JP4975519B2 - Rotating body measuring apparatus and measuring method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a measuring device and a measuring technique of a rotor capable of measuring physical quantities of a rotor preferably. <P>SOLUTION: The measuring device of a rotor includes a rotating section 2 with a measured rotor, a fixed supporting section 3 supporting the rotating section 2 rotatably, an optical fiber 5 a FBG sensor section 4 is formed as a measuring means of the rotor, a rotary joint 6 connecting the optical fiber 5 between the rotating section 2 and the fixed supporting section 3 so as to elongate the optical fiber 5 from the rotor to the fixed supporting section 3, a luminous source 7 emitting light to the optical fiber 5 continuously, an optical circulator 8 separating reflected light from the FBG sensor section 4, and a signal processing section 12 computing physical quantities of the rotor by processing the signal of reflected light. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a rotating body measuring apparatus and measuring method for measuring physical quantities such as strain and temperature of a rotating body to be measured.

  In general, when measuring strain and temperature of a rotating body such as a wheel, the rotating body to be measured is arranged with respect to the rotating part that is rotatably supported by the fixed support part, and the rotating body is rotated by the rotating part. At the same time, strain is measured using a strain gauge, or temperature is measured using an electric sensor of a thermocouple.

  At this time, a slip ring and a telemeter are provided between the fixed support portion and the rotating portion so as to transmit a signal of the rotating body from the rotating portion to the fixed support portion.

  Here, the slip ring is configured by providing a sliding surface on the electrode portion, and noise is easily generated. Further, since heat is generated by rotation on the sliding surface of the electrode part, there is a problem that a frequency that can be used for measurement is restricted. Further, when the number of measurement points of the rotating body is large, there is a problem that the sliding surface of the electrode portion becomes large and the testing machine becomes large.

  On the other hand, the telemeter is configured to transmit a radio signal from the rotating unit to the measuring means, and since a power source such as a battery is installed in the rotating unit, a power source space is required in the rotating unit and time is required for measurement time. There is a problem of being subject to various restrictions. Further, when the number of measurement points of the rotating body is large, the number of sensors increases, and there is a problem that high-speed data transfer cannot be performed due to restrictions on the signal transmission speed.

  For this reason, when the number of measurement points of the rotating body is large, it is considered to use an optical fiber capable of performing high-speed data transfer from the sensor to the measurement means.

  As an example, an optical fiber and an optical fiber sensor are arranged on a rotating body, an information signal is transmitted from the rotating body to a fixed-side measuring unit through the optical fiber, and a lens or the like is provided in a gap between the rotating body and the fixed support section. There is one that transmits light and transmits an optical signal in a pulse manner at a predetermined position of a rotating body (for example, see Patent Document 1).

As another example, a pulse light source is used and an optical fiber and an optical fiber sensor are arranged on the rotating body, and an information signal is transmitted from the rotating body to the measuring unit on the fixed side by the optical fiber. In some cases, a lens or the like is provided in a gap between the two to transmit light (see, for example, Patent Document 2).
JP-A-2005-164326 JP 2006-84292 A

  However, in the example of Patent Document 1, since transmission of an optical signal is performed in a pulse manner at a predetermined position of a rotating body, when receiving a grounding load or a lateral load during one rotation like a car wheel, a physical quantity is set. There was a problem that it was not possible to measure and changes in physical quantities could not be measured continuously. Furthermore, in the example of Patent Document 2, since a pulse light source is used, there is a problem that a physical quantity cannot be continuously measured.

  In addition, since a single mode optical fiber generally used as an optical fiber has a very small core diameter of about 10 μm, it has a centering function so as to reduce loss due to connection when connecting optical fibers. It is necessary to use a dedicated connector or to connect the end portions of the optical fibers by fusion. When connecting optical fibers through lenses or the like as in References 1 and 2, the alignment function is In addition, there is a problem that the configuration of the optical transmission line is very difficult.

  Furthermore, when a light source for measurement of an optical communication device is used as the light source, the light intensity of the light source is about 10 dBm (10 mW), the reflected light band is very narrow, and the light intensity is small. When collimated light having a large beam diameter is used, the light is attenuated, resulting in a problem that the noise level of a room lamp or the like increases, resulting in a signal unsuitable for measurement and signal processing. In addition, in optical transmission using a lens that is not sealed, there is a problem in that optical transmission loss increases due to contamination of the lens and the like, resulting in signal attenuation and noise increase.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a measuring device and a measuring method for a rotating body that can suitably measure a physical quantity of the rotating body.

