Gyroscope sensor and control method thereof

Abstract

A gyroscope sensor and a control method of the gyroscope sensor are provided. A gyroscope sensor uses a control unit (10) having PLLs (140, 141), AGC (130, 131), a detection gain ratio correction unit (106), and a drive gain ratio correction unit (153) to drive and control a sensor unit comprising an oscillator (2) and a mounting substrate (3) having a plurality of electrodes facing the oscillator (2). With the two vibration axes of the vibrator as the x axis and the y axis, the detection gain ratio correction unit corrects the gain ratio of the detection signals from the x-axis vibration and the y-axis vibration of the sensor unit, and the drive gain ratio correction unit corrects the gain ratio of the drive signals for the x-axis vibration and the y-axis vibration of the sensor unit. The control unit has an angle feedback unit (180) that, after the correction of the travel detection gain ratio and the drive gain ratio, calculates a rotation angle by means of an integral operation of the angular velocity on the basis of angular velocity information from the AGC, and performs feedback of the rotation angle.

Description

Technical Field

[0001] The present disclosure relates to a gyroscope sensor and a control method thereof. Background Art

[0002] Currently, a gyroscope sensor is known, which includes an oscillator having two vibration modes with different resonance angular frequencies, a mounting substrate having a plurality of electrodes surrounding the oscillator and used for driving and detecting vibrations, and a control unit for performing its drive control (for example, Patent Document 1).

[0003] The gyroscope sensor described in Patent Document 1 detects the angle of rotation applied to the oscillator in a state where the oscillator resonates in the first vibration mode and the second vibration mode by a control method called the Whole angle mode.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: US Patent No. 10520331 Specification Summary of the Invention

[0007] The Whole angle mode has advantages such as being able to obtain rotation angle information and being able to increase the range of angular velocity input to the oscillator. The oscillator in this gyroscope sensor can be regarded as a two-dimensional vibration model of a two-degree-of-freedom system that connects two vibration axes with two specified spring constants orthogonal to the mass point and two attenuation axes with two specified attenuation coefficients in a two-dimensional plane along the mounting substrate on which it is mounted. At this time, when the rotation angle in the Whole angle mode is set to θ, the angular velocity is represented by the following formula (1).

[0008] [Mathematical Formula 1]

[0009]

[0010] η in formula (1) is the Angular Gain, τ is the time constant, θ τ is the angle formed by the attenuation axis of the oscillator and the electrode axis, θ ω is the angle formed by the vibration axis of the oscillator and the electrode axis, Q is the energy of useless vibration called Quadrature error, Δω is the difference in resonance angular frequencies of the two vibration axes, and E is the vibration energy.

[0011] According to equation (1), in the full-angle mode, due to the frequency error of the oscillator called Angle Dependent Bias and the error of the time constant depending on the Q value, an error will occur in the measured angle. In addition, when the two vibration axes of the oscillator are set as the x-axis and the y-axis, due to the machining error of the oscillator, etc., a gain error of the drive signal between the x-axis and the y-axis and a gain error of the detection signal of the vibration will occur. Therefore, these gain errors will become the main cause of the error in the measured angle in the full-angle mode.

[0012] In view of the above points, an object of the present disclosure is to provide a gyro sensor and a control method thereof that are controlled in the full-angle mode and can reduce the error in the measured angle caused by the gain error of the drive signal between the two vibration axes of the oscillator and the gain error of the detection signal of the vibration.

[0013] According to one aspect of the present disclosure, a gyro sensor includes:

[0014] An oscillator having a first vibration mode and a second vibration mode with different resonant angular frequencies;

[0015] A mounting substrate having a plurality of electrodes opposed to the oscillator; and

[0016] A control unit that performs drive control of the oscillator,

[0017] Define the radial direction with an imaginary straight line passing through the center of the region surrounded by the plurality of electrodes and along the thickness direction of the mounting substrate as the axis. The direction along the vibration direction of the first vibration mode and as the radial direction is set as the x-axis, and the direction along the vibration direction of the second vibration mode and as the radial direction is set as the y-axis.

[0018] The control unit includes:

[0019] A PLL for driving the oscillator on two axes of the first vibration mode and the second vibration mode;

[0020] A detection gain ratio correction unit that corrects the detection gain ratio, which is the ratio of the gain of the first detection signal from the first detection electrode that detects the vibration on the x-axis of the oscillator among the plurality of electrodes to the gain of the second detection signal from the second detection electrode that detects the vibration on the y-axis of the oscillator;

[0021] A first coordinate conversion unit that uses the plane coordinate axes formed by the radial direction as the actual coordinate axes and converts the signal from the detection electrode from the actual coordinate axes to the coordinate axes for calculation;

[0022] A drive gain ratio correction unit that corrects a drive gain ratio, which is the ratio of the gain of a first drive signal for a first drive electrode that causes an oscillator to vibrate in a first vibration mode among a plurality of electrodes to the gain of a second drive signal for a second drive electrode that causes the oscillator to vibrate in a second vibration mode;

[0023] A second coordinate conversion unit that converts the signal corrected by the drive gain ratio correction unit from the operation coordinate axes to the actual coordinate axes;

[0024] A first demodulation block that performs operations of a first demodulation output based on a first detection signal and a first drive signal and a second demodulation output based on the first detection signal and a second drive signal;

[0025] A second demodulation block that performs operations of a third demodulation output based on a second detection signal and a first drive signal and a fourth demodulation output based on the second detection signal and a second drive signal;

[0026] An AGC that performs operations of a drive output for maintaining the vibration amplitudes in the first vibration mode and the second vibration mode of the oscillator; and

[0027] An angle feedback unit that has an integration circuit that calculates a rotation angle by integrating an angular velocity based on information of the angular velocity input from the AGC after the detection gain ratio and the drive gain ratio are corrected, and feeds back the calculated rotation angle to the first coordinate conversion unit and the second coordinate conversion unit.

[0028] This gyro sensor drives the oscillator in two vibration modes respectively through two independent PLLs and AGCs, and calculates four demodulation outputs obtained by combining one of the detection signals in the two vibration modes with one of the drive signals through two demodulation blocks. In addition, based on the demodulation outputs, this gyro sensor uses a detection gain ratio correction unit and a drive gain ratio correction unit to correct the gain ratios of the detection signals and drive signals of the x-axis and y-axis of the oscillator, and reduces the influence of the gain ratios of the drive / detection signals of the oscillator on the x-axis and y-axis. Therefore, this gyro sensor is controlled in a full-angle mode and reduces the measurement angle error caused by the gain ratios of the detection signal and the drive signal.

[0029] According to another aspect of the present disclosure, a control method of a gyro sensor is a control method of a gyro sensor in which an oscillator having a first vibration mode and a second vibration mode with different resonant angular frequencies is mounted on a mounting substrate having a plurality of electrodes opposed to the oscillator, and includes:

[0030] Driving the oscillator on two axes in the first vibration mode and the second vibration mode through two independent PLLs and AGCs;

[0031] Define the radial direction with an imaginary straight line passing through the center of the region surrounded by multiple electrodes and along the thickness direction of the mounting substrate as the axis. Set the direction along the vibration direction of the first vibration mode as the x-axis in the radial direction, and the direction along the vibration direction of the second vibration mode as the y-axis in the radial direction. Calculate and determine the detection gain ratio, which is the ratio of the gain of the first detection signal from the first detection electrode among the multiple electrodes that detects the vibration of the oscillator on the x-axis to the gain of the second detection signal from the second detection electrode among the multiple electrodes that detects the vibration of the oscillator on the y-axis;

[0032] Calculate and determine the drive gain ratio, which is the ratio of the gain of the first drive signal for the first drive electrode that causes the oscillator to vibrate on the x-axis among the multiple electrodes to the gain of the second drive signal for the second drive electrode that causes the oscillator to vibrate on the y-axis among the multiple electrodes;

[0033] Through the demodulation block, perform operations on the demodulation outputs based on the first detection signal and the first drive signal, the demodulation output based on the first detection signal and the second drive signal, the demodulation output based on the second detection signal and the first drive signal, and the demodulation output based on the second detection signal and the second drive signal;

[0034] Set the x-axis and y-axis as the vibration axes. Define the radial direction with an imaginary straight line passing through the center of the region surrounded by multiple electrodes and along the thickness direction of the mounting substrate as the axis. Set the direction along the drive electrode among the multiple electrodes that drives in the first vibration mode and the second vibration mode as the electrode axis. After determining the detection gain ratio, based on the results calculated in the demodulation block, calculate the angle formed by the vibration axis of the oscillator and the electrode axis, i.e., the offset angle, and perform feedback control of the offset angle;

[0035] After performing the feedback control of the offset angle, based on the frequency signal corresponding to the first vibration mode and the frequency signal corresponding to the second vibration mode output from the PLL, calculate the difference in resonance frequencies between the first vibration mode and the second vibration mode, i.e., Δf, and perform feedback control of Δf;

[0036] After performing the feedback control of Δf and determining the drive gain ratio, calculate the rotation angle of the gyroscope sensor through integral operation of the angular velocity, and feedback the calculated rotation angle to the operations of the rotation angle in the detection direction and the rotation angle in the drive direction of the vibration of the oscillator; and

[0037] After performing the feedback of the rotation angle, measure the angle and angular velocity of the gyroscope sensor.

