Gyro device and method for controlling gyro device

Abstract

To provide a gyro device capable of correction according to a mismatch of a two-dimensional oscillator while detecting an angular velocity.SOLUTION: A gyro device includes: a single two-dimensional oscillator 15 that is driven by a drive signal corresponding to a first rotation oscillation mode and a drive signal corresponding to a second rotation oscillation mode, and outputs an output signal corresponding to the first rotation oscillation mode and an output signal corresponding to the second rotation oscillation mode; a first modulation processing unit 301 that modulates an amplitude of the drive signal corresponding to the first rotation oscillation mode by a first modulation method; a second modulation processing unit 501 that modulates an amplitude of the drive signal corresponding to the second rotation oscillation mode by a second modulation method; a first demodulation processing unit 401 that demodulates a first error composition corresponding to the second rotation oscillation mode by a first demodulation method corresponding to the first modulation method; and a second demodulation processing unit 601 that demodulates a second error composition corresponding to the first rotation oscillation mode by a second demodulation method corresponding to the second modulation method.SELECTED DRAWING: Figure 29

Description

[Technical Field]

[0001] The present invention relates to a gyro device and a control method for a gyro device, and more particularly to a gyro device having a single (one) mode-matched two-dimensional vibrator (resonant frequencies of two orthogonal axes match), and a control method for a gyro device. [Background technology]

[0002] Gyro devices for detecting angular velocity of rotation have been proposed in the past, and the present inventor has also proposed a gyro device using a two-dimensional vibrator, as disclosed in the following Patent Document 1. In the gyro device disclosed in Patent Document 1, a phase adjustment process is performed by a phase adjustment unit and an amplitude adjustment process is performed by an amplitude adjustment unit in order to cancel deviations in frequency and Q value in the X and Y directions (hereinafter, these may also be referred to as mismatches) that may occur due to imperfections in the two-dimensional vibrator. [Prior art documents] [Non-patent literature]

[0003] [Patent Document 1] International Publication No. 2017 / 159429 Summary of the Invention [Problem to be solved by the invention]

[0004] The technology described in Patent Document 1 can appropriately correct mismatches in two-dimensional vibrators. However, a period is required to detect the mismatch and set parameters for correction (for example, a calibration period when the gyro device is started), and there is a problem in that the gyro device cannot be used during that period.

[0005] An object of the present invention is to provide a new and useful gyro device and a method for controlling the gyro device that solves these problems. [Means for solving the problem]

[0006] One aspect of the present invention is a single two-dimensional vibrator that is driven by a drive signal corresponding to a first rotational vibration mode and a drive signal corresponding to a second rotational vibration mode, and that outputs an output signal corresponding to the first rotational vibration mode and an output signal corresponding to the second rotational vibration mode; a first modulation processing unit that modulates the amplitude of a drive signal corresponding to a first rotational vibration mode using a first modulation method; a second modulation processing unit that modulates the amplitude of a drive signal corresponding to a second rotational vibration mode using a second modulation method; a first error component detector that detects a first error component corresponding to the second rotational vibration mode, the first error component being included in the output signal corresponding to the first rotational vibration mode; a second error component detector that detects a second error component corresponding to the first rotational vibration mode and that is included in the output signal corresponding to the second rotational vibration mode; a first demodulation processing unit that demodulates a first error component corresponding to the second rotational vibration mode by a first demodulation method corresponding to the first modulation method; a second demodulation processing unit that demodulates a second error component corresponding to the first rotational vibration mode by a second demodulation method corresponding to a second modulation method; Equipped with It is a gyro device.

[0007] Another aspect of the present invention is a single two-dimensional oscillator driven by a drive signal corresponding to a first rotational vibration mode and a drive signal corresponding to a second rotational vibration mode outputs an output signal corresponding to the first rotational vibration mode and an output signal corresponding to the second rotational vibration mode; a first modulation processing unit modulating the amplitude of a drive signal corresponding to a first rotational vibration mode using a first modulation method; a second modulation processing unit modulating the amplitude of the drive signal corresponding to the second rotational vibration mode using a second modulation method; a first error component detection unit detecting a first error component corresponding to the second rotational vibration mode, the first error component being included in an output signal corresponding to the first rotational vibration mode; a second error component detection unit detecting a second error component corresponding to the first rotational vibration mode, the second error component being included in an output signal corresponding to the second rotational vibration mode; a first demodulation processor demodulates a first error component corresponding to the second rotational vibration mode using a first demodulation method corresponding to the first modulation method; a second demodulation processing unit demodulating the second error component corresponding to the first rotational vibration mode by a second demodulation method corresponding to the second modulation method; A control method for a gyro device. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a gyro device that can correct mismatches in a two-dimensional vibrator while detecting angular velocity. Note that the effects exemplified in this specification should not be construed as limiting the scope of the present invention. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram to which reference is made when describing the technology related to the present invention. [Figure 2] 1 is a diagram to which reference is made when describing the technology related to the present invention. [Figure 3] 1 is a diagram to which reference is made when describing the technology related to the present invention. [Figure 4] 1 is a diagram to which reference is made when describing the technology related to the present invention. [Figure 5] 1 is a diagram to which reference is made when describing the technology related to the present invention. [Figure 6] 1 is a diagram to which reference is made when describing the technology related to the present invention. [Figure 7] 1 is a diagram to which reference is made when describing the technology related to the present invention. [Figure 8] 1 is a diagram to which reference is made when describing the technology related to the present invention. [Figure 9] 1 is a diagram to which reference is made when describing the technology related to the present invention. [Figure 10] 1 is a diagram to which reference is made when describing the technology related to the present invention. [Figure 11] 1 is a diagram to which reference is made when describing the technology related to the present invention. [Figure 12] 1 is a diagram to which reference is made when describing the technology related to the present invention. [Figure 13] 1 is a diagram to which reference is made when describing the technology related to the present invention. [Figure 14] 1 is a diagram to which reference is made when describing the technology related to the present invention. [Figure 15] 1 is a diagram to which reference is made when describing the technology related to the present invention. [Figure 16] 1 is a diagram to which reference is made when describing the technology related to the present invention. [Figure 17] 1 is a diagram to which reference is made when describing the technology related to the present invention. [Figure 18] 1 is a diagram to which reference is made when describing the technology related to the present invention. [Figure 19] 1 is a diagram to which reference is made when describing the technology related to the present invention. [Figure 20] 1 is a diagram to which reference is made when describing the technology related to the present invention. [Figure 21] 1 is a diagram to which reference is made when describing the technology related to the present invention. [Figure 22] 1 is a diagram to which reference is made when describing the technology related to the present invention. [Figure 23] 1 is a diagram to which reference is made when describing the technology related to the present invention. [Figure 24] 1 is a diagram to which reference is made when describing the technology related to the present invention. [Figure 25] 1 is a diagram to which reference is made when describing the technology related to the present invention. [Figure 26]1 is a diagram to which reference is made when describing the technology related to the present invention. [Figure 27] FIG. 2 is a diagram that is referred to when describing the configuration of a detection unit according to one embodiment. [Figure 28] FIG. 10 is a diagram to be referred to when describing the configuration of another detection unit according to an embodiment. [Figure 29] FIG. 1 is a diagram illustrating an example of the configuration of a gyro device according to an embodiment. [Figure 30] 3 is a diagram illustrating an example of the configuration of a first modulation processing unit and a first demodulation processing unit according to an embodiment. FIG. [Figure 31] 3 is a diagram for explaining an example of the configuration of a second modulation processing unit and a second demodulation processing unit according to an embodiment. FIG. [Figure 32] FIG. 10 is a diagram for explaining experimental results. [Figure 33] FIG. 10 is a diagram for explaining experimental results. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The description will be made in the following order. <Technologies related to the present invention> <One embodiment> <Modification> The embodiments and the like described below are preferred specific examples of the present invention, and the content of the present invention is not limited to these embodiments and the like.

[0011] <Technologies related to the present invention> The inventor of this patent application previously proposed a gyro device and a method for controlling a gyro device. The proposed content was published as a patent document, JP 2020-169819 A. The content described in this patent document can be applied to this patent application. To facilitate understanding of the present invention, the content described in the publication will be explained and issues to be considered in the present invention will be mentioned.

[0012] First, a general gyro device (gyroscope) will be described. In the following description, a small vibration type gyro device using MEMS (Micro Electro Mechanical Systems) will be used as an example. The gyro device detects the angular velocity of rotation (hereinafter referred to as the rotational angular velocity). The rotational angular velocity Ω z There are several known methods for detecting the angular velocity. The first method is known as the AM (Amplitude Modulation) mode. In AM mode, when vibration is applied in the drive axis (e.g., X axis) direction, the amplitude (displacement) in the sense axis (e.g., Y axis) direction, which changes due to the Coriolis force, is measured to obtain the angular velocity. The amplitude in the sense axis direction is expressed as the rotational angular velocity Ω. z Since the amplitude is proportional to z In AM mode, the resonance frequencies in the drive axis and sense axis directions are set to be different (mode mismatch), taking into account the fact that vibrations applied in the drive axis direction directly excite vibrations in the sense axis direction. However, in AM mode, measurements are taken at frequencies far from the resonance frequency, which can lead to problems such as reduced sensitivity. Furthermore, in AM mode, there is a theoretical trade-off between sensitivity and measurement bandwidth, making it impossible to achieve both high sensitivity and a wide bandwidth.

