JP2000229779A - Running aligning speed controller for bridge-shaped crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a running aligning speed controller for a bridge-shaped crane necessitating no constituent element requiring large cost for installation and maintenance such as a rack. SOLUTION: This running aligning speed controller has a first position detector 18 and a second position detector 19 for detecting positions of both leg parts of a bridge-shaped crane and a control part 15' aligning running speeds so that a girder of the bridge-shaped crane takes a positional relation orthogonal to a running rail based on the positions of both leg parts detected by these position detectors. A third position detector and a fourth position detector by means of GPS are provided in both leg parts, respectively. The control part compensates to the positions detected by the first and second position detectors based on data of the positions detected by the third and fourth position detectors and the positions detected by the first and second position detectors.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling speed control device for a bridge type crane.

[0002]

2. Description of the Related Art Bridge-type cranes are also called portal cranes. Usually, large-type cranes have a large distance between legs.
A drive source for traveling is provided for each leg. In this case, it is necessary to control the drive sources in both legs so that the girder of the bridge crane has a positional relationship perpendicular to the traveling rail.
This control is called alignment speed control, and it is necessary to detect the position of each leg for alignment speed control. The drive source is controlled such that the position of one leg is used as a reference and the other leg always follows this reference in parallel. A bridge crane having such a speed control function is also called a Goliath crane.

As a conventional example of the uniforming speed control, a traveling wheel (a driving wheel or a driven wheel) or a detection wheel called a touch roller is turned by friction with a traveling rail, and the amount of rotation of the wheel is detected by an absolute encoder. A method for calculating the position of a part is known. The position of the leg is calculated in the form of the amount of movement from the reference point. However, this method has a problem that not only the dimensional error of the wheel diameter is accumulated as an error in the calculated position, but also the slip of the wheel becomes an error.

To solve such a problem, a method called a rack method has been proposed (for example, Japanese Patent Publication No. 53-42).
No. 930). In this rack system, racks are respectively laid along two traveling rails, and pinions meshing with the racks are attached to both legs of the bridge crane. Then, the rotation amount of each pinion is detected by an absolute encoder, and the positions of both legs of the bridge crane are calculated. Further, from these calculated positions, it is calculated how much the position of the two legs is deviated from the positional relationship in which the traveling rail and the girder are orthogonal to each other, and the speed at which the driving source of the two legs is corrected during traveling is corrected. By sending a command with a difference, control is performed to minimize the amount of deviation from the positional relationship where the traveling rail and the girder are always orthogonal.

[0005]

However, even with this rack system, enormous costs are required for laying and maintaining the rack. Significant maintenance costs are incurred for the following reasons.
That is, the rack is deformed by being stepped on by the vehicle crossing the traveling rail. In addition, the rack is filled with earth and sand or corroded. On the other hand, in order to minimize the occurrence of deformation due to the vehicle, it is necessary to restrict places where the vehicle passes, and the usability of the yard deteriorates.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a traveling speed control device for a bridge crane which does not require a component such as a rack which requires a great deal of cost for installation and maintenance.

[0007]

According to a first aspect of the present invention, there is provided:
The present invention is applied to a bridge-type crane having a driving source for traveling individually on both legs of a bridge-type crane that can travel on a traveling rail, and a position detector by GPS is provided on each of the legs, and these positions are provided. The traveling position error between the two legs is calculated from the position data detected by the detector, and the girder of the bridge-type crane has a positional relationship perpendicular to the traveling rail. A traveling uniforming speed control device comprising a control unit for controlling the driving source.

In the first embodiment, the receiver in the GPS position detector samples received data at a predetermined sampling timing, and means for synchronizing the sampling timings of the position detector in the two legs. It is preferable to provide

According to a second aspect of the present invention, both legs of a bridge-type crane capable of traveling on a traveling rail are individually provided with a driving source for traveling, and the rotational speed of a traveling wheel or the rotational speed of a touch roller is provided. And the first and second position detectors for detecting the position of each leg are provided. Based on the positions of the two legs detected by the first and second position detectors, the girder of the bridge crane In a traveling speed controller for a bridge-type crane having a controller for uniforming traveling speeds so as to have a positional relationship perpendicular to the traveling rail, a third position detector and a fourth position detector by GPS are respectively provided on the both legs. And the control unit controls the first and second positions based on the position data detected by the third and fourth position detectors and the positions detected by the first and second position detectors. Position detected by position detector And performing correction.