[0038] The control method of the gyro sensor drives the oscillator in two vibration modes respectively through two independent PLLs and AGCs, and obtains four demodulation outputs by combining one of the detection signals in the two vibration modes with one of the drive signals through the operation of two demodulation blocks. In addition, based on the demodulation output, the control method of the gyro sensor determines the gain ratio of the detection signals of the x-axis and y-axis of the oscillator, that is, the detection gain ratio, through calculation, and then calculates the offset angle between the vibration axis and the electrode axis of the oscillator and performs feedback of the offset angle. In addition, based on the two drive signals corresponding to the two vibration modes from the two PLLs, the control method of the gyro sensor calculates the difference Δf of the resonance frequencies and performs feedback thereof, and calculates and determines the gain ratio of the drive signals of the x-axis and y-axis, that is, the drive gain ratio.

[0039] After performing the above processing, the control method of the gyro sensor performs the calculation of the angle and angular velocity, thereby obtaining the effect of reducing the error of the measured angle caused by the gain ratios of the x-axis and y-axis of the detection signal and the drive signal. Brief Description of the Drawings

[0040] Figure 1 It is a perspective view showing a structural example of a sensor element in a gyro sensor.

[0041] Figure 2 It shows Figure 1 a cross-sectional view of the cross-sectional structure at the II-II line of

[0042] Figure 3 It is equivalent to Figure 2 a drawing of

[0043] Figure 4 It is an explanatory drawing regarding the vibration axis and electrode axis of the sensor element.

[0044] Figure 5 It is a drawing showing a two-dimensional vibration model of the oscillator of the gyro sensor.

[0045] Figure 6 It is a block diagram showing the structure of the gyro sensor according to the embodiment.

[0046] Figure 7 It is a block diagram showing the circuit structure of the offset angle correction unit.

[0047] Figure 8 It is a block diagram showing the circuit structure of the mode matching control unit.

[0048] Figure 9 It is a block diagram showing the circuit structure of the angle feedback unit.

[0049] Figure 10It is an explanatory diagram of the first vibration mode and the second vibration mode of an oscillator vibrating in a wine glass mode.

[0050] Figure 11 It is an explanatory diagram of a demodulation output calculated by a demodulation block.

[0051] Figure 12 It shows the demodulation output, the output waveform, and θ ω The diagram of the relationship of polarities.

[0052] Figure 13 It is an explanatory diagram of the first operation for detecting a gain ratio.

[0053] Figure 14 It is an explanatory diagram of the second operation for detecting a gain ratio.

[0054] Figure 15 It is an explanatory diagram of the third operation for detecting a gain ratio.

[0055] Figure 16 It is an explanatory diagram of the operation of a drive gain ratio.

[0056] Figure 17 It is a flowchart showing an example of a process for reducing an error in a measured angle. Detailed implementation mode

[0057] Hereinafter, embodiments of the present disclosure will be described based on the drawings. In addition, in the following embodiments, the same or equivalent parts in each other are denoted by the same reference numerals for description.

[0058] (First Embodiment)

[0059] The gyro sensor 1 of the first embodiment will be described with reference to the drawings.

[0060] [Basic Structure]

[0061] For example, as Figure 1 shown, the gyro sensor 1 of the present embodiment includes a sensor element having an oscillator 2 and a mounting substrate 3, and the oscillator 2 is mounted on the mounting substrate 3. The gyro sensor 1 can detect the angular velocity and the rotation angle applied to the gyro sensor 1 based on the change in the electrostatic capacitance between a part of the thin-walled oscillator 2 that can vibrate in the first vibration mode and the second vibration mode and a plurality of first electrode portions 51 in the mounting substrate 3. The gyro sensor 1 is controlled, for example, by a control unit 10 described later in a full-angle mode, and correction and feedback processing for reducing the error in the measured angle are performed.

[0062] For example, as Figure 2As shown, the oscillator 2 is a minute vibrating body having a three-dimensional substantially symmetric structure with a curved surface portion 21 and a mounting portion 22. The curved surface portion 21 includes the outer shape of a three-dimensional curved surface of a substantially hemispherical shape, and the mounting portion 22 extends from the vertex side of the imaginary hemisphere formed by the curved surface portion 21 toward the center side of the hemisphere. For example, conductive films (not shown) are formed on both the front and back surfaces of the oscillator 2, and a voltage can be applied from the mounting substrate 3. Moreover, in the oscillator 2, for example, an edge 23 at an end of the curved surface portion 21 opposite to the mounting portion 22 faces a plurality of first electrode portions 51, and the edge 23 vibrates in a resonant mode by the electrostatic force generated between the first electrode portions 51 and the edge 23.

[0063] In addition, for example, the oscillator 2 can be manufactured by preparing a plate material made of any reflow soldering material such as quartz and a mold having a bowl-shaped recess and a pillar portion at the center of the recess, placing the plate material in the mold, and heating and softening it while reducing the pressure in the recess.

[0064] In addition, for example, as Figure 3 shown, the oscillator 2 may also have a substantially disk shape having a disk-shaped portion and a columnar connecting portion joined to the mounting substrate 3 at the center of the portion. In this case, an edge 23 is at the end of the hollow disk-shaped portion of the oscillator 2, and this portion is surrounded by a plurality of first electrode portions 51. Thus, the oscillator 2 may have any structure as long as it can vibrate in a first vibration mode and a second vibration mode by a driving electrode among the plurality of first electrode portions 51. In addition to the above structure, other known structures may also be used.

[0065] For example, as Figure 1 and Figure 2 shown, the mounting substrate 3 includes a lower substrate 4 and an upper substrate 5, and is a structure formed by joining them. For example, the mounting substrate 3 is obtained by performing wiring film formation, etc. on the lower substrate 4 made of borosilicate glass as an insulating material, then anodically bonding the upper substrate 5 made of silicon as a semiconductor material to the lower substrate 4, and patterning. For example, the mounting substrate 3 forms a plurality of first electrode portions 51 and second electrode portions 52 by performing dry etching such as DRIE on the anodically bonded upper substrate 5. DRIE is an abbreviation for Deep Reactive Ion Etching. In addition, for example, when the oscillator 2 is Figure 2 shown in the shape of a birdbath, a circular ring-shaped groove (not shown) along the edge 23 may be formed on the lower substrate 4 as needed so as not to contact the edge 23.

[0066] A plurality of first electrode portions 51 surround, for example, the edge 23 of the vibrator 2, and are arranged at equal intervals and separated from each other in a manner of depicting a ring on the plane of the mounting substrate. Each of the plurality of first electrode portions 51 forms an electrode film (not shown) on its upper surface. The plurality of first electrode portions 51 can control their potentials, for example, by connecting wires (not shown) to the electrode film (not shown) and electrically connecting to an external circuit board or the like. The plurality of first electrode portions 51 are all in a state of being separated from the edge 23 of the vibrator 2 by a predetermined distance, and form capacitors with the vibrator 2 respectively, and can detect the electrostatic capacitance between them and the vibrator 2. A part of the plurality of first electrode portions 51 is a detection electrode for detecting the electrostatic capacitance, and the other part is a drive electrode for applying an electrostatic force to the edge 23 of the vibrator 2.

[0067] For example, as Figure 1 shown, the second electrode portion 52 has a frame shape surrounding the plurality of first electrode portions 51, forms an electrode film (not shown) on its upper surface, and connects wires (not shown) to the electrode film (not shown). The second electrode portion 52 is connected to a conductive film (not shown) of the vibrator 2 through wirings (not shown) or the like, and is configured to be able to apply a voltage.

[0068] Hereinafter, for the sake of convenience of explanation, the sensor element composed of the vibrator 2 and the mounting substrate 3 and a circuit (such as a current-voltage conversion circuit or the like) (not shown) for applying a voltage to the plurality of first electrode portions 51 are sometimes collectively referred to as a "sensor unit".

[0069] When the vibrator 2 is observed from the normal direction with respect to the plane direction formed by the mounting substrate 3 (hereinafter referred to as "top view observation"), by applying a voltage to a part of the first electrode portion 51, for example, as Figure 4 shown, it becomes a resonant state in which the number of antinodes and nodes of the vibration amplitude of the outer contour of the edge 23 is 2n respectively. n is an integer of 2 or more, and such a resonant state of the vibrator 2 is called a "wine-glass mode". In addition, in Figure 4 the state shown as a representative example is the resonant mode with n = 2 in the wine-glass mode, and the vibration axes x, y and the electrode axes X, Y described later coincide, but the vibrator 2 can also vibrate in a higher-order wine-glass mode with n = 3 or more.

[0070] Hereinafter, for the sake of convenience of explanation, as Figure 4As shown, with the center position of the edge 23 when viewed from above as the center C, the radial direction with the straight line passing through the center C and along the thickness direction of the mounting substrate 3 as the axis is called the "substrate radial direction", and the circumferential direction with this straight line as the axis is called the "substrate circumferential direction". In addition, the direction along the substrate radial direction passing through the position of the antinode of the vibration at the edge 23 of the oscillator 2 in the first vibration mode (resonant angular frequency ω1) is called the "vibration axis x", and the direction passing through the position of the node is called the "vibration axis y". At this time, in the wine glass mode where n = k (k: an integer of 2 or more), the angle formed by the vibration axis x and the vibration axis y is (360 / 4k)°. For example, in the wine glass mode where n = 2, the angle formed by the vibration axis x and the vibration axis y is 45°.

[0071] A plurality of first electrode portions 51 are arranged separated from each other along the substrate circumferential direction, for example, and are arranged in such a manner that the distances from the edge 23 in the non-vibrating state are substantially the same. Hereinafter, for the sake of convenience of explanation, for example, as Figure 4 shown, one direction on the actual plane where the plurality of first electrode portions 51 are arranged is set as the "X r direction", and the direction orthogonal to the X r direction on this plane is set as the "Y r direction", and the plane to which the X r direction and the Y r direction belong is set as the "X r Y r plane". Moreover, one direction on the X r Y r plane is defined as the "electrode axis X", and the direction toward which the electrode axis X is rotated counterclockwise by (360 / 4k)° along the substrate circumferential direction on the X r Y r plane is defined as the "electrode axis Y".