The present invention relates to a rotating unit that includes a rotating body to be measured, a fixed support unit that rotatably supports the rotating unit, and measurement of the rotating body that uses an FBG sensor as a means for measuring strain generated in the rotating body. In the device
An optical fiber in which a plurality of FBG sensor parts are formed;
A rotary joint for transmitting and receiving signals in the optical fiber between the rotating part and the fixed support part so as to extend the optical fiber from the rotating body to the fixed support part;
FBG sensor part for rotation compensation attached to the axial center part of the rotating part that does not cause distortion change of the rotating part and formed on the optical fiber,
A broadband light source that is placed outside the rotating unit and outputs light continuously to the FBG sensor disposed in the rotating unit via the rotary joint;
An optical circulator located between the rotary joint of the fixed support portion and the broadband light source and disposed in the middle of the optical fiber;
An optical splitter through which reflected light from the FBG sensor is guided through the optical circulator;
An optical filter for determining the amount of strain detected by the FBG sensor, which is arranged at the rear stage of the circuit of the optical fiber so as to be positioned on the output side of each wavelength band of the optical splitter;
A set of photoelectric converters that convert light intensity signals from the optical filter into electrical signals;
When measuring the rotating body, the FBG sensor unit signal is used to determine the apparent distortion change due to the optical transmission loss variation that occurs during one rotation of the rotary joint, and further the FBG sensor unit signal for rotation compensation From this, the apparent distortion change during one rotation of the rotary joint is obtained, and the apparent distortion change in the FBG sensor signal is corrected with the apparent distortion change in the FBG sensor signal for rotation compensation. In addition, the present invention relates to a rotating body measuring apparatus configured to remove the influence of optical transmission loss of a rotary joint and perform distortion measurement compensation.

The present invention relates to a rotating unit that includes a rotating body to be measured, a fixed support unit that rotatably supports the rotating unit, and measurement of the rotating body that uses an FBG sensor as a means for measuring strain generated in the rotating body. In the method
An optical fiber in which a plurality of FBG sensor parts are formed;
A rotary joint for transmitting and receiving signals in the optical fiber between the rotating part and the fixed support part so as to extend the optical fiber from the rotating body to the fixed support part;
FBG sensor part for rotation compensation attached to the axial center part of the rotating part that does not cause distortion change of the rotating part and formed on the optical fiber,
A broadband light source that is placed outside the rotating unit and outputs light continuously to the FBG sensor disposed in the rotating unit via the rotary joint;
An optical circulator located between the rotary joint of the fixed support portion and the broadband light source and disposed in the middle of the optical fiber;
An optical splitter through which reflected light from the FBG sensor is guided through the optical circulator;
An optical filter for determining the amount of strain detected by the FBG sensor, which is arranged at the rear stage of the circuit of the optical fiber so as to be positioned on the output side of each wavelength band of the optical splitter;
A set of photoelectric converters that convert light intensity signals from the optical filter into electrical signals;
When measuring the rotating body, the FBG sensor unit signal is used to determine the apparent distortion change due to the optical transmission loss variation that occurs during one rotation of the rotary joint, and further the FBG sensor unit signal for rotation compensation From this, the apparent distortion change during one rotation of the rotary joint is obtained, and the apparent distortion change in the FBG sensor signal is corrected with the apparent distortion change in the FBG sensor signal for rotation compensation. In addition, the present invention relates to a rotating body measuring method, wherein distortion measurement compensation is performed by removing the influence of optical transmission loss of a rotary joint .

  According to the measuring device and the measuring method of the rotating body of the present invention described above, the rotating body to be measured is measured using the FBG sensor unit and the optical fiber, and a rotary joint is interposed between the rotating unit and the fixed support unit. Since the optical fiber is connected, the rotating body is continuously measured, and the physical quantity of the rotating body can be suitably measured even when the physical quantity changes during one rotation of the rotating body. In addition, since a rotary joint is arranged between the rotating part and the fixed support part to connect the optical fiber, the configuration of the optical transmission path is facilitated and the restrictions due to the light source and the lens are reduced, and the physical quantity of the rotating body is suitably set. It can be measured. Furthermore, it is possible to prevent optical transmission loss due to dirt on the lens. Furthermore, since the noise caused by the rotary joint is reduced by using the FBG sensor unit and the compensation FBG sensor unit, various excellent effects can be obtained that the physical quantity of the rotating body can be measured more suitably.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIGS. 1-8 is an example which implements the measuring device and measuring method of the rotary body of this invention.

