JP3415461B2 - Resonant optical fiber gyro - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to detection of a rotational angular velocity.
Optical fiber using optical fiber loop resonator
About Badajiro. [0002] 2. Description of the Related Art Moving objects (such as airplanes and ships)
By calculating the rotational angular velocity of
And speed can be captured. Therefore, airplanes,
For ships and submarines, the vast sky and the vast ocean
To operate accurately and without hesitation toward the target value with the power of
Is equipped with a gyroscope to measure the rotational angular velocity
I have. Gyroscopes include mechanical and optical
The present invention is directed to an optical gyroscope. [0003] Resonant optical fiber gyroscopes (jars)
Iro) is a laser with a traveling waveform to an optical fiber resonator.
Make an outgoing call and rotate it clockwise (CW: C
Lock Wise direction laser light and counterclockwise
(CCW: CounterClock Wise)
Input the laser beam in the direction. Then, the resonance type optical fiber gyro
As the system rotates, it propagates to the CW in the optical fiber resonator
Between the laser beam transmitted and the laser beam propagated to the CCW
Are different due to the Saniyak effect. At this time
Since the frequency of the laser beam is in the high region,
Large phase difference is measured even if it is small
And the detection accuracy is high. Therefore, the resonance type optical fiber
Iva gyroscopes have been widely used in recent years as gyroscopes.
It is becoming like. A description will be given of a conventional resonance type optical fiber gyro.
This is performed using FIG. FIG. 5 shows a conventional resonance type optical fiber device.
FIG. 2 is a block diagram illustrating a configuration of a gyro. Smell this figure
Reference numeral 101 denotes a light source unit, for example, a semiconductor laser or the like.
Laser light source. Further, the light source unit 101 emits light.
The generated laser light L is emitted to the optical fiber 102. 10
Reference numeral 3 denotes a fiber coupler, which rotates the laser beam L clockwise.
The light is distributed to the light LCW and the counterclockwise laser light LCCW. An optical fiber 104a is a fiber optic cable.
Clockwise in the fiber ring via plastic 105
The clockwise laser beam LCW is shared with the fiber ring so that
Propagation to the shaker 106. Similarly, 104b is an optical fiber
And a fiber ring via the fiber coupler 105.
Counterclockwise laser light so that it is counterclockwise inside
The LCCW propagates to the fiber ring resonator 106. The fiber coupler 105 is a PZT
(Zircon / lead titanate ceramic) Modulator 107
The frequency-modulated laser beam LCW 'is
4b, and the frequency is similarly changed by the PZT modulator 107.
The modulated laser light L CCW ′ is emitted to the optical fiber 104a.
Put out. The PZT modulator 107 is a fiber ring resonator 1
06 and the low frequency generated by the oscillator 108.
Fiber ring resonator due to mechanical vibration caused by electric signal
A sinusoidal expansion / contraction movement with respect to the time axis in the optical path length LD of 106
Make the work. The optical fiber 104b is a laser beam LC.
W ′ is transmitted to the optical receiver 110 through the fiber coupler 109.
Carry. Further, the optical fiber 104a is a laser light LCC.
W ′ is transmitted to the optical receiver 112 through the fiber coupler 111.
Carry. The light receiver 110 receives the incoming laser light LCW '.
The radiation intensity is converted into an electric signal SCW shown in FIG.
Output to the period detector 113. The light receiver 112 is incident
The incident intensity of the laser light L CCW ′ is shown in FIG.
The signal is converted to a signal SCCW and output to the synchronous detector 114. The synchronous detector 113 outputs the output of the oscillator 108.
Of the input electric signal SCW by the low-frequency electric signal
Synchronous detection is performed, and the detection result shown in FIG.
The signal QCW is output to the signal processing unit 115. Similarly, sync
The detector 114 is a low-frequency electric signal output from the oscillator 108.
Signal performs synchronous detection of the input electric signal SCCW.
The electric signal QCCW shown in FIG.