[0072] At this time, for example, as Figure 5 shown, the sensor unit connects two springs with spring constants k x 、k y along its vibration direction and two objects with damping coefficients C x 、C y when viewed from above, and can be regarded as a vibrating body of a two-degree-of-freedom system vibrating in a two-dimensional plane. In addition, Figure 5 and the following Figure 10 represent the X r Y rThe vibration axes x and y and the electrode axes X and Y on the plane are respectively converted into an orthogonal coordinate system, and the origins of the vibration axes x and y are made to coincide with the origins of the electrode axes X and Y. The converted orthogonal coordinate system corresponds to the axes for calculation in the control unit 10. The vibration axes x and y may also be referred to as spring axes. Hereinafter, the vibration axes x and y may sometimes be simply referred to as the "x-axis" and the "y-axis", respectively.

[0073] Spring constant k x , k y are the spring constants on the respective vibration axes x and y, and the attenuation coefficient C x , C y are the attenuation coefficients of the vibrations on the respective vibration axes x and y. θ ω is Figure 5 the angle formed by the electrode axes X and Y in the orthogonal coordinate system shown and the vibration axes x and y as spring axes, that is, the offset angle, θ τ is the angle formed by the electrode axes X and Y in this orthogonal coordinate system and the attenuation axis along the direction of vibration attenuation. Unless special processing or the like is performed, the sensor unit is generally θ ω ≠0.

[0074] The above is the basic structure of the sensor part in the gyro sensor 1 of this embodiment. Next, the control unit 10 that performs the drive control of the gyro sensor 1 will be described in detail.

[0075] In addition, in Figure 1 , as a representative example, the case where the mounting substrate 3 has 16 first electrode portions 51 and one frame-shaped second electrode portion 52 is illustrated, but it is not limited thereto. The mounting substrate 3 may, for example, appropriately change the number, arrangement, shape, etc. of the first electrode portion 51 and the second electrode portion 52.

[0076] [Control Unit]

[0077] Next, the control unit 10 of the gyro sensor 1 will be described.

[0078] The control unit 10 is, for example, an electronic control unit that mounts various electronic devices such as a CPU, a ROM, and a RAM on a circuit board (not shown) and performs the drive control of the gyro sensor 1. CPU is an abbreviation for Central Processing Unit (central processor), ROM is an abbreviation for Read Only Memory (read-only memory), and RAM is an abbreviation for Random Access Memory (random access memory).

[0079] For example, as Figure 6As shown in the figure, the control unit 10 includes detection circuits 101 and 102 for detecting vibrations in the x-axis and y-axis of the oscillator 2, and ADCs 103 and 104 for converting the analog signals of the detection circuits 101 and 102 into digital signals. ADC is the abbreviation of Analog to Digital Converter. For example, the detection circuit 101 detects signals from the detection electrodes for detecting vibrations in the x-axis among the plurality of first electrode portions 51. The detection circuit 102 detects signals from the detection electrodes for detecting vibrations in the y-axis among the plurality of first electrode portions 51. The ADC 103 converts the analog signal from the detection circuit 101 into a digital signal. The ADC 104 converts the analog signal from the detection circuit 102 into a digital signal.

[0080] For example, the control unit 10 includes a first coordinate conversion unit 105, a detection gain ratio correction unit 106, a first demodulation block 110, and a second demodulation block 120, which are input with signals from the ADCs 103 and 104.

[0081] The first coordinate conversion unit 105 performs, for example, a rotation matrix operation. Through this rotation matrix operation, the input signals from the ADCs 103 and 104 are coordinate-converted to the coordinate axes for operation where the electrode axes X and Y are orthogonal and the vibration axes x and y are orthogonal. In addition, this rotation matrix operation is the same matrix operation as the operation of formula (5) for converting the electrode axes X and Y to the vibration axes x and y, which will be described later. In addition, the control unit 10 performs operation processing from the first coordinate conversion unit 105 to the second coordinate conversion unit 154 on the above-converted coordinate axes. For example, after the correction of the detection gain ratio G pxy , the feedback control of θ ω , and the feedback control of Δf are sequentially performed, the feedback of the rotation angle θ is performed from the angle feedback unit 180, which will be described later, to the first coordinate conversion unit 105. The rotation angle θ mentioned here refers to the azimuth formed by the current vibration direction of the oscillator 2 on the vibration axes x and y of the converted coordinates. The detection gain ratio G pxy and its calculation, the feedback control of θ ω and Δf will be described later.

[0082] The detection gain ratio correction unit 106 corrects, for example, the gain ratio of the detection signals in the x-axis and y-axis, that is, the detection gain ratio G pxy , based on the information from the demodulation blocks 110 and 120 when the AGCs 130, 131, PLLs 140, and 141, which will be described later, are operating. The detection gain ratio G pxy calculated by the detection gain ratio correction unit 106 or the demodulation output operation unit 113 is used for the feedback control of θ ω .

[0083] The first demodulation block 110 calculates a demodulation output related to the vibration axis x, for example, based on an input signal from the detection gain ratio correction unit 106. In addition, the first demodulation block 110 outputs an amplitude component in phase with the frequency signal and an amplitude component with a phase shifted by 90° from the frequency signal, for example, based on the frequency signal related to the vibration axis x from the PLL 140 described later. The first demodulation block 110 includes, for example, a first demodulation unit 111, a second demodulation unit 112, and a demodulation output calculation unit 113.

[0084] The first demodulation unit 111 calculates, for example, the demodulation outputs V X , V Xi1 , based on the first drive signal for driving the oscillator 2 in the first vibration mode at the resonance angular frequency ω1 and the detection signal V from the detection electrode of the vibration in the first vibration mode. Xq1 The demodulation outputs V Xi1 , V Xq1 are the demodulation output in phase (In Phase) with the first drive signal and the demodulation output in quadrature phase with the drive signal, respectively. The second demodulation unit 112 calculates, for example, the demodulation outputs V X , V Xi2 , based on the second drive signal for driving the oscillator 2 in the second vibration mode at the resonance angular frequency ω2 and the detection signal V Xq2 . In a system where the resonance angular frequencies ω1, ω2 of the oscillator 2 are maintained by two independent PLLs 140, 141 described later, the detection signal V X includes information on the vibration amplitude in the y-direction of the vibration axis related to the second vibration mode, and thus this is achievable. The demodulation outputs V Xi2 , V Xq2 are the demodulation output in phase (In Phase) with the second drive signal and the demodulation output in quadrature phase with the drive signal, respectively. The demodulation output calculation unit 113 calculates, for example, the amplitude and phase of the first vibration mode of the oscillator 2 based on V Xi1 , V Xq1 , V Xi2 , V Xq2 . In addition, the first drive signal and the second drive signal correspond to the frequency signal related to the vibration axis x and the frequency signal related to the vibration axis y, respectively, and are input from the PLL 140 to the demodulation blocks 110, 120.

[0085] The second demodulation block 120 calculates a demodulation output related to the vibration axis y based on, for example, an input signal from the detection gain ratio correction unit 106. In addition, the second demodulation block 120 outputs an amplitude component in phase with the frequency signal and an amplitude component with a phase shifted by 90° from the frequency signal, based on, for example, a frequency signal related to the vibration axis y from a PLL 141 described later. The second demodulation block 120 includes, for example, a first demodulation unit 121, a second demodulation unit 122, and a demodulation output calculation unit 123.

[0086] The first demodulation unit 121 calculates a demodulation output V based on, for example, a second drive signal and a detection signal V from a detection electrode of vibration from a second vibration mode. Y The demodulation outputs V Yi2 and V Yq2 are calculated. The demodulation outputs V Yi2 and V Yq2 are, for example, a demodulation output in phase (InPhase) with the second drive signal and a demodulation output in quadrature phase with the drive signal, respectively. The second demodulation unit 122 calculates demodulation outputs V Y and V Yi1 based on, for example, a first drive signal and a detection signal V Yq1 . Since the detection signal V Y includes information on the vibration amplitude in the x direction of the vibration axis of the first vibration mode, the demodulation by the second demodulation unit 122 is achievable. The demodulation outputs V Yi1 and V Yq1 are, for example, a demodulation output in phase (In Phase) with the first drive signal and a demodulation output in quadrature phase with the drive signal, respectively. The demodulation output calculation unit 113 calculates the amplitude and phase of the second vibration mode of the oscillator 2 based on V Yi1 , V Yq1 , V Yi2 , and V Yq2 . The calculation of each of the above demodulation outputs is described later.

[0087] The control unit 10 includes an AGC 130 and a PLL 140 for resonantly driving the oscillator 2 in the first vibration mode and maintaining the resonance, and an AGC 131 and a PLL 141 for resonantly driving the oscillator 2 in the second vibration mode and controlling the maintenance of the resonance mode. AGC is an abbreviation for Automatic Gain Control, also known as automatic gain control. PLL is an abbreviation for Phase Locked Loop, also known as a phase-locked loop.

[0088] The AGC 130 is input, for example, with the amplitude information in the vibration axis x direction of the first vibration mode of the oscillator 2 from the first demodulation block 110, and performs an operation and signal output for controlling the amplitude in the first vibration mode to a specified constant value based on the amplitude information. The AGC 130 outputs, for example, a control signal for fixing the amplitude to the modulation unit 151, and outputs a signal for calculating the angular velocity to the angular velocity calculation unit 191.