In the second embodiment, each of the third and fourth position detectors has a receiver for sampling received data at a predetermined sampling timing. It is preferable to provide a means for synchronizing the sampling timing of the position detector.

[0011] In the second embodiment, the control unit may determine whether the position calculated from the position data detected by the third position detector and the position detected by the first position detector during traveling. Performing the correction when the difference or the difference between the position calculated from the position data detected by the fourth position detector and the position detected by the second position detector is equal to or greater than a predetermined value, During travel stop, the position detected by the first and second position detectors is always corrected to match the position calculated from the position data detected by the third and fourth position detectors, respectively. I do.

In the second embodiment, the control section performs the position calculation by the third and fourth position detectors a plurality of times while the vehicle is stopped, and uses an average value of the calculation results for correction. Is preferred.

[0013] In the second embodiment, the control unit may further include a receiver in the third position detector on an input side of one receiver in order to use a receiver in the third and fourth position detectors. Switch means for switching between a received signal from an antenna and a received signal from the antenna in the fourth position detector is provided, and the switching by the switch means is performed every sampling at a predetermined sampling timing. May be.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. In FIG. 2, the bridge crane 20 has two legs 21 and 22 that can travel on two traveling rails 31. The leg 21 is provided with a drive wheel 23a and a driven wheel 23b, and the leg 22 is also provided with a drive wheel 24a and a driven wheel (not shown). Each drive wheel is driven by a drive source such as a motor. A girder 25 is bridged between the legs 21 and 22. A trolley 26 having suspending means runs on the girder 25. In addition, this type of bridge crane 20
In, one of the two legs is structurally made to have a rigid structure, which is called a rigid leg, and the other is called a swing leg.

In this embodiment, GPS (Global Positioning) is attached to the legs 21 and 22, respectively.
System). 1 and 2, the position detector provided on the leg 21 includes an antenna 11 and a receiver 12, and the position detector provided on the leg 22 includes an antenna 13 and a receiver 14. As is well known, this type of receiver calculates the current longitude and latitude immediately below the antenna based on data received from a plurality of satellites, and outputs position data representing the longitude and latitude.

The control unit 15 calculates a travel position error between the legs 21 and 22, that is, a displacement, from the position data detected by these position detectors, and the girder 25 of the bridge crane 20 is attached to the travel rail 31. The driving sources 16 and 17 in the legs 21 and 22 are controlled based on the traveling position error so as to have a right-angled positional relationship. Specifically, the control unit 15 first converts the position data from the receivers 12 and 14 into position coordinate data on the traveling rail 31. To facilitate this conversion, the antennas 11, 13
Are desirably provided so as to be located directly above the traveling rail 31 and on a line segment perpendicular to the traveling rail 31, respectively. Next, the control unit 15 uses the position coordinate points (points immediately below the antenna 13) set on the travel rail 31 on the side of the leg 22 by the coordinate conversion at a certain time as a reference, and calculates the travel rail 31 from this position coordinate point. The intersection of the virtual line extending at right angles to the running rail 31 on the leg 21 side, and the position coordinate points on the running rail 31 obtained by converting the position data from the receiver 12 at the same time as the above-mentioned certain time Is calculated as the travel position error. Control unit 15
Controls the drive source 16 on the side of the leg 21 so that the amount of deviation approaches zero. As a result, the drive source 16 on the leg 21 side
Is controlled so that a point immediately below the antenna 11 follows the reference position coordinate point on the side of the leg 22 in parallel.

For example, when the leg 22 is ahead of the leg 21, the drive source 16 is decelerated, and when the leg 22 is behind the leg 21, the drive source 16 is decelerated. 16 is accelerated. Of course, when the leg 22 is ahead of the leg 21, the drive source 17 is accelerated. When the leg 22 is behind the leg 21, the drive source 17 is decelerated. Control may be performed.

