JP3427119B2 - Vibration test system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration test system, a vibration control device and a method in a vibration test, and in particular, control is performed by considering a change in transfer characteristics of a controlled system and the presence of various error factors. It is intended to improve the function.

[0002]

2. Description of the Related Art In a conventional vibration test of waveform reproduction by an electrodynamic vibration generator, feedforward control is generally used in a method of reproducing the vibration given as waveform data as the waveform itself.

In this case, before the vibration test, the controlled system is modeled by performing test vibration and measuring the transfer function of the controlled system. Then, based on the measured transfer function and target signal, a drive signal is calculated so that the response signal at the control point matches the target signal. The error caused by the non-linearity of the transfer characteristic of the controlled system is corrected by reflecting the correction signal determined from the information of the control error of the actual vibration on the next drive signal.

[0004]

However, the conventional vibration test system as described above has the following problems.

First, in the vibration test, there are cases where the test vibration cannot be performed or the drive signal cannot be repeatedly adjusted.

Secondly, there is a case where the target signal must be changed in real time according to the response of the specimen during the actual vibration.

Then, it is conceivable to apply feedback control to solve the first and second problems.
In this case, if the model of the controlled system considered in advance and the characteristics of the actual controlled system match within a certain range, sufficient accuracy can be obtained by feeding back the deviation. However, when the characteristics of the controlled system change during vibration, or because the controlled system has many non-linear elements, accurate modeling is difficult. In some cases, the control performance of feedback control may be significantly deteriorated. In particular, the transfer characteristic of the electrodynamic vibration generator in the low frequency region may have non-linearity, and the problem as described above occurs in that region. Further, the transfer characteristic of the hydraulic vibration generator has many non-linear elements as compared with the electrodynamic vibration generator, and thus causes a similar problem.

It is an object of the present invention to solve the above problems and provide a vibration test system capable of following a non-linear transfer characteristic of a controlled system or a change in the transfer characteristic in real time.

[0009]

Means for Solving the Problems and Effects of the Invention
The vibration test system according to (1) directly receives the drive signal from the vibration control device and directly applies the electrodynamic vibration device for vibrating the test object and the vibration of the test object vibrated by the electrodynamic vibration device. or a vibration detecting means for detecting indirectly, receives the output of the target signal and the vibration detection means, met vibration system <br/> control device outputs a drive signal so that the output of the vibration detecting means matches the target signal And a drive signal for matching the output of the vibration detection means with the target signal based on the transfer characteristics of the test object which is the controlled system and the electrodynamic vibration exciter. Vibration control device that feeds back the output sequentially and controls so that the error from the target signal becomes small
And the vibration control device performs robust control.
It is characterized by.

Therefore, since the control response vibration is fed back at any time, it is not necessary to perform test vibration and it is not necessary to repeatedly correct the drive signal by actual vibration. Further, even when the target signal has to be changed in real time according to the response of the specimen during the actual vibration, that is possible.

[0011]

[0012] In addition, than conventional enables the creation of complex controller, it becomes possible to high-precision control than ever. Further, modeling error of the controlled system, characteristic change during vibration, disturbance noise, etc. can be designated as uncertainty during controller design. That is, the uncertainty is a difficult part to be modeled exactly, and a controller having a width in the model of the controlled system is created by the uncertainty. The magnitude of this uncertainty influences the control performance, where the limit of the control performance of the controller can be predetermined according to the uncertainty.

That is, even if the model of the controlled system considered by the controller and the actual characteristic of the controlled system are different due to a change in the characteristic of the controlled system during vibration, disturbance noise, etc. Within the range of uncertainty considered at the time of design, desired control performance and robust and stable control can be performed.

A vibration test system according to a third aspect of the present invention is characterized in that the plurality of vibration control devices simultaneously control the controlled system.

Therefore, it is possible to control the same controlled system at the same time with a plurality of controlled variables (eg, displacement, velocity, acceleration). Further, if robust control is performed, the limit of the control performance of the controller can be determined in advance, so that the band in which each control amount is effective can be designated, and multivariate control can be easily performed.

