JP2015072242A - Control device of test device and control method of test device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device of a test device and a control method of a test device that can respond immediately to a change in a state of a test piece and the like with a shorter correction time.SOLUTION: A waveform correction calculation part 24 is provided that comprises a harmonic calculation part 26 for performing calculation processing of a fundamental wave component and an arbitrary n-fold harmonic of a response waveform from a test device to a control waveform input to the test device, a high frequency generation part 28 for performing calculation processing of a phase and amplitude of the arbitrary n-fold harmonic calculated by the harmonic calculation part 26, and an addition part 30 for inputting and aggregating the phase and amplitude of the arbitrary n-fold harmonic calculated by the high frequency generation part 28 and the fundamental wave component, and generating a control waveform to the test device.

Description

  The present invention relates to, for example, a control device for a test apparatus and a test apparatus for performing various tests such as a load test in which an external force is applied to a structure such as a shock absorber of a vehicle, a bridge, a building, a house, or a building. Relates to the control method.

  Conventionally, as a test apparatus of this type, a test apparatus 100 having a structure as shown in FIG. 7 has been proposed in order to test an object to be tested, for example, a shock absorber of a vehicle.

  That is, as shown in FIG. 7, the conventional test apparatus 100 includes a test apparatus main body 102 for performing a test. In this embodiment, the test apparatus main body 102 is composed of a vibration apparatus as an example of a test.

  As shown in FIG. 7, the test apparatus main body 102 includes a gantry frame 104, and an actuator 106 formed of a cylinder is provided below the gantry frame 104. The actuator 106 includes a piston 108 for loading the test piece A and a displacement detector 110 for detecting displacement. Although not shown, a speed detector for detecting the speed and an acceleration detector for detecting the acceleration are provided at the tip of the piston 108.

  Further, an upper frame 118 is provided above the gantry frame 104, and a guide rod 112 is provided between the upper frame 118 and the gantry frame 104 in the upper frame 118.

  A ball screw 114 is provided between the lower portion of the guide rod 112 and the upper frame 118, and a cross head 116 that can be moved up and down with respect to the piston 108 by the ball screw 114 is provided. In addition, the cross head 116 is provided with a detector 120 configured by, for example, a load sensor so as to face the piston 108.

  In the test apparatus 100 configured as described above, the test is performed as follows.

  As shown in FIG. 7, a test piece A such as a shock absorber is loaded on the upper surface of the piston 108, and the crosshead 116 is lowered with respect to the piston 108 by the ball screw 114 by a driving mechanism (not shown). The test piece A is sandwiched between the upper surface of the piston 108 and the lower surface of the cross head 116.

  Based on a program stored in advance in a control device (not shown), setting of test conditions and the like, execution of tests, and collection of test data are performed.

  That is, as shown in FIG. 7, an actuator power source (not shown) connected to the control device is driven under a predetermined condition under the control of the control device. As a result, the actuator 106 connected to the actuator power source is driven under a predetermined condition to give a constant vibration to the test piece A.

  The displacement of the test piece A is detected by a displacement detector 110 provided in the actuator 106, and the displacement data of the test piece A is input to the control device. On the other hand, a load or the like applied to the test piece A is detected by the detector 120 provided in the crosshead 116, and load data or the like applied to the test piece A is input to the control device.

  Further, based on these test data, a feedback command signal is output from the control device to the actuator power source according to the program of the control device, and the actuator 106 is driven under a predetermined condition.

Japanese Patent No. 3055788

  Conventionally, in such a test apparatus 100, when amplitude control is performed, when the actuator 106 is a hydraulic actuator, the hydraulic resonance of the hydraulic fluid and the respective sliding portions in the actuator 106 are controlled. Due to the influence, the velocity waveform of the velocity detector provided in the actuator 106 and the acceleration waveform of the acceleration detector provided at the tip of the piston 108 are represented by the portion A in FIG. ) Will be distorted as shown by the B part.

  8A shows an input waveform, FIG. 8B shows a velocity waveform, and FIG. 8C shows an acceleration waveform.

であり、余分な高調波成分（すなわち、上記式の第２項以降の高調波成分）が存在し、誤差（歪）が生じるおそれがある（図８（Ｂ）のＡ部分と、図８（Ｃ）のＢ部分参照）。 That is, the actual measurement waveform f (t) is

There is an excess harmonic component (that is, a harmonic component after the second term of the above formula), and there is a possibility that an error (distortion) may occur (A portion in FIG. 8B and FIG. (See part B of C)).

  For this reason, for example, in the case of a vibration test or the like, the accuracy of vibration energy applied to the test piece A is impaired by this distortion, and there is a possibility that an accurate vibration test result cannot be obtained.