  The rotating body measuring apparatus includes a rotating unit 2 that arranges a rotating body 1 to be measured, a fixed support unit 3 that rotatably supports the rotating unit 2, and an FBG sensor unit 4 as a measuring unit for the rotating body 1. A single-mode optical fiber 5 and a rotary that connects the optical fiber 5 between the rotating portion 2 and the fixed support portion 3 so as to extend the optical fiber 5 from the rotating body 1 to the fixed support portion 3 via the rotating portion 2. A joint 6, a light source 7 that outputs light from the fixed support 3 to the optical fiber 5, an optical circulator 8 disposed between the rotary joint 6 and the light source 7, an optical splitter 9 to an optical splitter 9, an optical filter 10, And a signal processing unit 12 connected via a photoelectric converter 11.

  As shown in FIG. 3, the rotating unit 2 includes a rod-shaped rotating unit main body 14 and a disk-shaped mounting member 15 disposed at the tip of the rotating unit main body 14, and the rotating member 1 to be measured is mounted on the mounting member 15. Can be fastened with a bolt or the like (not shown). Further, the rotating part body 14 extends along the longitudinal direction of the rotating part body 14 from the center hole 1a of the rotating body 1 through the through hole 15a of the mounting member 15 to the fixing part 6a (see FIG. 2) of the rotary joint 6. An extending axial space 2a is formed. Here, in FIG. 3, the rotating body 1 to be measured is a road wheel, and the axial center space 2a of the rotating body 1 is connected to the shaft hole (center hole 1a) of the road wheel. The rotating body 1 to be measured is not limited to a road wheel, but may be a vehicle hub or the like, and is not particularly limited as long as it is necessary to measure a physical quantity such as distortion.

  As shown in FIGS. 2 and 3, the fixed support portion 3 includes a rotation support structure (not shown) such as a bearing positioned between the rotary body 1 and a drive means (not shown) such as a power motor. The rotating part 2 and the rotating body 1 are axially rotated. Here, the fixed support unit 3 includes the fixed unit 6a of the rotary joint 6, the optical circulator 8, the light source 7, the optical splitter 9, the optical filter 10, the photoelectric converter 11, and the signal processing unit 12 as one unit. As shown in FIG. 2, the unit from the optical circulator 8 to the light source 7, the optical splitter 9, the optical filter 10, the photoelectric converter 11, the signal processing unit 12, and the unit of the fixing unit 6 a of the rotary joint 6. The signal processing unit 12 may be provided in another PC or the like.

  As shown in FIGS. 1 to 3, the optical fiber 5 is connected to the first optical fiber portion 5 a that guides incident light from the light source 7 to the optical circulator 8, and the optical circulator 8 to the fixed portion 6 a of the rotary joint 6. A second optical fiber portion 5b serving as a waveguide for communication of incident light and reflected light, an axial space 2a of the rotating portion 2 from the rotor portion 6b of the rotary joint 6, a through hole 15a of the mounting member 15, and a rotating body. A third optical fiber portion 5c that extends to the surface of the rotator 1 through one central hole 1a and serves as a waveguide for incident light and reflected light, and extends in the direction from the optical circulator 8 to the signal processing portion 12 And a fourth optical fiber portion 5d. Further, the optical fiber 5 has the bent portion 5r arranged with a large radius of curvature so as to prevent breakage due to bending, and the entire length is minimized as much as possible so as to reduce the attenuation of the optical signal intensity. I am doing it. Further, the third optical fiber portion 5c has an end connecting portion disposed coaxially with the rotating shafts of the rotating body 1 and the rotating portion 2, and continuously transmits signals by axial rotation. The fourth optical fiber portion 5d connects the optical circulator 8 to the photoelectric converter 11. 1 and 2, the photoelectric converter 11 and the signal processing unit 12 are connected by an electric signal wiring 13.