[0013] The second method is called force rebalancing, in which feedback control is applied so that the amplitude of the AM mode in the sense axis direction is always a constant value (0 in most cases), and the rotational angular velocity is obtained from the magnitude of the feedback signal. In this case, a vibrator in which the resonant frequencies of the drive axis and sense axis are matched (mode matched) can be used. However, there are problems such as the scale factor (magnitude of output relative to rotational angular velocity) fluctuating due to temperature, etc.

[0014] In consideration of the problems with the first and second methods described above, the embodiment described below employs a gyro device driven in FM mode. Compared to other methods, FM mode has the advantages of providing accurate and stable sensitivity (scale factor), superior temperature characteristics in principle, and a wide dynamic range. FM modes are broadly divided into quadrature FM and Lissajous FM types, but this specification will only focus on quadrature FM types unless otherwise specified.

[0015] Here, the basic principles of FM mode will be explained. The principles of FM mode are well known, so only a brief explanation will be given here. An FM mode gyro is composed of an oscillator (also called a resonator or resonator) that vibrates in two orthogonal (independent) axial directions. In FM mode, an oscillator (degenerate oscillator) is used that has the same resonance frequency and Q value for each axis. In this state, when a rotational angular velocity is applied to the oscillator, it is known that the relationship expressed in the following equation 1 holds. In equation 1, λ is the resonance frequency, ω is the resonance frequency when no rotation is applied (since it is degenerate, the resonance frequency is the same for both axes), and Ω is the resonance frequency when no rotation is applied (since it is degenerate, the resonance frequency is the same for both axes), z represents the rotational angular velocity applied to the oscillator.

[0016] Note that the vibrations mentioned below are not limited to linear vibrations (for example, X and Y directions), but any vibration can be used as long as it is a degenerate orthogonal vibration mode. For example, in the case of a ring-shaped resonator, as shown in Figures 1 and 2, two orthogonal vibrations do not necessarily result in simple linear vibrations, but if the displacement state in each vibration mode is expressed in modal coordinates (generalized coordinates), it can be treated exactly the same as linear vibration. In the following, including these modal coordinates (generalized coordinates), one mode will be referred to as the "X axis (or X direction)" and the mode orthogonal to it as the "Y axis (or Y direction)" (Note that modes 1 and 2 in Figures 1 and 2 indicate a state in which they are orthogonal mathematically or vibrationally).

[0017]

number

[0018] The following formula 2 is derived from formula 1.

[0019]

number

[0020] That is, as shown in Equation 2, when no rotation is applied, the resonance frequencies in the X-axis and Y-axis directions are the same, i.e., degenerate. However, when rotation is applied, the resonance frequency λ becomes ω+Ω. z and ω-Ω z If these two resonance frequencies are λ1 and λ2, then the resonance frequency λ 1、 The difference (deviation) of λ2 is the rotational angular velocity Ω z Since the rotational angular velocity Ω is proportional to the resonance frequency λ1, λ2, the rotational angular velocity Ω can be calculated by the following equation 3. z can be obtained.

[0021]

number

[0022] Here, λ1(=ω+Ω z ) corresponds to clockwise (CW) motion, and λ2(=ω-Ω z ) corresponds to a counterclockwise (CCW) motion. In other words, when a rotation is applied to a degenerate oscillator, the natural vibration mode is not linear (vibration in either the X or Y direction alone), but rotational vibration (two-dimensional vibration in which the phases of the X and Y vibrations are shifted by ±90 degrees (°)). Note that the actual rotation of the oscillator is a superposition of these CW and CCW modes.

[0023] "Methods for detecting components of each mode" The FM mode has been described above. For example, in the above-mentioned FM mode, control is performed to excite one oscillator (hereinafter referred to as a two-dimensional oscillator) that is degenerated along two axes. Therefore, the rotational angular velocity Ω zTo obtain this, it is necessary to independently detect the CW mode (first rotational vibration mode) component and the CCW mode (second rotational vibration mode) component contained in the rotational vibration (output) of the two-dimensional oscillator. Therefore, next we will explain a method for separating and detecting the CW mode component and the CCW mode component from the output of the two-dimensional oscillator.

[0024] FIG. 3 is a diagram illustrating a typical synchronous detection method. A signal having a certain amplitude and phase is input as an input signal (Signal) SI. The input signal SI is split and input to multipliers (mixers) 1 and 3, respectively. In the synchronous detection method, two signals with a phase difference of 90 degrees are used as reference signals, and these reference signals are multiplied by separate multipliers 1 and 3, and then filtered to obtain a demodulated output. For example, a cosine wave and a sine wave are used as reference signals, and multiplier 1 multiplies the input signal SI by the cosine wave, while multiplier 3 multiplies the input signal SI by the sine wave.

[0025] The signal output from the multiplier 1 is input to an LPF (Low Pass Filter) 2 and filtered. As a result of the filtering process by the LPF 2, only components that have the same frequency and phase as the reference signal (cosine wave in this example) are output from the LPF 2.

[0026] Meanwhile, the signal output from the multiplier 3 is input to the LPF 4 and filtered. As a result of the filtering process by the LPF 4, only components that have the same frequency and phase as the reference signal (sine wave in this example) in the multiplier 3 are output from the LPF 4.

[0027] The input signal SI is demodulated by the outputs from the LPFs 2 and 4, and the amplitude r and phase θ of the input signal SI are detected based on the demodulated output.

[0028] This synchronous detection method is developed and applied to detect the CW mode component and the CCW mode component. In the following explanation, an example is described in which only the CW mode component is detected from a signal that combines CW mode and CCW mode generated in a two-dimensional vibrator, but the CCW mode component can also be detected by similar processing.

[0029] 4 is a diagram for explaining a method for detecting a CW mode component from an input signal SI. A signal output from a two-dimensional oscillator is input as the input signal SI. When a two-dimensional oscillator is used, the input signal SI can be expressed as a vector including components in the X and Y directions, as shown in the figure.

[0030] An input signal SI is split and input to multipliers 1 and 3. Signals CW-I (In phase) and CW-Q (Quadrature Phase) are used as reference signals, and multiplier 1 multiplies the input signal SI by the signal CW-I, while multiplier 3 multiplies the input signal SI by the signal CCW-I. As symbolically shown in Figure 4, signals CW-I and CW-Q have the same amplitude, frequency, and direction of rotation but are out of phase with each other by 90 degrees.

[0031] Input signal SI is multiplied by signal CW-I in multiplier 1, and the output is supplied to LPF 2. Input signal SI is multiplied by signal CW-Q in multiplier 3, and the output is supplied to LPF 4. As a result of filtering by each of LPFs 2 and 4, input signal SI is demodulated, and the amplitude r and phase θ of the CW mode component contained in input signal SI can be detected based on the demodulated output.

[0032] 5 is a diagram illustrating a detailed configuration example of the above-mentioned multipliers 1 and 3. Multiplier 1 includes, for example, multiplier 1a, multiplier 1b, and adder 1c. Multiplier 3 includes, for example, multiplier 3a, multiplier 3b, and adder 3c.

[0033] As described above, in the case of a two-dimensional vibrator, signals (amplitudes) in the X-axis and Y-axis directions (hereinafter referred to as signals SIX and SIY as appropriate) are input as input signal SI to multiplier 1. Multiplier 1a multiplies signal SIX by the X-axis component of signal CW-I, and multiplier 1b multiplies signal SIY by the Y-axis component of signal CW-I. Adder 1c adds the outputs of multipliers 1a and 1b and outputs the result to LPF 2.

[0034] Multiplier 3a multiplies signal SIX by the X-axis component of signal CW-Q, and multiplier 3b multiplies signal SIY by the Y-axis component of signal CW-Q. Adder 3c adds the outputs of multipliers 3a and 3b and outputs the result to LPF 4.

[0035] The above-described method for detecting the CW mode component contained in the output of a two-dimensional oscillator will be described in more detail with reference to FIGS. 6 to 9. The example shown in FIG. 6 illustrates detection using the signal CW-I as a reference signal. In this example, the signal in the X-axis direction of CW-I is a sine wave, and the signal in the Y-axis direction is a cosine wave. If the input signal SI is assumed to contain only the component of signal CW-I, the output waveform of multiplier 1a is waveform WA1a, and the output waveform of multiplier 1b is waveform WA2a. The waveform of the signal obtained by adding the outputs of the multipliers in adder 1c is waveform WA3a. When this signal waveform is passed through LPF 2, the filtering process by LPF 2 is equivalent to a process of obtaining an average, and the resulting signal waveform is waveform WA4a (DC component) similar to waveform WA3a. In other words, if the input signal SI contains a component of signal CW-I, that component can be detected by detection using signal CW-I.

