JP2009098003A - Vibration displacement detecting device and method of detecting displacement and vibration - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration displacement detecting device which can be simply configured at low cost, allows easy adjustment of a measurement range of displacement and vibration and is easily maintained. <P>SOLUTION: A light receiving part 3 fixed on a reference point 2 of a structure 1 forming a part of a building, and a light emitting part 5 fixed on a moving platform 4 which is an object to be measured located distant from the reference point 2 are provided. The light receiving part 3 comprises a photodetector 6 and an optical system 7 for forming an image of the light emitting part 5 on a light receiving surface of the photodetector 6, and detects relative displacement or vibration between the reference point 2 and the object to be measured 4. The optical system 7 is a telescope type optical system, and the light emitting part 5 is constituted by a light emitting diode (LED). The photodetector 6 and the optical system 7 are integrally fixed and an adjustment tool 8 for adjusting a position of the photodetector 6 is provided on the connection portion between them. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a displacement vibration detection apparatus and method for detecting displacement and vibration of an object, and more particularly to a measurement object on the same or another structure located at a location away from a reference point on a structure such as a building or apparatus. The present invention relates to a displacement vibration detection apparatus and method for detecting displacement or vibration.

  Conventionally, there are various methods for detecting displacement and vibration of an object, such as a method using a magnet or a coil, a method for detecting a change in capacitance, a method using a piezoelectric element, and an optical method. It is used together. In particular, the optical method is suitable for the purpose of detecting the displacement and vibration of the object to be measured from a remote location.

  When performing any operation on or moving the same or another structure located at a location away from a certain point or an object installed there, for safety measures or for the operation, It may be necessary to detect displacement and vibration. Conventionally, in such cases, a laser displacement meter method that detects the distance, displacement, and vibration from the arrival time difference by irradiating the object to be measured with a modulated laser light beam and detecting the reflected light, or laser from a reference point There is a method of detecting vibration by irradiating a measurement point with light and measuring the displacement of the position by a triangulation method. An example of such a distance measurement method is shown in Patent Document 1. A laser Doppler vibrometer that utilizes Doppler shift of reflected light due to the movement of an object as in Patent Document 2 can also be used. Furthermore, a method is generally known in which an image of an object to be measured is taken and vibration is detected from a change in the image.

JP-A-6-229755 JP 2004-101186 A

  However, the above-described conventional method using a laser displacement meter or triangulation requires a special laser device or detection device, which increases the cost of the device and also increases the maintenance cost in order to maintain the required accuracy. turn into. On the other hand, the laser Doppler vibrometer is expensive because it requires a special detection device, and it cannot detect a slow displacement. The method of performing detection based on a captured image also has a high apparatus cost, and the measurement target is limited. In practice, it is desirable that the measurement range of displacement and vibration can be easily adjusted. In consideration of a wide range of applications, the distance between the reference point and the object to be measured is about several to 100 m, the displacement due to vibration is about 0.3 mm or more, and the vibration frequency is about 0.1 to 1 kHz. desirable.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a displacement vibration detection device and a displacement vibration detection method that can be realized with a simple configuration at low cost, can easily adjust the measurement range of displacement and vibration, and can be easily maintained.

  In order to solve the above problems, the displacement vibration detection device of the present invention includes a light receiving unit fixed to a reference point of a structure and a light emitting unit fixed to an object to be measured located away from the reference point. The light receiving unit includes a photodetector and an optical system that forms an image of the light emitting unit on a light receiving surface of the photodetector, and the reference point and the reference point according to a change in the amount of light detected by the photodetector. Relative displacement or vibration between the measured objects is detected.

  The optical system is preferably a telescopic optical system.

  In addition, the photodetector and the optical system may be fixed integrally, and a means for adjusting the position of at least one of the photodetector or the optical system may be provided.

  Further, the photodetector may be a divided photodiode having a light receiving surface divided.

  The light emitting unit may be formed of a light emitting diode.

  A light source installed in a portion different from the light emitting unit; and an optical fiber that guides light emitted from the light source, and the light emitting unit emits light guided by the optical fiber. It may be an end face.

  In addition, a wavelength filter that allows a wavelength of light emitted from the light emitting unit to pass through may be installed on the light incident side of the photodetector.

  Further, the intensity of the light emitted from the light emitting unit may be modulated at a frequency higher than the frequency of the vibration.

  According to the present invention, the light receiving unit is installed at the reference point of the structure, the light emitting unit is installed at the object to be measured located away from the reference point, and on the light receiving surface of the photodetector of the light receiving unit. A displacement vibration detection method is provided in which an image of the light emitting section is formed and relative displacement or vibration between the reference point and the object to be measured is detected by a change in the amount of light received by the light receiving surface.