  Further, the third optical fiber portion 5c of the optical fiber 5 is provided with a plurality of FBG (fiber Bragg grating) sensor portions 4 that are formed continuously with one optical fiber 5 (three in the figure). As shown in FIGS. 3 and 4, the plurality of FBG sensor units 4 are arranged in order from the outer peripheral side in the radial direction of the rotating body 1 so as to be arranged at the measurement site of the rotating body 1. The second FBG sensor unit 4b and the third FBG sensor unit 4c are fixed by fixing means such as an adhesive or a fixing tape so as to be in close contact with the surface of the rotating body 1. Further, all the FBG sensor units 4a, 4b, and 4c are set to different Bragg wavelengths in the band of 1200 to 1600 nm, preferably in the band of 1530 to 1565 nm. Here, the FBG sensor unit 4 has a diffraction grating formed at regular intervals along the optical axis direction in the core portion of the optical fiber 5, and changes the reflection wavelength due to distortion or temperature change of the inspection object, thereby inspecting the inspection object. The distortion etc. are detected. Note that the number of FBG sensor units 4 to be formed is not particularly limited, and may be one or two or four or more depending on the size and type of the measurement target.

  Further, the third optical fiber portion 5c of the optical fiber 5 includes one or more compensation FBG sensor portions 16 in the same optical fiber 5 as the plurality of FBG sensor portions 4, and the compensation FBG sensor portion. 16 is arranged in the middle position of the axial space 2a of the rotating portion 2 so as not to be affected by the distortion of the optical fiber 5 between the FBG sensor portion 4 and the rotary joint 6, and in the axial space 2a, FIG. As shown in FIG. 2, the material is fixed by a filler 18 such as an adhesive via a pipe 17. The compensation FBG sensor unit 16 is set in a band of 1200 to 1600 nm, preferably in a band of 1530 to 1565 nm, like the first FBG sensor unit 4a, the second FBG sensor unit 4b, and the third FBG sensor unit 4c. ing. Further, the compensation FBG sensor unit 16 is positioned and fixed at the axial center in the axial space 2a and is reinforced by the pipe 17 and the filler 18, and causes noise such as distortion, blurring and vibration when the rotating body 1 rotates. Is not generated.

  Here, as shown in FIG. 6, the optical fiber 5 is arranged along the axial direction on the outer peripheral surface of the rotating body 1 so that the third optical fiber portion 5 c rotates as the rotating body 1 rotates. Maintenance may be facilitated. At this time, the third optical fiber portion 5c has the compensation FBG sensor portion 16 disposed in the space 2b behind the axis of the rotating portion 2, and the outer peripheral surface of the rotating body 1 from the compensating FBG sensor portion 16 through the communication hole 2c. , Further passes through the through hole 15b of the attachment member 15 to reach the rotating body 1, and a predetermined FBG sensor unit 4 is arranged at a measurement site of the rotating body 1.

  On the other hand, as shown in FIGS. 1 and 2, the rotary joint 6 includes a fixing portion 6a that connects the end of the second optical fiber portion 5b, and has a structure that rotates with respect to the fixing portion 6a. A rotor portion 6b is provided for connecting the end portions of the three optical fiber portions 5c. The space between the fixed portion 6a and the rotor portion 6b is provided with a sealing structure that is sealed from outside air by filling a gas such as inert gas or clean air, or a liquid such as glycerin, and has an optical transmission path. Forming. Here, the gas or liquid sealed in the space between the fixed portion 6a and the rotor portion 6b is not particularly limited as long as attenuation of the optical signal intensity is suppressed.

  As the light source 7, a broadband light source that continuously outputs light to the first optical fiber portion 5a of the optical fiber 5 is applied.

  The optical circulator 8 is configured to control the direction of the guided light by the incident light or reflected light of the optical fiber 5, and specifically, the incident light from the light source 7 is transmitted from the first optical fiber portion 5a to the second optical fiber. In addition to being guided to the second optical fiber portion 5b, the reflected light from the FBG sensor portion 4 is guided from the second optical fiber portion 5b to the optical splitter 9 via the fourth optical fiber portion 5d. Yes.

  The optical splitter 9 reflects reflected light including different Bragg wavelengths from the first FBG sensor unit 4a, the second FBG sensor unit 4b, the third FBG sensor unit 4c, and the compensation FBG sensor unit 16 in each Bragg wavelength band. And is sent to the optical filter 10. Here, when the FBG sensor unit 4 and the compensation FBG sensor unit 16 are configured with other numbers, the optical splitter 9 also divides the Bragg wavelength band corresponding to the FBG sensor unit 4 and the compensation FBG sensor unit 16. It is preferable.

