JP3396425B2 - Shaking table controller - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaking table control device applied to a shaking table system.

[0002]

2. Description of the Related Art Conventionally, in a vibrating table system, a test sample is mounted on a table that serves as a vibrating table, and a target waveform is reproduced to check the strength of the test sample against an input waveform. It is used for the purpose. The shaking table control device used in this shaking table system needs to accurately reproduce the target wave, and the actual control method is to make the response waveform follow the target waveform as much as possible.

FIG. 8 is an overall system diagram of a conventional shaking table controller. The acceleration signal measured by the accelerometer 3 during the vibration experiment by the vibrating table 1 is amplified by the amplifier 4 and taken into the computer 6 via the A / D converter 5. On Calculator 6,
Next, calculate the compensation of the input wave for the next excitation,
The signal for the next vibration is input to the actuator 9 via the D / A converter 7 and the servo amplifier 8, and the vibration table 1
Vibrate.

FIG. 9 is a flow chart of input wave compensation calculation for explaining specific calculation contents in the computer 6. There are two types of calculation contents. one,
This is a calculation during vibration when grasping the transfer characteristics from the input to the shaker to the table response (characteristic grasping vibration).

In this case, as shown in FIG. 9, the acceleration signal serving as the input 27 is converted from the time data into the frequency data by the Fourier transform 10, the acceleration is converted into the displacement signal by the second integral 11, and this displacement signal is further converted. By performing the inverse Fourier transform 12, a displacement signal in the time domain that is input to the vibration exciter is obtained. Excitation 13 represents a system including an exciter and a table (vibration table 1).

The response acceleration signal in the time domain observed on the table is converted into frequency data by Fourier transform 14, and this frequency data and Fourier transform 1
Frequency response calculation from both input signals converted by 0
The transfer characteristic of the vibrating table system is obtained by performing The transfer characteristic obtained here has a 6 × 6 matrix configuration because the table is generally controlled with 6 degrees of freedom.

Another operation is an operation for compensating an input wave for excitation using the transfer characteristic obtained above (input compensation excitation). In this case, first, the result of performing the inverse characteristic calculation 17 of the transfer characteristic obtained above and the target wave 28
The initial input compensation calculation 19 is performed from both the target wave data in the frequency domain obtained by the Fourier transform 18 of. Then, the obtained initial input compensation wave is subjected to second-order integration 20 and inverse Fourier transform 21 to generate an input signal to the vibration exciter.

Further, the signal obtained by the deviation 29 between the response acceleration signal of the table and the target wave 28 is Fourier transformed 24, the input compensation 25 is repeatedly calculated, and the input compensation wave is generated.

[0009]

As described above, the conventional control method executes the compensation program to generate the input wave to be excited next time after the excitation by the generated input wave for the fixed time is completed. Since this is a so-called discrete excitation control method, there is a problem in that a plurality of compensation calculations are required to completely reproduce an input signal, which takes a lot of time.

An object of the present invention is to provide a shaking table control device for performing compensation calculation in a short time and continuously outputting a compensation wave to control vibration of the shaking table.

[0011]

In order to solve the above problems and achieve the object, the shaking table control device of the present invention is configured as follows.

(1) The shaking table control device of the present invention is a shaking table control device for controlling the vibration of the shaking table based on the acceleration measured on the shaking table to be observed. First calculation means for vectorizing a harmonic component of the acceleration signal in the direction of the vibration axis, and a compensation wave of the acceleration signal vectorized by the first calculation means based on a compensation signal input to the vibrating table. It is composed of a second calculating means for generating a signal and a vibrating means for vibrating the vibrating table by the compensation wave signal generated by the second calculating means.

(2) The shaking table control device of the present invention is the device according to the above (1), and the second computing means inputs from the compensation signal and the acceleration signal in the vibration axis direction. The transfer characteristic of the vibration table with respect to the frequency component of the harmonic is identified for each compensation signal to be generated, and the compensation wave signal is generated.

