JPH06201388A - Gyro device - Google Patents

Abstract

PURPOSE:To shorten the rise time after the input of a power source. CONSTITUTION:The light from a light source part 33 is propagated clockwise and counterclockwise to a fiber coil 30 and interfered, and the intensity of the interfered light is detected by a light receiving part 37, whereby angle speed is detected. The output signal of the light receiving part 37 is synchronously detected by a lock-in amplifier 46 on the basis of a reference signal corresponding to phase modulation. In the lock-in amplifier 46, the DC component of the output signal of the light receiving part 36 is also detected. On the basis of this DC component, a control device 51 feedback controls a light source driving circuit 47 and a phase modulator driving circuit 41. Just after the power source input, the light source driving circuit 41 and the phase modulator driving circuit 41 are controlled on the basis of a control initial value stored in an non-volatile memory 52. The control initial value is a value such that a light of a determined light quantity can be generated from the light source part 33 and a determined phase modulation factor can be attained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gyro device such as an optical fiber gyro which is used by being mounted on a moving body such as a vehicle, an airplane and a ship and used for detecting a turning angular velocity of the moving body. It is a thing.

[0002]

2. Description of the Related Art For example, in a vehicle-mounted navigation system, a current position is displayed together with a road map on a display device arranged near the driver's seat. The current position is calculated based on the detection result of the moving distance of the vehicle and the traveling direction of the vehicle. A gyro device is often used to detect the traveling direction of the vehicle. The gyro device detects the turning angular velocity of the vehicle, and angle information can be obtained by integrating the output signal of the gyro device.

Some gyros are mechanical type, but recently, from the viewpoint of detection accuracy, a ring laser gyro,
Optical fiber gyros, vibrating gyros and the like have been mainly used. For example, in an optical fiber gyro, a single mode optical fiber is wound to form a fiber coil, and clockwise and counterclockwise light is passed through the fiber coil, and light corresponding to the phase difference Δ of the light output from the fiber end face is generated. By detecting the rotational angular velocity Ω about the winding axis of the fiber coil. The phase difference Δ is proportional to the angular velocity Ω.

When the angular velocity Ω is zero, the phase difference Δ becomes zero, and the clockwise and counterclockwise lights are detected in the same phase, so these are mutually strengthened to obtain the maximum output. That is, the output of the fiber optic gyro is extracted in the form of cos Δ. Considering that the phase difference Δ is proportional to the angular velocity Ω, the output is proportional to cos (C ₀ Ω) with the proportionality coefficient C ₀ . However, C ₀ = 4πLa / cλ. Where L is the fiber length, a is the coil radius,
c is the speed of light, and λ is the wavelength of the propagating light.

However, the function cos (C ₀ Ω) is Ω = 0
Since the amount of change in the vicinity of is small, the detection sensitivity is poor.
Since it is an even function, there is a drawback that the direction of rotation cannot be detected. The problem is that the output of the optical fiber is sin (C
If it can be taken out in the form of ₀ Ω), it will be solved. One technique for that purpose is a phase modulation method in which the light wave itself is phase-modulated and the modulated signal is synchronously detected.
That is, when the angular frequency of the modulation signal is ω, the detection signal V (ω, Ω, ξ) detected at the fiber end face is
It is given by equation (1).

[0006]

[Equation 1]

That is, the detection signal V (ω, Ω, ξ) contains various harmonic components. In the equation (1), ξ is the modulation factor, J _n is the Bessel function of the nth order, E ₁ is the clockwise light wave intensity, E ₂ is the counterclockwise light wave intensity, and t is time. If the detection signal V (ω, Ω, ξ) is synchronously detected at the angular frequency ω, the coefficient term of sin ωt can be extracted, and sin (C ₀ Ω)
An output proportional to is obtained. The coefficient term of the fundamental wave component (n = 1) includes the light intensity levels E ₁ and E ₂ , but in order to cancel the influence, it is divided by an even-order term, for example, the term of the 4th harmonic component. hand,

[0008]

[Equation 2]

Calculating And if you calculate tan ^-1 ,
The angular velocity Ω is obtained. Also, tan ^-1 has a problem that the rate of change becomes small when the angular velocity Ω is large, and the accuracy of the calculation deteriorates.
A method of calculating only the numerator by assuming that E ₁ E ₂ J ₄ (ξ) cos (C ₀ Ω), which is the denominator of the equation (2), is constant is also adopted. In this case, sin ^-1 will be calculated.

In this case, however, the detection error may increase when the light amount of the light source fluctuates greatly.
Therefore, the light quantity of the light source is feedback-controlled using the fourth harmonic component. In this case, control such that E ₁ E ₂ ∝1 / cos (C ₀ Ω) (3) is performed, so that E
_{Even if 1} E ₂ J ₄ (ξ) cos (C ₀ Ω) is regarded as constant, t
The calculation of an ^-1 will be performed.

In this way, since an output signal of the form proportional to sin (C ₀ Ω) is obtained, the vicinity of Ω = 0 can be detected with good sensitivity, and the rotation direction can be detected together.
The specific configuration of the optical fiber gyro device that detects the angular velocity by the above-described processing is shown in FIG. The light from the light source unit 1 composed of a light emitting diode or the like passes through the coupler 2, is polarized by the polarizer 3, and is then branched by the coupler 4 to be input to the fiber coil 5 as clockwise and counterclockwise light. It The light propagating clockwise or counterclockwise through the fiber coil 5 is input from the coupler 4 to the light receiving unit 6 including a photodiode and the like via the polarizer 3 and further via the coupler 2.