  The optical filter 10 includes a first filter 10a, a second filter 10b, a third filter so as to correspond to the first FBG sensor unit 4a, the second FBG sensor unit 4b, the third FBG sensor unit 4c, and the compensation FBG sensor unit 16. 10c and a compensation filter 10d. Each of the optical filters 10a, 10b, 10c, and 10d converts the reflected light of the Bragg wavelength band divided by the optical splitter 9 into two lights (light intensity signals). ).

  The photoelectric converter 11 includes a set of first photoelectric conversion units 11a, a set of so as to receive a light intensity signal corresponding to the first filter 10a, the second filter 10b, the third filter 10c, and the compensation filter 10d. A second photoelectric conversion unit 11b, a set of third photoelectric conversion units 11c, and a set of compensation photoelectric conversion units 11d are configured, and each set of photoelectric conversion units 11a, 11b, 11c, and 11d includes two units. The two light intensity signals are converted into respective electric signals.

  The signal processing unit 12 is configured to receive electrical signals from all the photoelectric conversion units 11a, 11b, 11c, and 11d of the photoelectric converter 11, and internally has a control program for processing the electrical signals. I have.

  The operation of the embodiment for carrying out the measuring device and the measuring method of the rotating body of the present invention will be described below.

  When measuring physical quantities such as strain, temperature, acceleration, AE (acoustic emission), etc. for the rotating object 1 to be measured, the rotating object 1 is first placed on the mounting member 15 of the rotating object 1 as a preparation stage. Then, the first FBG sensor unit 4a, the second FBG sensor unit 4b, and the third FBG sensor unit 4c of the FBG sensor unit 4 are fixed on the surface of the rotating body 1 along the radial direction of the rotating body 1, such as an adhesive. To fix.

  Next, measurement is started simultaneously with the rotation of the rotating body 1 via the rotating unit 2. Here, at the time of measurement, the measurement light (incident light) is continuously emitted from the broadband light source 7 to the first optical fiber portion 5a of the optical fiber 5 (step S1) by the optical circulator 8. The light passes through the optical fiber portion 5b (step S2), and then enters from the second optical fiber portion 5b into the fixed portion 6a of the rotary joint 6 (step S3), and further through the transmission optical path of the rotary joint 6 the rotor portion 6b. The first FBG sensor unit 4a and the second FBG of the FBG sensor unit 4 are caused to be incident on the third optical fiber unit 5c in an axially rotated state (step S4) and a physical quantity signal is emitted from the measurement part of the rotating body 1. The sensor unit 4b and the third FBG sensor unit 4c generate reflected light with different Bragg wavelengths, and the compensation sensor unit generates reflected light with another Bragg wavelength (step S5).

  After the reflected light having the Bragg wavelength is generated by the FBG sensor unit 4 and the compensation FBG sensor unit 16, the reflected light enters the rotor unit 6 b of the rotary joint 6 through the third optical fiber unit 5 c of the optical fiber 5 ( Step S6), then, enters the second optical fiber portion 5b from the fixed portion 6a via the transmission optical path of the rotary joint 6 (Step S7), and further, the reflected light is separated by the optical circulator 8 and the fourth optical fiber. Is incident on the unit 5d (step S8), then is incident on the optical splitter 9, and corresponds to the first FBG sensor unit 4a, the second FBG sensor unit 4b, the third FBG sensor unit 4c, and the compensation FBG sensor unit 16, respectively. The light is divided into light of the Bragg wavelength band (step S9), and the divided light is then divided into the first filter 10a, the second filter 10b, and the third filter 10c of the optical filter 10, respectively. The light enters the compensation filter 10d, is divided into two light beams from the respective optical filters 10a, 10b, 10c, and 10d (steps S10 and S11). The light is incident on the photoelectric conversion unit 11a, the set of second photoelectric conversion units 11b, the set of third photoelectric conversion units 11c, and the set of compensation photoelectric conversion units 11d, and is converted into two output signals (electric signals) ( In step S12), all the converted output signals (electrical signals) are input to the signal processing unit 12. Here, A in FIGS. 7 and 8 indicates that the flows are continuously connected.

  The signal processing unit 12 acquires an electrical signal via the compensation photoelectric conversion unit 11d and the like by the reflected light from the compensation filter unit that is not affected by the distortion of the optical fiber 5, and calculates it according to a predetermined control program. The noise (see FIG. 9) of the optical transmission loss change per rotation that occurs when the joint 6 makes one rotation is detected as an apparent Bragg wavelength change (step S13). Here, the noise of the rotary joint 6 is caused by misalignment of the optical fibers 5 (second optical fiber portion 5b and third optical fiber portion 5c) of the rotating portion 2 and the fixed support portion 3 facing each other. When the frequency of the noise of the rotary joint 6 is analyzed, it is clear that there is a peak in the order integer as shown in the spectrum of FIG.

