JP2009068841A - Vibration displacement measuring device for micro mechanical-electric structure (mems) - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration displacement measuring device suitable for being used in development or maintenance management of a vibration type power generation device constituted of micro mechanical-electric structure. <P>SOLUTION: This device has as components, a probe part 1 by an optical fiber cable using a multimode fiber wherein a condensing function such as a lens is added to the tip, a visco-elastic material is used for vibration buffer, and the maximum group delay difference is below 1 nanosecond/meter; a light source part 2 by a laser light source 2-1 oscillating continuously; a photoelectric conversion part 3 by a photodiode; an optical circulator 10 for transferring an optical interference beat signal; a signal collection part 4 for converting an interference beat signal including a power generation voltage or power generation current value and vibration displacement information into a digital signal; an analysis part 5 by a computer, and a storage part 6. In the device, the principle of an optical homodyne interferometer is used for instantaneous displacement detection of vibration. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vibration displacement measuring apparatus used for design development, inspection, and maintenance management of a vibration power generation apparatus that converts mechanical vibration energy of vibration noise drifting in the environment into electric energy and uses it as electric power.

  As a power source for each node of a wireless sensor network composed of a small and power-saving sensor group, research and development of a vibration power generation apparatus is progressing (for example, see Non-Patent Document 1). A known vibration type power generator is composed of a vibrator that collects vibration noise from the external environment and obtains mechanical energy, an electrical energy converter using a mechanical-electrical coupling element, and an electrical circuit such as rectification and storage. Has been.

  The electrical energy converter uses an electromagnetic induction effect using a coil and a magnet, a piezoelectric effect using a piezoelectric material such as lead zirconate titanate, or a mechanical-electrical device using an electrostatic induction effect using an electret material. A coupling element is used.

  Examples of the vibration source serving as an energy source include a living body such as a human body and a tree, a building, a vehicle, a transport device, or a mechanical vibration of an acoustic vibration using air or water as a medium.

  As a physical mechanism of this power generation, mechanical energy moves between the environmental vibration outside the element and the vibration response of the vibrator, and then the mechanical energy of the vibrator is converted into electrical energy by the mechanical-electric coupling element. After being converted to, and through a conversion process such as rectification and storage, usable electric power is produced.

  In order to disseminate and expand the application range of vibration power generators, it is required to achieve high-efficiency and high-density power generation capability that is better than known and public technologies. Therefore, from the above-mentioned physical mechanism of energy conversion, the mechanical energy coupling efficiency between the vibration in the environment and the vibrator is improved, and the mechanical vibration of the vibrator in the mechanical-electric coupling element is changed to electric energy. Improvement of conversion efficiency is a fundamental issue. In addition, since this vibrator is not a mere mechanical vibrator but a vibrator having a mechanical and electrical action, in the present invention, it is specifically called a mechanical-electric vibrator (abbreviated as “ME vibrator”). To do.

  Vibration noise in the environment generally has a wide distribution when looking at its power density spectrum because the vibration source, vibration wave scattering source and vibration transmission medium are not invariant in space and time. The phase of the component is not fixed and has random characteristics. In order to strongly couple the mechanical vibration in such an environment with the ME vibrator, a non-linear response mechanism so as to correlate with the vibration component in the non-resonant band away from the natural frequency of the ME vibrator. Add a dynamic control mechanism that adapts the vibration response of the ME vibrator or adapts the vibration response of the ME vibrator to it, or expands the frequency range covered using coupled vibration, Etc. are necessary. The vibration response of the ME vibrator to which such a mechanism is added will show a random anharmonic vibration response in the same manner as the environmental vibration.

  From the viewpoint of portability and economy, the vibration power generation apparatus is required to be small and light, and accordingly, the size of the ME vibrator is several cm to several mm or less. Further, among the above-mentioned environmental vibration sources, in consideration of electrical transmission loss, vibrations having an amplitude of about several millimeters to several tens of nm and a frequency of about 1 Hz to 100 kHz are used as energy sources in practice. For example, refer nonpatent literature 2). The mechanical vibration amplitude of the ME vibrator also exhibits a vibration response having an amplitude smaller than that of the environmental vibration because the mechanical energy is reduced to the same degree as that of the environmental vibration or due to conversion to electric energy.