Between the coupler 4 and the fiber coil 5,
A phase modulator 7 is provided for performing phase modulation on the light wave. The phase modulator 7 phase-modulates light by utilizing an acousto-optic effect, and is composed of, for example, PZT. The phase modulator 7 is supplied with a drive voltage from the phase modulator control circuit 11 composed of an analog circuit. As a result, the light propagating in the optical fiber is phase-modulated with the angular frequency ω and the modulation degree ξ.

The phase modulator control circuit 11 inputs a reference signal for phase modulation to the phase control circuit 12. The phase control circuit 12 shifts the phase of the given reference signal to create a reference signal. This reference signal is line 13
To the lock-in amplifier 14. The output signal of the light receiving unit 6 is input to the lock-in amplifier 14,
This signal is synchronously detected based on the reference signal. The lock-in amplifier 14 also detects the second harmonic component of the angular frequency 2ω and the fourth harmonic component of the angular frequency 4ω. Then, a value obtained by dividing the fundamental wave component of the synchronously detected angular frequency ω by the fourth harmonic component is output as a rotation signal corresponding to the angular velocity Ω.

The second harmonic component detected by the lock-in amplifier 14 is input to the phase modulator control circuit 11 from the line 15. Furthermore, the 4th harmonic component is line 1
6 to the light source control circuit 17 for controlling the light source unit 1. With this configuration, the angular velocity Ω is detected in the form of tan (C ₀ Ω). Further, the amount of light generated by the light source unit 1 is feedback-controlled by the 4th harmonic component.

The amount of light reaching the light receiving section 6 and the modulation factor of the phase modulator 7 are important factors that determine the scale factor of the optical fiber gyro device. Therefore, in order to accurately detect the angular velocity, it is necessary to control these constants. However, the amount of light generated by the light source unit 1 and the degree of modulation by the phase modulator 7 change due to changes in environmental conditions. Therefore, the configuration of FIG. 9 is adopted for the light source control circuit 17 to stabilize the generated light quantity, and the configuration of FIG. 10 is adopted for the phase modulator control circuit 11 to stabilize the modulation degree. There is.

First, the light source control circuit 17 will be described with reference to FIG. The light source control circuit 17 is supplied with the fourth harmonic component detected by the lock-in amplifier 14. The 4th harmonic component is input to the drive circuit 22 via the limiter circuit 21, and the drive circuit 22 controls the drive current or drive voltage of the light source unit 1. The drive current or drive voltage of the light source unit 1 is supplied via the line 23 to the limiter circuit 21.
Is being monitored by.

The limiter circuit 21 sets a maximum drive current or drive voltage that does not damage the semiconductor elements constituting the light source unit 1. The maximum drive current or drive voltage is set by the variable resistor VR. It is adjustable. This variable resistor VR is adjusted for each individual optical fiber gyro device at the production stage. With this configuration, the drive current or voltage of the light source unit 1 is feedback-controlled so that the quadruple harmonic component reaches a predetermined level, and the amount of light is stabilized. Moreover, since the limiter circuit 21 functions to prevent application of overcurrent or overvoltage to the light source unit 1, destruction of the light source unit 1 is reliably prevented.

Next, the phase modulator control circuit 11 will be described with reference to FIG. The phase modulator control circuit 11 has
The modulation degree of the phase modulation is controlled so that the second harmonic component given from the lock-in amplifier 14 becomes zero, for example.
Explaining in more detail, the second harmonic component is the integration circuit 2
5 is added up, and this integrated value is multiplied digital /
The analog (D / A) converter 26 converts the analog signal. By driving the phase modulator 7 by this analog signal, the modulation degree of the light wave by the phase modulator 7 is feedback-controlled.

The phase modulator control circuit 11 is provided with a reference signal generator 27 which generates a reference signal for phase modulation. The reference signal generated by the reference signal generator 27 is given to the D / A converter 26 and also to the phase control circuit 12. Phase control circuit 12
Is provided with a phase setting unit 28 that shifts the phase of the reference signal generated by the reference signal generation unit 27 to create a reference signal and gives the reference signal to the lock-in amplifier 14. The amount of phase shift in the phase setting unit 28 is set by the DIP switch 29. When the setting of the DIP switch 29 is changed, the phase shift amount in the phase setting unit 28 changes and the phase of the reference signal changes. The dip switch 29 is set so that the clockwise or counterclockwise rotation signal (angular velocity signal) is maximized for each individual optical fiber gyro device in the production process.

[0020]

In the optical fiber gyro device having the above-mentioned configuration, the drive current of the light source unit 1 when the 4th harmonic component reaches a predetermined level and the 2nd harmonic component when it becomes zero. The drive voltage of the phase modulator 7 varies depending on each optical fiber gyro device. Therefore, even if the light source control circuit 17 and the phase modulator control circuit 11 are configured to have constant characteristics, it is possible to avoid setting a drive current or a drive voltage that is far from the optimum value immediately after the power is turned on. Absent. Therefore, there is a problem that the rising time from the startup until the angular velocity can be detected stably is long.

In the manufacturing process, the light source control circuit 1
Adjustment of variable resistance VR in 7 and phase control circuit 1
It is necessary to set the dip switch 29 in 2. Therefore, the number of manufacturing steps is large, which is one of the causes of deterioration of productivity. Further, the light source control circuit 17 includes the light source unit 1
Limiter circuit 2 for protecting the semiconductor elements constituting the
There is also a problem that the circuit configuration is complicated because it is necessary to provide 1.

Further, since there is no means for knowing the usage status such as the total operating time and the usage frequency of the optical fiber gyro device,
There is also a problem that maintenance is difficult because it is not possible to know when to replace the optical components or circuit components and the cause of the failure. Then, the objective of this invention is providing the gyro apparatus which solves the said technical subject and can shorten the rise time immediately after starting.