  Further, the conventional test apparatus 100 attempts to improve waveform distortion by correcting a transfer function measured in advance. However, in this method, when a change in the transfer function due to a change in the state of the test piece A or the like occurs, the change cannot be instantaneously handled.

That is, in the conventional test apparatus 100, as shown in the graph of FIG. 9, the frequency characteristic for each Δf is obtained for one period by Fast Fourier Transform (FFT).
The input waveform X = Y / H is obtained from the transfer function H = Y / X, and then amplitude control is performed to generate a control signal by Fourier transform (IFFT). Here, Y is an output signal and X is an input signal.

  That is, in the conventional test apparatus 100, the amplitude control is performed as shown in the flowchart shown in FIG.

  First, control is started in step S101, and a transfer function is measured in step S102. In step S103, the system is identified, and in step S104, a control waveform is created.

  Next, in step S105, the test is started, and in step S106, it is determined whether or not the end conditions such as the preset time and the number of times are satisfied. If the end conditions are determined, the process proceeds to step S107 and the control is performed. Is terminated. On the other hand, if it is determined in step S106 that the end condition is not satisfied, the process returns to step S106 and it is repeatedly determined whether or not the end condition is satisfied.

  However, in such a control method of the conventional test apparatus 100, as shown in FIG. 10, the programs (programs (1) to (3) are known for each item and cannot be corrected by a series of flows. As shown in FIG. 10, for example, the program (1) takes 30 minutes and the program (2) takes 60 minutes.

  Even if the control waveform is created in the program (2), if the target system changes during the process of the program (3), it cannot cope with the change.

  Further, in such a control method of the conventional test apparatus 100, a pair of Fourier transform and inverse Fourier transform is performed on waveform length data longer than the period of the excitation frequency where the target waveform length necessary for correction is one cycle. Therefore, the number of calculation processes increases, the calculation load of the control device increases, and a high-performance and expensive microprocessor unit (MPU) is required, resulting in high cost.

  Further, in the conventional control method of the test apparatus 100, the target waveform length necessary for correction is one cycle, so it is necessary to obtain the frequency characteristics for each Δf for the waveform data length equal to or longer than the period time of the excitation frequency. Therefore, when the correction time becomes long and the transfer function changes due to a change in the state of the test piece A or the like, the change cannot be instantaneously handled.

  Further, in the conventional control method, the peak is not controlled after the waveform correction, so that the amplitude error is not corrected accurately and there is a possibility that an accurate vibration test result cannot be obtained. .

  In view of such a current situation, the present invention has no excessive harmonic components, there is no risk of error (distortion), and the accuracy of vibration energy applied to the test piece is not impaired. It is an object of the present invention to provide a control device for a test apparatus and a control method for the test apparatus.

  Further, the present invention does not require a pair of Fourier transform and inverse Fourier transform as in the conventional control method, reduces the number of calculation processes, reduces the calculation load of the control device, and is high performance and expensive. An object of the present invention is to provide a test apparatus control apparatus and a test apparatus control method that can reduce the cost without requiring a special microprocessor unit (MPU).

  Further, according to the present invention, unlike the conventional control method, there is no need to obtain the frequency characteristic for each Δf for the waveform data length equal to or longer than the period time of the excitation frequency in which the target waveform necessary for correction is one cycle. An object of the present invention is to provide a test apparatus control apparatus and a test apparatus control method capable of instantaneously responding to a change in the state of a test piece or the like when the correction time is shortened.

  Furthermore, the present invention can control a peak while performing waveform correction to accurately correct an amplitude error, and can provide an accurate vibration test result. It aims to provide a method.

The present invention was invented in order to achieve the problems and objects in the prior art as described above.
A control device for a test apparatus for performing various tests by applying an external force to a structure under test,
A response waveform from the test apparatus with respect to the control waveform input to the test apparatus, a fundamental wave component, and a harmonic calculation unit that calculates up to an arbitrary n-th harmonic,
A high-frequency generator that calculates the phase and amplitude of the arbitrary n-th harmonic calculated by the harmonic calculator;
An adder for generating a control waveform to the test apparatus by inputting and summing the phase and amplitude of the arbitrary n-fold harmonics processed by the high-frequency generator and the fundamental component;
And a waveform correction calculation unit.

The control method of the test apparatus of the present invention is
A test apparatus control method for performing various tests by applying an external force to a structure under test,
A harmonic calculation step for calculating a response waveform from the test apparatus to the control waveform input to the test apparatus, up to a fundamental wave component and an arbitrary n-th harmonic;
A high-frequency generation step for calculating the phase and amplitude of the arbitrary n-th harmonic calculated by the harmonic calculation unit;
An addition step of generating a control waveform to the test apparatus by inputting and summing the phase and amplitude of the arbitrary n-th harmonic wave processed by the high-frequency generator and the fundamental wave component;
It is characterized by providing.