A vibration test system according to a fourth aspect of the present invention is a vibrating device for vibrating a specimen in response to a drive signal from a vibration control device, and a specimen vibrated by the vibrating device. Vibration detection means for directly or indirectly detecting the vibration of
A feedback control unit that receives the target signal and the output of the vibration detection unit and outputs a first control signal so that the output of the vibration detection unit matches the target signal, and a control parameter that considers the transfer function of the controlled system used includes a vibration control device for the output of the vibration detecting means and a feed-forward control unit for outputting a second control signal to match the target signal, the vibration control device and the output of the vibration detecting means It is characterized in that the control parameter of the feedforward control unit is sequentially changed according to the error from the target signal.

Therefore, the vibration test can be performed without performing the test vibration. Further, it is not necessary to repeatedly correct the drive signal by actual vibration.

A vibration test system or a vibration control device according to a sixth aspect is characterized in that a feedback control unit provided in the vibration control device performs robust control. The vibration test system according to claim 7, wherein a plurality of the vibration control systems are provided.
The controller controls multiple physical quantities simultaneously for the controlled system.
It is characterized by performing.

Therefore, in the vibration test, even if the transfer characteristic of the controlled system itself has non-linearity, and the transfer characteristic of the controlled system changes during the test, the transfer characteristic used in the feedback control unit is obtained in advance. Even if there is an error between the model and the actual transfer characteristic, which exceeds the uncertainty range considered by the feedback control unit, the feedforward unit can follow the error in real time, and the control function will deteriorate. There is no.

[0020]

The vibration detecting means is for detecting an amount (for example, vibration displacement, acceleration) representing the motion of the sample.
Further, in the embodiment, a sensor corresponds to this, and there are a sensor for detecting with a laser and a sensor for directly detecting the laser by attaching it to a specimen.

In the embodiment, the feedback control section corresponds to the control term of the transfer function K in FIGS.

In the embodiment, the feedforward control unit corresponds to the control term of the transfer function F / P 'in FIG.

The target signal is data of a target vibration waveform, and the target waveform corresponds to this in the embodiment.

The first control signal is an output signal of the feedback control unit, and in the embodiment, u in FIGS.
1 corresponds to this.

The second control signal is an output signal of the feedforward control unit, and in the embodiment, it is shown in FIGS.
U2 corresponds to this.

[0027]

DETAILED DESCRIPTION OF THE INVENTION

1. Overall Configuration The overall configuration will be described with reference to FIG. It is mainly composed of an electrodynamic vibration generator 11 which is a vibrating device, a sensor 12 which is a vibration detecting means, a controller 13 which is a control device, and an amplifier 14.

The sensor 12 detects the vibrational displacement of the motion of the test body 15 which is a test body vibrated by the electrodynamic vibration generator 11 by means of a laser. The amplifier 14 amplifies the drive signal calculated by the controller 13.

An exciting power source 16 and a cooling device 17 are also provided for driving the vibration exciter 11.

In this embodiment, the electrodynamic vibration generator 11 is used as the vibrating device, but a hydraulic vibration generator may be used.

2. The structure and characteristics of the vibrating device electrodynamic vibration generator 11 will be described below.

FIG. 2 shows a simplified structure of the electrodynamic vibration generator 11. The electrodynamic vibration generator 11 is mainly composed of a drive coil 21, an exciting coil 22, a suspension system 23, and a movable part 24.

By passing an exciting current through the exciting coil 22, a magnetic field is generated in the direction of arrow A. When a drive current is passed through the drive coil 21 existing in this magnetic field, an exciting force is generated according to Fleming's left-hand rule. The excitation force vibrates the movable portion 24 in the direction of arrow B via the suspension system 23. The test body 15 is attached to the movable part 24, and the test body 15 also vibrates when the movable part 24 vibrates.

Next, FIG. 3 shows the result of measurement of the steady-state characteristics of the electrodynamic vibration generator 11.

Here, y on the vertical axis is the vibration displacement y of the movable portion 24, and u is the input voltage to the amplifier 14. At this time, the input voltage to the amplifier 14 is set to 200, 150, 100 (mVrms), the speed of the movable part 24 is changed, and the frequency response of the electrodynamic vibration generator 11 is measured.