Another object of the present invention is to provide a gyro device capable of preventing the gyro sensor section from being broken with a simple structure. A further object of the present invention is to provide a gyro device capable of increasing productivity. Still another object of the present invention is to provide a gyro device capable of knowing the usage status of the device and performing good maintenance.

[0024]

In order to achieve the above object, a gyro device according to claim 1 detects a gyro sensor section for outputting a signal corresponding to an angular velocity and an operating state of the gyro sensor section. And a control means for feedback-controlling the gyro sensor section based on the detection result of the detecting means to stabilize the operation of the gyro sensor section in a predetermined stable state, and the gyro sensor section by the control section. The control means includes a non-volatile storage means for storing a control initial value corresponding to the control, and a reading means for reading the control initial value stored in the storage means at the time of starting the apparatus and giving it to the control means. It is characterized in that it includes means for controlling the gyro sensor section based on the given control initial value when the apparatus is activated.

With this configuration, when the apparatus is activated, the gyro sensor section is controlled based on the control initial value stored in the nonvolatile memory. Therefore, the control initial value is
If the operation state of the gyro sensor unit is made to correspond to the control state when it reaches a predetermined stable state, the operation of the gyro sensor unit can be promptly stabilized in the period immediately after the start of the apparatus. Therefore, when the gyro sensor unit is feedback-controlled based on the output of the detection means, the rising time until reaching a predetermined stable state can be shortened.

In the gyro device according to a second aspect of the invention, the gyro sensor section includes a light source for generating light for angular velocity detection, and the detection means detects the amount of light emitted from the light source. The control means drives and controls the light source so as to stabilize the light amount generated from the light source to a predetermined value based on the detection result of the detection means, and the control initial value is the light source. Is a value corresponding to a drive current or voltage capable of obtaining a predetermined amount of light when applied to.

In this structure, the control means drives and controls the light source for angle detection to stabilize the amount of light generated from this light source to a predetermined value. In this case, a non-volatile storage means stores a control initial value capable of generating the predetermined amount of light from the light source, and the drive control of the light source may be performed using this control initial value immediately after starting. A predetermined amount of light can be generated from the light source immediately after starting. As a result, the amount of light generated by the light source is quickly stabilized, so that the angular velocity can be detected immediately from the period immediately after startup.

In the gyro device according to a third aspect of the invention, the gyro sensor section has a fiber coil formed by winding a single mode optical fiber, and light for angular velocity detection is made incident from both ends of the fiber coil, and the fiber coil is rotated clockwise. And a means for interfering the light propagating counterclockwise, a light receiving means for measuring the intensity of the interfered light, and a phase modulating means for performing phase modulation on the light propagating through the fiber coil, the detecting means, A variable related to the modulation degree by the phase modulation means is detected based on the output signal of the light receiving means, and the control means determines the modulation degree by the phase modulation means based on the detection result of the detection means. The phase control means is driven and controlled so as to be stabilized to a value, and the control initial value is a predetermined change when applied to the phase modulation means. Characterized in that it is a value corresponding to the drive voltage can be obtained degrees.

With this configuration, a phase modulation type optical fiber gyro device is constructed. In this case, the phase modulation means is feedback-controlled by the control means so that the modulation degree by the phase modulation means interposed in the optical path becomes a predetermined value. Then, the control initial value corresponding to the predetermined modulation degree is stored in the nonvolatile storage means. Immediately after the device is activated, the phase modulation means is controlled based on the control initial value, whereby the desired degree of modulation is quickly achieved. In this way, the gyro device can be activated quickly.

A gyro apparatus according to a fourth aspect of the present invention includes means for generating a control set value corresponding to a control state of the gyro sensor section, and the control setting when the operating state of the gyro sensor section is in a predetermined stable state. The reading means further includes a writing means for writing a value in the storage means, and the reading means reads the last stored control setting value from the storage means at the time of starting the apparatus, and the control setting value is the control initial value. Is given to the control means as above.

In this configuration, when the operation of the gyro sensor section reaches a predetermined stable state by the feedback control by the control means, the control set value corresponding to the control state at that time is stored in the non-volatile storage means. Then, when the apparatus is activated, the last stored control set value is adopted as the control initial value, and the gyro sensor unit is controlled immediately after activation based on this initial value. Therefore, immediately after starting, the gyro sensor unit can be reliably led to a stable state.

A gyro device according to a fifth aspect of the invention is compatible with a gyro sensor section for outputting a signal corresponding to an angular velocity, a control means for variably controlling the operation of the gyro sensor section, and a control of the gyro sensor section by the control means. And a reading means for reading the control limit value stored in the storage means and giving it to the control means. The control means is defined by the control limit value. It includes a means for controlling the gyro sensor unit within a range.

According to the above arrangement, the operation of the gyro sensor section is variably controlled by the control means. A control limit value corresponding to this variable control is stored in the non-volatile storage means, and the control means variably controls the operation of the gyro sensor unit within a range defined by the control limit value. Thereby, for example, the gyro sensor unit can be operated in a range where the destruction does not occur.

With such a configuration, in the production process of the gyro device, the control limit value corresponding to the characteristics of the gyro sensor unit may be written in the storage means. That is, complicated work such as adjusting the variable resistance is not required. Further, as compared with the case where the operating range of the gyro sensor unit is defined by a variable resistor or the like, there is an advantage that the circuit configuration for driving and controlling the gyro sensor unit becomes simple. .

In the gyro device according to the sixth aspect, the gyro sensor section includes a light source for generating light for angular velocity detection, and the control means variably controls a drive current or a drive voltage applied to the light source. The control limit value is a value corresponding to a maximum value of a drive current or a drive voltage that can drive the light source without destroying the light source.