(3) The shaking table control device of the present invention is a shaking table control device for controlling the vibration of the shaking table based on the acceleration measured on the shaking table as a target, and the shaking table observed on the shaking table is used. First calculation means for vectorizing a harmonic component of the acceleration signal in the swing axis direction, and a compensation wave signal of the acceleration signal vectorized by the first calculation means based on a compensation signal input to the vibrating table. And a third calculating means for vectorizing a harmonic component of an acceleration signal observed in the vibrating table in an interference axis direction other than the excitation axis direction,
Fourth computing means for generating a compensation wave signal of the acceleration signal vectorized by the third computing means on the basis of a compensation signal input to the vibrating table, and compensation generated by the second computing means. A first vibrating means for vibrating the vibrating table with a wave signal; and a second vibrating means for vibrating the vibrating table with a compensating wave signal generated by the fourth computing means. ing.

(4) The shaking table control device of the present invention is the device according to (3) above, and the second computing means inputs from the compensation signal and the acceleration signal in the direction of the excitation axis. The transfer characteristic of the vibrating table with respect to the frequency component of the harmonic is identified for each compensation signal to generate the compensation wave signal, and the fourth calculation means is configured to detect the compensation signal and the direction other than the excitation axis direction. From the acceleration signal in the interference axis direction,
The transfer characteristic of the vibrating table with respect to the frequency component of the fundamental wave is identified for each input compensation signal, and the compensation wave signal is generated.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 is an overall system diagram of a single-axis shaking table controller according to a first embodiment of the present invention. In FIG. 1, the same parts as those in FIG. 8 are designated by the same reference numerals.

As shown in FIG. 1, a test piece 2 is mounted on a vibrating table 1, and an accelerometer 3 is attached. The accelerometer 3 includes an amplifier 4 and an A / D converter 5.
Is connected to the control device 30 via
Is connected to an actuator 9 via a D / A converter 7 and a servo amplifier 8. A displacement meter 31 is attached to the actuator 9, and the displacement meter 31 is connected to the servo amplifier 8.

An acceleration signal in the direction of the vibration axis measured by the accelerometer 3 during a vibration test using the vibration table 1 is amplified by the amplifier 4 and taken into the control device 30 via the A / D converter 5.

FIG. 2 is a diagram showing a calculation outline of the control device 30. As shown in FIG. 2, the control device 30 includes a first calculation unit 301 and a second calculation unit 302. The specific calculation contents of the control device 30 will be described below. Control device 3
At 0, the first calculation unit 301 and the second calculation unit 302 perform the following calculations to generate a signal that compensates for harmonics.

The first calculation unit 301 vectorizes the harmonic component of the acceleration signal in the direction of the vibration axis observed on the table of the vibration table 1. The contents of the calculation are shown below.

A periodic signal x (t) having a period T (sec) is
As shown in the following equations (1) to (4), it can be expanded to a Fourier series.

[0022]

[Equation 1]

Here, a0 represents the DC component of the signal, and the others represent the nth harmonic component. Coefficients an, b
n is a reference signal cos (nωt) and sin (n
The same harmonic component as ωt) is extracted, and cos
Extract the size of the component and the sin component. The nth-order harmonic component extracted here can be displayed as a vector diagram of the Nth-order harmonic by a complex Fourier coefficient as shown in FIG. In this way, the complex Fourier coefficients an and bn enable vectorization of the nth harmonic.

The second computing unit 302 calculates the vibration table transfer characteristic for the frequency component of the Nth harmonic from the compensation signal input to the vibration table 1 and the acceleration signal in the direction of the vibration axis observed on the table. Identify and generate a compensation wave of the Nth harmonic. The contents of the calculation are shown below.

FIG. 4 is a control block diagram in the direction of the excitation axis by compensation calculation. As shown in FIG. 4, X on the table
Assume that the Nth harmonic having a complex Fourier coefficient of 0 is observed (shown in equation (5)).

Next, when the Nth-order compensating wave having the complex Fourier coefficient of Y1 is input, the following equation (6) is established in consideration of the shaking table transfer function having the complex Fourier coefficient of H.

[0027]

[Equation 2]

At the stage where the equation (6) is completed, X0, Y1
, X1 are known vectors, the shaking table transfer function vector H1 can be easily obtained.

Assuming that the complex Fourier coefficients of X0, H, Y1 and X1 are as follows, the equation (6) becomes the following equation (7).

[0030]

[Equation 3]

This is expressed by a matrix.

[0032]

[Equation 4]

Therefore, the shaking table transfer function vector can be estimated by the following equation (8).

[0034]

[Equation 5]

Next, the shaking table transfer function vector estimated by the equation (8)

[Equation 6]

Therefore, the compensating wave Y2 input the second time can be obtained from the following equation (9).

