JPH11311583A - Vibrating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately synchronize a plurality of vibrating machines and to mount a large distributed load, by inputting an external instruction signal and the output of a displacement meter to either one hydraulic vibrating machine, and inputting the output of an own displacement meter and the output of the displacement part of the above vibrating machine and an input signal to a servo amplifier to another vibrating machine. SOLUTION: In a vibrating machine A7, a control operator 5 performs processing to the deviation between an input signal and the output of a displacement meter 6 with a control processing block 8 and outputs a signal to a servo amplifier 4. The amplifier 4 inputs a drive current to a servo valve 3, thus controlling an hydraulic oil from a hydraulic source 20 and driving a piston rod 2 in a cylinder 1. A vibrating machine B17 reads an input signal to the amplifier 4 by a control operator 15 and multiplies its deviation by a specific coefficient. Then, the sum of the output signals of coefficient multiplication blocks 18 and 19 is obtained and is inputted to a servo amplifier 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibrating device used for applying a deformation or a load to a structure to grasp characteristics affecting seismic response or to verify the strength and reliability. It relates to a vibration test method. Also, for the same purpose, the present invention relates to a shaking table for loading an earthquake acceleration on a structure.

[0002]

2. Description of the Related Art Conventionally, a structure is loaded with a deformation or a load, for example, to grasp characteristics affecting seismic response,
Alternatively, FIG. 2 schematically shows a configuration of a hydraulic exciter used for verification of strength and reliability. Piston rod 22 housed in cylinder 21 and having a pressure receiving section, servo valve 23, servo amplifier 24, control calculator 25, hydraulic source 20, displacement gauge 2
6 and the like. The tip of the piston rod is connected to a structure (not shown) that carries the displacement.

The control calculator 25 generates a control signal which reduces the deviation between the input signal and the output of the displacement meter (hereinafter referred to as displacement measurement value) as a feedback signal.
And outputs the control current to the servo valve 23 based on this.
The servo valve 23 changes the valve opening degree based on the control current to control the direction and flow rate of the high-pressure oil supplied from the hydraulic pressure source 20 to the pressure receiving unit. The piston rod 22 driven in this manner
Loads a displacement on the structure.

[0004] Here, the "displacement control" for making the exciter displacement coincide with the target value has been described. However, the "load control" in which the piston rod is connected to a structure via a load meter and the measured load value is used as a feedback signal. It can also be.
Literature on this hydraulic shaker includes, for example,
There is 5-10158 publication.

The dynamic characteristics of such a hydraulic exciter greatly depend on the dynamic characteristics of the servo valve 23, and tend to deteriorate as the flow rate increases. Therefore, it is often difficult to accurately and quickly load a structure with a large load with one hydraulic exciter. Also, it may be desirable to apply the load in a distributed manner, such as when the structure is long,
With one hydraulic exciter, a load can be applied only locally even if an appropriate jig is used.

Therefore, it is conceivable that a plurality of hydraulic vibrators are driven in synchronization with each other and used as one vibrating device.
As a result, the flow rate of the servo valve per unit can be small, so that a vibrating device having good dynamic characteristics can be obtained. In addition, a distributed load can be created by arranging the vibrators at a distance. .

A vibrating table apparatus uses a plurality of vibrators as described above. The schematic diagram is shown in FIG. A vibration exciter 32 is connected to the table 31 via a static pressure bearing 33 to reproduce a predetermined acceleration. A test sample 34 is set on the table 31. The vibrator 32 is fixed to the reaction wall, but is not shown here for convenience. Among these shakers, for example, the shaker 32a and the shaker 3
2b are driven in the same direction, but if they are not synchronized, a rotational motion occurs on the table, and an unexpected acceleration is loaded on the specimen 34.

[0008] For a shaking table apparatus using a plurality of hydraulic exciters, see, for example, Sugano, "Servo mechanism of three-dimensional six-degree-of-freedom shaking table," Mechanical Design, April 1991, or
No. 58-1962115. As a technique for achieving synchronous control of a plurality of vibrators in a shaking table, there is a technique described in Japanese Patent No. 1073678.

This is to improve not only the displacement but also the speed and acceleration as feedback signals for controlling the individual exciters, thereby improving the respective frequency characteristics and improving the synchronism. No attempt has been made to reduce the displacement error between machines.

