detection delay is minimized, and the steadying and positioning accuracy are improved. can do.

Next, a method of controlling the overhead crane constructed as described above will be described with reference to FIGS. When the steady rest positioning device 22 is started, first, an initial value on a program is set (step S1), the system is self-diagnosed, and the presence or absence of an abnormality in a peripheral device is checked (step S2). Then, from /
The to-data is received (step S3), and the rope length is detected (step S4). Then, control parameters are calculated based on these data (step S5), and basic speed patterns (see FIG. 5) of the trolley 2 and the club 3 are created (step S6).

Subsequently, winding is started (step S).
7) The initial shake of the hanging tool 6 is measured by the TV camera 21 (step S8). If there is an initial shake (step S9), the acceleration set in the basic speed pattern is corrected to a value corresponding to the shake angle (step S10). Then, when a predetermined transport height is reached (step S11), a steadying acceleration is output to shift to acceleration operation (step S11).
12) In this acceleration operation section, the initial swing of the hanging tool 6 is suppressed.

When the target speed is reached (step S13),
The output is switched from the acceleration control to the constant speed control, and the operation shifts to the constant speed operation (step S14). During the constant speed operation, the lifting gear 6
Is measured (step S15), and when the deflection angle exceeds the target value (step S16), the acceleration correction coefficient in the control parameter is corrected to reflect it in the basic speed pattern of the next cycle (step S15). S17).
In this way, it is possible to suppress the deflection caused by mechanical factors such as how to hang the rope 5.

During the constant speed operation, the deceleration and deceleration time set in the basic speed pattern are updated based on the transient runout and the control data at the time of acceleration to correct the deceleration pattern (step S18). . Then, the shake amount and the final stop position are simulated with this deceleration pattern (step S19), and the deceleration point is corrected according to the result (step S20). With this configuration, the deceleration point can be accurately determined by taking into account the position deviation generated by the steadying control during acceleration.

When the deceleration point is reached (step S2)
1), the updated deceleration for steady rest is output, and the operation shifts to deceleration operation (step S22). During the deceleration operation, the residual vibration of the hanging tool 6 is measured (Step S23). If the vibration angle exceeds the target value (Step S24), the deceleration is corrected again to a value corresponding to the residual vibration. (Step S2
5), the residual vibration of the hanging tool 6 is suppressed.

Thereafter, when the creep speed is reached (step S26), the output is switched from deceleration control to low speed control, and the operation shifts to low speed operation (step S27). During this low-speed operation, the stop point set in the basic speed pattern is corrected based on the control data at the time of deceleration (step S28). In this case, the stop point can be accurately determined by taking into account the position deviation generated by the steadying control during deceleration. Therefore, when the stop point is reached (Step S29), if a stop command is output (Step S30), the hanger 6 is almost stationary,
The suspended load 8 can be accurately stopped at the target position.

The present invention is not limited to the above embodiment, but may be applied to a container crane, a billet transporting crane, or the like, and may appropriately change the shape and configuration of each part without departing from the gist of the present invention. It is also possible to make it concrete.

[0018]

As described in detail above, according to the present invention,
Create the basic speed pattern of the moving body, correct the acceleration according to the initial vibration, correct the deceleration pattern and deceleration point based on the control data at the time of acceleration, correct the deceleration according to the residual vibration, and The method of correcting the stop point based on the control data and outputting the stop command at the stop point is adopted, so that both the steady rest control and the positioning control can be achieved, and both the steady rest accuracy and the positioning accuracy can be improved. It has the effect.

[Brief description of the drawings]

FIG. 1 is a front view of an overhead crane showing one embodiment of the present invention.

FIG. 2 is a block diagram showing a control system of the overhead crane of FIG.

FIG. 3 is a block diagram showing the steady rest positioning device of FIG. 2 in detail.

FIG. 4 is a flowchart illustrating a method for controlling an overhead crane according to the present invention.

FIG. 5 is a time chart showing a basic speed pattern.

[Explanation of symbols]

2. Trolley, 3. Club, 4. Hoisting machine, 5.
Rope, 6 ·· Hanging tool, 19 ·· Laser laser distance meter, 20
.. traversing laser range finder, 22. steady rest positioning device, 26, 37, 38 .. pulse generator, 41 .. speed pattern creation unit, 42 .. position data correction unit, 45 ..
Steady positioning control unit.

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Claims (1)

[Claims] An overhead crane in which a hoist is installed on a moving body and a hoist is supported on the hoist via a rope.
A basic speed pattern of the moving object is created based on the m / to data and the rope length, an initial run-out of the hanger is measured after the hoisting is started, and the acceleration of the basic speed pattern is corrected to a value corresponding to the initial run-out. Perform acceleration operation, shift to constant speed operation at the target speed, measure the transient vibration of the lifting gear during constant speed operation, correct the deceleration pattern and deceleration point based on the transient vibration and control data during acceleration, and decelerate At the point, shift to deceleration operation, measure the residual vibration of the lifting gear during deceleration operation, correct the deceleration of the deceleration pattern to a value according to the residual vibration, shift to low speed operation at creep speed, and A control method comprising correcting a stop point based on control data at the time of deceleration and outputting a stop command at the stop point.