[0037]

[Equation 7]

Second compensation wave Y2 calculated by equation (9)
And the resulting observed wave vector on the table is X2, the following equation (10) is established.

[0039]

[Equation 8]

Since the complex Fourier coefficients of X1, Y2 and X2 are known, H can be easily estimated.

Assuming that the complex Fourier coefficients of X1, H, Y2 and X2 are as follows, the equation (10) becomes the following equation (11). That is,

[Equation 9]

Then,

[Equation 10]

It becomes

Since the shaking table transfer function vector is a constant,

[Equation 11]

It becomes Therefore, the shaking table transfer function vector is estimated from the equations (7) and (11).

[0046]

[Equation 12]

The matrix formed by the complex Fourier coefficients of the compensation wave on the right side of the equation (13) is a rectangular matrix of 4 rows and 2 columns, and there is no inverse matrix.

However, if a pseudo-inverse matrix is introduced as in the following equation (14), the shaking table transfer function vector

[Equation 13]

Can be estimated.

[0050]

[Equation 14]

In this way, the estimated shaking table transfer function vector

[Equation 15]

From this, the compensating wave Y3 to be input the third time can be obtained.

The process of sequentially updating the shake table transfer function vector estimation value is performed until the magnitude of the vector observed on the table is sufficiently smaller than the fundamental wave. The compensation wave signal generated by the control device 30 in this way is amplified by the servo amplifier 8 via the D / A converter 7 and sent to the actuator 9.

The vibrating table control apparatus according to the first embodiment is
Unlike the conventional discrete excitation method that requires the excitation to be stopped and the calculation of the compensation wave for the next excitation to be performed, the compensation wave is output continuously until the harmonic components converge to a specified value. There are advantages. This shaking table controller realizes a sinusoidal response to a sinusoidal input signal that is a single frequency component that does not include harmonic components on the shaking table. In the process, the Nth harmonic converges to a predetermined value. Then, the content of the calculation is such that the process moves to compensation of the (N + 1) th harmonic, and a few seconds after the compensation control is started, a sine wave response can be realized on the vibration table.

(Second Embodiment) FIG. 5 is an overall system diagram of a 6-axis shaking table controller according to a second embodiment of the present invention. 5, the same parts as those in FIG. 1 are designated by the same reference numerals.

As shown in FIG. 5, a test piece 2 is mounted on a vibrating table 1, and an accelerometer 3 is attached. The accelerometer 3 is connected to the controller 40 via the amplifier 4 and the A / D converter 5, and the controller 40 includes the input controller 32, the D / A converter 7, and the servo amplifier 81.
Is connected to the actuator 9a via. A displacement meter 31 is attached to the actuator 9 a, and the displacement meter 31 is connected to the servo amplifier 81. Also, D
Two actuators 9b and 9b are connected to the / A converter 7 via a servo amplifier 82, and displacement gauges 32 and 32 are attached to each actuator 9b and 9b.

The acceleration signal in the vibration axis direction (the number of signals 1) measured by the accelerometer 3 during the vibration experiment by the vibrating table 1 and the acceleration signal in the interference axis (the number of signals 5) other than the vibration axis direction is detected by the amplifier 4. It is amplified and taken into the control device 40 via the A / D converter 5.

FIG. 6 is a diagram showing an outline of calculation of the control device 40. As shown in FIG. 6, the control device 40 includes a first calculation unit 401 and a second calculation unit 401 that generate a compensation wave in the excitation axis direction.
402 and third and fourth arithmetic units 403 and 404 that generate a compensation wave in the interference axis direction other than the excitation axis. The specific calculation contents of the control device 40 will be described below.

The first and second arithmetic units 401 and 402 for generating the compensation wave in the excitation axis direction are the first and second arithmetic units 301 and 3 of the control device 30 in the above-described first embodiment.
The same process as 02 is performed. With respect to the directions of the interference axes other than the vibration axis, the third and fourth calculation units 403 and 404 perform the following calculations to generate a signal that compensates the fundamental wave for the interference axes other than the vibration axis.

The third computing unit 403 vectorizes the fundamental wave component of the acceleration signal observed on the table of the vibrating table 1 in the direction of the interference axis other than the vibration axis. The contents of the calculation are shown below.

Fundamental wave signal x (t) of period T (sec)
Can be expanded into a Fourier series as shown in the following equations (15) to (18).