In this configuration, the control limit value is a value corresponding to the maximum current or voltage that can be driven without destroying the light source. Therefore, it is possible to reliably prevent an excessive current or voltage from being applied to the light source by the variable control by the control means. The gyro device according to claim 7,
A gyro sensor unit that outputs a signal corresponding to the angular velocity,
A non-volatile storage means for storing a predetermined control constant value to be fixedly set corresponding to the characteristic of the gyro sensor section; and a reading means for reading the control constant value stored in the storage means. And a control unit that controls the operation of the gyro sensor unit based on the read control constant value.

According to this structure, the nonvolatile storage means stores a predetermined control constant value that should be fixedly set for the characteristic peculiar to the gyro sensor unit. Based on this, the operation of the gyro sensor unit is controlled. Therefore, in the production process of the gyro device, it suffices to write a value corresponding to the characteristics of the gyro sensor unit in the storage means, which facilitates production as compared with the case where the control constant value is determined by setting a switch or the like. As well,
Compared to setting the control constant value with a switch,
There is also an advantage that the circuit configuration becomes simple.

In the gyro device according to the eighth aspect, the gyro sensor section has a fiber coil formed by winding a single mode optical fiber, and light for angular velocity detection is made incident from both ends of the fiber coil, and the fiber coil is rotated clockwise. And a means for interfering the light propagating counterclockwise, a light receiving means for measuring the intensity of the interfered light, and a phase modulating means for performing phase modulation on the light propagating through the fiber coil, the gyro device, Means for generating a reference signal corresponding to the phase modulation in the phase modulating means, and synchronously detecting the output signal of the light receiving means based on the generated reference signal,
The control means further includes a detection means for detecting a phase-modulated signal component as a rotation signal corresponding to an angular velocity, and the control means controls the phase of the reference signal, and the control stored in the nonvolatile memory. The constant value is a phase control value set such that the phase control of the reference signal is performed by the control means so that the rotation signal can be maximized.

In the above arrangement, the phase of the reference signal corresponding to the phase modulation in the phase modulation means is controlled by the control means. At this time, the control means controls the phase of the reference signal based on the control constant value stored in the storage means. The control constant value is a value at which phase control is performed so that the rotation signal can be maximized when a rotation signal is obtained by synchronously detecting the phase-modulated signal component based on the reference signal. . Thereby, the rotation signal can be detected well.

A gyro device according to a ninth aspect of the present invention is a gyro device which measures an operation time of the device for detecting an angular velocity, and a non-volatile storage device for storing the operation time measured by the time measurement device. And a writing means for writing the operating time measured by the time measuring means in the non-volatile storage means.

According to this structure, since the operating time of the device is stored in the non-volatile storage means, it is possible to easily know the replacement time of the parts constituting the device by reading the contents of the storage means. it can. A gyro device according to claim 10, wherein the gyro sensor unit outputs a signal corresponding to an angular velocity, a detection unit that detects an operation state of the gyro sensor unit, and the gyro sensor unit based on a detection result of the detection unit. Feedback control is performed to stabilize the operation of the gyro sensor unit to a predetermined stable state, a unit for generating a control set value corresponding to the control state of the gyro sensor unit, and a plurality of the control set values are stored. And a writing means for writing the control set value in the storage means at a predetermined timing when the operating state of the gyro sensor unit is in a predetermined stable state. And

According to this structure, the control setting value when the control state of the gyro sensor section is stabilized is written in the non-volatile storage means at a predetermined timing. A plurality of control set values can be stored in the storage means. Therefore, by reading a plurality of control set values stored in the non-volatile storage means, it is possible to know the change over time of the control set values. This facilitates detection of the cause when the gyro device fails.

[0043]

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a block diagram showing a basic configuration of an optical fiber gyro device which is a gyro device according to an embodiment of the present invention. This optical fiber gyro device applies clockwise and counterclockwise light to a fiber coil 30 around which an optical fiber is wound to cause interference, and the intensity of the interference light is detected by a light receiving unit 37 to detect the intensity of the fiber coil 30.
For detecting the rotational angular velocity around the winding axis of the gyro sensor unit 31 including the fiber coil 30 and the like, and a signal processing unit for controlling the gyro sensor unit 31 and processing an output signal of the gyro sensor unit 31. And 32.

The gyro sensor section 31 is provided with a light source section 33 composed of a light emitting diode or the like. The light generated from the light source unit 33 passes through the coupler 34, is subjected to polarization processing by the polarizer 35, and is then branched by the coupler 36 into clockwise light and counterclockwise light and applied to the fiber coil 30. The right-handed and left-handed lights that have passed through the fiber coil 30 are combined by a coupler 36, pass through a polarizer 35, and are guided from the coupler 34 to a light-receiving unit 37 formed of a photodiode or the like.

Between the fiber coil 30 and the coupler 36, a phase modulator 38 for phase-modulating the light propagating through the optical fiber at an angular frequency ω is interposed. This phase modulator 3
Reference numeral 8 is made of, for example, PZT, and performs phase modulation on the light wave by the acousto-optic effect. Phase modulator 3
8 is driven by the drive voltage from the phase modulator drive circuit 41 provided in the signal processing unit 32. The phase modulator drive circuit 41 changes the drive voltage based on a control signal given from the control unit 42 via the line 43, and changes the modulation degree ξ of the phase modulation. Further, an oscillation circuit for generating a reference signal for phase modulation is provided inside.

The above reference signal for phase modulation is input to the phase setting circuit 44. This phase setting circuit 44
A reference signal is created by shifting the phase of the input standard signal. This reference signal is input to the lock-in amplifier 46 as a detecting means via the line 45. The phase shift amount in the phase setting circuit 44 is set based on the control signal from the control unit 42. By changing this phase shift amount, the phase of the reference signal changes.