  In order to measure the operation of such an ME vibrator, a vibration having a spatial resolution of 100 μm or less for identifying a measurement site, and capable of measuring vibrations having a frequency of about 10 Hz to 100 kHz and a displacement amplitude of about 100 nm to 100 μm. A displacement meter is required.

  In addition, the ME vibrator is housed in a container for the purpose of enhancing the mechanical impedance matching due to the protection from the external environment and the resonance effect of the cavity. The power generation / vibration response characteristics of ME vibrators taken out of containers and vibration-type power generators moved from actual working locations differ from actual operating conditions. There is a demand for a vibration displacement measuring device having

  There is also a need for an installation method in which the measurement apparatus can be installed with the vibrations insulated so as not to be affected by the surrounding vibrations even under the conditions for measuring the ME vibrator in the container as described above.

  In addition, in order to maintain and manage a vibration power generator in actual operation, there is a demand for a vibration displacement measuring instrument that can perform measurement with as little effort as possible by installing the apparatus and analyzing measurement data.

  The displacement measurement method using an optical method is suitable for measurement of a vibration power generator because it does not give mechanical or electrical action. The optical displacement measurement method includes a triangulation method, a method of measuring a change in reflected light intensity using an optical fiber bundle, and an optical interference measurement method. Among them, the optical interferometry method using an optical fiber probe can avoid the technical problems of the above-mentioned methods, and it can be used for measurement of vibration power generators in a working environment for the reasons described later. Most suitable.

  In the optical interferometer, since the information on the vibration displacement is conveyed to the phase of the interference beat signal, it is not affected by fluctuations in the intensity of the signal light due to disturbance. Further, it is not affected by signal components (generally noise) having different frequencies. Since the absolute amount of displacement can be measured based on the wavelength of the light beam used for the measurement, calibration is not required, and variations in values for each measurement can be eliminated.

  Known examples of optical interferometers include optical homodyne detection methods (see, for example, Patent Document 1) and optical heterodyne detection methods (see, for example, Patent Document 2). In general, the optical homodyne detection method has the advantage that a simple arrangement of optical components can be used with a small number of components, and that the displacement value can be easily derived from the interference beat signal, but the displacement direction cannot be determined. have. Although the optical heterodyne detection method has the advantage that it can be derived including the direction of displacement, it requires high frequency stability to the light source and is expensive because it requires the addition of an optical modulator. It has the disadvantage that it is necessary to use operations for optical configuration and complex demodulation.

  By using an optical fiber probe for the optical interferometer, optical interference measurement can be performed by arbitrarily securing a non-linear optical path, making measurement difficult by other methods such as a narrow space in a container or a remote place. It becomes possible to correspond to the measurement of the place. As a public example in this case, it may be used for probe position control of a scanning probe microscope (for example, see Patent Document 3).

SPBeeby, RNTorah, MJTudor, P.Glynne-Jones, T.O'Donnell, CRSaha, S.Roy, “A Micro Electromagnetic Generator For Vibration Energy Harvesting”, Journal of Micromechanics and MicroEngineering, 2007, 17, p .1257-1265 Shad Roundy, Paul k. Wright, Jan Rabaey, “a study of low level vibrations as A power source for wireless sensor nodes”, Computer Communications, 2003, 6, p.1131-1144 JP-A-7-83608 JP 2003-90704 A JP-A-11-44693

  As for the displacement measuring device used for design development, inspection and maintenance management of the vibration power generator as described above, the hardware and software etc. to prevent the measurement accuracy from being deteriorated due to vibration disturbance and reduce the labor during operation New and progressive technological improvements are needed.

  The optical interference measurement method using the optical fiber probe of the prior art is based on the premise that the measurement is performed in a quiet environment, and measures the vibration displacement of the ME vibrator of the vibration power generator that actively picks up vibration noise. Therefore, it is a problem to add a measure for suppressing disturbance due to vibration noise when the probe is installed.

  In addition, when measuring the vibration displacement of the ME vibrator in the container of the vibration power generator where it is not desirable to take up an extra volume, even if it is not possible to use a fine movement mechanism such as a micrometer, it can be operated with bare hands. The problem is how to simplify the operation so that the measurement part can be aligned and the optical axis angle can be aligned.

  Another problem is to add a method to reduce the labor of the operator, such as parameter setting in calculation processing when calculating instantaneous displacement from the interference beat signal obtained by optical interference measurement of the ME vibrator that vibrates randomly. Become.