The signal is output to the signal processing unit 115. The signal processing unit 115 converts the electric signal QCW
"0" crossing frequency (resonance frequency) fCW and electric signal
Find resonance frequency difference Δf from QCCW resonance frequency fCCW
You. In addition, the signal processing unit 115 calculates the resonance frequency difference Δ
The rotation angular velocity ΩR based on f
Obtained from arithmetic processing. ΩR = (λp / 4Ar) Δf (1) Here, λ is generated by the light source unit 101.
Is the wavelength of the laser beam L in vacuum, and p is
A is the circumference of the burring resonator 106, and A is the fiber ring
Is the closed area of the ring resonator 106, and r is the fiber ring
The radius of the fiber ring in the resonator 106. The signal processing unit 115 calculates the obtained rotation angle.
External circuit not shown with speed ΩR as data signal JD
Output to Reference numeral 116 denotes a servo mechanism, and an electric signal Q
By monitoring the voltage of CW, the light source 101
The control is performed to keep the intensity of the laser light L constant. Next, referring to FIG. 5, FIG. 6 and FIG.
The operation of the conventional example will be described. For example, a resonant optical fiber
If the ivagyro system rotates in the direction of arrow Z,
Of the laser light LCW propagating through the fiber ring resonator 106
The optical path becomes apparently longer, and the resonance frequency shown in FIG.
The number fCW becomes lower. On the other hand, the fiber ring resonator 106
The optical path of the laser light L CCW propagating through
And the resonance frequency f CCW shown in FIG. 7 increases. The signal processing unit 115 has a resonance frequency
The laser beam LCW 'and the laser beam are calculated based on fCW and the resonance frequency fCCW.
The resonance frequency difference [Delta] f from the light LCCW 'is determined. This allows
The signal processing unit 115 includes a resonance type optical fiber that rotates in the arrow Z direction.
The rotational angular velocity ΩR of the fiber gyro system is calculated based on equation (1).
It is obtained by arithmetic processing. Further, for example, a resonance type optical fiber gy
Assuming that the system b rotates in the opposite direction to arrow Z,
Light of laser light LCW propagating through the fiber resonator 106
The path becomes apparently shorter and the resonance frequency shown in FIG.
fCW increases. On the other hand, the fiber ring resonator 106 is
The optical path of the propagating laser light LCCW is apparently long
Therefore, the resonance frequency f CCW shown in FIG. The signal processing section 115 has a resonance frequency
The laser beam LCW 'and the laser beam are calculated based on fCW and the resonance frequency fCCW.
The resonance frequency difference [Delta] f from the light LCCW 'is determined. This allows
The signal processing unit 115 is of a resonance type that rotates in the direction opposite to the arrow Z.
The rotational angular velocity ΩR of the optical fiber gyro system is given by equation (1).
It is determined by an arithmetic process based on the above. [0017] By the way, the conventional resonance
Type optical fiber gyro, laser beam LCW '
Corresponding to the receiver light L CCW ′, respectively.
And a light receiver 112 are provided. Therefore, conventional
The resonance type optical fiber gyro includes a light receiver 110 and a receiver.
Characteristics change due to light receiving sensitivity between the optical device 112 and temperature change
The light receiving device 110 and the light receiving
Fine adjustment of the output gain for the
There was no disadvantage. In addition, it is completely
Since the difference from the device 112 cannot be eliminated, the laser
The problem is that high precision cannot be achieved due to the use
is there. The present invention has been made under such a background.
Therefore, the adjustment is simple and the high accuracy
The purpose is to provide ivagyro. [0019] [Means for Solving the Problems]The invention of the present application
A laser that generates laser light of a predetermined frequency according to the injection amount
Light source and an optical path length equal to the wavelength of the predetermined resonance frequency.
Ring in which the optical fiber is formed in a ring shape
A resonator, an oscillator that outputs a pulse signal having a constant period,
Output from the laser light source based on the pulse signal
An optical switch for splitting the laser light in a time-division manner,
One of the laser beams split by the switch
Incident clockwise to the fiber ring resonator.
And counteract the other with respect to the fiber ring resonator.
Inject in the counterclockwise direction, and
One and the other laser light propagating in the ring resonator
Take out each from the fiber ring resonator and individually
A first fiber coupler for emitting light, and the first fiber coupler.
