JP4801134B2 - Vibration test apparatus and vibration test method - Google Patents

Description

  The present invention relates to a vibration test apparatus that vibrates a test object, and more particularly to an apparatus that performs a vibration test using a plurality of control amounts.

  A conventional vibration test apparatus will be described with reference to FIG. The vibration test apparatus 1100 is provided with a plurality of controllers (two-degree-of-freedom system control apparatus to which adaptive control is applied) in order to perform multivariate control. The vibration test apparatus 1100 includes a displacement controller 1131 effective in the low frequency region, a speed controller 1132 effective in the medium frequency region, and an acceleration controller 1133 effective in the high frequency region. These controllers 1131 to 1133 are determined in advance so as not to output in an area other than the area in which each controller 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. 8 are the same target waveform r represented by different physical quantities (r1 is displacement, r2 is velocity, and r3 is acceleration). Further, the displacement sensor 1121, the speed sensor 1122, and the acceleration sensor 1123 are attached to the test body 115, and the displacement control response signal y1, the speed control response signal y2, and the acceleration control response signal y3 of the test body 115 are fed back to the controllers 1131 to 1133. To do.

  The displacement controller 1131 outputs the operation amount x1 from the target waveform r1 and the feedback amount y1, the speed control controller 1132 outputs the operation amount x2 from the target waveform r2 and the feedback amount y2, and the acceleration control controller 1133 feedbacks the target waveform r3. The operation amount x3 is output from the amount y3. Then, the operation amount x1 becomes the drive signal u in the low frequency region, the operation amount x2 in the medium frequency region, and the operation amount x3 in the high frequency region.

  Therefore, according to this system, it is possible to perform accurate control in a wide frequency band at the same time.

JP 2001-133357 A

  The vibration test apparatus 1100 described above has the following points to be improved. The vibration test apparatus 1100 performs control by dividing a plurality of controlled variables into frequency bands, but does not adjust the characteristics of the transfer function for each controlled variable. The characteristics of the transfer function for each controlled variable are affected by the characteristics of the physical quantity indicated by each controlled variable appearing in the vibration test apparatus 1100, the characteristics of the sensor used corresponding to each controlled variable, etc. In the vibration test apparatus 1100, Such characteristics of the transfer function for each controlled variable are not taken into consideration. For this reason, there has been a problem that stable control may not be possible in all frequency bands.

  Therefore, an object of the present invention is to provide a vibration test apparatus capable of performing a vibration test using a drive waveform in which the influences of a plurality of control amounts are equally reflected.

Means for solving the problems relating to the present invention and effects of the present invention will be described below.

  In the vibration test apparatus, the vibration test method, and the drive waveform generation method according to the present invention, when generating the drive waveform based on the state quantity, the transfer function relating to each of the control amounts is adjusted, and the adjusted transfer function A drive waveform is generated using an inverse function.

  As a result, when the drive waveform is generated, it is possible to prevent the influence of the transfer function relating to any control amount from increasing.

  In the vibration test apparatus according to the present invention, the drive waveform is generated by adjusting the gain of the transfer function related to each of the control amounts in accordance with the frequency domain.

  As a result, when the drive waveform is generated, it is possible to prevent the influence of the transfer function related to any one of the control amounts from being increased by dividing into several frequency regions.

  In the vibration test apparatus according to the present invention, adjustment is performed so that the difference in gain of the transfer function relating to each of the control amounts becomes small.

  As a result, when the drive waveform is generated, it is possible to equalize the influence of the transfer function regarding all the controlled variables.

  In the vibration testing apparatus according to the present invention, the displacement and acceleration of the test specimen mounting portion are acquired as state quantities.

  As a result, when the drive waveform is generated, it is possible to easily prevent the influence of the transfer function related to any control amount from increasing.

  In the vibration testing apparatus according to the present invention, by adjusting so as to increase the gain of the transfer function for the displacement in the low frequency region, and adjusting to increase the gain of the transfer function for the acceleration in the high frequency region, Adjustment is made so that the difference in gain of the transfer function for each of them becomes small.

  Thereby, when the drive waveform is generated, it is possible to equalize the influence of the transfer function regarding displacement and acceleration.

  Examples of the vibration test apparatus according to the present invention will be described below.