  With this configuration, unlike the conventional control method, it is not necessary to perform the Fourier transform and the inverse Fourier transform in pairs, the number of calculation processes is reduced, the calculation load of the control device is reduced, and the high performance In addition, an expensive microprocessor unit (MPU) is unnecessary, and the cost can be reduced.

  In addition, it is an operation up to an arbitrary n-th harmonic, there is no extra harmonic component, there is no risk of error (distortion), and the accuracy of vibration energy applied to the test piece is not impaired and accurate. Vibration test results are obtained.

  Further, unlike the conventional control method, it is not necessary to obtain the frequency characteristic for each Δf for the waveform data length equal to or longer than the period time of the excitation frequency where the target waveform necessary for correction is one cycle, and the correction time is short. Therefore, even when the state change of the test piece or the like occurs, the change can be dealt with instantaneously.

において、前記任意のｎ倍高調波について、フーリエ級数展開を行い、
位相、

と、振幅、

を求めるように構成されていることを特徴とする。
ここで、ａ_ｎ、ｂ_ｎは、それぞれ、

であり、
Ｔは、加振周波数の１周期の時間、ω_０は加振周波数ｆ_０［Ｈｚ］の角周波数ω_０＝２πｆ_０である。 Moreover, the test apparatus of the present invention is configured such that the harmonic waveform calculation unit has a measured waveform f (t).

In the above-mentioned arbitrary n-th harmonic, Fourier series expansion is performed,
phase,

And amplitude,

It is comprised so that it may obtain | require.
Here, a _n and b _n are respectively

And
T is the time of one cycle of the excitation frequency, and ω ₀ is the angular frequency ω ₀ = 2πf ₀ of the excitation frequency f ₀ [Hz].

において、前記任意のｎ倍高調波について、フーリエ級数展開を行い、
位相、

と、振幅、

を求めるように構成されていることを特徴とする。
ここで、ａ_ｎ、ｂ_ｎは、それぞれ、

であり、
Ｔは、加振周波数の１周期の時間、ω_０は加振周波数ｆ_０［Ｈｚ］の角周波数ω_０＝２πｆ_０である。 The control method of the test apparatus of the present invention is
In the harmonic calculation step, the measurement waveform f (t)

In the above-mentioned arbitrary n-th harmonic, Fourier series expansion is performed,
phase,

And amplitude,

It is comprised so that it may obtain | require.
Here, a _n and b _n are respectively

And
T is the time of one cycle of the excitation frequency, and ω ₀ is the angular frequency ω ₀ = 2πf ₀ of the excitation frequency f ₀ [Hz].

  By configuring in this way, it is an operation up to an arbitrary n-th harmonic, there is no extra harmonic component, there is no risk of error (distortion), and the accuracy of vibration energy applied to the test piece is high Accurate vibration test results can be obtained without damage.

  In addition, since the phase and amplitude are obtained by frequency analysis up to an arbitrary n-th harmonic and complex Fourier series expansion, there is no need to perform a Fourier transform and an inverse Fourier transform in pairs as in the conventional control method, and a calculation process The number is reduced, the calculation load of the control device is lightened, a high-performance and expensive microprocessor unit (MPU) is unnecessary, and the cost can be reduced.

  Further, unlike the conventional control method, it is not necessary to obtain the frequency characteristic for each Δf for the waveform data length equal to or longer than the period time of the excitation frequency where the target waveform necessary for correction is one cycle, and the correction time is short. Therefore, even when the state change of the test piece or the like occurs, the change can be dealt with instantaneously.

を生成するように構成されていることを特徴とする。 In addition, the test apparatus of the present invention is
In the high frequency generation unit, based on the phase and amplitude obtained by performing the arithmetic processing in the harmonic calculation unit, a control waveform,

It is characterized by producing | generating.

を生成することを特徴とする。 The control method of the test apparatus of the present invention is
In the high frequency generation step, based on the phase and amplitude obtained by performing the arithmetic processing in the harmonic calculation step, a control waveform,

Is generated.

  By configuring in this way, it is an operation up to an arbitrary n-th harmonic, there is no extra harmonic component, there is no risk of error (distortion), and the accuracy of vibration energy applied to the test piece is high Accurate vibration test results can be obtained without damage.

In addition, the test apparatus of the present invention is
Obtain the data for one period of an arbitrary excitation frequency in advance, calculate the amplitude, multiply the difference from the amplitude obtained by the peak detection of the response waveform from the test device, the control waveform from the adder, A peak calculation unit for generating a control waveform for the test apparatus is provided.