Clockwise and counterclockwise
A second fiber coupler for collecting laser light;
A laser beam having the resonance frequency of the fiber resonator
Modulating means for modulating a sine wave of
Clockwise direction and counterclockwise direction emitted from iva coupler
Converting means for converting each laser beam in each direction into an electric signal;
Detects electrical signals and outputs detection signals as detection results
Detecting means for detecting the detection signal of the laser light in the clockwise direction.
Rotational angular velocity based on detection signal of clockwise laser light
Signal processing unit for determining the degreeIt is characterized by the following. [0020] [0021] [0022] BRIEF DESCRIPTION OF THE DRAWINGS FIG.
An embodiment will be described. FIG. 1 shows an embodiment of the present invention.
Block diagram showing the configuration of a resonant optical fiber gyro
It is. In this figure, reference numeral 1 denotes a light source unit, for example,
Laser light generation by Fabry-Perot type semiconductor laser
Source. Further, the light source unit 1 emits the generated laser light L
Inject to switch 2 (see FIG. 2 (a)). The optical switch 2 converts the incident laser light L into light
Laser light LCW propagating in fiber 4 and optical fiber 5
The pulse generated by the oscillator 3 with the laser light L CCW propagating through
2 (see FIG. 2B). here,
The laser light LCW has, for example, a pulse signal of “H” level.
Is emitted into the optical fiber 4 and a fiber ring resonator
Laser light propagating clockwise through fiber ring 6
Becomes The laser light L CCW is, for example, a pulse signal.
Is output to the optical fiber 5 when the signal is at the “L” level.
Turn the fiber ring of the equaling resonator 6 counterclockwise.
Laser light that propagates through The optical fiber 4 is connected via a fiber coupler 7
Clock so that it is clockwise in the fiber ring.
The surrounding laser light LCW is propagated to the fiber ring resonator 6.
Let Similarly, the optical fiber 5 is connected via a fiber coupler 7.
To be counterclockwise in the fiber ring
The counterclockwise laser beam L CCW is supplied to the fiber ring resonator 6.
To propagate. The fiber coupler 7 is made of PZT (Jill).
Frequency by the modulator 8
The modulated laser light LCW 'is emitted to the optical fiber 5, and
Light L frequency-modulated by the PZT modulator 8
CCW ′ is emitted to the optical fiber 4. The PZT modulator 8 is
The oscillator 9 is disposed in the fiber ring resonator 6.
The mechanical vibration caused by the low-frequency electrical signal
Sinusoidal wave with respect to the time axis for the optical path length LS of the balring resonator 6
The telescopic movement is performed. The optical fiber 5 transmits the laser beam LCW '.
Via fiber coupler 10 and fiber coupler 11
The light is transmitted to the light receiving unit 12. Further, the optical fiber 4 is
Laser light L CCW ′ to the fiber coupler 13 and the fiber coupler
The light is transmitted to the light receiving unit 12 via the plastic 11. Light receiving section 12
Fig. 2C shows the incident intensity of the incident laser beam LCW '.
And outputs it to the synchronous detector 16
I do. Similarly, the light receiving section 12 receives the incident laser light L CC
The incident intensity of W 'is converted into the electric signal SCCW shown in FIG.
Then, the signal is output to the synchronous detector 16. The synchronous detector 16 outputs a signal from the oscillator 9.
Synchronous detection of input electric signal SCW by high frequency electric signal
Wave, and the electric signal Q shown in FIG.
The CW is output to the signal processing unit 14. Similarly, synchronous detector 1
6 is an input by the low-frequency electric signal output from the oscillator 9.
Synchronous detection of the electrical signal SCCW
The electric signal QCCW shown in FIG.
Output. The signal processing unit 14 outputs "0" of the electric signal QCW.
Crossing frequency (resonance frequency) fCW and electric signal QCCW
The resonance frequency difference Δf is determined from the resonance frequency f CCW of FIG. Ma
In addition, the signal processing unit 14 performs the processing based on the obtained resonance frequency difference Δf.
Rotation angular velocity ΩR based on equation (1) shown in the conventional example.