1. Configuration of Vibration Test Apparatus 1 The overall configuration of a simplified vibration test apparatus 1 is shown in FIG. The vibration test apparatus 1 includes a vibration generator 111, a displacement sensor 131, and an acceleration sensor 133.

  The configuration of the vibration generator 111 in FIG. 1 is shown in FIG. The vibration generator 111 mainly includes a test specimen mounting part 121, an excitation coil 123, a drive coil 125, a movable part support mechanism 127, and an excitation power source 129 (not shown).

  A magnetic field is generated by passing an exciting current through the exciting coil 123 using the exciting power source 129. When a drive current is passed through the drive coil 125 existing in the magnetic field, an excitation force is generated. The excitation force vibrates the specimen mounting part 121 in a predetermined direction. A test body (not shown) is attached to the test body mounting portion 121, and the test body also vibrates when the test body mounting portion 121 vibrates.

  Returning to FIG. 1, the displacement sensor 131 detects the amount of displacement of the test specimen mounting portion 121 along a predetermined axis. The acceleration sensor 133 detects the acceleration generated in the test specimen placement unit 121.

  FIG. 3 shows a hardware configuration when the control unit 141 is realized using the CPU 411. The control unit 141 includes a CPU 411, a memory 412, a hard disk 413, a display 416, a CD-ROM drive 417, a D / A conversion circuit 418, and an A / D conversion circuit 419.

  The CPU 411 performs processing based on other applications such as an operating system (OS) and a drive waveform generation program recorded in the hard disk 413. The memory 412 provides a work area for the CPU 211. The hard disk 413 records and holds an operating system (OS), other applications such as a drive waveform generation program, and various parameters.

  A display 416 displays a user interface and the like. The CD-ROM drive 417 reads data from the CD-ROM such as a drive waveform generation program from the CD-ROM 410. The A / D conversion circuit 418 converts an analog signal into a digital signal. The D / A conversion circuit 419 converts a digital signal into an analog signal.

2. Operation of Control Unit 141 The operation of the control unit 141 based on the drive waveform generation program will be described with reference to FIG. The CPU 411 of the control unit 141 executes scaling processing when the specimen inspection apparatus 1 is powered on (S401). The CPU 411 acquires each parameter stored in the memory 412 (S403). When the CPU 411 acquires the target waveform from the CD-ROM 410 via the CD-ROM drive 417 (S405), the CPU 411 generates a drive waveform using the parameters acquired in step S403 (S407). The CPU 411 outputs the generated drive waveform to the vibration generator 111 via the D / A conversion circuit 418 (S409).

  The CPU 411 outputs the drive waveform to the vibration generator 111 via the D / A conversion circuit 418, and operates the vibration generator 111 (S411).

  Hereinafter, the scaling process in step S401 will be described.

2.1. Scaling process
2.1.1. Outline of Scaling Process An outline of the scaling process executed by the CPU 411 will be described. When the vibration state of the specimen is controlled using the displacement amount obtained from the displacement sensor 131 and the acceleration obtained from the acceleration sensor 133, the transfer characteristic regarding the specimen can be expressed by the following equation (1).

Here, y _acc is the value of the acceleration sensor 133 (acceleration response), y _disp is the value of the displacement sensor 131 (displacement response), x _drv is the drive waveform, G _s is the transfer characteristic, and G _acc is the acceleration. G _disp indicates the transfer characteristic, and G _disp indicates the transfer characteristic of displacement. The symbol * indicates a convolution operation.

Further, the transfer characteristic G _{s at} a certain frequency can be expressed by the following equation (2).

  An example of the diagonal component of the transfer characteristic shown in Formula (1) regarding the vibration test apparatus 1 is shown in FIG. As shown in FIG. 5, the transmission characteristic based on displacement is dominant in most frequency bands, and the transmission characteristic based on acceleration is dominant in the high frequency band from around 5 Hz. However, the gain of acceleration in the high frequency band where the transfer characteristic based on acceleration is dominant is smaller than the gain of displacement in the low frequency band where the transfer characteristic based on displacement is dominant. For this reason, a good control result can be obtained for displacement, but a good control result for displacement cannot be obtained.