In the position detector using the GPS, the position is detected by sampling measurement. That is, the reception data is sampled at a predetermined sampling cycle (usually 200 msec), the reception data sampled at a certain timing is analyzed, the position data is output after the analysis is completed, and the sampling is performed at the next sampling timing. Start analysis on the received data. In order to provide such a GPS position detector on the two legs 21 and 22, if the sampling timings of the position detectors on the two legs 21 and 22 are not matched, the position is shifted by the product of the difference between the traveling speed and the sampling timing. The position will be detected.

In order to solve this problem, a synchronizing means for synchronizing the sampling in the two position detectors is provided. As shown in FIG. 1, the synchronizing means may make it possible to use a timing signal generated for defining a sampling timing in one position detector as a sampling timing signal of the other position detector. . Alternatively, a common sampling timing signal generation unit may be provided for the two position detectors, and the sampling timing signal from this may be supplied to the receivers 12 and 14 of the two position detectors.

As described above, the position detectors at the legs 21 and 22 detect the respective position data, and
Converts the position data into position coordinate data on the traveling rail 31 based on these position data, calculates the position shift between the legs 21 and 22, and further drives the drive sources 16 and 17 so that the position shifts closer to zero.
Is controlled so that the girder 25 has a positional relationship perpendicular to the traveling rail 31.

As is apparent from the above description, in this embodiment, it is important to calculate the displacement between the legs 21 and 22, and the movement from the running reference point as described in the conventional example is important. Knowing the distance is not important. In other words, with respect to the point of one antenna at a certain time,
If the amount of deviation between the intersection of the imaginary line extending at right angles to the traveling rail 31 from the reference point and the traveling rail 31 on the other antenna side and the point immediately below the other antenna at the same point in time is known, good. This is the running rail 31
Is not limited to a straight orbit.

Next, a second embodiment of the present invention will be described with reference to FIG. This second embodiment is also applied to the bridge-type crane shown in FIG. 2. In addition to the configuration of the first embodiment shown in FIG. 1, each of the legs 21 and 22 is provided with a touch roller. First and second position detectors 1
8 and 19 are provided. The touch roller is, as is well known, provided with a roller that rotates in contact with the travel rail 31 and detects the number of revolutions of this roller with an absolute encoder or the like, so that the travel rail 31 can be moved from a reference position set in advance. This is for detecting a position by calculating a movement amount. Of course, without providing a touch roller,
The position can also be detected by calculating the amount of movement from the reference position by detecting the rotational speed of the driving wheel or the driven wheel with an absolute encoder. The positions detected by the first and second position detectors 18 and 19 correspond to the antenna 1
Needless to say, it is a point on the running rail 31 just below the points 1 and 13. This is only required to add the distance from the position where the touch roller is installed to a point on the running rail 31 directly below the antennas 11 and 13 to the movement amount as a constant.

The control unit 15 'in the present embodiment includes a leg 21, which is detected by the first and second position detectors 18, 19,
Based on the position of 22, the girder 25 performs the uniforming speed control to equalize the traveling speed so that the girder 25 has a positional relationship perpendicular to the traveling rail 31. The control unit 15 ′ particularly includes two receivers 12, 1
4, the position calculated from the position data detected in
The position detected by the first and second position detectors 18 and 19 is corrected based on the positions detected by the second position detectors 18 and 19. In this embodiment, the two receivers 1
The positions of the legs 21, 22 calculated based on the position data detected in 2, 14 are positions on the traveling rail 31 with the reference position set in the description of the touch roller as a reference point. This is because, as described above, in the case of a touch roller, an error may occur due to slippage, and the error is accumulated. In addition, in the case of a driving wheel or a driven wheel, there is a problem that a dimensional error of a wheel diameter is accumulated as an error at a calculated position in addition to an error due to slip. For this reason, frequent corrections must be made to enable the use of a position detection method using a touch roller or the like.