Obtained from arithmetic processing. The signal processing section 14 calculates the rotation angular velocity
ΩR as a data signal JD to an external circuit not shown
Output. Reference numeral 15 denotes a servo mechanism, which controls the electric signals QCW and
By monitoring the voltage of the electrical signal QCCW
Control to keep the intensity of the laser beam L generated by the light source 1 constant.
Is going. Next, refer to FIG. 1, FIG. 2, FIG. 3, and FIG.
Of the operation of the resonant optical fiber gyro according to the embodiment.
Make a light. The light source unit 1 has a predetermined transmission frequency shown in FIG.
A laser beam L having a wave number is emitted to the optical switch 2. And
The optical switch 2 is, for example, a diagram input from an oscillator 3.
The pulse signal shown in FIG. 2 (b) changes from time t0 to time t1.
During the voltage “VH”.
The laser beam is branched and propagated to the bar 4 as a laser beam LCW. As a result, the laser beam LCW is
Fiber ring via fiber 4 and fiber coupler 7
It is injected into the shaker 6. Here, the fiber ring resonator 6
The optical path length LS is output from the oscillator 9 by the PZT modulator 8.
By vibrating based on low-frequency electrical signals,
On the other hand, it changes like a sine wave. Thereby, the laser light LCW
Is the frequency-modulated laser light L having different wavelengths
Modulated to CW '. The resonance frequency of the fiber ring resonator 6
The laser light LCW 'having the same frequency as the wave number is
No signal is output from the baccoupler 7. On the other hand, fiber ring
Laser light L having a frequency different from the resonance frequency of the vibrator 6
CW 'is output from the fiber coupler 7 to the optical fiber 5.
You. The light receiving unit 12 includes the fiber coupler 10 and
Laser light LCW 'input via fiber coupler 11
Is converted to a sinusoidal electric signal SCW of FIG.
Convert. This electric signal SCW is used by the PZT modulator 8.
It contains the frequency components of the low frequency electrical signal used. This
Thereby, the synchronous detector 16 converts the electric signal LCW into the oscillator 9
Synchronously detected by the sine-wave low-frequency electrical signal output by
This is shown in FIG. 3A having frequency characteristics of the intensity of the interference light.
The signal is output to the signal processing unit 14 as an electric signal QSW. This
In the waveform of the air signal QCW,
That is, the frequency having the maximum value in the derivative of the frequency
fCW is the resonance frequency of the fiber ring resonator 6. So
Then, the signal processing unit 14 transmits the data of the frequency fCW and the electric power.
The waveform data of the air signal QCW is stored. Next, the light source unit 1 is provided with a predetermined light source shown in FIG.
Is emitted to the optical switch 2.
The optical switch 2 is connected to the oscillator 3 as shown in FIG.
The pulse signal shown in (b) changes from time t1 to time t2.
During the voltage “VL”, the laser light L
The light is branched and propagated as laser light L CCW to the bar 5. As a result, the laser light L CCW is
Fiber ring via fiber 5 and fiber coupler 7
It is injected into the resonator 6. Where the fiber ring resonator
The optical path length LS of the PZT modulator 8 is output from the oscillator 9.
Vibration based on low-frequency electrical signals
Changes sinusoidally with respect to. Thereby, the laser light L
CCW is a frequency modulated laser with different wavelengths
The light is modulated to LCCW '. The resonance frequency of the fiber ring resonator 6
The laser light L CCW ′ having the same frequency as the wave number
It is not output from the iva coupler 7. Meanwhile, fiber ring
Laser light having a frequency different from the resonance frequency of the resonator 6
LCCW 'is output from the fiber coupler 7 to the optical fiber 4.
Is done. The light receiving section 12 is connected to the fiber coupler 10 and the
And laser light L input through the fiber coupler 11
The electric signal having the sine wave shape shown in FIG.
Convert to SCCW. The electric signal SCCW is converted by the PZT modulator 8
Contains the frequency components of the low frequency electrical signals used.
As a result, the synchronous detector 16 oscillates the electric signal SCCW.
Synchronous detection by sine wave low frequency electric signal output from detector 9
FIG. 3 showing the frequency characteristic of the intensity of the interference light
(B) Output to the signal processing unit 14 as the electric signal QSW
You. In the waveform of the electric signal QSSW, “0” cross
Part, that is, the maximum value of the frequency derivative
Frequency fCCW is the resonance frequency of the fiber ring resonator 6.