As is apparent from FIG. 3, the linearity is shown in the high frequency region of 20 (Hz) and above, but the nonlinear characteristic which is different depending on the input voltage is shown in the frequency region below 20 Hz.

3. Hardware Configuration FIG. 4 shows the hardware configuration when the controller 13 of FIG. 1 is realized by using the CPU 61. In FIG. 4, the CPU 61 includes a memory 62, a display 63,
Hard disk 64, CD-ROM drive 65, D /
An A conversion device 66 and an A / D conversion device 67 are connected. Earthquake waveform data A64 is stored in the hard disk 64.
1, seismic waveform data B642, an operating system (OS) 643, and a control program 644 are stored. Earthquake waveform data A641, Earthquake waveform data B64
2 and the control program 644 are installed from the CD-ROM 68 via the CD-ROM drive 65.

The two-degree-of-freedom control to which the adaptive filter of the CPU 61 is applied will be described below. This two-degree-of-freedom control is a control method that combines feedback control and feedforward control.

First, for simplicity of explanation, the two-degree-of-freedom control to which the adaptive filter is not applied will be described.

3.1 Two-degree-of-freedom control system to which adaptive control is not applied A block diagram when a two-degree-of-freedom control system is used as the control program 644 in FIG. 4 is shown in FIG. Here, r is a target waveform that is a target signal, F / P ′ is a feedforward control term that is a feedforward control unit, K is a feedback control term that is a feedback control unit, F is a target model, and P is an electrokinetic vibration. The controlled system including the generator 11 and the test body 15 is shown. Note that P'is a model of the controlled system P.

The feedback control term K is W given below.
Compute the H _∞ controller using s, Wt.

Ws (s) = γ _s・ [(10 ・ 7 ・ 2π) / {(s + 7) ・ 2π}] ・ [(2 ・ 2π) / {(s + 2) ・ 2π}] ・ ・・ (1) Wt (s) = 0.1 ・ {(10 ・ 2π) ^-1 s + 1} ・ {(50 ・ 2π) ^-1 s + 1} ・ {(100 ・ 2π) ^-1 s + 1} ・.. (2) Ws: frequency weighting function for sensitivity function γ _s : design parameter for adjusting gain Wt: frequency weighting function for complementary sensitivity function Further, the target model F is represented by a third-order low-pass filter.

When the target waveform r is input to this control system,
R ′ is calculated in the target model term F. Then r '
And the deviation e of y which is the output signal of this control system is calculated,
This deviation e is calculated in the feedback control term K, and the first control signal u1 is calculated. Further, the second control signal u2 is calculated from the target waveform r and the feedforward control term F / P ′. And
The drive signal u is the first control signal u1 and the second control signal u2.
It is calculated from the sum of When the drive signal u passes through the controlled system P, y which is a control response signal for the movable portion 23 and the test body 15 is output.

That is, since the feedforward term is a predetermined transfer function F / P ', it cannot follow the actual change in the characteristic of the controlled system.

3.2 Two-Degree-of-Freedom Control System Applying Adaptive Control Next, when a two-degree-of-freedom control system applying adaptive control to the feedforward control term F / P ′ is used as the control program 644 in FIG. A block diagram of is shown in FIG. Here, for example, an adaptive filter is used for this adaptive control, and the algorithm of the adaptive filter 81 uses the adaptive filter 81
In consideration of the fact that the characteristic of the controlled system P is included up to the summing point 82 where the error is calculated from the output of
-X LMS method is used. In this case, the adaptive filter 81 has a FI
An R filter is used, and the filter coefficient update formula of the Filtered-X LMS method is calculated by the following formula.

W _{k + 1} = W _k −2 μe _k R _k (3) W _k : filter coefficient R _k : signal through characteristic of controlled system e _k : error signal μ: step parameter subscript k : Sample time, that is, e _k, which is the deviation between r ′ and y calculated by the above target model term F, is taken into the adaptive filter 81 at any time,
The filter coefficient W _k is modified at any time.