The lock-in amplifier 46 synchronously detects the output signal of the light receiving section 37 based on the reference signal, and as a result,
For example, it outputs a rotation signal corresponding to the rotation angular velocity in the form of sin (C ₀ Ω). This rotation signal is input to the control unit 42. In addition, the lock-in amplifier 46
Detects the DC component in the output signal of the light receiving section 37 and supplies it to the control section 42. The control unit 42 further controls a light source drive circuit 47 that applies a drive current or a drive voltage to the light source unit 33.

The control unit 42 comprises a control device 51 including a microcomputer and the like, and a non-volatile memory 52 capable of exchanging data with the control device 51 and reading and writing data. . This non-volatile memory 5
2 may be composed of an optically or electrically erasable PROM (programmable read only memory), a battery-backed static RAM (random access memory), an IC card, a flash memory, or the like.

The following data is stored in the non-volatile memory 52. Light source control setting value corresponding to control of light source driving circuit 47 Light source control upper limit value corresponding to control of light source driving circuit 47 Phase modulator control setting value corresponding to control of phase modulator driving circuit 41 Should be given to phase setting circuit 44 Phase control value Total operating time of the optical fiber gyro device The light source control setting value and the phase modulator control setting value for each constant time, of which, the light source control upper limit value and the phase control value are the non-volatile memory 52 in the production process. Written in. The light source control upper limit value and the phase control value are values appropriately determined for each optical fiber gyro device.
Specifically, the light source control upper limit value does not cause the destruction of the semiconductor elements forming the light source unit 33, and the light source control upper limit value can be set.
3 is a control value corresponding to the maximum drive current or the maximum drive voltage capable of driving No. 3. Further, the phase control value is the phase shift amount corresponding to the phase control value.
By setting it to 4, the phase of the reference signal can be set to a phase that maximizes the counterclockwise or clockwise rotation signal.

The light source control upper limit value and the phase control value are held at constant values unless there are special circumstances such as when the components of the gyro sensor section 31 are replaced. That is, it is not rewritten. On the other hand, the light source control set value is a control value corresponding to the drive current or drive voltage of the light source unit 33 when the amount of light received by the light receiving unit 37 reaches a predetermined value. The phase modulator control set value of is a control value corresponding to the drive voltage of the phase modulator 38 when the phase modulation is performed with a predetermined modulation degree.
These control set values are used as control initial values in a period immediately after the start of the device, for example, immediately after the power is turned on.

These control set values are updated each time the amount of light received by the light receiving section 37 reaches a predetermined value or the modulation factor ξ of the phase modulation by the phase modulator 38 reaches a predetermined value. The total operating time of the optical fiber gyro device is written in the non-volatile memory 52 by the control device 51. That is, a timer device (not shown) included in the control device 51 measures the total operation time of the optical fiber gyro device and writes the measurement result in the non-volatile memory 52.

The operation time is written every time the timer device measures the elapse of a fixed time (for example, 10 minutes). When this operating time is written in the nonvolatile memory 52, the light source control setting value and the phase modulator control setting value at that time are written in the nonvolatile memory 52. This corresponds to the above value. This control set value is stored separately from the control set value, and a storage area capable of storing a plurality of control set values in time series is secured in the non-volatile memory 52. Has been done.

FIG. 2 is a block diagram showing a configuration of a portion related to control of the light source section 33. The control device 51 includes a memory writing device 61 for writing data in the non-volatile memory 52 and a memory reading device 62 for reading the data stored in the non-volatile memory 52. The light source control upper limit value is read from the nonvolatile memory 52, and the light source control upper limit value is input to the limiter control unit 63.

The limiter control unit 63 calculates the light source control set value based on the DC component of the output signal of the light receiving unit 37 detected by the lock-in amplifier 46 so that this DC component becomes a predetermined constant value. . This light source control setting value is D
The / A converter 64 converts the analog signal into an analog signal, and the analog signal is supplied to the light source drive circuit 47 as a control signal. However, when the obtained light source control set value exceeds the light source control upper limit value, this light source control upper limit value is input to the D / A converter 64. As a result, feedback control is performed so that the amount of light received by the light receiving unit 37 becomes constant, and a driving current or a driving voltage is supplied so that a current large enough to destroy the semiconductor element forming the light source unit 33 is not supplied to the light source unit 33. Is limited.

Further, the limiter control section 63 includes the light receiving section 3
When the amount of received light of No. 7 reaches a predetermined value, the light source control setting value at that time is written in the non-volatile memory 52 via the memory writing device 61. On the other hand, during the period immediately after the power is turned on and the device is activated, the memory reading device 62
Reads the above light source control setting value as a control initial value and supplies it to the limiter control unit 63. At this time, the limiter controller 63 sets the control initial value to the D / A converter 6 regardless of the magnitude of the DC component input from the lock-in amplifier 46.
Give to 4. As a result, from the period immediately after startup, the light source unit 3
It is possible to generate an almost desired amount of light from No. 3.

FIG. 3 is a flow chart for explaining the operation of the control device 51 related to the control of the light source section 33. At step a1, it is determined whether or not it is the period immediately after the start. This determination is made, for example, by checking whether or not the time measured by the timer that starts the time counting operation upon the start of activation has exceeded a predetermined time. If it is the period immediately after startup, in step a2, the nonvolatile memory 52
The above light source control set value is read out as a control initial value, and the light source control upper limit value is also read out. These values are given to the limiter control unit 63. Next, in step a3, the read control initial value is set as the drive control value. As a result, in step a4, the light source unit 33 is driven by the drive current or voltage corresponding to the control initial value.