Also, Japanese Patent Application Laid-Open No. 61-34438, or Iemura et al., "Substructure Hybrid Experiment Using a Three-Degree-of-Freedom Loading Tester", Proceedings of the 43rd Symposium on Applied Mechanics, Heisei Published on December 28, 5
From page 81 to page 582, a device for loading a structure using a plurality of shakers is described.
It does not necessarily take into account that the exciters are driven synchronously, and the control method is not described.

[0011]

As described above, a vibration device having various features can be obtained by forming a vibration device with a plurality of hydraulic vibration devices as described above. It is difficult to drive with accurate synchronization.
This is because it is difficult to strictly match the dynamic characteristics of the individual hydraulic exciters, and therefore, different displacements are realized even when controlled by the same excitation signal. Therefore, there is a problem that unnecessary deformation occurs in the test specimen.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problem, and it is possible to drive a plurality of hydraulic exciters in synchronization with high accuracy, and to provide a hydraulic exciter equivalent to a large exciter having good dynamic characteristics. It is another object of the present invention to provide a vibration device capable of applying a distributed load to a structure. Another object of the present invention is to provide a vibration table device capable of accurately applying acceleration to a structure.

[0013]

Means for accurately synchronizing a plurality of vibrators and applying a predetermined displacement to a structure is that one of a plurality of hydraulic vibrators includes a plurality of hydraulic vibrators. A command signal given from outside and the output of the displacement meter of the hydraulic vibrator are input to a control calculator of the hydraulic vibrator (vibrator A), and at least one hydraulic pressure different from the hydraulic vibrator is used. The output of the displacement meter of the shaker A, the output of the displacement meter of the shaker B, and the input signal to the servo amplifier of the shaker A are input to the control arithmetic unit of the shaker (exciter B). This is achieved by outputting an input signal to the amplifier.

More specifically, the control calculator of the shaker A outputs an input signal to the servo amplifier such that the deviation between the command signal given from the outside and the output of the displacement meter of the hydraulic shaker is reduced. The control arithmetic unit of the shaker B is
The difference between the output of the displacement meter of the shaker A and the output of the displacement meter of the shaker B multiplied by a predetermined coefficient, and another predetermined coefficient for the input signal to the servo amplifier of the shaker A Is output as an input signal to the servo amplifier, and is achieved by controlling as described above.

Applying a predetermined load to a structure by synchronizing a plurality of vibrators with high precision means that a plurality of hydraulic vibrators are connected to the hydraulic vibrator and the hydraulic vibrator is generated. In a vibrating device constituted by a load cell for measuring a load to be applied, a control signal of one of the hydraulic vibrators (vibrator A) and a command signal given from outside and an output of the load cell are inputted. The control arithmetic unit of at least one hydraulic exciter (exciter B) different from the hydraulic exciter includes an exciter A
This is achieved by inputting the displacement meter output of the vibrator B, the displacement meter output of the shaker B, and the input signal to the servo amplifier of the shaker A, and outputting the input signal to the servo amplifier.

More specifically, the control arithmetic unit of any one of the hydraulic exciters (exciter A) is provided with a servo amplifier which reduces a deviation between an externally applied command signal and an output of the load cell. The control arithmetic unit of at least one hydraulic vibrator (vibrator B) different from the hydraulic vibrator includes a displacement meter output of vibrator A and a vibrator. B
The sum of a product obtained by multiplying the deviation from the output of the displacement meter by a predetermined coefficient and a product obtained by multiplying the input signal to the servo amplifier of the shaker A by another predetermined coefficient is input to the servo amplifier. It is output as a signal and is achieved by controlling as described above.

Further, in order to perform high-precision vibration without being affected by noise in the use environment, in the above-described vibration device, the control arithmetic units of the vibration exciters A and B are digital computers. The input signal to the servo amplifier of the shaker A and the output of the displacement meter of the shaker A are transferred as digital signals to the control calculator of the shaker B.