When the target waveform r is input to this control system,
R'is calculated in the target model term F. Then r '
And the deviation e of the control response signal y_kIs calculated and this bias
Difference e _kIs calculated in the feedback control term K,
The control signal u1 of 1 is calculated. Also, the target waveform
r and the feedforward control term, that is, the adaptive filter W
_kThus, the second control signal u2 is calculated.
Also, the deviation e_kAre introduced into the adaptive filter 81,
From the formula (3), the filter coefficient W_kIs fixed. And drive
The motion signal u is the first control signal u1 and the second control signal u2.
Calculated from the sum. The drive signal u passes through the controlled system P
Then, it becomes a control response signal of the movable part 23 and the test body 15.
Y is output.

[0049] That is, 2 by applying the adaptive filter 81 in place of the feed-forward term F / P 'in degree of freedom control system, to modify the filter coefficients W _k of the adaptive filter in consideration of the control response signal y at any time A suitable drive signal u according to the actual characteristics of the controlled system can be given to the controlled system. Therefore, the deviation resulting from the error between the predetermined model and the actual transfer characteristic can be sequentially corrected in the feedforward term, and the control function can be improved.

4. Below, the CPU 6 when the CPU 61 is used as the controller 13 and the two-degree-of-freedom control system to which the adaptive filter 81 is applied as the control program 644 is used.
This series of operations in 1 is shown in the flowchart of FIG.

The CPU 61 reads the target waveform r at time t from the earthquake waveform data A641 stored in the hard disk 64 (ST1), and calculates r'from the target model term K (ST2). Next, the sensor 12 detects the control response signal y of the test body 15 at time t, and the A / D
Conversion is performed (ST3). Next, a deviation e _k between r ′ calculated by the target model term K and y at time t is calculated (ST4),
Based on the deviation e _k , the first control signal u1 is calculated in the feedback control term K (ST5). Further, the adaptive filter 81 calculates the second control signal u2 based on the target signal r (ST6). Next, the deviation e _k is also given to the feedforward control term, that is, the adaptive filter 81, and the filter coefficient Wk of the adaptive filter 81 is corrected by the equation (3) shown above (ST7). And
The drive signal u is converted into the first control signal u1 and the second control signal u2.
It is calculated from the sum of (ST8). After this drive signal u is D / A converted (ST9), it is given to the controlled system P (ST1.
0).

Therefore, by feeding back the control response signal y of the test body 15 detected by the sensor 12 as needed, the filter coefficient Wk of the adaptive filter 81 is modified at any time, and the drive signal u is also modified.

5. Effect 2 The control results with and without adaptive control applied to the feedforward control terms of the free control system are shown in FIGS. 8A and 8B, respectively. Here, the adaptive filter described above is used as the adaptive control. The vertical axis of these is vibration displacement y, and the horizontal axis is time. Further, respective error signals e are shown in FIG. 8C. At this time, the target signal is the displacement waveform of the east-west component of the Hyogoken Nanbu Earthquake.

These figures show that when the adaptive filter 81 is not applied, the response value becomes smaller than the target value due to the modeling error of the controlled system P. Further, when the adaptive filter 81 is applied, the modeling value of the controlled system P is followed, and the target value and the response value substantially match.

Therefore, by using the two-degree-of-freedom control system to which the adaptive filter 81 is applied, the transfer characteristic of the controlled system P itself has non-linearity, and the transfer characteristic model obtained in advance and the actual transfer characteristic are used. Error occurs, and even if it exceeds the uncertainty range considered in the feedback control term, the error can be tracked in real time by the adaptive control of the feedforward control term, so the control function does not deteriorate. . 6. In the above-described embodiment, a plurality of controllers (two-degree-of-freedom system control device to which adaptive control is applied) may be provided as shown in FIG. 9 in order to perform multivariate control. This system is composed of a displacement control controller 131 that is effective in a low frequency region, a speed control controller 132 that is effective in a medium frequency region, and an acceleration control controller 133 that is effective in a high frequency region. These controllers 131 to 133 are preset so as not to perform output in an area other than the area in which each of them is effective. For example, the displacement controller performs control in the low frequency region but does not output in the medium frequency and high frequency regions.