  The present invention forms an image of the light emitting part fixed to the object to be measured on the light receiving surface of the detector, and detects vibration and displacement because the amount of received light changes when the image of the light emitting part is removed from the light receiving surface. Therefore, the detection range and sensitivity of the displacement and vibration amplitude can be selected by setting the relative size of the image of the light emitting unit with respect to the light receiving surface and the setting of the imaging position. In addition, the distance between the reference point and the object to be measured can be increased by using a high-magnification telescope optical system. An LED, a lamp, or the like can be used as the light source, and the configuration of the detection system is simple and no special parts are required.

  As described above, according to the present invention, it is possible to obtain a displacement vibration detection device that can be realized with a simple configuration and at low cost, can easily adjust the measurement range of displacement and vibration, and can be easily maintained.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram showing a configuration of a displacement vibration detecting apparatus according to a first embodiment of the present invention. In FIG. 1, the first embodiment is a light receiving unit 3 fixed to a reference point 2 of a structure 1 that is a part of a building, and a moving table that is a measurement object located at a location away from the reference point 2. 4 and a light emitting unit 5 fixed on the top of the unit 4. The light receiving unit 3 includes a light detector 6 and an optical system 7 that forms an image of the light emitting unit 3 on the light receiving surface of the light detector 6, and a relative displacement between the reference point 2 and the measured object 4 or Detect vibration. The distance between the reference point 2 and the moving table 4 is about several meters to 100 meters.

  The optical system 7 is an optical system having a telescope configuration, and its magnification is about 10 to 100 times. The light emitting unit 5 is composed of a light emitting diode (LED). The wavelength may be 1.3 μm band, infrared light such as 780 to 860 nm, or visible light such as 650 nm. Light-emitting diodes are smaller and lighter than lamps, have low power consumption, have a small light-emitting area, are highly reliable and can be modulated, and are low-cost compared to lasers and have a large radiation angle and are easy to adjust because they do not interfere with each other. It is suitable as a light source used in the present invention.

  The photodetector 6 and the optical system 7 are fixed as a single body, and an adjustment jig 8 for adjusting the position of the photodetector 6 is provided at the coupling portion. In order to increase the sensitivity, it is necessary to match the imaging point and the light receiving surface with high accuracy, and thus such an adjustment mechanism is necessary.

  FIG. 2 is a view showing a light receiving surface of the photodetector 6 used in the present embodiment. The photodetector 6 is a divided photodiode 16 having a light receiving surface 20 divided as shown in FIG. Alternatively, it may be a normal photodiode 17 having a single light receiving surface as shown in FIG.

  When the split type photodiode 16 is used, as shown in FIG. 2A, the light quantity of the image 11 of the light emitting portion is normally substantially equal to both of the two light receiving surfaces 20 divided without vibration displacement. When displacement occurs, the displacement is detected by causing a difference in the amount of light. By using such a split type photodiode, the vibration displacement amount of the light emitting portion can be easily and accurately converted into an electric signal.

  When a normal photodiode 17 is used, as shown in FIG. 2B, adjustment is made so that a part of the image 11 of the light emitting portion is incident on the light receiving surface 10, and the amount of displacement is converted from the change in the amount of received light. . The light receiving surface may have a shape of about 0.2 mm to 10 mm □.

  If a large amount of displacement is detected, the light emitting unit 5 may be a light source having a light emitting surface with a size corresponding to the displacement or a plurality of light emitting diodes installed in a region with a length corresponding to the displacement width. Good.

  Here, a wavelength filter that passes only the wavelength of the light emitting unit 5 may be provided on the incident side of the photodetector 6 or the optical system 7. In this case, since only the light from the light emitting unit 5 can be detected, measurement errors, sensitivity deterioration, instability, and the like due to noise light from the periphery can be avoided.

  Further, by intensity-modulating the light-emitting diode of the light-emitting unit 5 at a frequency sufficiently higher than the vibration frequency to be measured, for example, about several hundreds KHz to 10 MHz, and passing through a frequency filter after being converted into an electric signal by the photodetector 6. Thus, the influence of noise light of the same wavelength from the periphery and the influence of other electrical noise can be eliminated, and detection with higher sensitivity and higher accuracy becomes possible.