On the other hand, a difference of several times between the GPS sampling cycle and the sampling cycle required for control is expected (according to the GPS performance survey to date). In order to compensate for this difference, the present embodiment is characterized in that a position detection method using a touch roller or the like is combined with a detection position correction using a GPS. With GPS, sampling can be performed at about 200 (msec) at present, so a traveling speed of 60 (m / min) (maximum speed of this type of crane to date) is 200 (m
m) is equivalent to providing a correction point for each m), and a more accurate alignment speed control device can be configured by using a position detection method using a touch roller or the like together with GPS.

The control operation of the control unit 15 'will be described in detail with reference to FIG. FIG. 4 is a block diagram showing the function of the control unit 15 '. As described in the first embodiment, the control unit 15 ′ has a function of converting position data from the receivers 12 and 14 into position coordinate data on the traveling rail 31. The control unit 15 'also has a function of receiving a signal indicating whether the vehicle is running or stopped, determining whether correction is necessary, and calculating a correction value.

That is, when the control unit 15 'receives a signal indicating that the vehicle is traveling, the correction is performed only under the following conditions. While receiving the signal indicating that the vehicle is traveling, the control unit 15 ′ uses the position of the leg 21 calculated based on the position data detected by the receiver 12 and the position of the leg 21 by the first position detector 18. When the difference from the detected position is equal to or greater than a predetermined value, the position detected by the first position detector 18 is corrected. The correction value in this case is the above difference, and the subtraction is performed by the subtraction unit. Similarly, while receiving the signal indicating that the vehicle is traveling, the control unit 15 ′ receives the signal from the receiver 1
When the difference between the position of the leg 22 calculated based on the position data detected in Step 4 and the position detected by the second position detector 19 is equal to or greater than a predetermined value, the second position detector Correction is made for the position detected at 19.

This is done for the following reason.
During the traveling movement, a position error occurs due to a timing error between the position detection by the touch roller and the position detection by the GPS.
The correction is performed only when there is a large error from the position detection by the GPS, and is always made to match the position calculation value by the GPS during the stop of the travel. Furthermore, since the position does not change during stoppage, in order to improve the detection accuracy, position calculation based on the position data from the receivers 12 and 14 is performed a plurality of times at different sampling timings, and a value obtained by averaging the calculation results is obtained Used for correction. That is, this average value is used as the current position.

As described above, the detected position from the first and second position detectors 18 and 19 or the position corrected as necessary can be obtained. The control unit 15 'further aligns the legs 21 and 22 based on the detected position or the corrected position, that is, the girder 25
It has a function of outputting a speed command for uniforming speed control to the driving sources 16 and 17 so as to have a positional relationship perpendicular to 1. The control unit 15 ′ uses the position of the leg 22 at a certain time as a reference, and calculates a deviation amount between the reference position and the leg 21 as a travel position error. The control unit 15 'controls the drive source 16 on the leg 21 side so that the amount of displacement approaches zero. As a result, the drive source 16 on the side of the leg 21 is controlled so that the leg 21 follows the leg 22 in parallel.

In this embodiment, as in the first embodiment, a synchronization means for synchronizing the sampling of the two position detectors is provided. This synchronization means is shown in FIG.
In the same manner as described above, the timing signal generated for defining the sampling timing in one position detector can be used as the sampling timing signal for the other position detector. Of course, a common sampling timing signal generation unit may be provided for the two position detectors, and the sampling timing signal from this may be supplied to the receivers 12 and 14 of the two position detectors.

Further, as a modification of the second embodiment, the following configuration may be adopted. The receivers of the two position detectors by GPS can be shared. For this purpose, either the receiver 12 or 14 is installed as a receiver, and a switch for switching between a signal received from the antenna 11 and a signal received from the antenna 13 is provided on the input side of the receiver. The switching by this switch may be performed for each sampling at the sampling timing described above. In this case, the interval between the correction points described above becomes a double value.