The target waveforms r1, r2 and r3 in FIG. 9 represent the same target waveform r with different physical quantities (r
1 is displacement, r2 is velocity, and r3 is acceleration). Also,
The displacement sensor 121, the speed sensor 122, and the acceleration sensor 123 are attached to the test body 15, and each controller 13
The displacement control response signal y1, the velocity control response signal y2, and the acceleration control response signal y3 of the test body 15 are fed back to 1 to 133.

The displacement controller 131 determines the target waveform r
1, the operation amount x1 is output from the feedback amount y1, the speed control controller 132 outputs the operation amount x2 from the target waveform r2 and the feedback amount y2, and the acceleration control controller 133 outputs the operation amount x3 from the target waveform r3 and the feedback amount y3. Output. The operation amount x1 in the low frequency region, the operation amount x2 in the medium frequency region, and the operation amount x3 in the high frequency region are drive signals u, respectively.

Therefore, according to this system, accurate control can be performed in a wide frequency band at the same time. Here, it is possible to control the electrodynamic vibration generator 11 without providing the adaptive filters 811 to 813.

Further, in the embodiment shown in FIG. 1, the adaptive filter 81 may not be provided and the electrodynamic vibration generator 11 may be controlled. In this case, even if an error occurs between the model of the transfer characteristic obtained in advance and the actual transfer characteristic, if the error is within the uncertainty considered at the time of design, it is possible to follow the error in real time. Does not deteriorate. Further, since the control response signal of the test body 15 is fed back at any time, it is possible to perform a vibration test without performing test vibration, and it is not necessary to repeatedly correct the drive signal.

Further, not only the displacement of the test body 15 in the uniaxial direction, but also the control in the multiaxial direction may be performed.

[Brief description of drawings]

FIG. 1 is a diagram showing an overall configuration of a vibration test system in the present embodiment.

FIG. 2 is a diagram showing a configuration of an electrodynamic vibration generator 11 according to the present embodiment.

FIG. 3 is a diagram showing characteristics of the electrodynamic vibration generator 11 according to the present embodiment.

FIG. 4 is a diagram showing a hardware configuration in the present embodiment.

5 is a diagram showing a block diagram of a two-degree-of-freedom control system to which an adaptive filter 81 is not applied. FIG.

FIG. 6 is a diagram showing a block diagram of a two-degree-of-freedom control system to which an adaptive filter 81 is applied.

FIG. 7 is a flowchart showing a series of operations in the present embodiment.

FIG. 8A is a graph showing a control result when the adaptive filter 81 is not applied in the present embodiment.
FIG. 8B is a graph showing the control result when the adaptive filter 81 is applied in the present embodiment. FIG. 8C shows
In this embodiment, it is a graph which shows the control error when the adaptive filter 81 is applied and when it is not applied.

FIG. 9 is a diagram showing a configuration of a vibration test system provided with a plurality of control devices in another embodiment.

[Explanation of symbols]

11 ... Vibration device 12 ... Vibration detection means 13 ... Control device 15 ... Specimen

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masayuki Fujita 2-40-20 Otateno, Kanazawa-shi, Ishikawa Kanazawa University Faculty of Engineering, Department of Electrical and Information Engineering (56) Reference JP-A-2-213908 (JP, A) Hei 4-305138 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01M 7/02 G05D 19/02

Claims (11)