The control method of the test apparatus of the present invention is
Obtaining data for one period of an arbitrary excitation frequency in advance and calculating the amplitude, multiplying the difference from the amplitude obtained by peak detection of the response waveform from the test apparatus by the control waveform from the addition step, A peak calculation processing step for generating a control waveform for the test apparatus is provided.

  With this configuration, since the peak is controlled, the amplitude error can be corrected accurately, and an accurate vibration test result can be obtained.

  In the present invention, the control waveform is a periodic function of a sine wave.

  Thus, it is desirable that the control waveform is a periodic function of a sine wave.

  Furthermore, the present invention is characterized in that the control waveform is a superimposed control waveform.

  Thus, even if the control waveform is a superimposed control waveform, it can be used. For example, the present invention can be applied to a case where a test is performed by superimposing a load waveform of 5 Hz on a rotation waveform of 2 Hz.

  According to the present invention, unlike the conventional control method, it is not necessary to perform the Fourier transform and the inverse Fourier transform in pairs, the number of calculation processes is reduced, the calculation load of the control device is reduced, the performance is high, and the cost is high. A costly microprocessor unit (MPU) is not required and the cost can be reduced.

  In addition, it is an operation up to an arbitrary n-th harmonic, there is no extra harmonic component, there is no risk of error (distortion), and the accuracy of vibration energy applied to the test piece is not impaired and accurate. Vibration test results are obtained.

  Further, unlike the conventional control method, it is not necessary to obtain the frequency characteristic for each Δf for the waveform data length equal to or longer than the period time of the excitation frequency where the target waveform necessary for correction is one cycle, and the correction time is short. Therefore, even when the state change of the test piece or the like occurs, the change can be dealt with instantaneously.

FIG. 1 is a schematic block diagram showing an example in which the test apparatus of the present invention is applied to an excitation test apparatus that performs an excitation test as an example of a test. 2A is a graph showing a target waveform, FIG. 2B is an actual measurement waveform, and FIG. 2C is a graph showing a waveform corrected by the control device 10 of the present invention. FIG. 3 is a schematic diagram for explaining the outline of processing in the peak calculation unit 36 of the test apparatus 10 of the present invention. FIG. 4 is a flowchart showing a control method of the control device 10 of the test apparatus of the present invention. FIG. 5 is a flowchart showing a control parameter setting method of the control apparatus 10 of the test apparatus of the present invention. FIG. 6 is a graph showing a test apparatus control method by the control apparatus 10 of the test apparatus according to the present invention. FIG. 6A is an input waveform, FIG. 6B is a velocity waveform, and FIG. 6C is an acceleration waveform. It is a graph which shows. FIG. 7 is a front view of a conventional test apparatus 100. FIG. 8 is a graph showing a control method of the test apparatus by the conventional test apparatus 100, FIG. 8A is an input waveform, FIG. 8B is a velocity waveform, and FIG. 8C is a graph showing an acceleration waveform. is there. FIG. 9 is a graph showing a control method of the conventional test apparatus 100. FIG. 10 is a flowchart showing a control method of the conventional test apparatus 100.

  Hereinafter, embodiments (examples) of the present invention will be described in more detail with reference to the drawings.

  FIG. 1 is a schematic block diagram showing an embodiment in which the test apparatus of the present invention is applied to an excitation test apparatus for performing an excitation test as an example of a test, FIG. 2A is a target waveform, and FIG. Is an actual measured waveform, and FIG. 2C is a graph showing a waveform after correction by the control apparatus 10 of the present invention.

  In FIG. 1, reference numeral 10 generally indicates a control device 10 (hereinafter simply referred to as “control device 10”) of the test apparatus of the present invention.

  As shown in FIG. 1, the control apparatus 10 of the present invention controls the test apparatus with respect to the test apparatus main body 12 for performing the test.

  In this embodiment, the test apparatus main body 12 is composed of a vibration test apparatus that performs a vibration test as an example of a test.

  As shown in FIG. 1, the test apparatus main body 12 includes an actuator 14 made of, for example, a hydraulic cylinder. The actuator 14 includes a piston 16 for loading a test piece A which is a structure to be tested, for example, a vehicle shock absorber, and a displacement sensor, a speed sensor, an acceleration sensor, a load sensor, and the like. The detection sensor 18 is provided.

  In addition, the actuator 14 is provided with a drive unit 20 including, for example, a servo valve.

  Furthermore, the control device 10 of the present invention includes a control unit 22 that inputs an initial control waveform to the drive unit 20 of the test apparatus main body 12.