[0089] The AGC 131 is input, for example, with the amplitude information in the vibration axis y direction of the second vibration mode of the oscillator 2 from the second demodulation block 120, and performs an operation and signal output for controlling the amplitude in the second vibration mode to a specified constant value based on the amplitude information. The AGC 131 outputs, for example, a control signal for fixing the amplitude to the modulation unit 152, and outputs a signal for calculating the angular velocity to the angular velocity calculation unit 191.

[0090] The PLL 140 is input, for example, with the phase information of the first vibration mode of the oscillator 2 from the first demodulation block 110, and performs frequency control and signal output of the first drive signal for driving the oscillator 2 in the first vibration mode at the resonance angular frequency ω1. The PLL 140 includes, for example, a PI circuit and an NCO circuit (not shown). The PI circuit corrects the demodulated output V Xq1 of the signal, and the NCO circuit outputs a first drive signal of a specified frequency based on the corrected signal. PI is an abbreviation for Proportional Integral, and NCO is an abbreviation for Numerically Controlled Oscillator, which generates signals of frequencies such as sine waves and cosine waves, and is also called a numerically controlled oscillator. The PLL 140 outputs signals to the demodulation blocks 110, 120, and the modulation unit 151.

[0091] The PLL 141 is input, for example, with the phase information of the second vibration mode of the oscillator 2 from the second demodulation block 120, and performs frequency control and signal output of the second drive signal for driving the oscillator 2 at the resonance angular frequency ω2. The PLL 141 has, for example, the same structure as the PLL 140. The PI circuit corrects the demodulated output V Yq2 of the signal, and the NCO circuit outputs a second drive signal of a specified frequency based on the corrected signal. The PLL 141 outputs signals to the demodulation blocks 110, 120, and the modulation unit 152.

[0092] The control unit 10 includes, for example, a modulation unit 151 that is input with the output signals from the AGC 130 and the PLL 140, and a modulation unit 152 that is input with the output signals from the AGC 131 and the PLL 141. The modulation unit 151 superimposes, for example, the frequency signal f from the PLL 140 on the amplitude control signal input from the AGC 130x and outputs the superimposed signal to the drive gain ratio correction unit 153. The modulation unit 152 superimposes, for example, the frequency signal f from the PLL 141 on the amplitude signal input from the AGC 131 y and outputs the superimposed signal to the drive gain ratio correction unit 153.

[0093] The control unit 10 includes, for example, a drive gain ratio correction unit 153, a second coordinate conversion unit 154, DACs 155 and 156, and drive circuits 157 and 158.

[0094] Based on the input signals from the modulation units 151 and 152 when the AGCs 130 and 131 and the PLLs 140 and 141 are operating, the drive gain ratio correction unit 153 calculates the gain ratio of the drive signals for the x-axis and y-axis, that is, the drive gain ratio G fxy . After setting the detection gain ratio G pxy , the drive gain ratio correction unit 153 calculates the drive gain ratio G fxy and outputs a signal corresponding to the calculation result to the second coordinate conversion unit 154. The calculation of the drive gain ratio G fxy will be described later.

[0095] The second coordinate conversion unit 154 performs a rotation matrix operation to convert the input signal from the drive gain ratio correction unit 153 from the conversion coordinates converted by the first coordinate conversion unit 105 to the Figure 4 shown X r Y r coordinates, that is, the actual coordinates. For example, the rotation angle θ is fed back from the angle feedback unit 180 described later to the second coordinate conversion unit 154. The second coordinate conversion unit 154 outputs, for example, signals corresponding to the rotation angles of the drive directions of the calculated x-axis and y-axis to the DACs 155 and 156. The drive gain ratio G fxy and the calculation will be described later.

[0096] The DACs 155 and 156 convert, for example, the digital signals for driving control of the oscillator 2 input from the second coordinate conversion unit 154 into analog signals and output them to the drive circuits 157 and 158 respectively. DAC is the abbreviation of Digital to Analog Converter (digital-to-analog converter).

[0097] The drive circuits 157 and 158 generate, for example, analog drive signals for the x-axis and y-axis based on the output signals from the DACs 155 and 156 to vibrate the oscillator 2 in the resonant mode and output them to the drive electrodes in the plurality of first electrode portions 51. Thus, for the oscillator 2, a force F generated by electrostatic force acts on it on the x-axis x , and a force F generated by electrostatic force acts on it on the y-axis y, perform vibration control.

[0098] For example, the control unit 10 further includes an offset angle correction unit 160, a mode matching control unit 170, an angle feedback unit 180, an angle calculation unit 190, and an angular velocity calculation unit 191.

[0099] The offset angle correction unit 160, for example, based on either of D x , D y calculated by the demodulation blocks 110 and 120, performs offset angle correction to make the angle (hereinafter referred to as "offset angle") θ formed by the vibration axes x and y and the electrode axes X and Y zero. The offset angle correction unit 160 outputs, for example, a control signal Vθ ω to the sensor unit to control in such a way that either of D x , D y becomes zero, and controls to a state where the vibration axes x and y overlap with the electrode axes X and Y, that is, a state where θ ω = 0. For example, as ω shown, the offset angle correction unit 160 has two independent PIs 161 and 162. A signal corresponding to D Figure 7 is input from the first demodulation block 110 to PI161, and a signal corresponding to D x is input from the second demodulation block 120 to PI162. Moreover, the offset angle correction unit 160 outputs, for example, a control signal Vθ y from either of PI161 and 162 to the sensor unit to control in such a way that D x = 0 or D y = 0. The calculation of D ω , D x , D y will be described later.

[0100] The mode matching control unit 170, for example, after performing feedback control with θ ω = 0 by the offset angle correction unit 160, performs mode matching control to make the frequency difference Δf between the resonance angular frequency ω1 of the first vibration mode and the resonance angular frequency ω2 of the second vibration mode zero. For example, as Figure 8 shown, the mode matching control unit 170 has a PI171, and inputs a signal corresponding to the frequency difference Δf obtained based on the frequency signals f x , f y from the PLL140 to PI171. The mode matching control unit 170 outputs a control signal VΔf to the sensor unit to control in such a way that the frequency difference Δf = 0.

[0101] The angle feedback unit 180, for example, when detecting the gain ratio G pxyAfter being corrected, based on the angular velocity information input from the AGCs 130 and 131, the rotation angle θ is calculated by integrating the angular velocity. The angle feedback unit 180 outputs a signal corresponding to the calculated rotation angle θ to the first coordinate conversion unit 105 and the second coordinate conversion unit 154. For example, as Figure 9 shown, the angle feedback unit 180 includes a PI 181 that inputs angular velocity information from the AGCs 130 and 131 and an integration circuit 182. The PI 181 corrects the angular velocity information obtained by subtracting the output signals V Ω+ 、V Ω－ from each other, and outputs the corrected signal to the integration circuit 182. The integration circuit 182 performs an integration operation of the angular velocity based on the corrected angular velocity information from the PI 181, and calculates an angle (hereinafter referred to as "zero angle") that makes the angular velocity zero. The integration circuit 182 outputs a signal corresponding to the calculated zero angle to the first coordinate conversion unit 105 and the second coordinate conversion unit 154.

[0102] The angle operation unit 190 calculates, for example, the angle of the gyro sensor 1 based on the zero angle information from the angle feedback unit 180 and a previously measured scale factor.

[0103] The angular velocity operation unit 191 calculates, for example, the angular velocity externally applied to the gyro sensor 1 by dividing the value obtained by subtracting the input signals V Ω+ 、V Ω－ from each other by a previously measured scale factor, based on the input signals V Ω+ 、V Ω－ from the AGCs 130 and 131.

[0104] The above is the basic structure of the control unit 10.

[0105] [Calculation of Demodulation Output]

[0106] Next, the calculation of the demodulation output in the demodulation blocks 110 and 120 will be described. Here, the case where n = 2 in the wine glass mode is taken as a representative example for description. The cases of higher orders where n = 3 or more are basically the same, so the description thereof is omitted.

[0107] When the oscillator 2 is driven in both the first vibration mode and the second vibration mode of the resonance mode where n = 2, for example, as Figure 10 shown, it vibrates along two orthogonal vibration axes x and y. Moreover, the vibration amplitude and the resonance angular frequency on the vibration axis x are respectively set as A and ω1, the vibration amplitude and the resonance angular frequency on the vibration axis y are respectively set as B and ω2, and the angle formed by the vibration axis x and the electrode axis X is set as θ ω . At this time, the vibration amplitudes of the vibration axes x and y at time t are represented by the following equations (2) and (3).

[0108] x = Asin(ω1t + φ1) ··· (2)

[0109] y = Bsin(ω2t + φ2) ··· (3)

[0110] The φ1 in equation (2) and the φ2 in equation (3) are the phases with respect to the external forces applied from various directions. If the components of the vibration with amplitude A on the electrode axes X and Y are set as a X 、a Y , and the components of the vibration with amplitude B on the electrode axes X and Y are set as b X 、b Y , then according to the orthogonality of the vibration axes x and y, the deviation angle θ between the vibration axis x and the electrode axis X is expressed by the following equation (4) ω .

[0111]

Mathematical formula 2

[0112]

[0113] In addition, the conversion between the electrode axes X and Y and the vibration axes x and y is expressed by the following equation (5).

[0114]

Mathematical formula 3

[0115]

[0116] In addition, since the sum of the X components of the two vibration modes is on the electrode axis X and the sum of the Y components of the two vibration modes is on the electrode axis Y, the vibration amplitudes at time t of the electrode axes X and Y are expressed by the following equations (6) and (7).