[0062]

[Equation 16]

Here, a0 represents the DC component of the fundamental wave signal, and the coefficients a and b are co with respect to the reference signal.
The sizes of the s component and the sin component are shown. In this way, vectorization is possible with the complex Fourier coefficients a and b.

The fourth calculation unit 404 determines the shaking table transfer characteristic for the frequency component of the fundamental wave from the compensation signal input to the shaking table 1 and the signal in the interference axis direction other than the vibration axis observed on the table. It identifies and generates a compensation wave of the fundamental wave in the direction of the interference axis other than the excitation axis. The contents of the calculation are shown below.

FIG. 7 is a control block diagram in the direction of the interference axis other than the vibration axis by the compensation calculation. As shown in FIG.
When the input wave having the complex Fourier coefficient of is input and the interference component of the fundamental wave having the complex Fourier coefficient of C1 is observed on the table, the following expression (19) is established.

[0066]

[Equation 17]

From the equation (19), the shaking table transfer function vector Hc can be estimated by the following equation (20).

[0068]

[Equation 18]

Here,

[Formula 19]

Then, the following equation (21) is obtained.

[0071]

[Equation 20]

Therefore, the complex Fourier coefficient Z1 of the first compensation wave for the interference degree of freedom is given by the following expression (22). That is,

[Equation 21]

It becomes

The first compensation wave Z calculated by the equation (21)
If 1 is input and the resulting observed wave vector on the table is C2, the following equation (23) is established.

[0075]

[Equation 22]

Since the complex Fourier coefficients of C1, Z1 and C2 are known, the shaking table transfer function Hc can be easily estimated. Ie

[Equation 23]

Then,

[Equation 24]

It becomes Here, the shaking table transfer function vector is a constant

[Equation 25]

It becomes Therefore, formula (21) and formula (22)
Then, the shaking table transfer function vector is estimated.

[0080]

[Equation 26]

The matrix composed of the complex Fourier coefficients of the compensation wave on the right side of the equation (25) is a rectangular matrix of 4 rows and 2 columns, and there is no inverse matrix.

However, if a pseudo-inverse matrix is introduced as in the following equation (26), the shaking table transfer function vector

[Equation 27]

Can be estimated.

[0084]

[Equation 28]

Shaking table transfer function vector estimated in this way

[Equation 29]

The compensating wave Z2 input from the second time can be obtained from. That is,

[Equation 30]

It becomes

In this way, the shaking table transfer function vector estimation value is sequentially updated, and repeatedly executed until the magnitude of the interference freedom vector observed on the table becomes sufficiently small.

As described above, the compensation signal for each degree of freedom generated by the control device 40 is servo-controlled through the input controller 32 and the D / A converter 7 having the function of generating a command signal to each vibrator. The signals are amplified by the amplifiers 81 and 82 and sent to the actuators 9a, 9b and 9b.

The vibrating table control apparatus according to the second embodiment is
Unlike the conventional discrete excitation method that requires the excitation to be stopped once and the compensation wave to be calculated next time to be calculated, it continues until the harmonic component in the excitation axis direction converges to a specified value. Since the fundamental wave component can be continuously compensated for in the interference axis direction other than the excitation axis, it is possible to perform an extremely ideal uniaxial sine wave excitation test several seconds after starting the compensation control. .

The present invention is not limited to the above-mentioned respective embodiments, and can be carried out by appropriately modifying it without departing from the scope of the invention.

[0092]

According to the shaking table control device of the present invention, the compensation wave can be continuously output until the harmonic components converge to a predetermined value, and the compensation calculation is performed in a short time to control the vibration of the shaking table. Can be done. That is, by targeting a sine wave as the input signal, it is possible to continuously compensate for the reproduced wave on the vibrating table, so that it is possible to match the excitation target wave and the reproduced wave in a short time. According to the vibrating table control device of the present invention, since the transfer characteristic of the shaking table is identified for each input compensating wave from the compensating wave and the observed wave in the excitation direction, the compensating wave considering the transferring characteristic of the shaking table is identified. Can be generated.

According to the vibrating table control apparatus of the present invention, the harmonic components in the excitation axis direction can be continuously compensated until they converge to a predetermined value, and the fundamental wave component can be obtained in the interference axis direction other than the excitation axis. Can be continuously compensated, so that extremely ideal vibration control of the vibration table can be performed.