  In addition, when the optical homodyne detection method is used, it becomes a problem to add information on the displacement direction in order to compensate for the disadvantage that information on the direction of displacement cannot be obtained.

The features of the present invention, which is a means for solving the above-described problems, are listed below.
A vibration displacement measuring device according to the present invention is a vibration displacement measuring device for inspecting a vibration type power generation device using a micromechanical-electric structure, and a condensing function such as a lens is added to a tip, and a vibration buffering device is provided. Because of this, viscoelastic materials are used, the probe part is a fiber optic cable using a multimode fiber with a maximum group delay difference of 1 nanosecond / meter or less, the light source part is a laser light source that oscillates continuously, and the photoelectric conversion is performed by a photodiode. , An optical circulator that delivers an optical interference beat signal, a signal collection unit that converts an interference beat signal including a generated voltage or generated current value, and vibration displacement information into a digital signal, an analysis unit using a computer, and a storage unit And using the principle of an optical homodyne interferometer for detecting the instantaneous displacement of vibration.

As the measurement principle of the vibration displacement meter, an interference measurement method using optical homodyne detection is used.
In order to measure the mechanical operation of the ME vibrator in the sealed space, a probe using an optical fiber cable having an outer diameter of 1 mm or less that can ensure an optical path in the vibration type power generation apparatus with minimal invasiveness is used. In addition, the tip of the fiber serving as the probe has a function of focusing light like a lens. In addition, for the purpose of vibrational insulation from vibrators and external vibrations, the viscoelastic material used in the installation and fixing of the optical fiber cable is polymer silicon, urethane polymer, butyl rubber, polyisoprene, polyester, polyethylene, It is preferable to use any one or a mixture of polyvinyl chloride and honeynite rubber as a raw material.

  Light irradiation for interference measurement and reception of reflected / scattered light from the measurement site are performed using the same optical fiber probe, and vibration displacement in a direction parallel to the optical axis of the light beam irradiated from the probe is measured. In the present invention, the displacement information of the ME vibrator is made into a phase by optical homodyne detection by interference between the reflected / scattered light irradiated to the ME vibrator and subjected to phase modulation by vibration and the reference light not subjected to modulation. An interfering beat signal is obtained.

As the optical fiber, a multi-mode fiber having a maximum group delay difference between the waveguide modes of 1 × 10 ⁻⁹ seconds / meter or less is used. In particular, a refractive index distribution (GI) type multimode fiber having a refractive index distribution that can be approximated by a square distribution is suitable because the maximum group delay difference is small. Regarding the group delay difference δτ _g , from the light velocity c in the vacuum, the core refractive index n ₁ , and the relative refractive index difference Δ, δτ _g ≈n ₁ Δ ÷ c, the square distribution refractive index in the step-type refractive index distribution optical fiber. With a distributed optical fiber, it can be approximately obtained as a relationship of δτ _g ≈n ₁ Δ ² ÷ 2c.

As the light source unit, a continuous wave laser light source having a narrow band, stable intensity, polarization state, frequency, and phase is used. The relationship between the coherence distance L and the wavelength width d when the wavelength is λ can be approximately obtained as a relationship of L≈λ ² ÷ d. In order to visually recognize the light irradiation position by the naked eye, λ is preferably 400 nm to 720 nm. In order to secure a sufficient coherence distance and several mm to several cm, the wavelength width is desirably 0.05 nm or less. For example, a stabilized He-Ne laser, a distributed feedback (DFB) laser diode, or a laser to which frequency stabilization by external resonator control using a narrow-band absorption line of a gas atom or molecule is added. Used in the light source section.

  The photoelectric conversion unit that converts an optical signal into an electrical signal uses a photodetector such as a high-speed responsive photodiode that can detect an interference beat signal of 1 MHz or more so that a wide range of vibration frequencies and vibration displacements can be measured. .

  The optical interferometer body is constituted by an optical circulator. In the present invention, this optical circulator has a light input / output terminal of 3 ports or more and functions as a circulator, as long as it uses a polarizing beam splitter and a wave plate, or an optical fiber coupler and a magneto-optical effect element. Any method or form may be used.

  The interference beat signal converted into an electrical signal by the photoelectric conversion unit is converted into a digital signal by the signal collection unit and passed to the analysis unit by the electronic computer.