  Moreover, the control apparatus 10 of this invention is provided with the waveform correction calculating part 24, as shown with the dashed-dotted line of FIG. As shown by the broken line in FIG. 1, the waveform correction calculation unit 24 performs a harmonic calculation for processing the response waveform from the detection sensor 18 of the test apparatus main body 12 up to the fundamental wave component and an arbitrary n-th harmonic. A portion 26 is provided.

  Further, the waveform correction calculation unit 24 includes a high-frequency generation unit 28 that calculates the phase and amplitude of an arbitrary n-fold harmonic calculated by the harmonic calculation unit 26. As shown in FIG. 1, the high-frequency generator 28 includes a plurality of harmonic generators 28 a that calculate up to an arbitrary number of n-th harmonics set by a user or the like.

  In addition, the waveform correction calculation unit 24 inputs and adds the phase and amplitude of the arbitrary n-fold harmonics and the fundamental wave component, which are calculated by the high-frequency generation unit 28, and adds them together, thereby driving the drive unit 20 of the test apparatus main body 12. An adder (adder) 30 for generating a control waveform is provided.

  Further, as shown in FIG. 1, the control device 10 of the present invention is connected to the variable gain device 32 connected to the adding unit 30 and the variable gain device 32, and is connected to the drive unit 20 of the test apparatus main body 12. An amplifier (AMP) 34 for amplifying the control waveform (control signal) is connected.

  Further, the control device 10 of the present invention includes a peak calculation unit 36 as shown by a two-dot chain line in FIG. 1, and this peak calculation unit 36 detects the peak of the response waveform from the detection sensor 18. For this purpose, a peak detector 38 is provided.

  The peak calculation unit 36 includes an amplitude instruction value calculation unit 40 connected to both the control unit 22 and the peak detection unit 38. The amplitude instruction value calculation unit 40 obtains data for one period of an arbitrary frequency stored in advance in the control unit 22 and calculates the amplitude, and the peak calculation unit 36 performs peak processing of the response waveform from the detection sensor 18. A difference from the amplitude obtained by the detection is applied to the control waveform from the adder 30.

  The control device 10 of the present invention configured as described above is configured to perform the following control.

  By the way, when the amplitude control of the test apparatus main body 12 is performed, when the actuator 14 is a hydraulic actuator, the speed is influenced by the hydraulic resonance of the hydraulic oil and the influence of the sliding portions in the actuator 14. The waveform and the acceleration waveform are distorted as shown in the graph of FIG.

  2A shows the target waveform, FIG. 2B shows the actual measurement waveform, and FIG. 2C shows the waveform corrected by the control device 10 of the present invention.

  That is, in the control device 10 of the test apparatus of the present invention, the initial control waveform is input to the drive unit 20 of the test apparatus body 12 by the control unit 22.

  Further, in the harmonic calculation unit 26 of the waveform correction calculation unit 24, the response waveform from the detection sensor 18 is calculated up to the fundamental wave component and any n-th harmonic.

  Further, in the high frequency generation unit 28 of the waveform correction calculation unit 24, the phase and amplitude of an arbitrary n-fold harmonic calculated by the harmonic calculation unit 26 are processed.

  Then, in the addition unit 30 of the waveform correction calculation unit 24, the phase and amplitude of the arbitrary n-fold harmonics and the fundamental wave component calculated by the high frequency generation unit 28 are input and summed, and the test apparatus main body 12 is added. The control waveform to the drive unit 20 is generated.

  Specifically, in the harmonic calculation unit 26, the phase and the amplitude are obtained by performing Fourier series expansion for any n-th harmonic as follows.

First, assuming that the measurement waveform f (t) is obtained, f (t) can be expressed by the following equation.

When the Fourier series expansion of the measurement waveform f (t) is performed, the following equation is obtained.

であり、
Ｔは、加振周波数の１周期の時間、ω_０は加振周波数ｆ_０［Ｈｚ］の角周波数ω_０＝２πｆ_０である。 Here, a _n and b _n are respectively

And
T is the time of one cycle of the excitation frequency, and ω ₀ is the angular frequency ω ₀ = 2πf ₀ of the excitation frequency f ₀ [Hz].

により、（１）式を置き換えると、計測波形ｆ（ｔ）は、下記の式のようになる。

And using Euler's formula,

Thus, when the equation (1) is replaced, the measured waveform f (t) is expressed by the following equation.

となる。 Further, when the expression (2) is expanded to a negative value, from the expression (1), a _n and b _n are respectively

It becomes.

とすると、
計測波形ｆ（ｔ）は、下記の式のようになる。

At this time,

Then,
The measurement waveform f (t) is expressed by the following equation.

とすると、振幅Ｆ（ｎ）は、下記の式のようになる。

And the amplitude F (n) is

Then, the amplitude F (n) is expressed by the following equation.