[0036] 7 is an example of detection using signal CW-I as a reference signal, but assumes that input signal SI is composed only of signal CW-Q components that are 90 degrees out of phase with signal CW-I. In this case, the output waveform of multiplier 1a is waveform WA1b, and the output waveform of multiplier 1b is waveform WA2b. The signal obtained by adding the outputs of these waveforms in adder 1c is 0 as shown, and therefore the output of LPF2 is also 0 as shown.

[0037] The example shown in Figure 8 is an example of detection using signal CW-I as a reference signal, but assumes that input signal SI consists only of components of signal CCW-I, which rotates counterclockwise in a direction different from that of signal CW-I. In this case, the output waveform of multiplier 1a is waveform WA1c, and the output waveform of multiplier 1b is waveform WA2c. The waveform of the signal obtained by adding the outputs of each multiplier in adder 1c is waveform WA3c, which is symmetrical about 0. When this signal with waveform WA3a is passed through LPF2, the output becomes 0 as shown in the figure.

[0038] The example shown in Figure 9 is an example of detection using signal CW-I as a reference signal, but assumes that input signal SI is a counterclockwise signal with a different rotation direction from signal CW-I, and that the input signal contains only the component of signal CCW-Q, which is 90 degrees out of phase with signal CCW-I. In this case, the output waveform of multiplier 1a is waveform WA1d, and the output waveform of multiplier 1b is waveform WA2d. The waveform of the signal obtained by adding the outputs of each multiplier in adder 1c is waveform WA3d, which is symmetrical about 0. When this signal with waveform WA3d is passed through LPF2, the output becomes 0, as shown in the figure.

[0039] In other words, if any two-dimensional vibration occurring within a two-dimensional oscillator (expressed as a linear combination of CW-I, CW-Q, CCW-I, and CCW-Q) is synchronously detected using signal CW-I as the reference signal, only the component of signal CW-I contained in the output signal of the two-dimensional oscillator can be obtained. This also applies to the components detected when other signals are used as the reference signal. Summarizing the above, we obtain Table 1 below.

[0040] [Table 1]

[0041] As shown in Table 1, if the output of the two-dimensional oscillator contains a CW-Q signal component, the reference signal can be detected as the CW-Q signal, while the output of other signal components will be 0. If the output of the two-dimensional oscillator contains a CCW-I signal component, the reference signal can be detected as the CCW-I signal, while the output of other signal components will be 0. If the output of the two-dimensional oscillator contains a CCW-Q signal component, the reference signal can be detected as the CCW-Q signal, while the output of other signal components will be 0. In other words, if two detectors are provided and the reference signals in each detector are set to the combination of CW-I and CW-Q, and the combination of CCW-I and CCW-Q, respectively, the CW mode component and CCW mode component can be detected independently from the output of the two-dimensional oscillator.

[0042] Based on the above explanation, a gyro device (gyro device 10) capable of detecting angular velocity will be described. Fig. 10 is a diagram showing an example configuration of the gyro device 10. The gyro device 10 includes, for example, a single two-dimensional vibrator 15, a drive signal generating unit 20, a first detecting unit 30a, a first PLL (Phase Locked Loop) circuit 40a as an example of a first oscillation circuit, a first AGC (Automatic Gain Control) unit 50a, a second detecting unit 30b, a second PLL circuit 40b as an example of a second oscillation circuit, a second AGC unit 50b, amplifiers 61a and 61b provided on the input side of the two-dimensional vibrator 15, and amplifiers 62a and 62b provided on the output side of the two-dimensional vibrator 15.

[0043] Although not shown, the gyro device 10 may include a DA (Digital to Analog) converter and an AD (Analog to Digital) converter, and perform each process by digital signal processing. In this case, the DA converter is provided, for example, before the amplifiers 61a and 61b, and is configured to convert the digital drive signal output from the drive signal generation unit 20 into an analog format. The AD converter is provided, for example, after the amplifiers 62a and 62b, and is configured to convert the analog signal output from the two-dimensional vibrator 15 into a digital format.

[0044] The two-dimensional oscillator 15 is, for example, a ring-shaped vibrating member that can be excited by drive signals corresponding to the CW mode and the CCW mode. The shape of the two-dimensional oscillator 15 is not limited to a ring shape, and it can be any shape, such as a square plate, a cylinder, a square prism, or a quadruple mass type using four masses.

[0045] The drive signal generating unit 20 multiplexes a drive signal (first drive signal) corresponding to the CW mode and a drive signal (second drive signal) corresponding to the CCW mode, and supplies the multiplexed drive signal to the two-dimensional vibrator 15. The two-dimensional vibrator 15 is excited by the drive signal supplied from the drive signal generating unit 20. In this example, a cosine wave (hereinafter referred to as cos cw signal), and a -sine wave (hereinafter referred to as -sin cw The drive signal does not necessarily have to be a cosine wave or a -sine wave, as long as the Y-direction signal is 90 degrees ahead of the X-direction signal. Also, a -cosine wave (hereinafter referred to as -cos) is used as the drive signal for the X-axis direction corresponding to CCW mode. CCW signal), and a -sine wave (hereinafter referred to as -sin CCWThe drive signal does not necessarily have to be a -cosine wave or a -sine wave, as long as the Y-direction signal is delayed in phase by 90 degrees compared to the X-direction signal. The drive signal generation unit 20 generates a drive signal corresponding to the CW mode based on a signal fed back from the first PLL circuit 40a, and generates a drive signal corresponding to the CCW mode based on a signal fed back from the second PLL circuit 40b. The drive signal generation unit 20 includes, for example, multipliers 201, 202, 203, 204, adder 205, and adder 206.

[0046] The first detector 30a detects the amplitude r of the CW component included in the output of the two-dimensional oscillator 15. cw and phase θ cw The first detector 30a will be described in detail later.

[0047] The first PLL circuit 40a includes a phase comparator 41a, a PID (Proportional Integral Differential) control unit 42a, and an oscillator 43a capable of changing the oscillation frequency such as a VCO (Voltage Controlled Oscillator) or an NCO (Numerical Controlled Oscillator). To avoid complicating the illustration, detailed illustration is omitted, but the output of the first PLL circuit 40a (which may be all of the output or a part of the output) is configured to be fed back to each of the drive signal generation unit 20 and the first detection unit 30a.

[0048] The first AGC unit 50a includes an amplitude comparator 51a and a PID control unit 52a. The output of the first AGC unit 50a is fed back to the drive signal generating unit 20.

[0049] The second detector 30b detects the amplitude r of the CCW component included in the output of the two-dimensional oscillator 15. CCW and phase θ CCW The second detector 30b will be described in detail later.

[0050] The second PLL circuit 40b includes a phase comparator 41b, a PID control unit 42b, and an oscillator 43b that can change the oscillation frequency of a VCO, NCO, etc. Although detailed illustration is omitted to avoid complication of the illustration, the output of the second PLL circuit 40b (which may be all of the output or a portion of the output) is configured to be fed back to each of the drive signal generation unit 20 and the second detection unit 30b.

[0051] The second AGC unit 50b includes an amplitude comparator 51b and a PID control unit 52b. The output of the second AGC unit 50b is fed back to the drive signal generating unit 20.

[0052] 11 is a diagram illustrating an example of the configuration of the first detection unit 30a. The first detection unit 30a includes detectors 31a and 32a to which the signal output from the two-dimensional oscillator 15 is branched and input, an LPF 33a that filters the output of the detector 31a, an LPF 34a that filters the output of the detector 32a, and an amplitude r of the CW component included in the output signal of the two-dimensional oscillator 15 based on the outputs from the LPF 33a and the LPF 34a. cw and phase θ cw The amplitude and phase detector 35a detects the amplitude and phase of the signal.

[0053] Detector 31a includes multiplier 310a to which the component in the X-axis direction of the output from two-dimensional oscillator 15 is input, multiplier 311a to which the component in the Y-axis direction of the output from two-dimensional oscillator 15 is input, and adder 312a that adds the outputs of multipliers 310a and 311a. Detector 32a includes multiplier 320a to which the component in the X-axis direction of the output from two-dimensional oscillator 15 is input, multiplier 321a to which the component in the Y-axis direction of the output from two-dimensional oscillator 15 is input, and adder 322a that adds the outputs of multipliers 320a and 321a.

[0054] In this example, the CW-I component in the X-axis direction is a sine signal, the CW-I component in the Y-axis direction is a cosine signal, the CW-Q component in the X-axis direction is a cosine signal, and the CW-Q component in the Y-axis direction is a -sine signal.