A signal processing algorithm for deriving the instantaneous displacement of the ME vibrator, which is performed in the analysis unit, will be described. The interference beat signal is subjected to smoothing processing for noise elimination, then standardized based on the maximum and minimum values of the interference beat signal data, and then the analysis signal is calculated by the Hilbert transform, The instantaneous phase φ (t) (rad) is calculated. The equation for calculating the instantaneous phase from the analytic signal is
φ (t) = sign × tan ⁻¹ (analysis signal imaginary part ÷ analysis signal real part) It is expressed as equation (1). Here, the sign in the expression (1) is a positive or negative sign and corresponds to the direction of vibration displacement. Since this sign cannot be determined only by optical homodyne detection, positive or negative determination is performed by the method described later.

Since the phase obtained by the equation (1) is convolved from −π to π (rad), a phase stitching process is performed to obtain a continuous instantaneous phase φ (t) (rad). An instantaneous displacement x (t) corresponding to each sampling time is obtained through conversion according to equation (2).
x (t) = φ (t) × λ ÷ 4π × cos θ (2) where λ is the wavelength of the laser beam used for measurement. θ is an angle between the optical axis of the laser beam irradiated from the probe and the measurement surface on the ME vibrator, and is smaller than the light receiving angle of the probe and is usually π / 16 (rad) or less.

  Each signal data obtained here is stored in the storage unit together with data of each sampling time. Moreover, the instantaneous power produced simultaneously is sent as a voltage value to the signal collecting unit, converted into a digital signal, and stored in the storage unit together with the instantaneous displacement amount.

  The following improvements are added to the above basic algorithm. When measuring anharmonic vibration, the number of beats in the interference beat signal is extracted in order to extract the phase from the signal in the appropriate frequency band without phase distortion from the data array of the interference beat signal for a specific period. Add a counter function to measure. The number of times that the code of the standardized interference beat signal for a specific period has changed is obtained as the number of beats. Automatically assigns the bandpass filter cut-off lower limit as beat count ÷ number of data arrays ÷ sampling time and upper limit as 2 ÷ sampling time ÷ beat count, for signals with upper and lower frequency limits Thus, Hilbert conversion is performed to obtain an analysis signal with a small phase error.

  The vibration displacement measuring apparatus according to the present invention may derive an analysis signal using a Hilbert transform approximated by differentiation or difference calculation in an arithmetic processing process for obtaining the instantaneous displacement from the interference beat signal. That is, in the present invention, as an approximation calculation of the Hilbert transform, a method may be used in which an array of solutions is used as an imaginary part of the analysis signal by using a differential or differential calculation of the interference beat signal data array.

  In addition, the vibration displacement measuring apparatus according to the present invention detects the reflected light intensity through a path different from the interference beat signal and obtains the phase code from the intensity change in order to obtain the phase code of the interference beat signal. A mechanism may be provided. In other words, when performing analysis including information on the direction of vibration displacement, the method for determining the relative displacement response from the change in reflected light intensity described above is applied as a method for determining the sign of the instantaneous phase, and the interference beat signal and May employ a method in which reflected / scattered light from the ME vibrator is detected by another path and the sign is determined from the intensity change. In the present invention, when the measurement site is irradiated with a diffused irradiation light beam with the reflected light intensity in the initial state where the ME vibrator is stationary as a reference, the displacement during a period in which the intensity is weaker than the reference is moved away from the probe. It is a displacement in a direction, and is defined as a displacement in a direction approaching in a period stronger than the standard.

  As another phase code determination method, the vibration displacement measuring apparatus according to the present invention uses the code of the generated voltage signal or the generated current signal as the phase code in order to obtain the phase code of the interference beat signal. It may be used. That is, a method of obtaining the phase code from the voltage value or current value of the power generation output before rectification that is simultaneously measured may be employed. Due to the mechanical-electrical coupling element, the vibration displacement speed of the ME vibrator and the effective generated voltage or the effective generated current response fluctuate substantially synchronously, and the sign of the effective generated voltage or current signal, or the sign of the difference between them. Can correspond to the sign of the vibration displacement. Since which code is used depends on the configuration of the mechanical-electrical coupling element, the mechanical-electrical coupling characteristics are obtained in advance, and an appropriate one is used for each configuration. This method is effective when the mechanical-electrical coupling is sufficiently strong.