[0117] X = a X sin(ω1t + φ1) + b X sin(ω2t + φ2) · · · (6)

[0118] Y = a Y sin(ω1t + φ1) + b Y sin(ω2t + φ2) · · · (7)

[0119] Furthermore, in the example shown in Figure 7 , the respective components a X , b X , a Y , b Y in equations (6) and (7) are respectively a X = Acosθ ω , b X = -Bsinθ ω , a Y = Asinθ ω , bY = B cosθ ω In addition, if the conversion coefficient from the amplitude to the voltage corresponding to the detection method is set to ξ X , ξ Y , then the voltages V XP , V YP on the detection electrodes of the electrode axes X and Y are represented by the following equations (8) and (9).

[0120] V XP = ξ X {a X sin(ω1t + φ1) + b X sin(ω2t + φ2)} ··· (8)

[0121] V YP = ξ Y {a Y sin(ω1t + φ1) + b Y sin(ω2t + φ2)} ··· (9)

[0122] The first demodulation unit 111 performs an operation on the demodulation outputs V XP of the external forces on the vibration axes x and y based on the voltage V Xi1 , V Xq1 . The demodulation output V Xi1 is calculated by multiplying the voltage V XP by sinω1t as shown in the following equation (10) and then eliminating the terms of the second harmonic and the sum of frequencies through a low-pass filter as shown in equation (11).

[0123]

Mathematical formula 4

[0124]

[0125]

Mathematical formula 5

[0126] V Xi1 = |2V XP sinω1t| LPF

[0127] = ξ x {a x cosφ1 + b x (cosφ2cosΔωt - sinφ2sin△ωt)}

[0128] = ξ x {a x cosφ1 + b x cos(△ωt + φ2)} … (11)

[0129] In formula (11), |f(t)| LPF This refers to the above-mentioned operation of eliminating the double wave and the term of the frequency sum by the low-pass filter. This is also the same for the following equations (13), (15), and (17).

[0130] Demodulation output V Xq1 By performing the voltage V as shown in the following formula (12): XP The multiplication by cosω1t is calculated by performing an operation to eliminate unnecessary terms through a low-pass filter as shown in equation (13).

[0131]

Mathematical formula 6

[0132]

[0133]

Mathematical formula 7

[0134] V Xq1 =|2V XP cosω1t| LPF

[0135] ξ x {a x cosφ1+b x (cosφ2cosΔωt+sinφ2cosΔωt)}

[0136] =ξ x {a X sinφ1+b X sin(△ω t +φ2)}…(13)

[0137] The second demodulator 112 generates a voltage V based on equation (8). XP , demodulate the external force on the vibration axis x, y and output V Xi2 、V Xq2 The second demodulation unit 112 obtains a frequency signal for driving the vibrator 2 at a resonant angular frequency ω2 from the PLL 141, for example, and performs demodulation to output V Xi2 、V Xq2 The demodulated output V Xi2 The voltage V is calculated as shown in the following formula (14): XP The multiplication by sin(ω2t+Δφ) is calculated by eliminating unnecessary terms through a low-pass filter as shown in equation (15). In addition, Δφ is, for example, the phase of the output signal of the oscillator circuit (not shown) in PLL140, 141 when the output signal of the oscillator circuit (not shown) in PLL140, 141 is used as a reference.

[0138] V XP sin(ω2t+△φ)=ξX {a X sin(ω1t + φ1) + b X sin(ω2t + φ2)}Sin(ω2t + △φ)…(14)

[0139]

Mathematical formula 8

[0140] V Xi2 =|2V XP sin(ω2t + △φ)| LPF

[0141] =ξ X {b X cos(φ2 - Δφ)+ a X cos(△ωt - φ1 + △φ)}…(15)

[0142] Demodulation output V Xq2 The demodulation output V is calculated by multiplying the voltage V as shown in the following equation (16) by cos(ω2t + Δφ) and then eliminating the unwanted terms through an operation using a low - pass filter as shown in equation (17). XP

[0143] V XP coS(ω2t + △φ)=ξ X {a X sin(ω1t + φ1) + b X sin(ω2t + φ2)}cos(ω2t + Δφ)…(16)

[0144]

Mathematical formula 9

[0145] V Xq2 =|2V XP cos(ω2t + △φ)| LPF

[0146] =ξ X {b X sin(φ2 - Δφ)+ a X sin(Δωt - φ1 + △φ)}…(17)

[0147] The first demodulation unit 121 performs the operation of the demodulation output V for the external forces on the vibration axes x and y based on the detected voltage V YP , and the second demodulation unit 122 obtains, for example, the frequency signal for driving the oscillator 2 at the resonance angular frequency ω1 from the PLL 140 and performs the operation of the demodulation output V Yi2 , V Yq2 . The demodulation output V based on the detected voltage V Yi1 , V Yq1 YP Yi1 ​​​, V Yq1 , V Yi2 , V Yq2 By performing the same arithmetic processing as the above V Xi1 , V Xq1 , V Xi2 , V Xq2 , are calculated respectively and represented by the expressions shown by Figure 11 . When φ1 = φ2 = Δφ = 0 is satisfied, these demodulation outputs can be transformed into mathematical expressions without the φ1, φ2, and Δφ terms.

[0148] The demodulation outputs V Xi1 , V Xq1 , V Xi2 , V Xq2 , V Yi1 , V Yq1 , V Yi2 , V Yq2 For example, they are output to the demodulation output arithmetic units 113, 123, etc., and are used for the arithmetic operation of the amplitudes of the first vibration mode and the second vibration mode and the calculation of the phase difference. Hereinafter, for the sake of convenience of explanation, the demodulation outputs V Xi1 , V Xq1 , V Xi2 , V Xq2 , V Yi1 , V Yq1 , V Yi2 , V Yq2 are collectively referred to as "each demodulation output".

[0149] [Arithmetic operation using the amplitude and phase of the demodulation output]

[0150] Next, the arithmetic operation of the amplitude and phase of the vibration mode using each demodulation output will be described.

[0151] For example, the demodulation output arithmetic units 113 and 123 have a structure including a high-pass filter (hereinafter referred to as "HPF"), an arithmetic unit that performs arithmetic operations using each demodulation output after passing through the HPF, and a phase comparison unit that calculates the phase difference of each demodulation output.

[0152] The demodulation output arithmetic unit 113, for example, calculates |ξ Xi1 , V Xq1 | by performing a sum-of-squares operation in which the squares of the demodulation outputs V X b X after passing through the HPF are respectively squared and then added by the arithmetic unit. The demodulation output arithmetic unit 113, for example, calculates |ξ Xi2 , V Xq2 | by performing a sum-of-squares operation based on the demodulation outputs V X a X|. Additionally, the demodulation output operation unit 113, for example, calculates the phase difference Δφ Xi1 V Xi2 based on the demodulation output V Xi after passing through the HPF, and calculates the phase difference Δφ Xq1 V Xq2 based on the demodulation output V Xq .

[0153] The demodulation output operation unit 123, for example, through the same processing as the demodulation output operation unit 113, calculates |ξ Yi1 V Yq1 | through the sum-of-squares operation based on the demodulation output V Y b Y |, and calculates |ξ Yi2 V Yq2 | through the sum-of-squares operation based on the demodulation output V Y a Y . Additionally, the demodulation output operation unit 123, for example, is the same as the demodulation output operation unit 113, and calculates the phase difference Δφ Yi1 V Yi2 based on the demodulation output V Yi V Yq1 V Yq2 and calculates the phase difference Δφ Yq .

[0154] The demodulation blocks 110, 120 can, for example, obtain the amplitude information of the resonant mode through the above operations of |ξ X a X |, |ξ Y a Y |, |ξ X b X |, |ξ Y b Y |, and obtain the phase information of the resonant mode through the above operations of the phase differences Δφ Xi Δφ Xq Δφ Yi Δφ Yq .

[0155] Hereinafter, for the sake of convenience of explanation, the operations of the above |ξ X a X |, |ξ Y a Y |, |ξ X b X |, |ξ Y b Y | for calculating the amplitude are simply referred to as "amplitude operations". Additionally, sometimes the demodulation outputs V Xi1 V Xq1Is referred to as the "first demodulation output", and the demodulation output V calculated by the first demodulation unit 121 Yi2 、V Yq2 Is referred to as the "second demodulation output". Additionally, the demodulation output V calculated by the second demodulation unit 112 Xi2 、V Xq2 Is sometimes referred to as the "third demodulation output", and the demodulation output V calculated by the second demodulation unit 122 Yi1 、V Yq1 Is referred to as the "fourth demodulation output".

[0156] [Feedback control of θ ω

[0157] Next, the calculation of θ ω Performed by the offset angle correction unit 160 and its feedback control will be described.

[0158] The control unit 10 is configured such that the first demodulation output calculation unit 113 performs an operation based on the first demodulation output and the third demodulation output, and the second demodulation output calculation unit 123 performs an operation based on the second demodulation output and the fourth demodulation output.

[0159] Here, the angle formed by the vibration axes x, y and the electrode axes X, Y, that is, the offset angle θ ω Can be calculated by the following equation (18) or (19).

[0160]

Mathematical formula 10

[0161]

[0162]

Mathematical formula 11

[0163]

[0164] If D X 、D Y In equations (18) and (19) are unified as D k , then D k Is represented by the following equation (20).

[0165] D k =|ξ k 2 a k b k | (k = X, Y) ··· (20)

[0166] The control unit 10 applies a control voltage from the offset angle correction unit 160 to the sensor unit based on the demodulation outputs calculated by the demodulation units 111, 112, 121, 122, so that |θ ω ​| = 0. According to equations (18) and (19), |θ ω | = 0 is the case where D X = 0 or D Y = 0.