[0055] 12 is a diagram illustrating an example of the configuration of the second detection unit 30b. The second detection unit 30b includes detectors 31b and 32b to which a signal from the two-dimensional oscillator 15 is branched and input, an LPF 33b that filters the output of the detector 31b, an LPF 34b that filters the output of the detector 32b, and an amplitude r of the CCW component included in the output signal of the two-dimensional oscillator 15 based on the outputs from the LPFs 33b and 34b. CCW and phase θ CCW The amplitude and phase detector 35b detects the amplitude and phase of the signal.

[0056] Detector 31b includes multiplier 310b to which the X-axis direction component of the output from two-dimensional oscillator 15 is input, multiplier 311b to which the Y-axis direction component of the output from two-dimensional oscillator 15 is input, and adder 312b that adds the outputs from multipliers 310b and 311b. Detector 32b includes multiplier 320b to which the X-axis direction component of the output from two-dimensional oscillator 15 is input, multiplier 321b to which the Y-axis direction component of the output from two-dimensional oscillator 15 is input, and adder 322b that adds the outputs from multipliers 320b and 321b.

[0057] In this example, the CCW-I component in the X-axis direction is a -sine signal, the CCW-I component in the Y-axis direction is a cosine signal, the CCW-Q component in the X-axis direction is a -cosine signal, and the CCW-Q component in the Y-axis direction is a -sine signal.

[0058] Next, an example of the operation of the gyro device 10 will be described with reference to Figs. 10 to 12. The drive signal generating unit 20 generates a drive signal for the two-dimensional vibrator 15. cos cw signal and -sin cwAfter each signal is multiplied by a signal fed back from the PID control unit 52a in multipliers 201 and 202, the output signal from multiplier 201 is supplied to adder 205, and the output signal from multiplier 202 is supplied to adder 206. -cos CCW signal and -sin CCW After each of the signals is multiplied by a signal fed back from the PID control unit 52b in multipliers 203 and 204, the output signal from multiplier 203 is supplied to adder 205, and the output signal from multiplier 204 is supplied to adder 206. Adder 205 adds the output signal from multiplier 201 and the output signal from multiplier 203 and outputs the result. After the output signal from adder 205 is amplified by amplifier 61a with an appropriate amplification factor, it is input to two-dimensional oscillator 15 as input X d On the other hand, the adder 206 adds the output signal from the multiplier 202 and the output signal from the multiplier 204 and outputs the result. The output signal from the adder 206 is amplified by an amplifier 61b with an appropriate amplification factor, and then input to the two-dimensional oscillator 15 as Y d is entered as

[0059] Input X d , Y d The two-dimensional oscillator 15 is excited by s , Y s The output X from the two-dimensional oscillator 15 is obtained. s , Y s is amplified by amplifiers 62a and 62b with an appropriate amplification factor, and then output as output X s is branched and input to the first and second detectors 30a and 30b, respectively, and the output Y s is branched and input to the first and second detectors 30a and 30b, respectively.

[0060] The first detection unit 30a detects the CW component included in the output of the two-dimensional oscillator 15. Specifically, a detector 31a in the first detection unit 30a performs detection using the signal CW-I, and the result is filtered by an LPF 33a to detect the CW-I component included in the output of the two-dimensional oscillator 15, and the detection result is supplied to an amplitude / phase detection unit 35a. Also, a detector 32a in the first detection unit 30a performs detection using the signal CW-Q, and the result is filtered by an LPF 34a to detect the CW-Q component included in the output of the two-dimensional oscillator 15, and the detection result is supplied to an amplitude / phase detection unit 35a. The amplitude / phase detection unit 35a detects the amplitude r of the CW component included in the output signal of the two-dimensional oscillator 15 based on the outputs from the LPFs 33a and 34a. cw and phase θ cw That is, as described above, by performing synchronous detection using the signals CW-I and CW-Q as reference signals, it is possible to detect only the CW component included in the output of the two-dimensional oscillator 15.

[0061] The phase θ detected by the first detector 30a cw is supplied to the first PLL circuit 40a. The phase comparator 41a in the first PLL circuit 40a calculates the phase θ cw and the set phase θ cw,set (In the following explanation, θ cw,set = 90°), and based on the comparison result, the PID control unit 42a controls the phase θ cw 90°, i.e., the resonant frequency f cw The oscillator 43a is controlled by the output from the PID control unit 42a, and the oscillator 43a outputs a resonance frequency f cw signal sin cw and signal cos cw These signals are fed back to the input side, and the resonant frequency of the drive signal corresponding to the CW mode is increased to the resonant frequency f cw The control is maintained by the signal sin cw and signal cos cwis fed back to the first detector 30a, and based on this, signals CW-I and CW-Q are generated as reference signals. In this example, a sin=sin cw , cos=cos cw , -sin=-1*sin cw The relationship is established.

[0062] The amplitude r obtained by the first detector 30a cw is supplied to the first AGC unit 50a. The amplitude comparator 51a in the first AGC unit 50a outputs the amplitude r cw and a predetermined first set value R set,cw Based on the comparison result, the PID control unit 52a controls the amplitude r cw is the predetermined first set value R set,cw The output from the PID control unit 52a is fed back to the drive signal generation unit 20, and the amplitude of the drive signal corresponding to the CW mode is controlled to the first set value R set,cw The gain is controlled so that the gain is maintained at .

[0063] Similar processing is also performed for the system that detects the CCW component included in the output of the two-dimensional oscillator 15. Specifically, detector 31b in the second detection unit 30b performs detection using signal CCW-I, and the result is filtered by LPF 33b to detect the CCW-I component included in the output of the two-dimensional oscillator 15, and the detection result is supplied to amplitude / phase detection unit 35b. Detector 32b in the second detection unit 30b also performs detection using signal CCW-Q, and the result is filtered by LPF 34b to detect the CCW-Q component included in the output of the two-dimensional oscillator 15, and the detection result is supplied to amplitude / phase detection unit 35b. The amplitude / phase detection unit 35b calculates the amplitude r of the CCW component included in the output signal of the two-dimensional oscillator 15 based on the outputs from LPF 33b and LPF 34b. CCW and phase θ CCW That is, as described above, by performing synchronous detection using the signals CCW-I and CCW-Q as reference signals, it is possible to detect only the CCW component included in the output of the two-dimensional oscillator 15.

[0064] The phase θ obtained by the second detector 30b CCW is supplied to the second PLL circuit 40b. The phase comparator 41b in the second PLL circuit 40b detects the phase θ CCW and 90°, and based on the comparison result, the PID control unit 42b adjusts the phase θ CCW 0, i.e., the resonant frequency f cw The oscillator 43b is controlled by the output from the PID control unit 42b, and the oscillator 43b outputs a phase-matched frequency, in other words, a resonant frequency f CCW signal sin CCW and signal cos CCW The resonance frequency f CCW is fed back to the input side, and the resonance frequency of the drive signal corresponding to the CCW mode becomes the resonance frequency f CCW In addition, the signal sin CCW and signal cos CCW is fed back to the second detector 30b, and based on this, signals CCW-I and CCW-Q are generated as reference signals. In this example, -sin=sin is used between the fed back signals and the reference signals. ccw , cos=cos ccw , -cos=-1*cos ccw , the relationship holds.

[0065] The amplitude r obtained by the second detector 30b CCW is supplied to the second AGC unit 50b. The amplitude comparator 51b in the second AGC unit 50b calculates the amplitude r CCW and the second set value R set,CCW Based on the comparison result, the PID control unit 52b controls the amplitude r CCW is the second set value R set,CCW The output from the PID control unit 52b is fed back to the drive signal generating unit 20, and the amplitude of the drive signal corresponding to the CCW mode is set to the second set value R set,CCW The gain is controlled so that the gain is maintained at .

[0066] FIG. 13 is a diagram showing a schematic diagram of the signal flow in the gyro device 10. The thick lines in FIG. 13 indicate the signal flow. The CCW component included in the output of the two-dimensional oscillator 15 is cut by the first detection unit 30a, and only the CW component loops through one system (the upper system in FIG. 13). The CW component included in the output of the two-dimensional oscillator 15 is cut by the second detection unit 30b, and only the CCW component loops through the other system (the lower system in FIG. 13).

[0067] Next, a configuration example of the angular velocity detection unit (angular velocity detection unit 70) will be described. In this example, the angular velocity detection unit 70 will be described as being incorporated into the gyro device 10, but it may also be incorporated into other devices.

[0068] 14 is a diagram showing an example of the configuration of the angular velocity detection unit 70. The angular velocity detection unit 70 includes, for example, a subtractor 71 and a multiplier 72. The angular velocity detection unit 70 calculates the resonant frequency f cw and the resonant frequency f output from the second PLL circuit 40b CCW The two resonance frequencies are subtracted by a subtractor 71, and the result is multiplied by a constant (1 / 2 in the case of an ideal vibrator with an angular gain of 1) by a multiplier 72. That is, the angular velocity detection unit 70 calculates the rotational angular velocity Ω by performing the same calculation as in Equation 3 above. z Detect.