  The signal data stored in these storage units is used as an additional function through an interface such as storage of each signal data in a data format that can be used by a personal computer or the like, or a graph display of each signal value.

  In the present invention, the principle of optical interference measurement is adopted, so that an effect of performing absolute measurement of the instantaneous displacement of the vibrator can be obtained without exerting mechanical and electromagnetic influences.

  Further, since the vibration displacement information is conveyed to the phase of the interference beat signal, the effect of being able to measure the instantaneous displacement value with position accuracy less than half of the measurement wavelength is strong against amplitude noise.

In addition, by using an optical fiber cable, even when it is difficult to ensure an optical path linearly, such as a vibrator housed in a container, an effect can be obtained in which the optical path can be secured and measured in a minimally invasive manner. By using a multimode fiber with a group delay difference smaller than ^10-9 seconds / meter, mode dispersion can be suppressed, the measurement band of interference beat signals can be secured sufficiently wide in practice, and reflected / scattered light from the measurement unit is received. The effect of reducing the connection loss at the time of increasing the throughput of the interference beat signal can be obtained.

  In addition, sufficient band margin and signal are taken into account, considering the tolerance to the additional group delay caused by bending of the fiber and the decrease in signal level due to bending loss so that measurement can be performed even with the vibrator placed in the container. The effect of giving a level margin is also obtained.

  In addition, the effect of easily adjusting the angle of the optical axis for receiving reflected / scattered light from the measurement unit is achieved by reducing the connection loss due to the multimode fiber and the coherence distance of 10 mm or more by using a narrow-band laser. can get.

  Further, the spatial resolution of the measurement site can be increased by the light focusing effect of the lens at the probe tip, and an effect can be obtained in which the vibration of the vibrator and the surrounding vibration can be separated and measured. By using the vibration-absorbing polymer as a vibration buffer material, it is possible to obtain an effect of vibration isolation when the optical fiber probe is fixed in the closed space.

  In the present invention, since an analysis signal is obtained by software from digital interference signal processing from one system of interference beat signals by optical homodyne detection, a simple hardware configuration with a small number of components can be achieved. As a result, it is possible to obtain an effect that the operation at the time of measurement and the ease of maintenance and management of the apparatus are excellent and an effect of measuring the economy of the apparatus.

  Further, in the present invention, as described above, as an approximation calculation of the Hilbert transform, it is possible to analyze by using a method of using the differential or difference calculation of the interference beat signal data array and the solution array as an imaginary part of the analysis signal. According to this approximate calculation, a phase error due to the uncertainty principle is less likely to occur in an analysis when a vibration component having a low frequency is included than in a normal Hilbert transform calculation, and the calculation burden on an electronic computer can be reduced. An effect is obtained.

  In addition, an algorithm that can automatically derive the instantaneous displacement from the interference beat signal measured by software in the above-described procedure can be adopted, so that an effect of reducing the burden on the operator in signal analysis can be obtained.

  The best mode for carrying out the present invention will be described below with reference to the drawings. Note that it is easy for a person skilled in the art to make other embodiments by changing or correcting the present invention within the scope of the claims, and these changes and modifications are included in the scope of the claims. Therefore, the following description is an example of the best mode of the present invention, and does not limit the scope of the claims.

  FIG. 1 is a schematic diagram of a vibration displacement measuring apparatus according to an embodiment of the present invention. The vibration displacement measuring apparatus according to the embodiment of the present invention basically includes a probe unit 1 using an optical fiber cable, a light source unit 2, a photoelectric conversion unit 3, a signal collection unit 4, an analysis unit 5, and a storage unit 6. It has a simple structure.

  The vibration-absorbing polymer material 7 for inserting and fixing the probe portion in the vibration power generator 19 is used as a buffer material. A polarization controller 8 is attached to the probe unit 1, and a coupling part between the light source unit 2 and the probe unit 1 is attached with an optical isolator 9 for cutting the return light to the light source unit 2, and the interferometer body is an optical circulator. 10.

  As the light source unit 2, a laser light source 2-1 composed of a frequency stabilized laser in a single longitudinal / transverse mode in a visible band that can be viewed with the naked eye is used. The laser beam output power from the probe unit 1 is suppressed to 100 μW or less, and a necessary signal level is obtained while suppressing the thermal influence on the ME vibrator 19-1.