The provision of a vibrating table capable of accurately applying acceleration to a structure is achieved by using a vibrator for vibrating a table and a method of controlling the same with the above-described configuration and method.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 4 shows an example of the configuration of a vibrating device using a plurality of hydraulic vibrators. The hydraulic vibrators 41 to 43 are fixed to the reaction frame 45. The distal end of the piston rod is fixed to a vibration jig 44, and the vibration jig 44 is connected to a structure (not shown) that is a specimen. Here, by driving the three vibrators in synchronization with each other, it is possible to provide a vibrator capable of loading a distributed load, equivalent to one vibrator having a large vibration capacity. In order to control these vibrators synchronously, one vibrator 41 is controlled and driven in the same manner as in the above-described conventional technique, and the other vibrators 42 and 43 are controlled to follow them. Can be considered.

A configuration example of a suitable vibration device for that purpose will be described with reference to FIG. The hydraulic exciter controlled in the same manner as in the prior art is referred to as a vibrator A, and the hydraulic exciter controlled to follow the exciter is referred to as a vibrator B. The input signal and the output (displacement measurement value) of the displacement meter 6 are input to the control calculator 5 of the shaker A7. Further, an input signal to the servo amplifier of the shaker A, a measured value of the displacement of the shaker A, and a measured value of the displacement of the shaker B are input to the control calculator 15 of the shaker B17. Then, each generates and outputs an input signal of the servo amplifier based on these signals.

More specifically, it is as follows. In the shaker A7, the input signal and the displacement meter 6
And outputs a signal to the servo amplifier 4 by applying appropriate processing to the deviation in the control processing block 8, based on which the servo amplifier 4 inputs a drive current to the servo valve 3. Accordingly, the direction and flow rate of the high-pressure hydraulic oil supplied from the hydraulic power source 20 are controlled, and the piston rod 2 accommodated in the cylinder 1 is driven according to the input signal. The vibration exciter B17 has the following configuration. The control arithmetic unit 15 receives the input signal to the servo amplifier of the shaker A and sets a predetermined coefficient to a coefficient multiplication block 19.
Is multiplied by

Also, the displacement measurement value of the exciter A and the displacement measurement value of the exciter B are taken in, the deviation is taken, and a predetermined coefficient is multiplied by a coefficient multiplication block 18. The sum of the output signals of the coefficient multiplication blocks 18 and 19 is taken as an input signal to the servo amplifier 14. The following servo valve 1
3. The driving of the piston rod 12 housed in the cylinder 11 is the same as that of the vibrator A.

With the above configuration, the driving state of the servo valve in the vibrator B is almost the same as that of the vibrator A, so that synchronization can be achieved. Furthermore, by adding a control based on the deviation of the displacement, a displacement control error such as a disturbance can be eliminated, so that a more precise synchronous control can be performed.

Another embodiment will be described with reference to FIG.
In the present embodiment, in addition to the above-described embodiment, a load cell 50 for measuring a load applied to the specimen (not shown) by the vibrator A is provided.
Further, a load measurement value is used as a feedback signal of the exciter A. According to the present apparatus, the vibration device for loading a predetermined load can be made large and can load a distributed load. In addition, in FIG.
Although 0 is connected only to the exciter A, there are various other methods for installing the load cell, and the method is not limited to the method shown here. For example, a load meter is also attached to the tip of the exciter B, and the combined output of these load meters can be used as a feedback signal. Further, the exciters A and B can be combined into one exciter jig. It is also conceivable to directly measure the load applied to the specimen by connecting them and installing a load cell between the vibration jig and the specimen. In short, it should be fair to best meet the test purpose.

Another embodiment will be described with reference to FIG. In this embodiment, the control calculators 5 and 15 are digital computers, and the signal transmission from the shaker A to the shaker B is a digital signal. The features of the present embodiment are indicated by thick lines in FIG. According to the present embodiment, a signal can be transmitted accurately without much influence of electromagnetic noise often seen in an environment in which the vibration device is used, and highly accurate control can be performed. When the servo amplifier requires a voltage signal, it is necessary to use a suitable output device, for example, a digital-analog converter, and when the output of the displacement meter is a voltage signal, a suitable input device is used. It goes without saying that an analog-to-digital converter is required, for example. Note that there are many methods for transmitting a digital signal, but it is only necessary to select an optimal signal from the viewpoint of transfer time, transfer distance, cost, and the like, and it is not limited to one method.