[0069] As described above, the gyro device 10 is configured using a single two-dimensional oscillator, which allows for a compact device and eliminates the need to match the characteristics and operating environment of the oscillators as is the case when multiple oscillators are used. Furthermore, components corresponding to CW and CCW modes can be detected independently from the output of the two-dimensional oscillator.

[0070] Here, we will explain the imperfection (XY asymmetry) of the vibrator (for example, the above-mentioned two-dimensional vibrator 15). The imperfection of the vibrator means the difference in the resonance frequency and damping coefficient in the X and Y directions, which occurs mainly due to the asymmetry of the structure caused by the manufacturing error of the vibrator.

[0071] An ideal vibrator (a vibrator driven by mode matching) will now be described with reference to Figs. 15 and 16. The upper part of Fig. 15A is a graph showing an example of a drive signal in the X direction, and the lower part of Fig. 15A is a graph showing an example of a drive signal in the Y direction. In each graph, the vertical axis represents the level of the drive signal, and the horizontal axis represents time (t). As shown, the phase difference (Δθ) between the drive signals in the X and Y directions is 90°.

[0072] Fig. 15B shows the vibrations that occur when a vibrator is excited with the drive vibration shown in Fig. 15A, with the upper part of Fig. 15B showing the vibrations in the X direction of the vibrator output and the lower part of Fig. 15B showing the vibrations in the Y direction of the vibrator output. The vibrations in each direction are delayed by 90° in phase with the drive signal in the corresponding direction, and the phase difference between the X and Y direction vibrations is maintained at 90°. In other words, when a vibrator is excited with a drive signal with a phase difference of 90° in the X and Y directions, ideally, as shown in Figs. 16A and 16B, the amplitudes of the vibrations in the X and Y directions will be the same at the resonance point (resonance frequency f0), and the phase difference between the vibrations in the X and Y directions will be 90°.

[0073] However, due to the above-mentioned imperfections (mode mismatch) of the vibrator, the vibration of the vibrator may become non-ideal. For example, as shown in Fig. 17A, if the resonance frequencies in the X and Y directions are different, the phase delay of the vibration relative to the drive signal (frequency f0) will be different in the X and Y directions, as shown in Fig. 17B. Therefore, as shown in Fig. 17B, the phase delay in the X and Y directions at the drive frequency f0 will not be 90°, resulting in a phase difference Δφ.

[0074] 18A and 18B, imperfections in the vibrator may cause the phase delay of the X-direction vibration to be smaller (or larger) than 90° relative to the phase of the X-direction drive signal, and the phase delay of the Y-direction vibration to be larger (or smaller) than 90° relative to the phase of the Y-direction drive signal. In such cases, the phase difference between the excited X-direction and Y-direction vibrations will not be 90°.

[0075] The influence of the mismatch described above on the processing system of the gyro device 10 will now be described. Fig. 19 is a simplified block diagram of the gyro device 10. Note that the first detection unit 30a detects the CW component contained in the vibration of the two-dimensional oscillator 15, and therefore is represented as a CW detector in Fig. 19. Similarly, the second detection unit 30b detects the CCW component contained in the vibration of the two-dimensional oscillator 15, and therefore is represented as a CCW detector in Fig. 19.

[0076] The occurrence of a phase difference at the drive frequency described above means that even if you intend to drive in CW (CCW), it is not possible to excite pure CW (CCW) vibration (vibration with a phase difference of 90° (-90°) between the vibrations in the X and Y directions) and a CCW (CW) component is generated simultaneously.

[0077] As described above (see FIG. 13, etc.), in the gyro device 10, the system in which the CW mode component loops and the system in which the CCW mode component loops should essentially be independent, but the unwanted CCW mode component contained in the CW mode component passes through the CCW detector. In other words, a signal containing CW mode information leaks into the CCW mode loop system, and the CW mode information enters the PLL (second PLL circuit 40b) in the CCW mode loop. As a result, the operation of the second PLL circuit 40b is disturbed by the unwanted CCW mode component contained in the CW mode, and the frequency to which the second PLL circuit 40b locks is disturbed.

[0078] In the above example, an example was described in which an unnecessary CCW mode component is included in a CW mode component, but the same applies when an unnecessary CW mode component is included in a CCW mode component. That is, the frequency locked by the first PLL circuit 40a is disturbed by the unnecessary CW mode component included in the CCW mode component.

[0079] To address this issue, the phase of the drive signal is shifted in advance (phase adjustment process) to cancel out unnecessary phase differences caused by imperfections in the two-dimensional vibrator 15. As shown in the upper parts of FIGS. 20A and 20B, for example, if the phase difference between the phase of the drive vibration and the phase of the vibration in the X direction is less than 90°, the phase difference, or the phase of the drive signal, is delayed in advance. Also, as shown in the lower parts of FIGS. 20A and 20B, for example, if the phase difference between the phase of the drive vibration and the phase of the vibration in the Y direction is greater than 90°, the phase difference, or the phase of the drive signal, is advanced in advance. This allows the phase difference between the vibration in the X direction and the vibration in the Y direction to be 90°, and a pure natural mode can be excited.

[0080] The phase difference to be compensated for can be determined, for example, from the difference in resonant frequency. Alternatively, the phase difference at which the vibration in the X direction and the vibration in the Y direction are most perpendicular to each other may be determined in advance by experiment or the like, and the phase of the drive signal may be delayed or advanced by the amount of the phase difference to compensate.

[0081] Imperfections in the vibrator not only cause the frequency deviation described above, but also cause a deviation between the Q value (damping) in the X direction and the Q value in the Y direction. When a deviation occurs between the Q values ​​in the X and Y directions, the amplitude of the vibration in the X direction and the amplitude of the vibration in the Y direction will differ at the resonance point, as shown in Figures 21 and 22. When the amplitudes of the vibration in the X direction and the vibration in the Y direction differ, the natural vibration (circular vibration) will no longer occur, and similar to the phenomenon described above, a problem will occur in which CCW mode components will be included in CW mode vibrations (CW mode components will be included in CCW mode vibrations).

[0082] Therefore, as shown in Fig. 23, the amplitude of the drive signal is shifted in advance to compensate for the deviation in the Q value (amplitude adjustment process). For example, as shown in Fig. 23B, the amplitude of vibration in the X direction and the amplitude of vibration in the Y direction that should match at the resonance point are set to amplitude A C This amplitude A C The amplitude of the drive signal in the X direction and the amplitude of the drive signal in the Y direction are shifted in advance by the amount of the shift relative to the amplitude of the drive signal in the X direction. In the example shown in the upper part of FIG. 23A, the attenuation of the vibration (ΔA x In the example shown in the bottom of FIG. 23A, the amplitude of the drive signal is increased by the increment of vibration (ΔA y Of course, there are also cases where compensation is required, such as reducing the amplitude of the drive signal in the X direction or increasing the amplitude of the drive signal in the Y direction.

[0083] The amount of amplitude compensation can be determined, for example, from the difference in Q value. Note that the amount of amplitude compensation at which the vibration in the X direction and the vibration in the Y direction are most perpendicular to each other may be determined in advance by experiment or the like, and the amplitude of the drive signal may be increased or decreased by the amount of amplitude compensation.

[0084] 24 is a block diagram showing an example configuration of a gyro device (gyro device 10A) to which the above-mentioned phase and amplitude adjustment functions are applied. The same components as those in the gyro device 10 are assigned the same reference numerals. In addition to the configuration of the drive signal generation unit 20, the drive signal generation unit 20A of the gyro device 10A has phase adjustment units 91, 92, 93, and 94 and amplitude adjustment units 95, 96, 97, and 98.

[0085] The phase adjustment unit 91 is connected to the input stage of the multiplier 201, and the amplitude adjustment unit 95 is connected to the output stage of the multiplier 201. In order to eliminate unnecessary phase differences and deviations in the Q value caused by imperfections in the two-dimensional oscillator 15, the phase adjustment unit 91 and the amplitude adjustment unit 95 perform the above-described phase adjustment processing and amplitude adjustment processing on the X-direction drive signal in CW mode.

[0086] The phase adjustment unit 92 is connected to the input stage of the multiplier 202, and the amplitude adjustment unit 96 is connected to the output stage of the multiplier 202. In order to eliminate unnecessary phase differences and deviations in the Q value caused by imperfections in the two-dimensional oscillator 15, the phase adjustment unit 92 and the amplitude adjustment unit 96 perform the above-described phase adjustment processing and amplitude adjustment processing on the Y-direction drive signal in CW mode.

[0087] The phase adjustment unit 93 is connected to the input stage of the multiplier 203, and the amplitude adjustment unit 97 is connected to the output stage of the multiplier 203. In order to eliminate unnecessary phase differences and deviations in the Q value caused by imperfections in the two-dimensional vibrator 15, the phase adjustment unit 93 and the amplitude adjustment unit 97 perform the above-described phase adjustment processing and amplitude adjustment processing on the X-direction drive signal in CCW mode.