[0167] For example, the first demodulation output operation unit 113 calculates the value of |ξ Xi1 、V Xq1 by performing a sum-of-squares operation in which the demodulation outputs V when φ1 = φ2 = Δφ = 0 are squared and then added together respectively. The second demodulation output operation unit 123 calculates the value of |ξYb X b X | in the same way, that is, by performing a sum-of-squares operation on the demodulation outputs V Yi2 、V Yq2 when φ1 = φ2 = Δφ = 0. These operation results are output to the control circuit 150, for example, for feedback control when D Y = 0 or D X = 0, that is, when |θ Y | = 0. ω | = 0.

[0168] In addition, in the feedback control when |θ ω | = 0, the offset angle correction unit 160 determines, for example, whether to rotate the vibration axes x and y clockwise or counterclockwise based on the operation of the phase information performed by the demodulation blocks 110 and 120. For example, as shown in Figure 12 , the offset angle correction unit 160 discriminates whether the output waveforms of the demodulation outputs V Xi 、V Xq and the output waveforms of the demodulation outputs V Yi 、V Yq are in-phase or out-of-phase. Figure 12 The polarity "+" of θ ω in ω means that the vibration axis is offset counterclockwise with respect to the electrode axis, and the polarity "-" of θ ω means that the vibration axis is offset clockwise with respect to the electrode axis. The offset angle correction unit 160 determines the rotation direction of the vibration axis to be the direction opposite to the offset direction according to the polarity of θ ω and outputs the determined control signal Vθ

[0169] [Calculation of Detection Gain Ratio, Driving Gain Ratio, and Attenuation Coefficient]

[0170] Next, the detection gain ratio and its calculation will be described.

[0171] For example, in Figure 6In the system for inputting a driving force to the vibrator 2 shown, the ratio of the non-ideal gains of the x-axis and the y-axis is used as the detection gain ratio G pxy The case where it exists is explored. In this case, the voltages input to each axis are set to V x 、V y , and through the voltages V x 、V y and the detection gain ratio G pxy the x and y of the vibration information of the vibrator 2 are represented by the following equation (21).

[0172]

Mathematical formula 12

[0173]

[0174] In order to cancel the non-ideal detection gain ratio G pxy in equation (21), it is only necessary to calculate the detection gain ratio G pxy by some means and multiply equation (21) by the determinant of the following equation (22).

[0175]

Mathematical formula 13

[0176]

[0177] For example, the detection gain ratio correction unit 106 performs a matrix operation of multiplying the determinant of equation (22), that is, the matrix including the reciprocal of the detection gain ratio 1 / G pxy by the determinant of the detection signal obtained via the detection circuits 101 and 102 shown in equation (21). When the control unit 10 calculates the detection gain ratio and the drive gain ratio, the gain ratio calculation process is performed in a state where no feedback of the rotation angle is performed, that is, in an offline state. In each gain ratio calculation mode, in the control unit 10, the detection signals of the x and y axis vibrations from the sensor unit are input to the demodulation blocks 110 and 120 via the detection circuits 101, 102 and the ADCs 103, 104, and each demodulation output and the amplitude calculation based on each demodulation output are performed. In addition, the demodulation outputs V Xq1 、V Yq2 are used for the calculation of the detection gain ratio G pxy . The detection gain ratio G pxy calculated in the gain ratio calculation mode is, for example, stored in a recording medium (not shown) held in the control unit 10, and then read from the recording medium and used in the calculation modes of the angular velocity and the angle and the angular velocity and the angle. The same applies to the drive gain ratio G fxy described later.

[0178] The calculation of the detection gain ratio G pxy is performed in a state where no angular velocity input is applied to the sensor unit, that is, in an offline state. The detection gain ratio G pxyIt is represented by the following formula (23).

[0179]

Mathematical formula 14

[0180]

[0181] D in formula (23) x 、D y For example, through Figure 13 、 Figure 14 The operations shown are calculated. Specifically, for example, as Figure 13 Shown, the first demodulation block 110 performs amplitude operations based on the demodulation output V Xi1 Of the amplitude operation, based on the demodulation output V Xq1 Of the amplitude operation, calculate the first addition value obtained by adding the two values obtained in each amplitude operation. In addition, for example, the first demodulation block 110 performs amplitude operations based on the demodulation output V Xi2 Of the amplitude operation, based on the demodulation output V Xq2 Of the amplitude operation, calculate the second addition value obtained by adding the two values obtained in each amplitude operation. For example, the first demodulation block 110 calculates the operation value D x By multiplying the first addition value by the second addition value.

[0182] For example, as Figure 14 Shown, the second demodulation block 120 performs amplitude operations based on the demodulation outputs V Yi1 、V Yq1 Respectively, and add the two values obtained, calculate the third addition value. In addition, for example, the second demodulation block 120 performs amplitude operations based on the demodulation outputs V Yi2 、V Yq2 Respectively, and add the two values obtained in each amplitude operation to calculate the fourth addition value, and then multiply the third and fourth addition values to calculate the operation value D y 。

[0183] Then, the detection gain ratio correction unit 106, for example, as Figure 15 Shown, perform an operation of taking the square root of the value obtained by dividing the calculated D x By D y To calculate the detection gain ratio G pxy 。Then, the detection gain ratio correction unit 106 calculates the detection gain ratio correction value shown in formula (22) based on the detection gain ratio G pxy And correct the detection gain ratio by multiplying it by formula (21).

[0184] Next, in the system that inputs the driving forces F x 、F y To the oscillator 2, for the driving force F x And the driving force F yThe ratio of the non-ideal gain is used as the drive gain ratio G fxy The case where it exists is explored. Let the output signal from DAC155 on the x-axis and the output signal from DAC156 on the y-axis be V Fx and V Fy respectively. Based on the driving forces F x and F y applied to the oscillator 2 from the driving circuits 157 and 158, including the drive gain ratio G fxy is expressed by the following equation (24).

[0185]

Mathematical formula 15

[0186]

[0187] To cancel the non-ideal drive gain ratio G fxy in equation (24), it is only necessary to calculate the drive gain ratio G fxy by some means and multiply the determinant of equation (24) by the determinant of the following equation (25).

[0188]

Mathematical formula 16

[0189]

[0190] For example, the drive gain ratio correction unit 153 performs a matrix operation of multiplying the determinant of equation (25), that is, the matrix including the reciprocal of the drive gain ratio, i.e., 1 / G fxy , by the determinant of equation (24). The operation of the drive gain ratio G fxy is the same as the operation of the detection gain ratio G pxy and is performed in an offline state. The drive gain ratio G fxy is expressed by the following equation (26).

[0191]

Mathematical formula 17

[0192]

[0193] For example, as Figure 16 shown, the drive gain ratio correction unit 153 calculates the drive gain ratio G x and the drive gain ratio correction value based on AGC x , AGC y , and Q y . AGC fxy is the AGC output related to the driving force F x on the x-axis output from AGC130 to the modulation unit 151, and AGC x is the AGC output related to the driving force F y on the y-axis output from AGC131 to the modulation unit 152 yRelated AGC output. Q x , Q y are the Q values of the vibration of the oscillator 2 on the x-axis and the Q value of the vibration of the oscillator 2 on the y-axis, respectively, which are pre-calculated by a known Q value measurement method and recorded in a recording medium (not shown). The drive gain ratio correction unit 153 calculates the first multiplication value obtained by multiplying the AGC x by Q x and the second multiplication value obtained by multiplying the AGC y by Q y , and calculates the drive gain ratio G fxy by a division operation of dividing the first multiplication value by the second multiplication value. Then, the drive gain ratio correction unit 153 calculates the drive gain ratio correction value represented by equation (25) based on the drive gain ratio G fxy and corrects the drive gain ratio by multiplying it by equation (24).

[0194] [Measurement error reduction processing]

[0195] Next, an example of the processing operation for reducing the error in the measurement of the angle or angular velocity of the gyro sensor 1 will be described.

[0196] The control unit 10 starts, for example, when a predetermined start condition such as the external power supply for driving the gyro sensor 1 becomes on, Figure 17 the control flow shown.

[0197] In step S100, the control unit 10, for example, sets the PLLs 140 and 141 to the enabled state and starts the frequency control of the first and second drive signals so that the oscillator 2 vibrates in the first and second vibration modes.

[0198] In step S110, the control unit 10, for example, sets the AGCs 130 and 131 to the enabled state and starts the control of the amplitude in the vibration of the oscillator 2 in the first and second vibration modes. Thus, the oscillator 2 is maintained, for example, in two vibration states: a vibration mode of the resonant angular frequency ω1 and a predetermined amplitude A, and a vibration mode of the resonant angular frequency ω2 and a predetermined amplitude B.

[0199] In step S120, the control unit 10 acquires the detection signals from the first detection electrode for detecting the vibration on the x-axis and the second detection electrode for detecting the vibration on the y-axis among the plurality of first electrode units 51. Then, the detection gain ratio correction unit 106 performs the calculation of the detection gain ratio G pxy by the above operation, that is, determination (fixation).

[0200] In step S130, the detection gain ratio correction unit 106, for example, by using the reciprocal 1 / G of the calculated detection gain ratiopxy For the above matrix operation of matrix multiplication, the setting, i.e., correction, of the detection gain ratio is performed. Thereby, the influence of the measurement error in the gyro sensor 1 caused by the gain ratio of the detection signals between the x-axis and the y-axis is reduced. In addition, the control unit 10 performs the processes of steps S120 and S130 in a state where the rotation angle feedback by the angle feedback unit 180 is deactivated, or in a state where the gain of the output signal of the PI181 is zero, i.e., in an offline state.