  The photoelectric conversion unit 3-1 uses an avalanche photodiode to detect a high-speed response and low-noise interference beat signal. In this configuration, the reflected light from the fiber end face at the tip of the probe unit 1 is used as the reference light.

  In order to obtain the phase code of the interference beat signal, an optical fiber 11 different from that for detecting the interference signal is attached to the tip of the probe by a two-hole ferrule. Transmits and irradiates light from a low-coherence white light source 13 in different wavelength bands, receives and transmits an intensity change signal of reflected / scattered light from the measurement unit by the optical fiber 11, and passes through the photoelectric conversion unit 3-3. Measured as an electrical signal.

  Further, the intensity fluctuation of the light source unit 2 is taken out from the optical path branch 14, and differential measurement is performed with the light intensity detected by the photoelectric conversion unit 3-2. Thus, in the interference beat signal measured by the photoelectric conversion unit 3-1. Extend the measurement band in the low frequency range by eliminating fluctuations.

  The interference optical filter 15 having a large optical density is arranged so that the light from the white light source 13 is not mixed into the photoelectric conversion unit 3-1, and the light from the light source unit 2 is not mixed into the photoelectric conversion unit 3-3 and reflected to stray light. An absorptive optical color filter 16 is arranged so as not to become.

  The signal collecting unit 4 and the analyzing unit 5 are generally provided with an analog-digital converter and an electronic computer using a digital signal processor (DSP) or a field programmable gate array (FPGA), or an analog-digital signal converter. A personal computer is used. For the storage unit 6, a semiconductor storage element or a hard disk is used alone or in combination. The signal processing in the analysis unit 5 is performed according to the algorithm described above.

  A generated voltage or current signal generated simultaneously with the vibration displacement is transmitted and measured by the generated power signal transmission path 17. If necessary, the measurement result is displayed on the display unit 18.

Hereinafter, an example in which a vibration type power generation apparatus is diagnosed using the vibration displacement measuring apparatus developed according to the present invention will be described.
The basic configuration of the vibration displacement measuring apparatus used at this time is based on FIG. A commercially available GI optical fiber cable having a core diameter of 62.5 μm, a numerical aperture of 0.275, and an outer diameter of 0.9 mm was used as the fiber cable, and a stabilized He-Ne laser that continuously oscillates at a wavelength of 632.8 nm was used as the light source. . In the vibration-absorbing polymer, a groove was formed in a 5 mm thick urethane elastomer plate, and an optical fiber cable was embedded in the groove and fixed. From the measurement experiment of the vibration in the container in this case, the probe fiber was able to measure the displacement even with a bending loss having a curvature radius of 10 mm. A microlens was attached to the probe tip, and the focal length was adjusted to 10 mm and the spot size was 10 μm. The coherence distance was 100 mm, and a good interference beat signal with a signal-to-noise ratio of 8 bits or more was detected near the focal point. Measurement position alignment and optical axis angle alignment were adjusted with bare hands without using a precision stage.

  The ME vibrator of the vibration power generator has a silicon cantilever structure, and a lead zirconate titanate (PZT) film is attached to one side of the cantilever with an electrode. The present invention was used for the development of a device and the development of a vibration type power generation device for generating electricity by electrostatic effect in which an electret film made of a fluorine-based polymer is attached to one side surface of a cantilever together with an electrode.

  As a power generation test, a vibration type power generation device was attached to the vibration stage, and a power generation test was performed with a vibration response parallel to the artificially induced vibration. Since the vibration direction of excitation is one direction, a vibration displacement measuring device for one system was also prepared. A probe was attached to the ME vibrator by adjusting the focal point and optical axis, and the instantaneous displacement value and instantaneous generated electromotive force value (1 MΩ load) of the vibrator were measured.

  FIG. 2 is a measurement result of the displacement of the vibrator according to one embodiment of the present invention. In a vibration type power generator using a mechanical-electrical coupling mechanism based on the piezoelectric effect, the ME vibrator when excited by a harmonic vibration of 3.05 kHz, which is a lower frequency than the natural frequency of the ME vibrator, is 19.3 kHz. Instantaneous displacement. This waveform shows a shape distorted from harmonic vibration, suggesting an anharmonic energy distribution process.

  FIG. 3 is a measurement result of electromotive force according to an embodiment of the present invention. A mechanical-electrical coupling occurs, confirming that power is being generated. The effective output power can be evaluated from the instantaneous electromotive force signal before rectification and the load resistance value.