の考え方から（４）式で求まったそれぞれの高調波成分の振幅と位相は、
振幅は、

位相は、

から、

となる。 here,

From the idea of (4), the amplitude and phase of each harmonic component found in equation (4)
The amplitude is

Phase is

From

It becomes.

が生成され、振幅ゲイン調整アンプへ出力される。 And based on the determined phase and amplitude, the control waveform,

Is generated and output to the amplitude gain adjustment amplifier.

  Further, in the control device 10 of the test apparatus of the present invention, the amplitude instruction value calculation unit 40 of the peak calculation unit 36 obtains data for one period of an arbitrary excitation frequency stored in advance in the control unit 22 and calculates the amplitude. A calculation process is performed, and a difference from the amplitude obtained by peak detection of the response waveform from the detection sensor 18 in the peak calculation unit 36 is multiplied by the control waveform from the addition unit 30.

  Specifically, the peak calculation unit 36 performs the following processing. That is, as shown in the schematic diagram of FIG. 3, data for one cycle of an arbitrary frequency is stored in the memory 42.

From the maximum value max and the minimum value min,
The command value AMP = (max−min) / 2.

Based on this, the current amplitude command value AmpNew is calculated based on the following equation.

  Here, AmpNew is the current amplitude command value, AmpOld is the previous amplitude command value, Amp Target is the target amplitude, Amp is the measured amplitude, and GainF is the amplitude adjustment gain.

  Specifically, the control device 10 of the test apparatus of the present invention that is arithmetically processed as described above is controlled as in the flowcharts shown in FIGS. 4 and 5.

  First, control is started in step S1 of FIG. 4, and parameters are set in step S2 of FIGS.

  This parameter is set as shown in the flowchart of FIG.

  That is, as shown in FIG. 5, in step S3, for example, a waveform to be excited such as a sine wave, a triangular wave, or a rectangular wave is set. In step S4, an amplitude value is set, and in step S5, for example, a control target such as displacement, load, speed, and acceleration is set.

  Next, in step S6, the parameter setting is completed and the flag is set ON.

  In step S7, the initial value of the amplitude gain adjustment amplifier is set, and in step S8, the high frequency generation unit 28 of the waveform correction calculation unit 24 calculates up to an arbitrary n-th harmonic wave set by the user. For the plurality of harmonic generators 28a, initial values of the respective harmonic generators 28a are set. Thereby, in step S9, the parameter setting completion is completed.

  On the other hand, when the parameter setting is completed and the flag is turned on in step S6, whether or not the parameter setting is completed and the flag is turned on in step S10 as shown in FIG. Is judged.

  In step S10, when it is determined that the parameter setting is completed and the flag is set ON, the process proceeds to step S11 as shown in FIG. 4, and an initial command signal is output from the control unit 22. .

  On the other hand, if it is determined in step S10 that the parameter setting has not been completed and the flag is not set to ON, the process returns to step S2 in FIGS. 4 and 5 to set the parameter again.

  Next, as shown in FIG. 4, after an initial command signal is output from the control unit 22 in step S11, in step S12, the initial command signal is controlled via the power converter. A control waveform (control signal) is input to the drive unit 20 of the main body 12.

  Then, in step S13, as described above, the calculation of the Fourier series expansion calculation is started in the harmonic calculation unit 26 of the waveform correction calculation unit 24 for the response waveform from the detection sensor 18 of the test apparatus body 12. .

  Next, in step S14, it is determined whether or not calculation has been performed up to an arbitrary multiple of the number set by the user or the like. If it is determined in step S14 that an arbitrary multiple has been calculated, the process proceeds to step S15.

  In step S15, the high-frequency generation unit 28 of the waveform correction calculation unit 24 extracts the phase and amplitude of an arbitrary n-fold harmonic from the calculation result (the above formulas (5) and (6)). reference).

  On the other hand, if it is not determined in step S14 that the operation has been performed up to an arbitrary multiple, the determination as to whether the operation has been performed up to an arbitrary multiple is repeated in step S14.

  In step S15, the high frequency generation unit 28 extracts the phase and amplitude of each arbitrary n-fold harmonic, and then in step S16, depending on the control target (for example, acceleration 180 °, speed 90 °, etc.). The phase and amplitude of each harmonic are adjusted.

  Next, in step S17, the phase and amplitude information obtained in step S16 is input to each harmonic generator 28a.

  In step S18, the control waveforms are simultaneously output to the adder (adder) 30 (see the above equation (7)).

  On the other hand, in step S13, the peak calculation unit 36 inputs an initial command signal as a control waveform (control signal) to the drive unit 20 of the test apparatus body 12 to be controlled via the power converter, Proceed to S19.