  Next, in the signal processing unit 12, two electric signals are respectively transmitted via the photoelectric converter 11 and the like by the reflected light of the measurement parts of the first FBG sensor unit 4a, the second FBG sensor unit 4b, and the third FBG sensor unit 4c. Is calculated and processed by a predetermined control program to calculate the physical quantity of the rotating body 1 (step S14). Here, a change in physical quantity (strain, temperature change, etc.) of the rotating body 1 causes a change in Bragg wavelength as strain on the first FBG sensor unit 4a, the second FBG sensor unit 4b, and the third FBG sensor unit 4c. It is calculated by appropriate comparison or function processing according to the electrical signal from the change of the Bragg wavelength. FIG. 11 shows a distortion waveform generated in the rotating body 1 when a load is applied while rotating the rotating body 1.

  Subsequently, in the signal processing unit 12, the first FBG sensor unit 4a, the second FBG sensor unit 4b, and the second FBG sensor unit 4b in step S14 are generated by the apparent Bragg wavelength change from the compensation FBG sensor unit 16 in step S13 according to a predetermined control program. The Bragg wavelength from the third FBG sensor unit 4c is appropriately corrected for calculation, and the noise of the rotary joint 6 is removed with respect to the change in the physical quantity of the rotating body 1 (step S15), and the physical quantity of the rotating body 1 is measured Exit. Here, when the change in the physical quantity of the rotating body 1 is large, the influence of noise on the rotary joint 6 is small, and steps S13 and S15 can be eliminated. On the other hand, when the change in the physical quantity of the rotating body 1 is small or when a small signal change in the optical fiber 5 is detected, the influence of the noise of the rotary joint 6 is large, and steps S13 and S15 are essential.

  Thus, according to the embodiment, the rotary body 1 to be measured is measured using the FBG sensor unit 4 and the optical fiber 5, and the rotary joint is interposed between the rotary unit 2 and the fixed support unit 3. 6, the rotating body 1 is continuously measured, and even if there is a change in physical quantity due to ground load or lateral load during one rotation of the rotating body 1, the rotating body It is possible to suitably measure the physical quantity or change of 1. Further, since the rotary joint 6 is arranged between the rotating part 2 and the fixed support part 3 and the optical fiber 5 is connected, the configuration of the optical transmission path is facilitated and the restrictions due to the light source 7 and the lens are reduced. One physical quantity can be suitably measured. Furthermore, it is possible to prevent optical transmission loss due to dirt on the lens.

  In the embodiment, the plurality of FBG sensor units 4 formed in one optical fiber 5 and the reflected light including the different Bragg wavelengths of the plurality of FBG sensor units 4 are transmitted to the Bragg wavelength bands of the respective FBG sensor units 4. Since the plurality of FBG sensor units 4 can be arranged with respect to the rotating body 1 when the optical splitter 9 is divided into two, the plurality of measurement parts of the rotating body 1 are measured, and the radial direction and the entire surface of the rotating body 1 are measured. Physical quantities and changes can be suitably measured. In addition, since the optical splitter 9 divides the wavelength into different Bragg wavelengths according to the plurality of FBG sensor units 4, it is possible to suitably measure the physical quantity and change of the rotating body 1 by each FBG sensor unit 4.

  In the embodiment, an optical filter 10 on which reflected light of one or a plurality of FBG sensor units 4 is incident and a photoelectric converter 11 that converts light (light intensity signal) from the optical filter 10 into an electric signal are provided. When the signal processing unit 12 is configured to measure and process the electrical signal output from the photoelectric converter 11, it can suitably process the Bragg wavelength from the FBG sensor unit 4 and the optical fiber 5. The physical quantity and change of the rotating body 1 can be suitably measured.

  In the embodiment, when the FBG sensor unit 4 and the compensation FBG sensor unit 16 are fixed by the fixing means, the FBG sensor unit 4 and the compensation FBG sensor unit 16 cause noise such as blurring and vibration due to the rotation of the rotating unit 2. The physical quantity and change of the rotating body 1 can be suitably measured. If the fixing means is an adhesive or the like, when the FBG sensor unit 4 is fixed to the rotating body 1 or the compensation FBG sensor unit 16 is fixed to the internal space of the rotating unit 2, the gap is completely eliminated. Etc. can be prevented. Furthermore, when the FBG sensor unit 4 is attached to the measurement part of the rotating body 1, it can suitably measure physical quantities and changes with respect to the measurement part of the rotating body 1.