  FIG. 4 is a measurement result of the displacement of the vibrator according to one embodiment of the present invention. This is an instantaneous displacement of the ME vibrator when the vibration is generated at a natural frequency of 17.8 kHz of the ME vibrator in the vibration power generation apparatus using the mechanical-electrical coupling mechanism based on the electrostatic induction effect.

  FIG. 5 shows the produced instantaneous electromotive force signal. As shown in FIGS. 4 and 5, waveform distortion is observed, and an output waveform reflecting the loss of one or both of the mechanical system and electrical system of the ME vibrator and the process of anharmonic energy conversion is observed.

  The vibration displacement measuring apparatus according to the present invention can be used for operation evaluation at the time of development of a vibration power generation apparatus, quality inspection in a mass production process, and maintenance management at the time of use in a production place. In addition, the optical path between the measurement target and the probe can be used for measuring the operation of a MEMS device that is difficult to linearly take.

It is a block diagram which shows the vibration displacement measuring device of embodiment of this invention. 3 is a graph showing measurement results of displacement of a vibrator in a vibration type power generation apparatus using a mechanical-electric coupling mechanism based on a piezoelectric effect by the vibration displacement measuring apparatus shown in FIG. 1. It is a graph which shows the measurement result of the generated electromotive force in the vibration type power generating device using the mechanical-electrical coupling mechanism by the piezoelectric effect by the vibration displacement measuring device shown in FIG. 3 is a graph showing measurement results of displacement of a vibrator in a vibration power generation apparatus using a mechanical-electric coupling mechanism based on electrostatic induction effect by the vibration displacement measuring apparatus shown in FIG. 1. It is a graph which shows the measurement result of the generated electromotive force in the vibration type power generating device using the mechanical-electrical coupling mechanism by the electrostatic induction effect by the vibration displacement measuring device shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Probe part 2 Light source part 2-1 Laser light source 3 Photoelectric conversion part 3-1 (For interference beat signal) Photoelectric conversion part 3-2 (For differential measurement) Photoelectric conversion part 3-3 (For phase code determination) Photoelectric conversion Unit 4 signal collection unit 5 analysis unit 6 storage unit 7 vibration absorbing polymer material 8 polarization controller 9 optical isolator 10 optical circulator 11 (for phase code determination) optical fiber 12 wavelength multiplexer 13 white light source 14 optical path branch 15 interference optical filter Reference Signs List 16 Optical color filter 17 Generated power signal transmission line 18 Display unit 19 Vibrating power generator 19-1 ME vibrator

Claims (5)

A vibration displacement measuring device for inspecting a vibration power generator using a micromechanical-electrical structure,
A probe unit with an optical fiber cable using a multimode fiber with a maximum group delay difference of 1 nanosecond / meter or less, in which a condensing function such as a lens is added to the tip and a viscoelastic material is used for vibration damping,
A light source unit by a continuous oscillation laser light source;
A photoelectric conversion unit by a photodiode;
An optical circulator delivering an optical interference beat signal;
A signal collecting unit for converting an interference beat signal including a generated voltage or generated current value and vibration displacement information into a digital signal;
An electronic computer analysis unit;
A storage unit as a component,
The principle of optical homodyne interferometer is used to detect the instantaneous displacement of vibration.
Characteristic vibration displacement measuring device.   In order to obtain the phase code of the interference beat signal, a mechanism for detecting the reflected light intensity through a path different from the interference beat signal and obtaining the phase code from the intensity change is provided. Item 2. The vibration displacement measuring device according to Item 1.   2. The vibration displacement measuring apparatus according to claim 1, wherein a sign of the generated voltage signal or the generated current signal is used as the phase code in order to obtain a phase code of the interference beat signal.   The vibration signal according to claim 1, 2, or 3, wherein an analytical signal is derived by using a Hilbert transform approximated by a differential or differential operation in an arithmetic processing step for obtaining the instantaneous displacement from the interference beat signal. Displacement measuring device. As the viscoelastic material used for installation and fixing of the optical fiber cable, any one or a mixture of polymer silicon, urethane polymer, butyl rubber, polyisoprene, polyester, polyethylene, polyvinyl chloride, and honeynite rubber is used as a material. 5. The vibration displacement measuring device according to claim 1, wherein the vibration displacement measuring device is used.

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