  In step S <b> 19, the peak detection unit 38 calculates the current amplitude (peak) from the response waveform from the detection sensor 18 of the test apparatus main body 12.

  Then, the process proceeds to step S20, where the amplitude instruction value calculation unit 40 calculates the difference from the set amplitude, and in step S21, the amplitude command value is recalculated using the previous difference. Next, in step S22, the previous calculation result is set as the parameter of the variable gain device 32 (see the above equation (8)).

  Then, as shown in FIG. 4, in step S <b> 18, based on the result that the respective control waveforms are simultaneously output to the adder (adder) 30 and the parameters set in step S <b> 22 in step S <b> 18. In the variable gain device 32, the amplitude is set.

  Next, in step S24, it is determined whether or not an end condition such as a preset number of times, time, or the like. If it is determined that the end condition is satisfied, the process proceeds to step S25 and the control is ended. On the other hand, if it is determined in step S24 that the condition is not an end condition, the process returns to step S13 again, and the command signal is transmitted to the drive unit 20 of the test apparatus body 12 to be controlled via the power converter. (Control signal) is input and the control is repeated.

  According to the control apparatus 10 of the test apparatus of the present invention configured as described above, it is not necessary to perform the Fourier transform and the inverse Fourier transform in pairs as in the conventional control method, and the number of calculation processes is reduced and the control is performed. The calculation load on the apparatus is lightened, a high-performance and expensive microprocessor unit (MPU) is unnecessary, and the cost can be reduced.

  In addition, it is an operation up to an arbitrary n-th harmonic, there is no extra harmonic component, there is no risk of error (distortion), and the accuracy of vibration energy applied to the test piece is not impaired and accurate. Vibration test results are obtained.

  Further, unlike the conventional control method, it is not necessary to obtain the frequency characteristic for each Δf for the waveform data length equal to or longer than the period time of the excitation frequency where the target waveform necessary for correction is one cycle, and the correction time is short. Therefore, even when the state change of the test piece or the like occurs, the change can be dealt with instantaneously.

  In addition, since the peak calculation unit 36 controls the peak, the amplitude error can be corrected accurately, and an accurate vibration test result can be obtained.

  FIG. 6 is a graph showing a test apparatus control method by the control apparatus 10 of the test apparatus according to the present invention. FIG. 6A is an input waveform, FIG. 6B is a velocity waveform, and FIG. 6C is an acceleration waveform. It is a graph which shows.

  As shown in part C of FIG. 6 (B) and part D of FIG. 8 (C), according to the control method of the test apparatus of the present invention, the part A of FIG. As compared with the portion B in FIG. 8C, the distortion is extremely reduced.

  Further, according to the control apparatus 10 of the test apparatus of the present invention, for example, the number of calculation steps is within 5000 steps (20 μsec) (1 cycle), and the target system is always taken into the control loop. It can correspond to.

  Furthermore, in the conventional test apparatus 100, for example, when using FFT, if n = 8, the number of calculations by Fast Fourier Transform (FFT) is 229368 times (calculation formula (N / 2 × log 2 (N) + (N / 2-2)) x 4).

  On the other hand, according to the control apparatus 10 of the test apparatus of the present invention, for example, assuming that the calculation up to the fourth harmonic is performed, the number of calculations including the fundamental wave is 25600, assuming that the number of data of one waveform is 1024. It can be seen that the processing can be performed in an extremely short time compared to the conventional test apparatus 100.

  In the control device 10 of the test apparatus of the present invention, the control waveform can be applied to, for example, a sine wave, a triangular wave, a rectangular wave, and the like, and is not limited at all, but is a periodic function of a sine wave. Is desirable

  Furthermore, the control device 10 of the test apparatus of the present invention can be used even if the control waveform is a superimposed control waveform. For example, the present invention can be applied to a case where a test is performed by superimposing a load waveform of 5 Hz on a rotation waveform of 2 Hz.

  In the control device 10 of the test apparatus of the present invention, the actuator 14 is preferably applied to a hydraulic actuator, but can also be applied to an electric actuator such as an electric servomotor.

  Furthermore, in the control apparatus 10 of the test apparatus of the present invention, the peak calculation unit 36 is provided in the above embodiment, but it is also possible to perform processing without providing the peak calculation unit 36.

  The preferred embodiment of the present invention has been described above. However, the present invention is not limited to this, and the test apparatus 10 according to the present invention can be used as a test apparatus, for example, an automobile component (such as a drive system or undercarriage). Metal parts, rubber parts, shock absorbers, etc.), automobile finished products, and civil engineering (bridge girder, bridges, seismic isolation rubber for buildings, etc.), material tests and vibration tests・ It can be applied to various testing equipment such as material testing equipment, vibration testing equipment, fatigue testing equipment, etc. for conducting fatigue testing and characteristic testing, and various modifications can be made without departing from the purpose of the present invention. is there.