  In the embodiment, the optical fiber 5 is connected to the first optical fiber portion 5 a that guides incident light from the light source 7 to the optical circulator 8, and the incident light is connected from the optical circulator 8 to the fixed portion 6 a of the rotary joint 6. And a second optical fiber portion 5b serving as a waveguide for communicating reflected light and a waveguide for incident light and reflected light connected to the FBG sensor portion 4 from the rotor portion 6b of the rotary joint 6 to the FBG sensor portion 4. The third optical fiber portion 5c and the fourth optical fiber portion 5d extending in the direction from the optical circulator 8 to the signal processing portion 12 perform high-speed data transfer and the FBG sensor portion 4 And since a lot of signals from compensation FBG sensor part 16 can be transmitted easily and suitably, the physical quantity and change of rotating body 1 can be measured suitably.

  Further, when the optical fiber 5 is arranged so as to rotate with the rotation of the rotating body 1, transmission from the rotating body 1 can be facilitated, and a physical quantity and a change of the rotating body 1 can be suitably measured.

  Further, when the connecting portion of the optical fiber 5 routed between the rotating portion 2 and the fixed support portion 3 is arranged coaxially with the rotating shaft of the rotating body 1, noise due to backlash or blurring is caused by the rotation of the optical fiber 5. It is possible to reduce the attenuation of the optical signal intensity by minimizing the overall length and reduce the attenuation of the optical signal intensity, and to suitably measure the physical quantity and change of the rotating body 1.

  In the embodiment, when the rotary joint 6 is configured to enclose gas or liquid in the space between the fixed portion 6a and the rotor portion 6b and prevent dust from entering, the rotary joint 6 is arranged between the fixed portion 6a and the rotor portion 6b. It is possible to appropriately measure the physical quantity and change of the rotating body 1 by optimizing the optical transmission path.

  In the embodiment, the compensation FBG sensor unit 16 is formed on the optical fiber 5 so as not to be affected by the distortion of the optical fiber 5 between the FBG sensor unit 4 and the rotary joint 6, and the signal processing unit 12 includes: When the change in the physical quantity of the rotating body 1 is small when the noise generated in the rotary joint 6 is removed by the reflected light signal from the FBG sensor unit 4 and the reflected light signal from the compensation sensor unit Even when a minute signal change in the optical fiber 5 is detected, the noise is greatly suppressed, so that the physical quantity and change of the rotating body 1 can be measured more suitably. Further, the signal processing unit 12 detects an apparent Bragg wavelength change due to a change in optical transmission loss of the rotary joint 6 that occurs during one rotation of the rotary joint 6 by the compensation FBG sensor unit 16, and the Bragg wavelength of the FBG sensor unit 4. When configured to correct the wavelength, noise corresponding to the rotation of the rotary joint 6 is appropriately removed, so that the physical quantity and change of the rotating body 1 can be optimally measured.

  In the embodiment, when the Bragg wavelength of the FBG sensor unit 4 is 1200 to 1600 nm, it is possible to use an optical fiber for long-distance optical communication, and even if the entire optical fiber 5 is long, the transmission loss of the optical fiber itself is long. The physical quantity and change of the rotating body 1 can be optimally measured. The Bragg wavelength is particularly preferably in the band of 1530 to 1565 nm because of the characteristic that the transmission loss of the optical fiber 5 is particularly small.

  In addition, the measuring device and measuring method of the rotating body of the present invention are not limited to the above-described embodiments, and other optical system members may be added as long as the physical quantity and change of the rotating body can be measured. The processing of the signal processing unit is not particularly limited as long as it calculates the physical quantity and change of the rotating body. The flowcharts of FIGS. 7 and 8 measure the physical quantity and change of the rotating body. Of course, if necessary, steps may be deleted or added, and various changes may be made without departing from the scope of the present invention.