At step a5, the lock-in amplifier 46
It is determined whether or not the DC component of the output signal of the light receiving unit 37 given by the above is a value corresponding to a predetermined light amount. If the amount of light received by the light receiving unit 37 is not appropriate, a new light source control set value is calculated in step a6. Further, in step a7, it is determined whether or not the calculated light source control set value exceeds the light source control upper limit value. If it exceeds, the light source control upper limit value is set as the drive control value, and if not, that value. Is set as a new drive control value, and the process proceeds to step a4 (steps a8 and a9).

When it is determined in step a5 that the amount of light received by the light receiving section 37 is appropriate, the drive control value at that time is written in the non-volatile memory 52 as the light source control set value in step a10. On the other hand, if it is determined in step a1 that the startup is not started, the light source unit 33 is driven based on the drive control value set at that time.

By such an operation, the light source control set value stored in the non-volatile memory 52 is adopted as the control initial value immediately after the power is turned on. Then, thereafter, the feedback control of the light source unit 33 is performed so that the amount of received light in the light receiving unit 37 becomes an appropriate value, and when the appropriate amount of received light is obtained, the above light source control stored in the nonvolatile memory 52 is performed. The set value is updated. In this way, the feedback control of the light source unit 33 can be promptly stabilized immediately after startup, so that the rise time immediately after startup can be shortened.

FIG. 4 is a block diagram showing a configuration related to the control of the phase modulator 38. The control device 51 controls the phase modulator control unit 65 that controls the phase modulation by the phase modulator 38 based on the DC component of the output signal of the light receiving unit 37 detected by the lock-in amplifier 46 so as to be performed at a predetermined modulation degree. Have The phase modulator control unit 65 can access the non-volatile memory 52 via the memory writing device 61 and the memory reading device 62.

The phase modulator control unit 65 calculates a phase modulator control set value based on the magnitude of the DC component of the output signal of the light receiving unit 37, and performs D / A conversion using this phase modulator control set value as a control value. Give to the vessel 66. The analog signal output from the D / A converter 66 is given to the phase modulator driving circuit 41. In this way, the feedback control of the phase modulator 38 is performed.

By this feedback control, when the DC component of the output signal of the light receiving section 37 reaches a value corresponding to a predetermined modulation factor, the phase modulator control section 65 causes the memory writing device 61 to operate.
The phase modulator control set value stored in the non-volatile memory 52 is updated to the phase modulator control set value at that point in time via. The control device 51 is also provided with a phase control device 67 for giving the phase control value to the phase setting circuit 62. This phase control device 67 is
Data stored in the nonvolatile memory 52 can be read out via the memory reading device 62.

Immediately after the power is turned on, the above-mentioned phase modulator control set value is read out from the non-volatile memory 52 as a control initial value, and further the phase control value is read out. Then, the phase modulator control unit 65 gives the above-mentioned initial value to the D / A converter 66. Therefore, the phase modulation can be performed with a substantially desired modulation degree from the period immediately after the start. Also,
The phase control value is given from the phase control device 67 to the phase setting circuit 44. The phase setting circuit 44 phase-shifts the reference signal for phase modulation generated by the phase modulator driving circuit 41 by a phase shift amount corresponding to the phase control value to generate a reference signal, and locks the reference signal. In-amp 4
Give to 6. As a result, the phase of the reference signal is adjusted so that the lock-in amplifier 46 can output the maximum rotation signal.

FIG. 5 is a flow chart for explaining the operation related to the control of the phase modulator 38. Step b
In 1, it is determined whether or not it is the period immediately after activation. In the period immediately after the start-up, in step b2, the phase modulator control set value is read out from the nonvolatile memory 51 as the control initial value. This control initial value is set as a control value in step b3, converted into an analog signal by the D / A converter 66 in step b4, and given to the phase modulator drive circuit 41. As a result, the phase modulator 38 is driven.

At step b5, the lock-in amplifier 46
It is determined whether the degree of phase modulation is appropriate or not based on the DC component detected in. If not, step b
6, the phase modulator controller 65 calculates a new phase modulator control set value. In step b7, the value is D
The control value given to the / A converter 66 is set, and the process returns to step b4. If the degree of phase modulation is appropriate,
In step b8, the control value at that time is written in the nonvolatile memory 52 as the phase modulator control set value.

When it is determined in step b1 that it is not the period immediately after the start-up, in step b4, the phase modulator 38 is operated based on the control value set at that time.
Will be driven. In this way, the phase modulator control set value stored in the non-volatile memory 52 is adopted as the control initial value in the period immediately after startup, and the DC component signal given from the lock-in amplifier 46 in the subsequent period. The feedback control is performed with reference to. Thereby, the feedback control of the phase modulator 38 can be stabilized from the period immediately after the start. That is, the startup time is shortened.

FIG. 6 is a block diagram showing a configuration related to the measurement of the total operating time. The control device 51 is provided with a timer device 70 which starts a time counting operation in response to power-on of the optical fiber gyro device. A predetermined storage area of the non-volatile memory 52 is provided with an area in which the total operating time is to be written. When the power is turned on and the driving of the gyro sensor unit 31 is started, the timer device 70
Starts timing operation. Then, for a certain period of time (for example, 1
The memory reading device 61 reads the total operating time from the non-volatile memory 52 every time 0 minutes). Then, the value obtained by adding the measurement time of the timer device 70 to this total operation time is written in the nonvolatile memory 52 by the memory writing device 61 as a new total operation time. At the same time, the timer device 70 is reset and starts a new time counting operation. By repeating such an operation, the non-volatile memory 52 stores the total operation time of the optical fiber gyro device.