[0088] The phase adjustment unit 94 is connected to the input stage of the multiplier 204, and the amplitude adjustment unit 98 is connected to the output stage of the multiplier 204. The phase adjustment unit 94 and amplitude adjustment unit 98 perform the above-mentioned phase adjustment processing and amplitude adjustment processing on the Y-direction drive signal in CCW mode to eliminate unnecessary phase differences and Q-value deviations caused by imperfections in the two-dimensional vibrator 15. Note that each phase adjustment unit may be provided at the output stage of each multiplier, but adjusting the phase of the drive signal before the arithmetic processing (multiplication) by the multiplier can simplify the circuit configuration. Furthermore, amplitude adjustment can also be achieved by individually adjusting the magnifications of the multipliers 201 to 204.

[0089] The outputs of amplitude adjustment units 95 and 97 are added together by adder 205, then amplified by amplifier 61a, and supplied to two-dimensional oscillator 15 as an X-direction drive signal. The outputs of amplitude adjustment units 96 and 98 are added together by adder 206, then amplified by amplifier 61b, and supplied to two-dimensional oscillator 15 as a Y-direction drive signal. Two-dimensional oscillator 15 is excited by drive vibrations corresponding to the respective directions. As described above, the phase and amplitude of the drive signals are adjusted in advance, so that the CW mode drive signal can excite only pure CW mode vibrations (the CCW mode drive signal can excite only pure CCW mode vibrations).

[0090] The effect of executing the processing in the gyro device 10A will be described. The horizontal axis of the graphs shown in FIGS. 25A and 25B represents time (t) (s), and the vertical axis represents the frequency f of the oscillator 43a. cw and the frequency f of oscillator 43b ccw The graph in FIG. 25A shows the results when the processing of this embodiment is not applied, and the graph in FIG. 25B shows the results when the processing of this embodiment is applied. As shown in FIG. 25A, the CW mode and CCW mode are not orthogonal due to a mismatch in the phase delay and Q value, so periodic frequency fluctuations due to interference are observed even when rotating at a constant speed. On the other hand, when the above-mentioned processing is applied and the phase and amplitude of the drive signal are adjusted, the orthogonality between the modes is improved, and the periodic frequency fluctuations shown in FIG. 25A are not observed. Therefore, angular velocity can be detected accurately.

[0091] <One embodiment> An embodiment will be described based on the related art described above. As described above, in the gyro device 10, the system in which the CW mode component loops (the upper loop in FIG. 13) and the system in which the CCW mode component loops (the lower loop in FIG. 13) should essentially be independent, but as shown schematically in FIG. 26, there is a problem in which unnecessary CCW mode components are included in the CW mode component, and there is a problem in which unnecessary CW mode components are included in the CCW mode component. To address this problem, as described above, the first and second phase / amplitude adjustment units each perform phase adjustment processing and amplitude adjustment processing. Note that when referring to an amplitude correction value, the amplitude correction value refers to the ratio of the correction value (absolute value) of the amplitude in the Y direction to the correction value (absolute value) of the amplitude in the X direction in the CW loop (A in the CW loop). cw,y / A cw,x , CCW loop: A ccw,y / A ccw,x ) As long as this ratio is satisfied, the amplitude (absolute value) can take any value.

[0092] However, with the above method, it is necessary to set a period of time to determine parameters for performing correction according to the mismatch. The simplest method is to measure the amount of mismatch that occurs when the device is stationary and determine parameters so that this amount becomes zero. However, in this case, it is necessary to ensure that the device is stationary (i.e., the angular velocity is zero), and there is a problem in that the gyro device cannot detect the angular velocity during that time. Therefore, in this embodiment, a method is proposed in which the gyro device detects the angular velocity while simultaneously detecting the mismatch.

[0093] [overview] An overview of this embodiment will be described. In gyro devices that perform the above-mentioned processing (FM gyros and integrated gyros developed from these), frequency (phase) information is used to detect angular velocity (angle), and amplitude information is essentially unimportant. In other words, changing the magnitude of the amplitude does not affect the measurement results of angular velocity (angle). Focusing on this point, this embodiment modulates the amplitude of the drive signal. Then, mismatch is detected by synchronously detecting the output of the two-dimensional vibrator with the modulated signal. This makes it possible to detect mismatch while measuring angular velocity (angle).

[0094] [Gyro device configuration example] A gyro device according to one embodiment (hereinafter referred to as gyro device 1000) has the above-described first detection unit 30a replaced with a detection unit 30A, and the second detection unit 30b replaced with a detection unit 30B. The detection unit 30A is arranged in a system where mainly the CW component loops, and the detection unit 30B is arranged in a system where mainly the CCW component loops.

[0095] 27 is a diagram showing an example of the configuration of the detection unit 30A. The detection unit 30A has a pair of detection units, a first detection unit 30a that functions as a CW detector and a third detection unit 30c (an example of a first error component detection unit) that functions as a CCW detector. The output of the two-dimensional oscillator 15 is supplied to each of them. The output of the first detection unit 30a is supplied to a first PLL circuit 40a and a first AGC unit 50a. The third detection unit 30c receives the same reference signal as the first detection unit 30a, i.e., the signal sin fed back from the first PLL circuit 40a. cw and signal cos cw is input as a reference signal. The output of the third detector 30c is supplied to a first demodulation processor 401, which will be described later.

[0096] 28 is a diagram showing an example of the configuration of the detection unit 30B. The detection unit 30B has a pair of detection units, a second detection unit 30b that functions as a CCW detector and a fourth detection unit 30d (an example of a second error component detection unit) that functions as a CW detector. The output of the two-dimensional oscillator 15 is supplied to each of them. The output of the second detection unit 30b is supplied to a second PLL circuit 40b and a second AGC unit 50b. The fourth detection unit 30d receives the same reference signal as the second detection unit 30b, i.e., the signal sin fed back from the second PLL circuit 40b. CCW and signal cos CCW is input as a reference signal. The output of the fourth detector 30d is supplied to a second demodulation processor 601, which will be described later.

[0097] When the signal input to the detector 30A is only a CW mode component, the third detector 30c detects the signal sin CW and signal cos CW Even if synchronous detection is performed using I as a reference signal, the output will be 0 (see Table 1). However, as described above, if the system of the detection unit 30A also contains a CCW mode component due to imperfections in the vibrator, I, which is an error component corresponding to the CCW mode (an example of a first error component), CCW and Q CCW is detected by the third detector 30c (see FIG. 26).

[0098] Similarly, when the signal input to the detector 30B contains only the CCW mode component, the fourth detector 30d detects the signal sin CW and signal cos CW Even if synchronous detection is performed using I as a reference signal, the output will be 0 (see Table 1). However, as described above, if the system of the detection unit 30A also contains a CCW mode component due to imperfections in the vibrator, I, which is an error component corresponding to the CCW mode (an example of a second error component), CW and Q CW is detected by the fourth detector 30d (see FIG. 26).

[0099] Fig. 29 is a block diagram showing an example of the configuration of a gyro device 1000 according to this embodiment. In the configuration shown in Fig. 29, components that are the same as or of the same quality as those in the gyro devices 10 and 10A are given the same reference numerals, and duplicated explanations will be omitted as appropriate.

[0100] The gyro device 100 includes a first modulation processing unit 301, a first demodulation processing unit 401, a second modulation processing unit 501, and a second demodulation processing unit 601. The first modulation processing unit 301 is connected to an amplitude comparator 51a of a first AGC unit 50a. The first demodulation processing unit 401 is connected to the output side of a detection unit 30A. The second modulation processing unit 501 is connected to an amplitude comparator 51b of a second AGC unit 50b. The second demodulation processing unit 601 is connected to the output side of a detection unit 30B.

[0101] 30, a description will be given of an example configuration of the first modulation processing section 301 and the first demodulation processing section 401. The first modulation processing section 301 has a signal generating section 311, a first modulation section 312, and an amplifier 313.

[0102] The signal generating unit 311 generates a modulated signal. For example, the modulated signal may be a sin(2πf) signal having a predetermined frequency (first frequency). AM, t) is used. Of course, other signals such as cosine waves or spectrum-spread wideband signals may be used as the modulating signal. The first modulating unit 312 modulates the modulating signal sin(2πf AM , t). Specifically, the first modulation unit 312 performs modulation processing using the first setting value R set,cw The modulating signal sin(2πf AM , t), and by providing an offset as necessary, the first set value R' set,cw Generate the first set value R' set,cw The gain of the signal is adjusted appropriately by the amplifier 313, and the signal is then supplied to the amplitude comparator 51a. The amplitude comparator 51a detects the amplitude r cw and the first set value R' set,cw Based on the comparison result, the PID control unit 52a controls the amplitude r cw is a predetermined first set value R' set,cw The output from the PID control unit 52a is fed back to the drive signal generating unit 20, and the amplitude of the drive signal corresponding to the CW mode is controlled to the first set value R' set,cw In other words, the gain is controlled so that the drive signal corresponding to the CW mode is maintained at the modulation signal sin(2πf AM ,t).