  FIG. 3 is a block diagram showing the overall configuration of the displacement vibration detecting apparatus of the present embodiment. The required intensity of the light emitting diode is set based on the distance between the light emitting unit 5 and the reference point 2, the telescope magnification of the optical system 7, and the sensitivity of the photodetector 6. The telescope magnification of the optical system 7 is determined from the distance between the light emitting unit 5 and the reference point 2, the amount of vibration displacement to be detected, and the shape of the light receiving surface of the photodetector. The position of the photodetector 6 is adjusted to an optimum position by the adjusting jig 8. A signal converted into an electric signal by the light receiving element is amplified by an amplifier, and it is determined whether the signal is a signal level or frequency to be displayed on the display device, and is output to the display device. When the light incident on the light receiving element is light modulated at a specific frequency as described above, noise is removed by passing through a frequency filter before input of the amplifier or after output of the amplifier.

  FIG. 4 is a diagram showing a configuration of a displacement vibration detecting apparatus according to the second embodiment of the present invention. This embodiment is the same as the first embodiment except for the light emitting portion. In FIG. 4, a light source 30 installed near the light receiving unit 3, which is a part different from the light emitting unit 35, and an optical fiber 31 that guides light emitted from the light source 30 are included. It consists of the end face of the optical fiber 31 from which the guided light is emitted.

  A light-emitting diode can be used as the light source 30, and a plastic optical fiber can be used as the optical fiber 31 at a low cost, easily coupled with the light source and easy to handle, and having a large radiation angle from the end face. The end portion of the optical fiber 31 is fixed by a holder 36 provided on the movable table 4 with the end surface facing the light receiving unit 3.

  Eliminates the need for power supply to the light emitting unit and batteries, and makes the light emitting unit lightweight, making it easy to install on the object to be measured, and the light emitting unit is excellent in environmental resistance because it contains no electrical components. . Here, a plurality of optical fibers may be used in order to secure a necessary light emission amount and light emission region.

  Needless to say, the present invention is not limited to the above-described embodiment. For example, the shape of the light-emitting portion and the shape of the light-receiving surface can be designed according to the purpose. Moreover, in the said embodiment, although the light-receiving part and the light emission part were installed on the same structure, you may install these on a separate structure.

FIG. 1 is a diagram showing a configuration of a displacement vibration detecting apparatus according to the first embodiment of the present invention. FIG. 2 is a diagram showing a light receiving surface of a photodetector used in the present embodiment, FIG. 2 (a) is a diagram showing a divided photodiode in which the light receiving surface is divided, and FIG. 2 (b) is a single diagram. It is a figure which shows the photodiode which has a light-receiving surface. FIG. 3 is a block diagram showing the overall configuration of the displacement vibration detection apparatus of the present embodiment. FIG. 4 is a diagram showing a configuration of a displacement vibration detecting apparatus according to the second embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Structure 2 Reference point 3 Light-receiving part 4 Moving stand 5, 35 Light-emitting part 6 Photo detector 7 Optical system 8 Adjustment jig 11 Image of light-emitting part 16 Split type photodiode 17 Photodiode 10, 20 Light-receiving surface 30 Light source 31 Light Fiber 36 holder

Claims (9)

  A light receiving portion fixed to a reference point of the structure, and a light emitting portion fixed to an object to be measured located at a location away from the reference point, the light receiving portion being a photodetector and a light receiving portion of the photodetector. An optical system that forms an image of the light emitting unit on a surface, and detects relative displacement or vibration between the reference point and the object to be measured by a change in the amount of light detected by the photodetector. Displacement vibration detection device characterized by the above.   The displacement vibration detecting apparatus according to claim 1, wherein the optical system is an optical system having a telescope configuration.   3. The displacement vibration detection according to claim 1, wherein the photodetector and the optical system are fixed integrally, and means for adjusting a position of at least one of the photodetector or the optical system is provided. apparatus.   The displacement vibration detection device according to any one of claims 1 to 3, wherein the photodetector is a split type photodiode in which a light receiving surface is split.   The displacement vibration detection device according to any one of claims 1 to 4, wherein the light emitting unit is formed of a light emitting diode.   A light source installed in a portion different from the light emitting unit; and an optical fiber that guides the light emitted from the light source, and the light emitting unit has an end face of the optical fiber from which the light guided by the optical fiber is emitted. The displacement vibration detection apparatus according to claim 1, wherein the displacement vibration detection apparatus is configured as follows.   The displacement vibration detection according to any one of claims 1 to 6, wherein a wavelength filter that allows a wavelength of light emitted from the light emitting unit to pass is installed on a light incident side of the photodetector. apparatus.   The displacement vibration detection device according to claim 1, wherein the intensity of light emitted from the light emitting unit is modulated at a frequency higher than the frequency of the vibration.   A light receiving unit is installed at the reference point of the structure, and a light emitting unit is installed at the object to be measured located away from the reference point. A displacement vibration detection method for detecting a relative displacement or vibration between the reference point and the object to be measured by a change in the amount of light received by the light receiving surface.

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