The wave number. Then, the signal processing unit 14 calculates the frequency f
Stores CCW data and waveform data of electric signal QCCW
You. As a result, the signal processing section 14 outputs the laser light L
Based on the resonance frequency of CW 'and the laser light LCCW',
The frequency difference Δf is obtained, and the equation (1) is obtained from the resonance frequency difference Δf.
To calculate the rotational angular velocity ΩR. Hour from time t0
Until t2, a system equipped with a resonant laser gyro
Has not changed direction, the rotational angular velocity ΩR is
It becomes “0 (rad / sec)” shown in (c). Soshi
The value of the rotational angular velocity Ω is determined by the gyro output signal JD.
And output to an external circuit (not shown). Next, from time t2 to time t4,
A resonance type laser gyro was mounted in the direction of arrow Z shown in FIG.
Suppose the system changes direction. The light source unit 1 is shown in FIG.
A laser beam L having a predetermined transmission frequency is emitted to the optical switch 2.
I do. The optical switch 2 is input from the oscillator 3
The pulse signal shown in FIG. 2B is applied from time t2 to time t3.
, Ie, during the voltage “VH”, the laser light L
The light is branched and propagated as laser light LCW to the fiber 4. As a result, the laser beam LCW is
Fiber ring via fiber 4 and fiber coupler 7
It is injected into the shaker 6. Here, the fiber ring resonator 6
The optical path length LS is output from the oscillator 9 by the PZT modulator 8.
By vibrating based on low-frequency electrical signals,
On the other hand, it changes like a sine wave. Thereby, the laser light LCW
Is the frequency-modulated laser light L having different wavelengths
Modulated to CW '. The resonance frequency of the fiber ring resonator 6
The laser light LCW 'having the same frequency as the wave number is
No signal is output from the baccoupler 7. On the other hand, fiber ring
Laser light L having a frequency different from the resonance frequency of the vibrator 6
CW 'is output from the fiber coupler 7 to the optical fiber 5.
You. The light receiving unit 12 includes the fiber coupler 10 and
Laser light LCW 'input via fiber coupler 11
Is converted to a sinusoidal electric signal SCW of FIG.
Convert. This electric signal SCW is used in the PZT modulator 8.
It contains the frequency components of the low frequency electrical signal used. This
Thereby, the synchronous detector 16 converts the electric signal LCW into the oscillator 9
Synchronously detected by the sine-wave low-frequency electrical signal output by
This is shown in FIG. 4A having frequency characteristics of the intensity of the interference light.
The signal is output to the signal processing unit 14 as an electric signal QCW. This
In the waveform of the air signal QCW,
That is, the frequency having the maximum value in the derivative of the frequency
fCW is the resonance frequency of the fiber ring resonator 6. So
Then, the signal processing unit 14 transmits the data of the frequency fCW and the electric power.
The waveform data of the air signal QCW is stored. Next, the light source unit 1 is provided with a predetermined light source shown in FIG.
Is emitted to the optical switch 2.
The optical switch 2 is connected to the oscillator 3 as shown in FIG.
The pulse signal shown in (b) changes from time t3 to time t4.
During the voltage “VL”, the laser light L
The light is branched and propagated as laser light L CCW to the bar 5. As a result, the laser light L CCW is
Fiber ring via fiber 5 and fiber coupler 7
It is injected into the resonator 6. Where the fiber ring resonator
The optical path length LS of the PZT modulator 8 is output from the oscillator 9.
Vibration based on low-frequency electrical signals
Changes sinusoidally with respect to. Thereby, the laser light L
CCW is a frequency modulated laser with different wavelengths
The light is modulated to LCCW '. The resonance frequency of the fiber ring resonator 6
The laser light L CCW ′ having the same frequency as the wave number
It is not output from the iva coupler 7. Meanwhile, fiber ring
Laser light having a frequency different from the resonance frequency of the resonator 6
LCCW 'is output from the fiber coupler 7 to the optical fiber 4.