[0103] The first demodulation processing unit 401 includes a multiplier 412, a multiplier 413, a multiplier 414, a multiplier 415, an LPF 416, an LPF 417, an LPF 418, an LPF 419, and a phase adjustment unit 420. CCW are supplied to the multipliers 412 and 413. CQW are supplied to multipliers 414 and 415, respectively.

[0104] The LPF 416 is connected to the output side of the multiplier 412. The LPF 417 is connected to the output side of the multiplier 413. The LPF 418 is connected to the output side of the multiplier 414. The LPF 419 is connected to the output side of the multiplier 415.

[0105] Modulation signal sin(2πf AM , t) is also supplied from the first modulation processing unit 301 to the first demodulation processing unit 401. The phase adjustment unit 420 advances the phase of the input signal by 90° to generate an orthogonal signal (cos(2πf AM ,t)) to generate sin(2πf AM , t) are fed to multipliers 412 and 414, respectively, and cos(2πf AM , t) are fed to multipliers 413 and 415, respectively.

[0106] The operation of the first demodulation processing unit 401 will be described. The multiplier 412 multiplies sin(2πf AM , t) is supplied from the third detection unit 30c. CCW The LPF 416 processes the multiplication result to extract signals below the cutoff frequency. This results in a modulation signal sin(2πf AM , t) and the in-phase component signal I c is extracted.

[0107] The multiplier 413 multiplies the signal whose phase has been adjusted by the phase adjustment unit 420 (in this example, cos(2πf AM , t)) is supplied from the third detection unit 30c. CCW The LPF 417 processes the multiplication result to extract signals below the cutoff frequency. This results in the modulation signal sin(2πf AM , t) and the phase of the I component signal I D is extracted.

[0108] Multiplier 414 multiplies sin(2πf AM , t) is supplied from the third detection unit 30c as Q CCW The LPF 418 processes the multiplication result to extract signals below the cutoff frequency. This results in the modulation signal sin(2πf AM , t) and the signal Q c is extracted.

[0109] The multiplier 415 multiplies the signal whose phase has been adjusted by the phase adjustment unit 420 (in this example, cos(2πf AM , t)) is supplied from the third detection unit 30c as Q CCW The LPF 419 processes the multiplication result to extract signals below the cutoff frequency. This results in the modulation signal sin(2πf AM , t) and the phase of the Q component signal Q D is extracted.

[0110] 31, a description will be given of an example configuration of the second modulation processing section 501 and the second demodulation processing section 601. The second modulation processing section 501 has a signal generating section 511, a second modulation section 512, and an amplifier 513.

[0111] The signal generating unit 511 generates a modulated signal. To prevent interference, the signal generating unit 511 generates a modulated signal that is different from the modulated signal used in the CW loop. For example, the signal generating unit 511 generates a modulated signal sin(2πf AM , t) and frequency (second frequency whose frequency is different from the first frequency) sin(2πf AM The signal generating unit 511 may generate a spread spectrum signal that is orthogonal to the modulation signal of the CW loop as the modulation signal. The second modulation unit 512 generates the modulation signal sin(2πf AM Specifically, the second modulation unit 512 performs modulation processing using the second setting value R set,ccw The modulating signal sin(2πf AM ',t) and add an offset as needed to obtain the second set value R' set,ccw The second set value R' is generated. set,ccw The gain of the signal is adjusted appropriately by the amplifier 513, and the signal is then supplied to the amplitude comparator 51b. The amplitude comparator 51b detects the amplitude r ccw and the second set value R' set,ccw Based on the comparison result, the PID control unit 52b controls the amplitude r ccw is a predetermined second set value R' set,ccwThe output from the PID control unit 52b is fed back to the drive signal generating unit 20, and the amplitude of the drive signal corresponding to the CCW mode is set to the second set value R' set,ccw In other words, the gain is controlled so that the drive signal corresponding to the CCW mode is maintained at the modulation signal sin(2πf AM ',t).

[0112] The second demodulation processing unit 601 includes a multiplier 612, a multiplier 613, a multiplier 614, a multiplier 615, an LPF 616, an LPF 617, an LPF 618, an LPF 619, and a phase adjustment unit 620. CW are supplied to the multipliers 612 and 613. CW are provided to multipliers 614 and 615, respectively.

[0113] The LPF 616 is connected to the output side of the multiplier 612. The LPF 617 is connected to the output side of the multiplier 613. The LPF 618 is connected to the output side of the multiplier 614. The LPF 619 is connected to the output side of the multiplier 615.

[0114] Modulation signal sin(2πf AM , t) is also supplied from the second modulation processing unit 501 to the second demodulation processing unit 601. The phase adjustment unit 620 adjusts the phase of the input signal by 90° to generate an orthogonal signal (cos(2πf AM ',t)) to generate sin(2πf AM ',t) is fed to multipliers 612, 614, respectively, and cos(2πf AM ',t) are fed to multipliers 613, 615, respectively.

[0115] The operation of the second demodulation processing unit 601 will be described. The multiplier 612 multiplies sin(2πf AM ', t) is supplied from the fourth detection unit 30d. CWThe LPF 616 processes the multiplication result to extract signals below the cutoff frequency. This results in a modulation signal sin(2πf AM ',t) and the signal I c ' is extracted.

[0116] The multiplier 613 multiplies the signal whose phase has been adjusted by the phase adjustment unit 620 (in this example, cos(2πf AM ', t)) is supplied from the fourth detection unit 40d. CW The LPF 617 processes the multiplication result to extract signals below the cutoff frequency. This results in a modulation signal sin(2πf AM ',t) and the phase of the I component signal I D ' is extracted.

[0117] Multiplier 614 multiplies sin(2πf AM ', t) is supplied from the fourth detection unit 40d as Q CW The LPF 618 processes the multiplication result to extract signals below the cutoff frequency. This results in a modulation signal sin(2πf AM ',t) and the Q component signal Q c ' is extracted.

[0118] The multiplier 615 multiplies the signal whose phase has been adjusted by the phase adjustment unit 620 (in this example, cos(2πf AM ', t)) is supplied from the fourth detection unit 40d. CW The LPF 619 processes the multiplication result to extract signals below the cutoff frequency. This results in the modulation signal sin(2πf AM ',t) and the phase of the Q component signal Q D ' is extracted.

[0119] The signal I obtained by the processing in the first demodulation processing unit 401 and the second demodulation processing unit 601 c , I D , Q c , Q D , and signal I c , I D , Qc , Q D is 0 if the two-dimensional oscillator is ideal and there is no mismatch. In this embodiment, the signal I c , I D , Q c , Q D , and signal I c , I D , Q c , Q D When a signal is detected, the amplitude correction value of the drive signal in each loop (A for the CW loop) is adjusted to zero the detected signal. cw,y / A cw,x , CCW loop: A ccw,y / A ccw,x ) and the phase adjustment values ​​in the phase adjustment units 91 to 94 are set. For example, the signal I c , I D , Q c , Q D , and signal I c , I D , Q c , Q DA table is prepared in which correction values ​​corresponding to the respective detected values ​​are written, and the correction value corresponding to the detected value is read out, and amplitude and phase adjustment processing is performed according to the read correction value. In addition, as a method for obtaining optimal parameters for amplitude and phase correction, it is also possible to use the methods previously proposed by the present inventors: "T. Tsukamoto and S. Tanaka, "Automated Frequency and Quality Factor Mismatch Compensation Method for MEMS Rate Integrating Gyroscope," in Proc. 2019 20th International Conference on Solid-State Sensors, Actuators and Microsystems Eurosensors XXXIII (TRANSDUCERS EUROSENSORS XXXIII), 2019, pp. 1831-1834." and "T. Tsukamoto and S. Tanaka, "Theoretical Consideration of Mismatch Compensation for MEMS Resonator Having Unaligned Principle Axes," in Proc. 2021 IEEE International Symposium on Inertial Sensors and Systems (INERTIAL), 2021, pp. 1--4."

[0120] [Experimental Example] The results of an experiment using an actual two-dimensional oscillator will be described with reference to Figures 32 and 33. The vertical axis of Figures 32A and 32B represents the signal I C , I D The horizontal axis of FIG. 32A indicates the mismatch in the Q factor, and the horizontal axis of FIG. 32B indicates the mismatch in frequency. The vertical axes of FIG. 33A and FIG. 33B indicate the mismatch in the Q factor of the signal in the CW loop. C , Q DThe horizontal axis of FIG. 33A indicates the mismatch in the Q value, and the horizontal axis of FIG. 33B indicates the mismatch in the frequency.