  The present invention relates to, for example, a control device for a test apparatus and a test apparatus for performing various tests such as a load test in which an external force is applied to a structure such as a shock absorber of a vehicle, a bridge, a building, a house, or a building. It can be applied to the control method.

DESCRIPTION OF SYMBOLS 10 Control apparatus 12 Test apparatus main body 14 Actuator 16 Piston 18 Detection sensor 20 Drive part 22 Control part 24 Waveform correction calculation part 26 Harmonic calculation part 28 High frequency generation part 28a Harmonic generator 30 Addition part 32 Variable gain unit 36 Peak calculation part 38 Peak detector 40 Amplitude instruction value calculator 42 Memory 100 Test device 102 Test device main body 104 Mounting frame 106 Actuator 108 Piston 110 Displacement detector 112 Guide rod 114 Ball screw 116 Crosshead 118 Upper frame 120 Detector 180 Acceleration A Test piece

Claims (12)

A control device for a test apparatus for performing various tests by applying an external force to a structure under test,
A response waveform from the test apparatus with respect to the control waveform input to the test apparatus, a fundamental wave component, and a harmonic calculation unit that calculates up to an arbitrary n-th harmonic,
A high-frequency generator that calculates the phase and amplitude of the arbitrary n-th harmonic calculated by the harmonic calculator;
An adder for generating a control waveform to the test apparatus by inputting and summing the phase and amplitude of the arbitrary n-fold harmonics processed by the high-frequency generator and the fundamental component;
A control apparatus for a test apparatus, comprising: a waveform correction calculation unit comprising: In the harmonic calculation unit, the measurement waveform f (t)

In the above-mentioned arbitrary n-th harmonic, Fourier series expansion is performed,
phase,

And amplitude,

A control device for a test apparatus, characterized in that:
Here, a _n and b _n are respectively

And
T is the time of one cycle of the excitation frequency, and ω ₀ is the angular frequency ω ₀ = 2πf ₀ of the excitation frequency f ₀ [Hz]. In the high frequency generation unit, based on the phase and amplitude obtained by performing the arithmetic processing in the harmonic calculation unit, a control waveform,

The control apparatus for a test apparatus according to claim 2, wherein the control apparatus is configured to generate   Obtain the data for one period of an arbitrary excitation frequency in advance, calculate the amplitude, multiply the difference from the amplitude obtained by the peak detection of the response waveform from the test device, the control waveform from the adder, The control apparatus for a test apparatus according to claim 1, further comprising a peak calculation unit that generates a control waveform for the test apparatus.   5. The control device for a test apparatus according to claim 1, wherein the control waveform is a periodic function of a sine wave.   6. The control device for a test apparatus according to claim 1, wherein the control waveform is a superimposed control waveform. A test apparatus control method for performing various tests by applying an external force to a structure under test,
A harmonic calculation step for calculating a response waveform from the test apparatus to the control waveform input to the test apparatus, up to a fundamental wave component and an arbitrary n-th harmonic;
A high-frequency generation step for calculating the phase and amplitude of the arbitrary n-th harmonic calculated by the harmonic calculation unit;
An addition step of generating a control waveform to the test apparatus by inputting and summing the phase and amplitude of the arbitrary n-th harmonic wave processed by the high-frequency generator and the fundamental wave component;
A control method for a test apparatus, comprising: In the harmonic calculation step, the measurement waveform f (t)

In the above-mentioned arbitrary n-th harmonic, Fourier series expansion is performed,
phase,

And amplitude,

A method for controlling a test apparatus, characterized in that:
Here, a _n and b _n are respectively

And
T is the time of one cycle of the excitation frequency, and ω ₀ is the angular frequency ω ₀ = 2πf ₀ of the excitation frequency f ₀ [Hz]. In the high frequency generation step, based on the phase and amplitude obtained by performing the arithmetic processing in the harmonic calculation step, a control waveform,

The test apparatus control method according to claim 8, wherein:   Obtaining data for one period of an arbitrary excitation frequency in advance and calculating the amplitude, multiplying the difference from the amplitude obtained by peak detection of the response waveform from the test apparatus by the control waveform from the addition step, The method for controlling a test apparatus according to claim 7, further comprising a peak calculation processing step for generating a control waveform for the test apparatus.   The method for controlling a test apparatus according to claim 7, wherein the control waveform is a periodic function of a sine wave.   The method for controlling a test apparatus according to claim 7, wherein the control waveform is a superimposed control waveform.

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