According to the shaking table controller of the present invention, the ratio of the magnitude of the Nth harmonic to the fundamental wave can be set to a predetermined value, and when the predetermined value is reached, the (N + 1) th harmonic Compensation is transferred continuously. In addition, the transfer characteristics of the shaking table are identified for each input compensating wave from the compensation wave and the observed wave in the direction perpendicular to the vibration of the shaking table, and the magnitude of the fundamental wave component of the observed wave in the direction perpendicular to the shaking is determined. Can be set to a value.

[Brief description of drawings]

FIG. 1 is an overall system diagram of a single-axis shaking table controller according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a calculation outline of the control device according to the first embodiment of the present invention.

FIG. 3 is a vector diagram of N-th harmonics by complex Fourier coefficients according to the first embodiment of the present invention.

FIG. 4 is a control block diagram in the excitation axis direction by compensation calculation according to the first embodiment of the present invention.

FIG. 5 is an overall system diagram of a 6-axis shaking table controller according to a second embodiment of the present invention.

FIG. 6 is a diagram showing a calculation outline of a control device according to a second embodiment of the present invention.

FIG. 7 is a control block diagram in the direction of the interference axis other than the excitation axis by the compensation calculation according to the second embodiment of the present invention.

FIG. 8 is an overall system diagram of a shaking table controller according to a conventional example.

FIG. 9 is a flowchart of input wave compensation calculation according to a conventional example.

[Explanation of symbols]

1 ... Shaking table 2 ... Specimen 3 ... Accelerometer 4 ... Amplifier 5 ... A / D converter 6 ... Calculator 7 ... D / A converter 8 ... Servo amplifier 81 ... Servo amplifier 82 ... Servo amplifier 9 ... Actuator 9a ... Actuator 9b ... Actuator 30 ... Control device 31 ... Displacement meter 32 ... Accelerometer 40 ... Control device 301 ... First calculation unit 302 ... Second arithmetic unit 401 ... First arithmetic unit 402 ... Second arithmetic unit 403 ... Third arithmetic unit 404 ... Fourth arithmetic unit

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-60-63676 (JP, A) JP-A-7-27664 (JP, A) Actual Kaihei 2-38610 (JP, U) (58) Field (Int.Cl. ⁷ , DB name) G01M 7/02 G05D 19/02

Claims (4)

(57) [Claims] 1. A vibrating table control device for controlling the vibration of the vibrating table based on the acceleration measured by the vibrating table as a target, wherein a harmonic of an acceleration signal in the vibrating axis direction observed on the vibrating table. First computing means for vectorizing the component, and second computing means for generating a compensation wave signal of the acceleration signal vectorized by the first computing means based on the compensation signal input to the vibrating table. And a vibrating means for vibrating the vibrating table by the compensation wave signal generated by the second computing means. 2. The second calculating means identifies, from the compensation signal and the acceleration signal in the excitation axis direction, a transfer characteristic of the vibration table with respect to a frequency component of a harmonic for each input compensation signal. The vibration table control device according to claim 1, wherein the compensation wave signal is generated. 3. A vibrating table control device for controlling the vibration of the vibrating table based on the acceleration measured on the vibrating table as a target, wherein a harmonic of an acceleration signal in the vibrating axis direction observed on the vibrating table. First computing means for vectorizing the component, and second computing means for generating a compensation wave signal of the acceleration signal vectorized by the first computing means based on the compensation signal input to the vibrating table. A third computing means for vectorizing a harmonic component of an acceleration signal in an interference axis direction other than the vibration axis direction observed on the vibrating table, and the third computing means based on a compensation signal input to the vibrating table. Fourth calculating means for generating a compensation wave signal of the acceleration signal vectorized by the calculating means, and first vibration for vibrating the vibrating table by the compensation wave signal generated by the second calculating means. Means, and the compensation wave generated by the fourth computing means Vibrating table control apparatus characterized by comprising a second vibration means for vibrating the vibrating table by No.. 4. The second calculating means identifies, from the compensation signal and the acceleration signal in the excitation axis direction, a transfer characteristic of the vibration table with respect to a frequency component of a harmonic for each input compensation signal. While generating the compensation wave signal, the fourth calculation means, from the compensation signal and the acceleration signal in the interference axis direction other than the excitation axis direction, the frequency component of the fundamental wave for each input compensation signal. The shake table control device according to claim 3, wherein the transfer characteristic of the shake table with respect to the shake table is identified, and the compensation wave signal is generated.