[0121] The values ​​of each axis may be expressed as arbitrary units (au) normalized using a predetermined reference value. Since it is difficult to change the mismatch of an actual two-dimensional oscillator, a correction value corresponding to the mismatch (amplitude correction value A cw,y / A cw,x , phase correction value Δφ CW ) from the optimal value (matching value) to introduce mismatch.

[0122] As shown in FIG. 32A, it was confirmed that the value on the vertical axis changes when the amplitude correction value is shifted from the optimal value (center value). Furthermore, when the phase correction value is changed to change the frequency, it was confirmed that the value on the vertical axis does not change, as shown in FIG. 32B. Furthermore, as shown in FIG. 33A, it was confirmed that in the case of the Q component signal, the value on the vertical axis does not change even when the amplitude correction value is shifted from the optimal value (center value). Furthermore, when the phase correction value is changed to change the frequency, it was confirmed that the value on the vertical axis changes, as shown in FIG. 33B. In other words, it was confirmed that a Q value mismatch in a two-dimensional vibrator can be detected based on the I component signal. It was also confirmed that a frequency mismatch in a two-dimensional vibrator can be detected based on the Q component signal.

[0123] [Effects Obtained by This Embodiment] As described above, according to this embodiment, a mismatch is detected using an amplitude signal that does not affect the detection result of the angular velocity, so a gyro device can be provided that can perform correction according to the mismatch while detecting the angular velocity. Therefore, there is no need to provide a period (such as calibration) for performing correction according to the mismatch.

[0124] <Modification> Although one embodiment of the present invention has been specifically described above, the present invention is not limited to the above-described embodiment and various modifications are possible.

[0125] In one embodiment, when mismatches in the CW loop and the CCW loop are detected separately, the same modulation signal may be used. Furthermore, when the mismatch amount of a two-dimensional vibrator is directly calculated, processing of only one loop (e.g., processing related to the first modulation processing unit 301 and the first demodulation processing unit 401) may be performed, and the result may be applied to the other loop (e.g., the CCW loop) to correct the drive signal in that loop. However, from the viewpoint of improving accuracy, it is preferable to perform processing to detect mismatches in both loops.

[0126] The signals generated by the signal generating units 311 and 511 are not limited to single-frequency sine waves, and other methods, such as spread spectrum technology using wideband signals, may be applied. That is, the first and second setting values ​​may be spread with predetermined spreading codes (first and second pseudorandom signals) and then despread in a subsequent demodulation process, thereby detecting a mismatch. That is, in one embodiment, amplitude modulation is used as the first modulation method performed by the first modulation processing unit and the second modulation method performed by the second modulation processing unit, but the present invention is not limited to this, and other known modulation methods and demodulation methods corresponding to the modulation methods may be applied to the present invention.

[0127] The method of correcting frequency and Q value mismatches is not limited to the method of adjusting the phase difference and amplitude ratio of the drive signals shown in the example, but methods such as electrostatic tuning may also be used.

[0128] The present invention is not limited to a specific shape, excitation method (electrostatic, electromagnetic, piezoelectric, etc.), etc., as long as the vibrator is two-dimensionally mode-matched.

[0129] The circuit that processes the output of the two-dimensional oscillator 15 can also be configured with an integrated circuit such as an ASIC (Application Specific Integrated Circuit).

[0130] As long as the effects of the present invention are achieved, the gyro device may be configured to include other circuit elements, etc. Also, some of the processing in the gyro device may be performed by another device, a cloud server, etc.

[0131] The gyro device of the present invention may be incorporated into and used in other devices (for example, various electronic devices such as game devices, imaging devices, smartphones, mobile phones, and personal computers, as well as moving objects such as automobiles, trains, airplanes, helicopters, small aircraft, and space equipment, and robots).

[0132] The configurations, methods, steps, shapes, materials, and numerical values ​​described in the above-described embodiments are merely examples, and different configurations, methods, steps, shapes, materials, and numerical values ​​may be used as necessary. Furthermore, the present invention can be realized by an apparatus, a method, or a system (such as a cloud system) consisting of multiple apparatuses, and the matters described in the multiple embodiments and modifications can be combined with each other as long as no technical contradictions arise. [Explanation of symbols]

[0133] 15, 15A... 2D vibrator 30a First detection unit 30b Second detection unit 40a First PLL circuit 40b Second PLL circuit 42a, 42b PID control section 301: First modulation processing section 311 Signal generator 312 First modulation section 401: First demodulation processing unit 412~415... Multiplier 416~419 LPF 420 Phase adjustment unit 501: First modulation processing section 511 Signal generator 512 First modulation section 601: First demodulation processing unit 612~615... Multiplier 616~619 LPF 620 Phase adjustment unit 1000···Gyroscope sensor CW: First rotational vibration mode CCW: Second rotational vibration mode

Claims

1. a single two-dimensional vibrator that is driven by a drive signal corresponding to a first rotational vibration mode and a drive signal corresponding to a second rotational vibration mode, and that outputs an output signal corresponding to the first rotational vibration mode and an output signal corresponding to the second rotational vibration mode; a first modulation processing unit that modulates the amplitude of a drive signal corresponding to the first rotational vibration mode using a first modulation method; a second modulation processing unit that modulates the amplitude of the drive signal corresponding to the second rotational vibration mode using a second modulation method; a first error component detector that detects a first error component corresponding to the second rotational vibration mode and that is included in an output signal corresponding to the first rotational vibration mode; a second error component detector that detects a second error component corresponding to the first rotational vibration mode and that is included in the output signal corresponding to the second rotational vibration mode; a first demodulation processing unit that demodulates a first error component corresponding to the second rotational vibration mode by a first demodulation method corresponding to the first modulation method; a second demodulation processing unit that demodulates a second error component corresponding to the first rotational vibration mode by a second demodulation method corresponding to the second modulation method; Equipped with Gyro device.

2. The amplitude and phase of the drive signal corresponding to the first rotational vibration mode and the amplitude and phase of the drive signal corresponding to the second rotational vibration mode are corrected so that a signal obtained by demodulation processing using the first demodulation method in the first demodulation processing unit and a signal obtained by demodulation processing using the second demodulation method in the second demodulation processing unit are set to zero.

2. The gyro device according to claim 1.

3. The frequencies and Q values ​​of the X-axis and Y-axis of the two-dimensional vibrator are electrically tuned so that the signal obtained by the demodulation process using the first demodulation method in the first demodulation processing unit and the signal obtained by the demodulation process using the second demodulation method in the second demodulation processing unit are set to zero.

2. The gyro device according to claim 1.

4. the first modulation method and the first demodulation method are modulation methods and demodulation methods using a signal of a first frequency, The second modulation method and the second demodulation method are modulation methods and demodulation methods using signals of a second frequency different from the first frequency.

4. The gyro device according to claim 1.

5. the first modulation scheme and the first demodulation scheme are modulation schemes and demodulation schemes using a first pseudorandom signal, The second modulation method and the second demodulation method are modulation methods and demodulation methods using a second pseudorandom signal different from the first pseudorandom signal.

4. The gyro device according to claim 1.

6. A mismatch in the Q value of the two-dimensional vibrator and a mismatch in the frequency of the two-dimensional vibrator are detected based on at least one of a signal obtained by demodulation processing using the first demodulation method in the first demodulation processing unit and a signal obtained by demodulation processing using the second demodulation method in the second demodulation processing unit.

6. The gyro device according to claim 1.

7. A mismatch in the Q value of the two-dimensional vibrator and a mismatch in the frequency of the two-dimensional vibrator are detected based on both a signal obtained by the demodulation process using the first demodulation method of the first demodulation processing unit and a signal obtained by the demodulation process using the second demodulation method of the second demodulation processing unit.

7. The gyro device according to claim 6.

8. The angle of rotation is detected based on the phase difference between the component corresponding to the first rotational vibration mode and the component corresponding to the second rotational vibration mode.

8. The gyro device according to claim 1.

9. a single two-dimensional oscillator driven by a drive signal corresponding to a first rotational vibration mode and a drive signal corresponding to a second rotational vibration mode outputs an output signal corresponding to the first rotational vibration mode and an output signal corresponding to the second rotational vibration mode; a first modulation processing unit modulating the amplitude of the drive signal corresponding to the first rotational vibration mode using a first modulation method; a second modulation processing unit modulating the amplitude of the drive signal corresponding to the second rotational vibration mode using a second modulation method; a first error component detection unit detecting a first error component corresponding to the second rotational vibration mode, the first error component being included in an output signal corresponding to the first rotational vibration mode; a second error component detection unit detecting a second error component corresponding to the first rotational vibration mode, the second error component being included in an output signal corresponding to the second rotational vibration mode; a first demodulation processing unit demodulating a first error component corresponding to the second rotational vibration mode by a first demodulation method corresponding to the first modulation method; a second demodulation processing unit demodulating a second error component corresponding to the first rotational vibration mode by a second demodulation method corresponding to the second modulation method; A control method for a gyro device.

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