[0201] In step S140, for example, the drive gain ratio correction unit 153 performs the calculation, i.e., determination (identification), of the drive gain ratio G based on the drive signal for the first vibration mode on the x-axis and the drive signal for the second vibration mode on the y-axis through the above operation. fxy

[0202] In step S150, for example, the drive gain ratio correction unit 153 performs the setting, i.e., correction, of the drive gain ratio by performing the above matrix operation of matrix multiplication with the reciprocal 1 / G of the calculated drive gain ratio. Thereby, the influence of the measurement error in the gyro sensor 1 caused by the gain ratio of the drive signals between the x-axis and the y-axis is reduced. fxy

[0203] In step S160, for example, the offset angle correction unit 160 outputs the control signal Vθ to the sensor unit so that one of the operation values D ω , D x , D y becomes zero. Thereby, the oscillator 2 is controlled to a state where the vibration axes x and y are substantially aligned with the electrode axes X and Y. In addition, in order to perform the Δf feedback control, it is necessary to minimize θ ω , so this θ ω control is performed before performing the Δf feedback control.

[0204] In step S170, for example, the mode matching control unit 170 outputs the control signal VΔf to the sensor unit based on the output signals from the PLL140 and 141 so that the frequency difference Δf between the resonance angular frequency ω1 of the first vibration mode and the resonance angular frequency ω2 of the second vibration mode becomes zero. Thereby, the oscillator 2, for example, generates an electro-spring effect by the electrostatic force between the edge 23 and a part of the plurality of first electrode portions 51, and controls one or both of the resonance angular frequencies ω1 and ω2 of the first and second vibration modes to be Δf = 0.

[0205] In step S180, the control unit 10 enables the angle feedback unit 180, drives the PI 181 and the integration circuit 182 based on the input signals from the AGCs 130 and 131, and calculates the rotation angle of the gyro sensor 1. Then, the angle feedback unit 180 outputs a signal corresponding to the calculated rotation angle to the first coordinate conversion unit 105 and the second coordinate conversion unit 154 to perform feedback of the rotation angle.

[0206] Finally, in step S190, the control unit 10 calculates the angular velocity and angle applied to the gyro sensor 1 through the angle calculation unit 190 and the angular velocity calculation unit 191. As a result, the gyro sensor 1 reduces the influence of the detection gain ratio G pxy and the drive gain ratio G fxy and performs Δf feedback control after θ ω control, improving the accuracy of the Δf feedback. Therefore, the error in the measured angle is reduced.

[0207] The above is an example of the process for reducing the error in the measured angle of the gyro sensor 1. As long as the process for reducing the error in the measured angle at least sequentially performs the correction of the detection gain ratio G pxy , θ ω control, and Δf feedback control, and performs the correction of the drive gain ratio G pxy after correcting the detection gain ratio G fxy . Therefore, regarding the correction of the drive gain ratio G fxy , it can be either between the θ ω control and the Δf feedback control or after the Δf feedback control. That is, regarding the correction of the gain ratio of the detection signal and the gain ratio of the drive signal, i.e., the gain mismatch correction, the correction of the drive gain ratio G pxy can be either the process immediately following the correction of the detection gain ratio G fxy or the correction of the drive gain ratio G fxy can be performed with other processes in between.

[0208] According to the present embodiment, the gyro sensor 1 performs the detection gain ratio G pxy of the x-axis and y-axis of the oscillator 2 and the drive gain ratio G fxyPerform correction of gain mismatch to reduce the influence of the gain ratio of the detection signal and the drive signal on the angle measurement. The gyro sensor 1 performs frequency control of the drive signals of two independent vibration modes through PLLs 140 and 141, and performs amplitude control in two independent vibration modes through AGCs 130 and 131. In addition, the gyro sensor 1 includes first demodulation units 111 and 121 that perform demodulation of the detection signal and its drive signal based on one of the first and second vibration modes, and second demodulation units 112 and 122 that perform demodulation of the detection signal of one of the two vibration modes and the drive signal of the other. In addition, the gyro sensor 1 has a first demodulation block 110 and a second demodulation block 120. The first demodulation block 110 includes a first demodulation unit 111 and a second demodulation unit 112, and the second demodulation block 110 includes a first demodulation unit 121 and a second demodulation unit 122. Therefore, the gyro sensor 1 can perform the operation value D through the demodulation outputs of the demodulation blocks 110 and 120 and the operation using the demodulation outputs. x 、D y 、the detection gain ratio G pxy 、the drive gain ratio G fxy 、θ ω 、Δf of various calculations. Moreover, the gyro sensor 1 reduces the error in the measurement of the angle or angular velocity by performing θ ω control by the offset angle correction unit 160, Δf control by the mode matching control unit 170, and various feedbacks of the rotation angle by the angle feedback unit 180.

[0209] (1) In the gyro sensor 1, based on the operation results of the demodulation blocks 110 and 120, the detection gain ratio correction unit 106 multiplies the matrix of equation (22) containing the reciprocal 1 / G pxy of the detection gain ratio by the determinant of equation (21). Thereby, the gyro sensor 1 performs matrix operations to cancel the non-ideal detection gain ratios G pxy of the x-axis and y-axis, and reduces the error in the measurement of the angle and angular velocity caused by the influence of the detection gain ratio G pxy .

[0210] (2) In the gyro sensor 1, the drive gain ratio correction unit 153 multiplies the matrix of equation (25) containing the reciprocal 1 / G fxy of the drive gain ratio by the determinant of equation (24). Thereby, the gyro sensor 1 performs matrix operations to cancel the non-ideal drive gain ratios G fxy of the x-axis and y-axis, and reduces the error in the measurement of the angle and angular velocity caused by the influence of the drive gain ratio G fxy .

[0211] (3) The first demodulation block 110 demodulates the output V based on the first detection signal and the first drive signalXi1 and the first demodulation unit 111 that performs the operation of V Xq1 and the second demodulation unit 112 that performs the operation of V based on the first detection signal and the second drive signal. The second demodulation block has a second demodulation unit 112 that demodulates and outputs V based on the second detection signal and the second drive signal Xi2 and the first demodulation unit 121 that performs the operation of V Xq2 and the second demodulation unit 122 that performs the operation of V based on the second detection signal and the first drive signal. Further, the control unit 10 has an offset angle correction unit 160 that corrects the offset angle θ Yi2 in the operation oscillator 2 based on the operation values D Yq2 calculated by the demodulation blocks 110 and 120 Yi1 and outputs a control signal Vθ Yq1 for the offset angle θ x Thereby, the offset angle θ y is minimized, and the control of Δf, that is, the accuracy in the mode matching control, can be improved ω . ω ω ω

[0212] (4) The control unit 10 has a mode matching control unit 170 that calculates the difference Δf between the resonance frequencies of the two vibration modes based on the frequency signals corresponding to the first and second vibration modes output from the PLL 140 and outputs a signal for controlling Δf. Thereby, the mode matching control of the oscillator 2 can be performed, and the measurement accuracy of the angle and the angular velocity can be improved

[0213] (5) The gyro sensor 1 according to the present embodiment reduces the measurement errors of the angle and the angular velocity by a control method including the following first to eighth steps. The first step is to drive the oscillator 2 on two axes of the first and second vibration modes by two independent PLLs 140 and 141 and AGCs 130 and 131. The second step is to calculate and determine the detection gain ratio G which is the ratio of the gain of the first detection signal of the vibration on the x-axis of the oscillator 2 to the gain of the second detection signal of the vibration on the y-axis of the oscillator 2 pxy . fxy The third step is to calculate and determine the drive gain ratio G which is the ratio of the gain of the first drive signal for vibrating the oscillator 2 on the x-axis to the gain of the second drive signal for vibrating the oscillator 2 on the y-axis Xi1 . Xq1 The fourth step is to perform demodulation output V Xi2 by the demodulation blocks 110 and 120 Xq2 . Yi1 Yq1 Yi2 Yq2 ​​​​​​operation. The fifth step is to calculate the offset angle θ of the oscillator 2 based on the operation results in the demodulation blocks 110 and 120 after determining the detection gain ratio G pxy and perform feedback control of the offset angle θ ω . The sixth step is to calculate the difference Δf in the resonance frequencies of these vibration modes based on the respective frequency signals corresponding to the first and second vibration modes output from the PLL 140 and perform feedback control of Δf after the feedback control of the offset angle θ ω . The seventh step is to calculate the rotation angle of the gyro sensor 1 by integrating the angular velocity and feedback the calculated rotation angle to the operation of the rotation angles in the detection direction and the driving direction of the vibration of the oscillator 2 after performing the feedback control of Δf and determining the driving gain ratio G ω . The eighth step is to measure the angle and angular velocity of the gyro sensor 1 after feedback of the rotation angle fxy .