Is done. The light receiving section 12 is connected to the fiber coupler 10 and the
And laser light L input through the fiber coupler 11
The electric signal having the sine wave shape shown in FIG.
Convert to SCCW. The electric signal SCCW is converted by the PZT modulator 8
Contains the frequency components of the low frequency electrical signals used.
As a result, the synchronous detector 16 oscillates the electric signal SCCW.
Synchronous detection by sine wave low frequency electric signal output from detector 9
4 having the frequency characteristic of the intensity of the interference light.
(B) Output to the signal processing unit 14 as the electric signal QCW
You. In the waveform of the electric signal QCCW, "0" cross
Part, that is, the maximum value of the frequency derivative
Frequency fCCW is the resonance frequency of the fiber ring resonator 6.
The wave number. Then, the signal processing unit 14 calculates the frequency f
Stores CCW data and waveform data of electric signal QCCW
You. As a result, the signal processing section 14 outputs the laser light L
Based on the resonance frequency of CW 'and the laser light LCCW',
The frequency difference Δf is obtained, and the equation (1) is obtained from the resonance frequency difference Δf.
To calculate the rotational angular velocity ΩR. At this time,
The system equipped with the vibrating optical fiber gyro is at time t3
From time t4 to direction Z in FIG.
The laser light LCW 'propagating clockwise.
The optical path length LS of the fiber ring resonator 6
, The resonance frequency of the fiber ring resonator 6
The number is a frequency fc lower than the inherent resonance frequency fcw (fcccw).
W1. On the other hand, a resonance type optical fiber gyro is mounted.
During the period from time t3 to time t4, the system shown in FIG.
Propagation in the counterclockwise direction due to turning in the Z direction
Of the fiber ring resonator 6 with respect to the
Since the optical path length LS becomes shorter by the amount of movement, the laser light L
The resonance frequency of the fiber ring resonator 6 with respect to CCW 'is
Frequency fCCW1 higher than the inherent resonance frequency fCCW (fCW)
Becomes As a result, the signal processing section 14 outputs the rotational angular velocity.
The degree ΩR is represented by “m (rad / sec)” shown in FIG.
To the external circuit not shown in the figure.
Output as D. External circuits not shown
Based on the JD, a resonance type optical fiber gyro is installed.
Control of the system. Also, the mounting of the resonance type optical fiber gyro
If the system is turned in the opposite direction to arrow Z in FIG.
In this case, the rotational angular velocity ΩR in FIG.
The polarity is reversed and the value is output. As described above, the resonance type optical fiber of one embodiment is described.
Inject the light from the fiber ring resonator 6 to the ivagyro.
Clockwise laser beam LCW 'and the counterclockwise
The light receiving unit 12 and the detection unit 12 having the same detection signal as the laser beam L CCW
And can be detected from the synchronous detector 16
The difference in the characteristic values of
Easy adjustment of badgyro and improved measurement accuracy
Has the effect of causing In one embodiment, the resonance type optical fiber
Unlike the distribution of the laser light L in the conventional example,
Laser light LCW 'propagating clockwise and counterclockwise
Of the same intensity as the laser light L CCW ′ propagating in the
Use of laser light has the effect of improving measurement accuracy.
is there. Furthermore, a resonance type optical fiber gyro according to one embodiment
And the laser light LCW 'propagating in the clockwise direction
Fiber with laser light L CCW 'propagated in the counterclockwise direction
The interference in the ring resonator 6 is eliminated, and an error component is generated.
Can be eliminated, which has the effect of improving measurement accuracy.
You. [0053] 【The invention's effect】According to the present invention, the injection current
Laser light source that generates laser light of a predetermined frequency according to
And light having the same optical path length as the wavelength of the predetermined resonance frequency.
Fiber ring resonator in which fiber is formed in ring shape
An oscillator for outputting a pulse signal having a constant period;
Laser output from the laser light source based on the pulse signal.
An optical switch for splitting the light in a time-division manner, and the optical switch.
One of the laser beams split by the switch
Make the clockwise incident on the equalizing resonator.