  Therefore, in order to obtain a good control result for both the displacement and the acceleration, the difference between the displacement gain in the low frequency band and the acceleration gain in the high frequency band is reduced. FIG. 6 shows an example of the diagonal component of the transfer characteristic obtained by reducing the difference between the displacement gain in the low frequency band and the acceleration gain in the high frequency band for the diagonal component of the transfer characteristic shown in FIG.

In this way, in order to reduce the difference between the gain of displacement in the low frequency band and the gain of acceleration in the high frequency band and to reflect the acceleration and displacement uniformly in the drive waveform, the transfer function G _s in equation (2) is expressed as follows: The frequency weighting characteristic w _s shown in Equation (3) is adjusted.

Here, w _a represents a scaling factor for acceleration, and w _d represents a scaling factor for displacement. Here, the frequency weighting characteristic w _s is a diagonal matrix.

  The inverse transfer characteristic related to the expression (1) in consideration of the frequency weight characteristic shown in the expression (3) is the following expression (4).

Here, F ⁺ indicates a generalized inverse matrix of the function F.

  The drive waveform is calculated by the following equation (5) using the reverse transfer characteristic calculated by the equation (4).

Here, r _acc represents the target acceleration, r _disp represents the target displacement, and x _drv represents the drive waveform.

2.1.2. Flowchart The scaling process executed by the CPU 411 will be described with reference to the flowchart shown in FIG. The CPU 411 measures the transfer characteristics of the vibration test apparatus (S701). In the measurement of transfer characteristics, displacement is acquired from the displacement sensor 131 and acceleration is acquired from the acceleration sensor 133.

The CPU 411 determines the frequency weighting characteristic shown in Expression (3) based on the measured transmission characteristics regarding displacement and acceleration (S703). Here, the scaling factor w _a for the acceleration and the displacement are used so that the difference between the gain of the displacement in the low frequency band and the gain of the acceleration in the high frequency band is reduced using the diagonal components of the displacement and acceleration and the respective transfer functions. A scaling coefficient w _d is calculated for, and a frequency weighting characteristic is determined. In determining the frequency weighting characteristic, the CPU 411 adjusts the difference between the displacement gain and the acceleration gain in each frequency band with respect to the frequency-gain curve of the diagonal component of the displacement, acceleration, and each transfer function. To do. At this time, for example, the CPU 411 calculates the average value of the higher-order lines having large amplitude values for the frequency-gain curves of the diagonal components of the respective transfer functions, and adjusts the average values to match. Then, the CPU 411 sets the scaling coefficient w _a for acceleration and the scaling coefficient w _d for displacement based on the adjustment of the average value, and determines the frequency weighting characteristic.

The CPU 411 calculates a reverse transfer characteristic using the formula (4) based on the determined frequency weight characteristic and the measured transfer characteristic (S705). The CPU 411 stores the calculated reverse transfer characteristic in the memory 412 (S707).

[Other Examples]
(1) Determination of Frequency Weight Characteristic In the first embodiment, in determining the frequency weight characteristic, the CPU 411 sets the scaling coefficient w _a for acceleration and the scaling coefficient w _d for displacement to determine the frequency weight characteristic. However, the present invention is not limited to the example as long as the frequency weight characteristic can be determined. For example, in determining the frequency weighting characteristics, the displacement-acceleration and the frequency-gain curve of the diagonal component of each transfer function are displayed on the display and the user confirms the gain and acceleration of the displacement in each frequency band. The CPU 411 may be adjusted so that the difference from the gain is small, and the CPU 411 may set the scaling coefficient w _a for acceleration and the scaling coefficient w _d for displacement based on the adjustment by the user to determine the frequency weighting characteristic. .

  In addition, the user adjusts the gain so that the maximum singular value of each transfer function is flat with respect to the frequency while checking the frequency-gain curve displayed on the display to determine the frequency weighting characteristic. You may make it do.

  Further, the CPU 411 may automatically perform the operation of adjusting the gain so that the overall values of the transfer functions are equal to determine the frequency weighting characteristic.

Note that the frequency weighting characteristic w _s may be determined to be a constant value through the frequency, or may be set for each frequency.