[0214] (6) When determining the detection gain ratio G pxy , the detection gain ratio G pxy is calculated through the demodulation blocks 110 and 120, and a matrix operation of multiplying a matrix containing 1 / G pxy is performed to cancel the detection gain ratio. Thus, the non-ideal detection gain ratios G pxy on the vibration axes x and y of the oscillator 2 are eliminated, and the errors in the measurement of the angle and angular velocity caused by the influence of the gain ratio G pxy are reduced

[0215] (7) When determining the driving gain ratio G fxy , a matrix operation of multiplying a matrix containing the reciprocal 1 / G of the driving gain ratio fxy is performed to cancel the driving gain ratio G fxy . Thus, the non-ideal driving gain ratios G fxy on the vibration axes x and y of the oscillator 2 are canceled, and the errors in the measurement of the angle and angular velocity caused by the influence of the driving gain ratio G fxy are reduced

[0216] (Other Embodiments)

[0217] The present disclosure has been described based on the embodiments, but it should be understood that the present disclosure is not limited to the embodiments or structures. The present invention also includes various modifications and modifications within the equivalent scope. Moreover, various combinations, manners, and other combinations, manners that include only one of them, include more elements or fewer elements also fall within the scope and the scope of the idea of the present disclosure

[0218] In addition, regarding the sensor element, a structure in which the oscillator 2 has a substantially hemispherical shape or a substantially disk shape and a plurality of first electrode portions 51 are arranged so as to surround the oscillator 2 has been described as a representative example, but is not limited to these forms. For example, as long as the gyro sensor 1 is in a form in which the sensor element can be regarded as Figure 5 the vibrating body of the two-degree-of-freedom system shown, the above control can be performed by the control unit 10. Therefore, the forms, arrangements, etc. of the oscillator 2 and the electrode portions 51 and 52 can also be other known forms, arrangements, etc.

[0219] The control unit 10 and its method described in the present disclosure can also be implemented by a dedicated computer, which is provided by a processor and a memory configured to execute one or more functions embodied by a computer program. Alternatively, the control unit 10 and its method described in the present disclosure can also be implemented by a dedicated computer, which is provided by a processor constituted by one or more dedicated hardware logic circuits. Alternatively, the control unit 10 and its method described in the present disclosure can also be implemented by one or more dedicated computers, which are constituted by a combination of a processor and a memory programmed to execute one or more functions and a processor constituted by one or more hardware logic circuits. In addition, the computer program can also be stored as instructions executed by a computer in a computer-readable non-transitory tangible storage medium.

[0220] Furthermore, in each of the above embodiments, regarding the elements constituting the embodiments, unless specifically stated as essential or clearly considered essential in principle, etc., they are not necessarily essential. In addition, in the above embodiments, when referring to numerical values such as the number, value, quantity, range, etc. of the elements constituting the embodiments, unless specifically stated as essential or clearly limited to a specific number in principle, etc., they are not limited to that specific number. In addition, in each of the above embodiments, when referring to the shape, positional relationship, etc. of the elements, etc., unless specifically stated or clearly limited to a specific shape, positional relationship, etc. in principle, etc., they are not limited to that shape, positional relationship, etc.

Claims

1. A gyro sensor, characterized in that: have: A vibrator having a first vibration mode and a second vibration mode with different resonant angular frequencies; A mounting substrate having a plurality of electrodes facing the vibrator; and a control unit that performs drive control of the vibrator, A radial direction is defined with an imaginary straight line passing through the center of the region surrounded by the plurality of electrodes and along the thickness direction of the mounting substrate as an axis, and a direction along the vibration direction of the first vibration mode as the radial direction is set as an x-axis, and a direction along the vibration direction of the second vibration mode as the radial direction is set as a y-axis, The control unit has: a PLL for driving the vibrator on two axes of the first vibration mode and the second vibration mode; The detection gain ratio correction unit performs detection gain ratio G pxy The correction of the detection gain ratio G pxy is a ratio of a gain of a first detection signal from a first detection electrode for detecting the vibration of the vibrator on the x-axis among the plurality of electrodes to a gain of a second detection signal from a second detection electrode for detecting the vibration of the vibrator on the y-axis among the plurality of electrodes; A first coordinate conversion unit, which uses the plane coordinate axis formed in the radial direction as an actual coordinate axis and converts the signal from the detection electrode from the actual coordinate axis into a coordinate axis for calculation; The drive gain ratio correction unit performs drive gain ratio correction. fxy The correction of the drive gain ratio G fxy is a ratio of a gain of a first drive signal to a first drive electrode among the plurality of electrodes for causing the vibrator to vibrate in the first vibration mode to a gain of a second drive signal to a second drive electrode among the plurality of electrodes for causing the vibrator to vibrate in the second vibration mode; a second coordinate conversion unit that converts the signal corrected by the drive gain ratio correction unit from the calculation coordinate axis to the actual coordinate axis; a first demodulation block that performs an operation for calculating a demodulation output of the detection gain ratio based on the first detection signal; a second demodulation block that performs an operation for calculating a demodulation output of the detection gain ratio based on the second detection signal; An AGC that performs a calculation for maintaining a drive output of the vibrator in the first vibration mode and the second vibration mode; as well as An angle feedback unit has an integration circuit that calculates a rotation angle by integrating the angular velocity based on information of the angular velocity input from the AGC after the detection gain ratio and the drive gain ratio are corrected, and feeds back the calculated rotation angle to the first coordinate conversion unit and the second coordinate conversion unit.

2. The gyro sensor according to claim 1, characterized in that: The detection gain ratio correction unit performs the following matrix operation: based on the calculation values ​​calculated by the first demodulation block and the second demodulation block, the detection gain ratio correction unit converts the inverse of the detection gain ratio, 1 / G pxy The matrix multiplication of offsets the detection gain ratio.

3. The gyro sensor according to claim 1, characterized in that: The drive gain ratio correction unit performs the following matrix operation: the inverse of the drive gain ratio, 1 / G fxy The matrix multiplication cancels out the drive gain ratio.

4. The gyro sensor according to claim 1, characterized in that: The first demodulation block includes: a first demodulation unit that performs calculations based on demodulation outputs of the first detection signal and the first drive signal; and a second demodulation unit that performs calculations based on demodulated outputs of the first detection signal and the second drive signal, The second demodulation block includes: a third demodulation unit that performs calculation based on the demodulation output of the second detection signal and the second drive signal; and a fourth demodulation unit that performs calculations based on the demodulated outputs of the second detection signal and the first drive signal, The x-axis and the y-axis are set as vibration axes, and the direction along the radial direction along the driving electrodes for driving in the first vibration mode and the second vibration mode among the plurality of electrodes is set as an electrode axis, The control unit further includes a deviation angle correction unit that calculates a deviation angle, which is an angle formed by the vibration axis and the electrode axis of the vibrator, based on calculation values ​​calculated by the first demodulation block and the second demodulation block, and outputs a control signal for the deviation angle.

5. The gyro sensor according to any one of claims 1 to 4, characterized in that: The control unit also includes a mode matching control unit, which calculates the difference in resonant frequency Δf between the first vibration mode and the second vibration mode based on the frequency signal corresponding to the first vibration mode and the frequency signal corresponding to the second vibration mode output from the PLL, and outputs a signal to control the Δf.

6. A method for controlling a gyro sensor, wherein a vibrator having a first vibration mode and a second vibration mode with different resonance angular frequencies is mounted on a mounting substrate having a plurality of electrodes facing the vibrator, wherein: include: driving the vibrator on two axes of the first vibration mode and the second vibration mode by two independent PLLs and AGCs; A radial direction with an imaginary straight line passing through the center of the region surrounded by the plurality of electrodes and along the thickness direction of the mounting substrate as an axis is defined, the radial direction along the vibration direction of the first vibration mode is set as the x-axis, and the radial direction along the vibration direction of the second vibration mode is set as the y-axis, and the detection gain ratio G is calculated and determined. pxy , the detection gain ratio G pxy is a ratio of a gain of a first detection signal from a first detection electrode for detecting the vibration of the vibrator on the x-axis among the plurality of electrodes to a gain of a second detection signal from a second detection electrode for detecting the vibration of the vibrator on the y-axis among the plurality of electrodes; Calculate and determine the drive gain ratio G fxy , the driving gain ratio G fxy is a ratio of a gain of a first driving signal for a first driving electrode among the plurality of electrodes for causing the vibrator to vibrate on the x-axis to a gain of a second driving signal for a second driving electrode among the plurality of electrodes for causing the vibrator to vibrate on the y-axis; By means of a demodulation block, operations are performed based on a demodulated output of the first detection signal and the first drive signal, a demodulated output based on the first detection signal and the second drive signal, a demodulated output based on the second detection signal and the first drive signal, and a demodulated output based on the second detection signal and the second drive signal; The x-axis and the y-axis are set as vibration axes, a radial direction is defined with an imaginary straight line passing through the center of a region surrounded by the plurality of electrodes and along the thickness direction of the mounting substrate as an axis, a direction along the radial direction along a driving electrode for driving in the first vibration mode and the second vibration mode among the plurality of electrodes is set as an electrode axis, after determining the detection gain ratio, an angle formed by the vibration axis of the vibrator and the electrode axis, i.e., an offset angle, is calculated based on a result calculated in the demodulation block, and feedback control of the offset angle is performed; After the feedback control of the offset angle is performed, based on the frequency signal corresponding to the first vibration mode and the frequency signal corresponding to the second vibration mode outputted from the PLL, a difference Δf between the resonant frequencies of the first vibration mode and the second vibration mode is calculated, and feedback control of Δf is performed; After performing the feedback control of Δf and determining the drive gain ratio, calculating the rotation angle of the gyro sensor by integrating the angular velocity, and feeding back the calculated rotation angle to calculations of the rotation angle in the detection direction and the rotation angle in the driving direction of the vibration of the vibrator; and After the rotation angle is fed back, the angle and angular velocity of the gyro sensor are measured.

7. The control method of the gyro sensor according to claim 6, characterized in that: When determining the detection gain ratio, the detection gain ratio is calculated by the demodulation block, and the inverse of the detection gain ratio, 1 / G pxy The matrix operation of the detection gain ratio is offset by matrix multiplication of the detection gain ratio.

8. The control method of the gyro sensor according to claim 6 or 7, characterized in that: When determining the driving gain ratio, the inverse of the driving gain ratio, 1 / G fxy The matrix multiplication of the drive gain ratio cancels out the matrix operation of the drive gain ratio.

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