In the second embodiment, the traveling rail 3
1 is not limited to only a straight line. Running rail 31
Has a trajectory that draws a curve, the positional relationship of the leg 21 with respect to one leg, for example, the leg 22, can be obtained. Therefore, a calculation process for calculating the position of the leg 21 from the position of the leg 22 is added. Can be dealt with. In this case, speed control for the leg 21 is performed based on the deviation between the current position of the leg 21 and the desired position of the leg 21 obtained as described above.

[0032]

According to the present invention, it is possible to perform the uniform speed control in the traveling operation without laying the rack, which is a bottleneck of the prior art, and to prevent the entire crane from skewing and the troubles associated therewith.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a first exemplary embodiment of the present invention.

FIG. 2 is a view schematically showing a bridge crane to which the present invention is applied.

FIG. 3 is a block diagram showing a configuration of a second exemplary embodiment of the present invention.

FIG. 4 is a block diagram illustrating functions of a control unit according to a second embodiment together with a connection relationship with other components.

[Explanation of symbols]

 11, 13 Antenna 12, 14 Receiver 15, 15 'Control unit 16, 17 Drive source 20 Bridge crane 21, 22 Leg 23a, 24a Drive wheel 23b Follower wheel 25 Girder 26 Trolley 31 Travel rail

Claims (7)

[Claims] 1. A bridge-type crane provided with a drive source for traveling individually on both legs of a bridge-type crane capable of traveling on a traveling rail, wherein a position detector by GPS is provided on each of the legs. The travel position error between the two legs is calculated from the position data detected by these position detectors, and the girder of the bridge crane is based on the travel position error based on the travel position error so as to have a positional relationship perpendicular to the travel rail. A traveling speed control device for a bridge-type crane, comprising a control unit for controlling the driving source in both legs. 2. The running speed control device according to claim 1, wherein a receiver in said GPS position detector samples received data at a predetermined sampling timing, and said position detector in said two legs. A traveling speed control device for a bridge-type crane, comprising: means for synchronizing sampling timing. 3. Each of the legs of a bridge-type crane that can travel on a traveling rail is provided with a drive source for traveling individually, and the position of each leg is determined by the number of revolutions of traveling wheels or the number of revolutions of a touch roller. First and second position detectors for detecting the position of the legs, and the girder of the bridge crane is positioned at right angles to the traveling rail based on the positions of the two legs detected by the first and second position detectors. To be in a relationship,
In a traveling speed control device for a bridge-type crane having a control unit for uniforming traveling speeds, a third and a fourth position detector by GPS are provided on each of the two legs, and the control unit comprises a third and a fourth position detector. Correcting the positions detected by the first and second position detectors based on the position data detected by the position detector and the positions detected by the first and second position detectors. A traveling speed control device for a bridge-type crane, characterized in that: 4. The travel alignment speed control device according to claim 3, wherein each of the third and fourth position detectors has a receiver that samples received data at a predetermined sampling timing. A traveling speed control device for a bridge-type crane, comprising: means for synchronizing the sampling timings of the third and fourth position detectors. 5. The traveling uniform speed control device according to claim 3, wherein the control unit is configured to determine a position calculated from position data detected by the third position detector during the traveling movement and the first and second positions. The difference between the position detected by the second position detector and the difference between the position calculated from the position data detected by the fourth position detector and the position detected by the second position detector is predetermined. When the travel is stopped, the position detected by the first and second position detectors is always the position data detected by the third and fourth position detectors, respectively. A traveling speed control device for a bridge-type crane, wherein the traveling speed is controlled so as to match a position calculated from the traveling speed. 6. The traveling speed control device according to claim 5, wherein the control unit performs the position calculation by the third and fourth position detectors a plurality of times while the vehicle is stopped, and averages the calculation results. A traveling speed control device for a bridge-type crane, wherein the corrected value is used for correction. 7. The traveling speed control device according to claim 3, wherein the third position is input to one of the third and fourth position detectors so that the third position is used as a receiver. Switch means for switching between a signal received from an antenna in the detector and a signal received from the antenna in the fourth position detector is provided, and the switching by the switch means is performed for each sampling at a predetermined sampling timing. A traveling speed control device for a bridge-type crane, wherein