In this embodiment, every time the total operating time stored in the non-volatile memory 52 is updated, the light source control set value and the phase modulator control set value at that time point are set to the respective control set values. As a non-volatile memory 52
Are stored in a predetermined storage area in a predetermined order in chronological order. With such a configuration, during maintenance, for example, the total operating time is read from the non-volatile memory 52 to determine the necessity of replacing the optical components forming the gyro sensor unit 31 and the circuit components of the signal processing unit 32. You can Furthermore, since it is possible to know the frequency of use of the optical fiber gyro device based on the total operating time, it is possible to predict the replacement time of parts and the like. This allows good maintenance.

Further, since the control set value for every fixed time is stored in the non-volatile memory 52 in time series, the history information of the control set value can be obtained. Therefore, when a failure occurs in the optical fiber gyro device, the cause of the failure can be detected based on the change over time of the control set value. This also improves the maintainability.

In the optical fiber gyro device of the present embodiment having the above-mentioned structure, the adjustment for preventing the application of overcurrent or overvoltage to the light source unit 33 is performed by the conventional variable resistor (see FIG. 9). .), But by writing the light source control upper limit value in the nonvolatile memory 52. Further, the adjustment for adjusting the phase of the reference signal is performed by a conventional dip switch (see FIG. 1).
See 0. ) Instead of setting the phase control value in the non-volatile memory 52. To write data in the non-volatile memory 52,
Since the operation is easier than the operation of the variable resistor and the dip switch, the optical fiber gyro device of this embodiment has remarkably good productivity as compared with the conventional configuration.

Furthermore, since a limiter circuit composed of an analog electric circuit having a variable resistor and an electric circuit related to the DIP switch are unnecessary, the circuit configuration related to the drive control of the light source unit 33 and the phase modulator 38 is remarkably large. It also has the effect of making it easier. FIG. 7 is a block diagram showing the basic configuration of an optical fiber gyro device according to another embodiment of the present invention. In FIG. 7, parts corresponding to the respective parts shown in FIG. 1 are designated by the same reference numerals. In this embodiment, in order to reliably prevent the light source drive circuit 47 from applying an overcurrent to the light source section 33, a light source control circuit 80 composed of an analog circuit is provided. That is,
The control circuit 80 controls the light source drive circuit 47 so as not to apply a current of a certain value or more to the light source unit 33. Accordingly, even if the control device 51 malfunctions, the light source unit 33 can be reliably prevented from being broken.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. For example, in the above embodiment, the non-volatile memory 52
The light source control set value and the phase modulator control set value stored in are updated at any time, and immediately after the power is turned on, the control set value written last is used as the control initial value. However, the control set value does not necessarily have to be written in the non-volatile memory 52. A certain control initial value set in the production line is written in the non-volatile memory 52 in advance, and the certain control initial value is set immediately after startup. You may make it control the light source part 33 and the phase modulator 38 using a value. However, in order to shorten the rise time immediately after the power is turned on, the above control initial value is set so that the received light amount of the light receiving section 37 becomes almost the desired light amount for each individual optical fiber gyro device, and the almost desired phase modulation is performed. It is necessary to set the value to obtain the degree.

In the above embodiments, the optical fiber gyro device has been described as an example, but the present invention can be applied to other gyro devices such as a ring laser gyro, a gas rate gyro and a vibration gyro. That is, a configuration may be adopted in which the control value related to the control of the gyro sensor unit, the total operating time, and the like are stored in the nonvolatile storage means.

Various other design changes can be made without departing from the spirit of the present invention.

[0075]

According to the present invention, the control initial value corresponding to the control state when the operating state of the gyro sensor unit becomes a predetermined stable state is stored in the non-volatile memory. The operation of the gyro sensor unit can be quickly brought to a stable state. Therefore, it is possible to shorten the rising time of the control when the gyro sensor unit is feedback-controlled based on the output of the detection means.

According to the fifth or sixth aspect of the invention, the control means variably controls the gyro sensor section within a range defined by the control limit value stored in the non-volatile storage means. With this, for example, it is possible to prevent an excessive current or voltage from being applied to the gyro sensor unit.
It is possible to prevent breakage of the gyro sensor unit. Moreover, since it is sufficient to store the control limit value in the storage means, the control limit value is set by adjusting the variable resistance, and the calculation efficiency is improved and the gyro is better than the conventional configuration. It is possible to simplify the configuration for driving and controlling the sensor unit.

According to the seventh or eighth aspect of the present invention, the non-volatile storage means stores a predetermined control constant value which should be fixedly set with respect to the characteristic peculiar to the gyro sensor section. Therefore, in the production process of the gyro device, it is sufficient to write a value corresponding to the characteristics of the gyro sensor unit in the storage means, which facilitates production. As well,
Compared to setting the control constant value with a switch,
There is also an advantage that the circuit configuration becomes simple.

According to the invention described in claim 9, since the operation time of the device is stored in the non-volatile storage means, it is possible to easily know the replacement time of the parts constituting the device and the maintenance can be performed well. . According to the tenth aspect of the invention, it is possible to know the change with time of the control set value based on the plurality of control set values stored in the nonvolatile storage means. As a result, it becomes easy to detect the cause when the gyro device fails, and maintenance can be favorably performed.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an optical fiber gyro device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration related to control of a light source unit.

FIG. 3 is a flowchart illustrating a control operation of a light source unit.

FIG. 4 is a block diagram showing a configuration related to control of a phase modulator.

FIG. 5 is a flowchart for explaining a control operation of the phase modulator.

FIG. 6 is a block diagram showing a configuration for measuring total operating time.

FIG. 7 is a block diagram showing a configuration of an optical fiber gyro device according to another embodiment of the present invention.