FIG. 7 shows an embodiment in which the present invention is applied to a shaking table apparatus. FIG. 7 shows a set of hydraulic vibrators used to vibrate the shaking table apparatus shown in FIG. 3 in the same direction;
32a and 32b are the vibration devices of the present invention. That is, the two vibrators are connected to the table 31 and drive the table synchronously to load acceleration on the specimen 34.
At this time, the conventional control is performed by using the vibrator 32a as the vibrator A, and the vibrator 32b performs the displacement measurement value of the vibrator A, the input of the servo amplifier, and the vibrator B as the vibrator B. Machine B
The control is performed based on the measured displacement value.

In the control of the vibrator 32a, for example,
A control system is provided in which an accelerometer 51 is installed on the table 31 and a feedback signal is used as a feedback signal to compare with an input signal that is an acceleration target value to create a target displacement of the shaker, so that the target acceleration is reproduced. I have. According to the present embodiment, the exciters 32a and 32b are controlled in synchronization with each other, so that accurate vibration can be performed without rotating the table, and a highly accurate seismic test can be performed. Become.

In the above embodiment, for simplicity of description, the description has been made assuming that there are two vibrators, but it is needless to say that the present invention is not limited to the case of two vibrators. Although one hydraulic pressure source is illustrated, a configuration in which a plurality of hydraulic pressure sources, for example, one vibrator has one hydraulic pressure source may be used. It can take various forms depending on the intended use of the device.

[0030]

According to the present invention, since a plurality of hydraulic vibrators can be driven in synchronization with high precision, the plurality of hydraulic vibrators can be handled as one vibration device. This is equivalent to a large shaker having good dynamic characteristics. Further, it is possible to provide a vibration device capable of applying a distributed load to a structure. Furthermore, by using this vibration device in a shaking table device, it is possible to provide a shaking table that can accurately apply acceleration to a structure.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of one embodiment of a vibration device according to the present invention.

FIG. 2 is a configuration diagram of a conventional hydraulic exciter.

FIG. 3 is a perspective view schematically showing a shaking table apparatus.

FIG. 4 is a perspective view showing the concept of an embodiment of the vibration device of the present invention.

FIG. 5 is a configuration diagram of another embodiment of the vibration device of the present invention.

FIG. 6 is a configuration diagram of another embodiment of the vibration device of the present invention.

FIG. 7 is a configuration diagram of an embodiment of a shaking table apparatus according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... cylinder of shaker A, 2 ... piston rod of shaker A, 3 ... servo valve of shaker A, 4 ... servo amplifier of shaker A, 5 ... control arithmetic unit of shaker A, 6: Displacement gauge of shaker A, 7: shaker A, 8: control processing block, 11: cylinder of shaker B, 12: piston rod of shaker B, 1
3 Servo valve of shaker B, 14 servo amplifier of shaker B, 15 control calculator of shaker B, 16 displacement meter of shaker B, 17 shaker B, 18, 19: Coefficient multiplication block, 20: Hydraulic power source, 21: Cylinder, 22: Piston rod, 23: Servo valve, 24: Servo amplifier, 25: Control arithmetic unit, 31: Table, 32: Hydraulic shaker, 33:
Static pressure bearings, 34: test specimens, 41 to 43: hydraulic vibrator,
44: a vibration jig, 45: a reaction force frame, 50: a load meter, 51: an accelerometer.

Claims (1)

[Claims] A servo valve for controlling a direction and a flow rate of hydraulic oil supplied to a cylinder, a piston rod, and a pressure receiving portion of the piston rod; a servo amplifier for outputting a drive current for the servo valve based on an input signal; In a vibrating device comprising a plurality of hydraulic vibrators, each of which includes a control arithmetic unit that outputs an input signal to a hydraulic pump and a displacement meter that measures the position of a piston rod, any one of the hydraulic vibrators (vibrators) A command signal given from outside and the output of the displacement meter of the shaker A are input to the control calculator of the shaker A), and at least one hydraulic shaker (shake shaker B) different from the hydraulic shaker Wherein the output of the displacement meter of the shaker A, the output of the displacement meter of the shaker B, and the input signal to the servo amplifier of the shaker A are input to the control arithmetic unit.