(2) Displacement sensor 131 and acceleration sensor 133
In the first embodiment described above, the displacement amount and the acceleration value of the test specimen mounting unit 121 are exemplified as the state quantities of the controlled system. However, other state quantities may be used as long as they can be acquired.

  In the first embodiment, the displacement is dominant in the low frequency band and the acceleration is dominant in the high frequency band. However, the transfer function of each control amount is adjusted according to the frequency domain. For example, it is not limited to the example.

(3) Drive Waveform Generation Processing In the first embodiment, the drive correction term is used for correcting the drive waveform. However, the drive waveform may be corrected by other methods.

1 is an overall configuration diagram of a vibration test apparatus 1 according to the present invention. 2 is a configuration diagram of a vibration generator 111. FIG. It is a hardware block diagram at the time of implement | achieving the control part 141 using CPU411. 3 is a flowchart showing the operation of a control unit 141. It is a frequency characteristic figure which shows the diagonal component of a transfer characteristic. It is a frequency characteristic figure which shows the diagonal component of the adjusted transfer characteristic. It is a flowchart which shows a scaling process. It is a figure which shows the conventional vibration test apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Vibration test apparatus 11 ... Test body 121 ... Test body mounting part 131 ... Displacement sensor 133 ... Acceleration sensor 141 ... Control part

Claims (8)

A test specimen mounting section for mounting the test specimen;
A vibration unit for vibrating the specimen mounting unit;
A drive waveform generator for generating a drive waveform for exciting the specimen,
A state quantity acquisition unit for acquiring a plurality of state quantities of the test specimen mounting unit controlled based on the drive waveform;
A control unit for controlling the vibration state of the vibration unit based on the drive waveform;
In a vibration test apparatus having
The drive waveform generating unit, as the gain of the transfer function for each of the state quantity difference is decreased in accordance with the frequency domain, to adjust the transfer function for the respective uses an inverse function of the transfer function adjusted the Generating drive waveforms,
Vibration test equipment characterized by In the vibration testing apparatus according to claim 1 ,
The state quantity acquisition unit, displacement and acceleration for said specimen mounting part, be obtained as the quantity of state,
Vibration test equipment characterized by In the vibration testing apparatus according to claim 2 ,
The drive waveform generator
By adjusting so as to increase the gain of the transfer function for the acceleration in a high frequency region as well as adjusted so as to reduce the gain of the transfer function for the displacement in the low frequency region, the difference in gain of the transfer function for each Adjusting it to be smaller,
Vibration test equipment characterized by   In the vibration testing apparatus according to any one of claims 1 to 3,
  The adjustment of the transfer function for each of the states is performed so that the difference in the maximum singular value of the gain of the transfer function for each of the state quantities is small.
  Vibration test equipment characterized by   In the vibration testing apparatus according to any one of claims 1 to 3,
  The adjustment of the transfer function for each of the states is performed so that the difference in the average value of the gains of the transfer functions for each of the state quantities becomes small.
  Vibration test equipment characterized by   In the vibration testing apparatus according to any one of claims 1 to 3,
  The adjustment of the transfer function for each of the states is performed so that the difference in overall value of the gain of the transfer function for each of the state quantities is small.
  Vibration test equipment characterized by Based on a drive waveform for vibrating the test body placed on the test body placing part by the vibration part, a vibration test method for vibrating the test body while controlling the vibration state of the vibration part There,
Obtaining a plurality of state quantities of the specimen mounting portion controlled based on the drive waveform;
When generating the drive waveform based on the state quantity, adjust the transfer function for each of the state quantities so that the gain of the transfer function for each of the state quantities becomes smaller depending on the frequency domain,
Generating the drive waveform by using the inverse function of the transfer function adjusted,
A vibration test method characterized by A program for causing a computer to execute a drive waveform generation process for generating a drive waveform for vibrating the test body placed on the test body placement unit by the vibration unit,
The computer performs the following steps:
When a plurality of state quantities of the test specimen mounting portion controlled based on the drive waveform are acquired, the transmission of each of the state quantities is reduced so that the difference in the gain of the transfer function for each of the state quantities decreases in accordance with the frequency domain. Adjust the function,
Generating the drive waveform by using the inverse function of the transfer function adjusted,
Drive waveform generation program characterized by

Images