(57) [Claims] Claim: What is claimed is: 1. An electrodynamic exciter for vibrating a specimen in response to a drive signal from a vibration control device, and direct or indirect vibration of the specimen vibrated by the electrodynamic exciter. receiving a vibration detection means for detecting the output of the target signal and the vibration detection means, the output of the vibration detecting means is a vibration control device for outputting a drive signal to match the target signal is the controlled system A drive signal for matching the output of the vibration detection means with the target signal is calculated based on the transfer characteristics of the test piece and the electrodynamic vibrator, and the output of the vibration detection means is sequentially fed back to obtain the target. Vibration controlled to reduce the error from the signal
A vibration test system comprising: a control device , wherein the vibration control device performs robust control . 2. A vibration detecting means for applying a drive signal to an electrodynamic vibrator for vibrating a specimen to directly or indirectly detect vibration of the specimen vibrated by the vibrator. A vibration control device that receives an output, and calculates the drive signal for matching the output of the vibration detection means with a target signal, based on the transfer characteristics of the test object that is the controlled system and the electrodynamic vibrator. At the same time, the output of the vibration detection means is sequentially fed back, and robust control is performed so that the error with the target signal becomes small.
Vibration control device characterized by. 3. The vibration test system according to claim 1 or 2.
Alternatively, in the vibration control device , a plurality of the vibration control devices simultaneously control a plurality of physical quantities for a controlled system. 4. A vibrating device for vibrating a specimen in response to a drive signal from a vibration control device, and a vibration detecting means for directly or indirectly detecting vibration of the specimen vibrated by the vibrating device. And a feedback control section that receives a target signal and the output of the vibration detection means and outputs a first control signal so that the output of the vibration detection means matches the target signal, and control considering the transfer function of the controlled system. a vibration test system comprising a vibration control device for the output of the vibration detecting means and a feed-forward control unit for outputting a second control signal to match the target signal using the parameters, the vibration control device Is a vibration test system characterized in that the control parameter of the feedforward control unit is sequentially changed according to the error between the output of the vibration detection means and the target signal. 5. A vibration control device for applying a drive signal to a vibrating device for vibrating a specimen and receiving an output of a vibration detecting means for directly or indirectly detecting the vibration of the specimen vibrated by the vibrating device. In consideration of the transfer function of the controlled system, a feedback control unit that receives the target signal and the output of the vibration detection unit and outputs a first control signal so that the output of the vibration detection unit matches the target signal A feedforward control unit that outputs a second control signal so that the output of the vibration detection unit matches the target signal by using the control parameter described above is provided. A vibration control device characterized in that a control parameter of a forward control unit is sequentially changed. 6. The vibration test system according to claim 4 or claim 5.
In the above vibration control device , the feedback control unit included in the vibration control device performs robust control. 7. The vibration test system according to claim 5 or 6 , wherein the plurality of vibration control devices simultaneously control a plurality of physical quantities for the controlled system. 8. Based on the transfer characteristics of the test subject, which is a controlled system, and the electrodynamic exciter, the output and target signals of the vibration of the test subject vibrated by the electrokinetic exciter are detected. Then, a vibration test method for calculating a drive signal for matching the output detected by the vibration of the specimen vibrated by the electrodynamic exciter with a target signal, and giving the drive signal to the electrodynamic exciter The robust control is performed so that the output that detects the vibration of the specimen vibrated by the electrodynamic exciter is sequentially fed back to reduce the error from the target signal.
Vibration test method. 9. An output that detects the vibration of a test piece vibrated by a vibrating device and a target signal, and an output that detects the vibration of a test piece vibrated by a vibrating device matches the target signal. The first control signal is output as described above, and the control parameter in consideration of the transfer function of the controlled system is used to detect the vibration of the specimen vibrated by the vibrating device so that the output matches the target signal. A vibration test method for outputting a second control signal and applying a drive signal obtained from the first control signal and the second control signal to a vibrating device, the characteristic of a controlled system being vibrated. A vibration test method characterized in that a control parameter of a feedforward control unit is sequentially changed according to a change. 10. A recording medium in which a vibration control program for controlling vibration of an electrodynamic vibration exciter by a computer is recorded, the computer comprising : Based on transfer characteristics
Then, the test piece vibrated by the electrodynamic exciter
Drive to match the output that detects the vibration of the
The motion signal is calculated, and the vibration of the specimen vibrated by the electrodynamic exciter is calculated.
The detected output is fed back sequentially and the
Vibration for robust control so that the difference becomes small
A recording medium recording a control program. 11. A recording medium in which a vibration control program for controlling the vibration of a vibrating device is recorded by a computer, wherein the output is the target when the computer detects the vibration of the specimen vibrated by the vibrating device. The first control signal is calculated so as to match the signal, and the output that detects the vibration of the specimen vibrated by the vibration exciter is used as the target signal using the control parameters that take the transfer function of the controlled system into consideration. A recording medium on which a vibration control program for calculating a second control signal so as to match and outputting a drive signal obtained from the first control signal and the second control signal is recorded. in response to the characteristic change in the controlled system, vibration <br/> turning control program recorded record medium for sequentially changing the control parameters of the feedforward control unit.