It is a conceptual diagram which shows the whole structure of the example which implements this invention. It is a conceptual diagram which shows the state divided by the rotation part and the fixed support part. It is sectional drawing which shows an example of the state of the rotation part which has arrange | positioned the rotary body, and an optical fiber. FIG. 4 is an arrow view in the IV-IV direction of FIG. 3. It is a conceptual diagram which shows the state which fixed the compensation FBG sensor part. It is sectional drawing which shows the other example of the state of the rotation part which has arrange | positioned the rotary body, and an optical fiber. It is the first half flow which shows the measurement step of a rotating body. It is the latter half flow which shows the step of measurement of a rotary body. This shows noise generated by one rotation of the rotary joint. The frequency analysis (horizontal axis rotation order) of the noise of a rotary joint is shown. It shows a distortion waveform generated in a rotating body when a load is applied while rotating the rotating body.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotating body 2 Rotating part 3 Fixed support part 4 FBG sensor part 5 Optical fiber 5a First optical fiber part 5b Second optical fiber part 5c Third optical fiber part 5d Fourth optical fiber part 6 Rotary joint 6a Fixed Unit 6b rotor unit 7 light source 8 optical circulator 9 optical splitter 10 optical filter 11 photoelectric converter 12 signal processing unit 16 compensation FBG sensor unit

Claims (2)

In the rotating unit that arranges the rotating body to be measured, the fixed support unit that rotatably supports the rotating unit, and the rotating body measuring device that uses the FBG sensor as means for measuring the strain generated in the rotating body,
An optical fiber in which a plurality of FBG sensor parts are formed;
A rotary joint for transmitting and receiving signals in the optical fiber between the rotating part and the fixed support part so as to extend the optical fiber from the rotating body to the fixed support part;
FBG sensor part for rotation compensation attached to the axial center part of the rotating part that does not cause distortion change of the rotating part and formed on the optical fiber,
A broadband light source that is placed outside the rotating unit and outputs light continuously to the FBG sensor disposed in the rotating unit via the rotary joint;
An optical circulator located between the rotary joint of the fixed support portion and the broadband light source and disposed in the middle of the optical fiber;
An optical splitter through which reflected light from the FBG sensor is guided through the optical circulator;
An optical filter for determining the amount of strain detected by the FBG sensor, which is arranged at the rear stage of the circuit of the optical fiber so as to be positioned on the output side of each wavelength band of the optical splitter;
A set of photoelectric converters that convert light intensity signals from the optical filter into electrical signals;
When measuring the rotating body, the FBG sensor unit signal is used to determine the apparent distortion change due to the optical transmission loss variation that occurs during one rotation of the rotary joint, and further the FBG sensor unit signal for rotation compensation From this, the apparent distortion change during one rotation of the rotary joint is obtained, and the apparent distortion change in the FBG sensor signal is corrected with the apparent distortion change in the FBG sensor signal for rotation compensation. And a rotating body measuring apparatus configured to perform distortion measurement compensation by removing the influence of the optical transmission loss of the rotary joint . In a measuring method for a rotating body using a FBG sensor as a means for measuring a rotating part that arranges a rotating object to be measured, a fixed support part that rotatably supports the rotating part, and a strain generated in the rotating body,
An optical fiber in which a plurality of FBG sensor parts are formed;
A rotary joint for transmitting and receiving signals in the optical fiber between the rotating part and the fixed support part so as to extend the optical fiber from the rotating body to the fixed support part;
FBG sensor part for rotation compensation attached to the axial center part of the rotating part that does not cause distortion change of the rotating part and formed on the optical fiber,
A broadband light source that is placed outside the rotating unit and outputs light continuously to the FBG sensor disposed in the rotating unit via the rotary joint;
An optical circulator located between the rotary joint of the fixed support portion and the broadband light source and disposed in the middle of the optical fiber;
An optical splitter through which reflected light from the FBG sensor is guided through the optical circulator;
An optical filter for determining the amount of strain detected by the FBG sensor, which is arranged at the rear stage of the circuit of the optical fiber so as to be positioned on the output side of each wavelength band of the optical splitter;
A set of photoelectric converters that convert light intensity signals from the optical filter into electrical signals;
When measuring the rotating body, the FBG sensor unit signal is used to determine the apparent distortion change due to the optical transmission loss variation that occurs during one rotation of the rotary joint, and further the FBG sensor unit signal for rotation compensation From this, the apparent distortion change during one rotation of the rotary joint is obtained, and the apparent distortion change in the FBG sensor signal is corrected with the apparent distortion change in the FBG sensor signal for rotation compensation. And a method for measuring a rotating body, wherein distortion measurement compensation is performed by removing the influence of optical transmission loss of a rotary joint .

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