FIG. 8 is a block diagram showing a configuration of a conventional optical fiber gyro device.

FIG. 9 is a block diagram showing a configuration related to control of a light source in the above conventional technique.

FIG. 10 is a block diagram showing a configuration related to control of a phase modulator in the above-mentioned conventional technique.

[Explanation of symbols]

 30 fiber coil 31 gyro sensor part 32 signal processing part 33 light source part 37 light receiving part 38 phase modulator 41 phase modulator drive circuit 42 control part 44 phase setting circuit 46 lock-in amplifier 47 light source drive circuit 51 control device 52 non-volatile memory 61 Memory writing device 62 Memory reading device 63 Limiter control unit 65 Phase modulator control unit 67 Phase control device 70 Timer device 80 Light source control circuit

Claims (10)

[Claims] 1. A gyro sensor section for outputting a signal corresponding to an angular velocity, a detection means for detecting an operation state of the gyro sensor section, and feedback control of the gyro sensor section based on a detection result of the detection means, Control means for stabilizing the operation of the gyro sensor section to a predetermined stable state, non-volatile storage means for storing a control initial value corresponding to the control of the gyro sensor section by the control means, and the storage section when the apparatus is started. Read-out means for reading the control initial value stored in the means and giving it to the control means, wherein the control means includes means for controlling the gyro sensor section on the basis of the given control initial value when the apparatus is activated. A gyro device including: 2. The gyro sensor section includes a light source for generating light for angular velocity detection, the detection means detects the amount of light generated from the light source, and the control means includes: Based on the detection result of the detection means, the light source is driven and controlled so as to stabilize the amount of light generated from the light source to a predetermined value, and the control initial value is a predetermined value when applied to the light source. The gyro device according to claim 1, wherein the gyro device has a value corresponding to a drive current or a voltage capable of obtaining the light amount of. 3. The gyro sensor section comprises a fiber coil wound with a single-mode optical fiber, and light for angular velocity detection incident from both ends of the fiber coil and propagating clockwise and counterclockwise through the fiber coil. Means for interfering with each other, and a light receiving means for measuring the intensity of the interfered light,
Phase detecting means for performing phase modulation on the light propagating through the fiber coil, wherein the detecting means detects a variable related to the modulation degree by the phase modulating means based on the output signal of the light receiving means. The control means drives and controls the phase modulation means so as to stabilize the modulation degree by the phase modulation means to a predetermined value based on the detection result of the detection means, and the control initial value is The gyro device according to claim 1, wherein the gyro device has a value corresponding to a drive voltage capable of obtaining a predetermined modulation degree when applied to the phase modulation means. 4. Means for generating a control set value corresponding to the control state of the gyro sensor section, and writing the control set value when the operating state of the gyro sensor section is in a predetermined stable state in the storage means. The reading means further includes a writing means, and the reading means reads out the last stored control setting value from the storage means when the apparatus is activated, and gives the control setting value to the control means as the control initial value. The gyro device according to any one of claims 1 to 3, wherein 5. A gyro sensor section for outputting a signal corresponding to an angular velocity, a control means for variably controlling the operation of the gyro sensor section, and a control limit value corresponding to the control of the gyro sensor section by the control means are stored. It includes a non-volatile storage means and a reading means for reading the control limit value stored in the storage means and giving it to the control means, wherein the control means is within the range defined by the control limit value. A gyro device including means for controlling a unit. 6. The gyro sensor section includes a light source for generating light for angular velocity detection, and the control means variably controls a drive current or a drive voltage applied to the light source. The gyro device according to claim 5, wherein the value is a value corresponding to a maximum value of a drive current or a drive voltage that can drive the light source without destroying the light source. 7. A gyro sensor section for outputting a signal corresponding to an angular velocity, and a non-volatile storage means for storing a predetermined control constant value to be fixedly set corresponding to the characteristic peculiar to the gyro sensor section. And a reading means for reading the control constant value stored in the storage means, and a control means for controlling the operation of the gyro sensor unit based on the read control constant value. . 8. The gyro sensor section comprises a fiber coil wound with a single-mode optical fiber and light propagating clockwise and counterclockwise through the fiber coil, with light for angular velocity detection incident from both ends of the fiber coil. Means for interfering with each other, and a light receiving means for measuring the intensity of the interfered light,
Including a phase modulation means for performing phase modulation on the light propagating through the fiber coil, the gyro device, a means for generating a reference signal corresponding to the phase modulation in the phase modulation means, based on the generated reference signal The output signal of the light receiving unit is synchronously detected, and further includes a detection unit that detects a phase-modulated signal component as a rotation signal corresponding to an angular velocity, and the control unit controls the phase of the reference signal. The control constant value stored in the non-volatile memory is a phase control value set so that the phase of the reference signal is controlled by the control means so that the rotation signal can be maximized. The gyro device according to claim 7, wherein: 9. A time measuring means for measuring an operation time of the device for detecting an angular velocity, a non-volatile storage means for storing the operation time measured by the time measuring means, and the time measuring means. A gyro device, comprising: a writing unit that writes the operating time to the nonvolatile storage unit. 10. A gyro sensor section for outputting a signal corresponding to an angular velocity, a detection means for detecting an operation state of the gyro sensor section, and feedback control of the gyro sensor section based on a detection result of the detection means, A control unit for stabilizing the operation of the gyro sensor unit to a predetermined stable state, a unit for generating a control set value corresponding to the control state of the gyro sensor unit, and a plurality of the control set values can be stored. A gyro device including a non-volatile storage means and a writing means for writing the control set value in the storage means at a predetermined timing when the operating state of the gyro sensor unit is in a predetermined stable state. .