The other counterclockwise with respect to the fiber ring resonator
Direction, and the fiber ring
In the clockwise and counterclockwise directions propagating in the resonator
Extract each laser beam from the fiber ring resonator
A first fiber coupler that emits light individually and
Clockwise and counterclockwise emission from fiber coupler
Second fiber cap for collecting each laser beam in the circumferential direction
And the resonance frequency of the fiber ring resonator.
Modulating means for modulating the laser light with a predetermined sine wave;
The clockwise direction emitted from the second fiber coupler
And convert each laser beam in the counterclockwise direction to an electrical signal.
Conversion means for detecting the electric signal and detecting the electric signal as a detection result.
Detection means for outputting a signal; and
Based on the detection signal and the detection signal of the laser beam in the counterclockwise direction
A signal processing unit for determining the rotational angular velocity
ClockwiseLaser beam detection signal andCounterclockwise directionof
The conversion means and the synchronization means having the same detection signal as the laser light;
Unique in the characteristics of each part that can be detected from the detector
Adjust the resonance type optical fiber gyro by eliminating the difference in the values
Is simpler and has the effect of improving the measurement accuracy.
You. [0054]According to the present invention, the laser light source
The output laser light is time-divided by an optical switch.
Be forkedTherefore, laser light can be branched at regular intervals,
Propagation clockwise, unlike distributing the light
Laser light and laser light propagating counterclockwise
Measurement accuracy because laser light of the same intensity can always be used
Has the effect of improving. [0055]Further, according to the present invention, the laser light source
The laser light output from the
Because it is branchedPropagation in fiber ring resonator
Laser light propagating clockwise
Is one of the laser beams propagating counterclockwise
Therefore, the laser light propagating in the clockwise direction
Eliminates interference with laser light propagating in the counterclockwise direction,
Eliminates causes of error components and improves measurement accuracy
Has the effect of causing

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a configuration of a resonance type optical fiber gyro according to one embodiment of the present invention. FIG. 2 is a timing chart illustrating the operation of the resonance type optical fiber gyro shown in FIG. FIG. 3 is a timing chart for explaining the operation of the resonance type optical fiber gyro shown in FIG. FIG. 4 is a timing chart for explaining the operation of the resonance type optical fiber gyro shown in FIG. FIG. 5 is a block diagram showing a configuration of a conventional resonance type optical fiber gyro. FIG. 6 is a timing chart for explaining the operation of the resonance type optical fiber gyro shown in FIG. FIG. 7 is a timing chart for explaining the operation of the resonance type optical fiber gyro shown in FIG. [Description of Signs] 1 Light source unit 2 Optical switch 3, 9 Oscillator 4, 5 Optical fiber 6 Fiber ring resonator (fiber) 7, 10, 11, 13 Fiber coupler 8 PZT modulator 12 Light receiving unit 14 Signal processing unit 15 Servo Mechanism 16 Synchronous detector

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01C 19/64-19/72

Claims (1)

(1) A laser light source for generating a laser beam having a predetermined frequency corresponding to an injection amount of an injection current, and a light having an optical path length equal to the wavelength of a predetermined resonance frequency. A fiber ring resonator in which a fiber is formed in a ring shape, an oscillator that outputs a pulse signal having a constant period, and an output from the laser light source based on the pulse signal.
An optical switch for branching time-divisionally the laser light, in the laser light split by the optical switch, whereas
Into the fiber ring resonator clockwise.
And the other to the fiber ring resonator
Inject each in the counterclockwise direction, and
Clockwise and counterclockwise propagation in an equalizing resonator
Each laser light in the surrounding direction is output from the fiber ring resonator.
First fiber couplers to be individually taken out, and clockwise and outgoing light emitted from the first fiber couplers.
And a second filer that collects each laser beam in the counterclockwise direction.
An optical coupler , a modulating means for modulating a laser beam of the resonance frequency of the fiber ring resonator with a predetermined sine wave, and a clockwise direction emitted from the second fiber coupler.
Converting means for converting each laser light in the counterclockwise direction into an electric signal, detecting means for detecting the electric signal, and outputting a detection signal as a detection result, and a detection signal of the clockwise laser light.
A signal processing unit for calculating a rotational angular velocity based on a detection signal of a laser beam in a counterclockwise direction .