Gyro sensor and control method for gyro sensor

Abstract

To reduce errors of measurement angle due to a drive signal gain error and an oscillation detection signal gain error between two oscillation axes of an oscillator in a gyro sensor.SOLUTION: A sensor unit of a gyro sensor is composed of an oscillator 2 and a mounting board 3 having a plurality of electrodes facing it, and is controlled for drive by a control unit 10 including PLLs 140, 141, AGCs 130, 131, a detection gain ratio correction unit 106, and a drive gain ratio correction unit 153. With two oscillation axes of the oscillator 2 defined as an axis x and an axis y, the detection gain ratio correction unit 106 corrects the gain ratio of the detection signals of the x- and y-axis oscillations from the sensor unit, and the oscillation gain ratio correction unit 153 corrects the gain ratio of the x- and y-axis drive signals to the sensor unit. The control unit 10 includes an angle feedback unit 180 which, after correction of the detection and drive gain ratios, calculates an angle of rotation by integrating calculation of an angular velocity on the basis of angular velocity information from the AGCs 130, 131, and executes feedback of the angle of rotation.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present disclosure relates to a gyro sensor and a method for controlling the gyro sensor.

Background Art

[0002] Conventionally, a gyro sensor is known that includes an oscillator having two vibration modes with different resonance angular frequencies, a mounting substrate that surrounds the oscillator and has a plurality of electrodes for driving and detecting vibrations, and a control unit that executes drive control thereof (for example, Patent Document 1).

[0003] The gyro 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.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The whole angle mode has advantages such as being able to obtain angular information of rotation and being able to increase the range of the angular velocity input to the oscillator. The oscillator in this type of gyro sensor can be regarded as a two-degree-of-freedom two-dimensional vibration model in which two vibration axes with two predetermined spring constants orthogonal to the mass point and two attenuation axes with two predetermined attenuation coefficients orthogonal thereto are connected on a two-dimensional plane along the mounting substrate on which it is mounted. At this time, assuming that the angle of rotation in the whole angle mode is θ, the angular velocity is expressed by the following equation (1).

[0006]

Equation

[0007] (1) In the formula, η is the angular gain, τ is the time constant, and θ τ is the angle between the attenuation axis and the electrode axis of the vibrator, and θ ω is the angle between the vibration axis and the electrode axis of the vibrator, Q is the energy of unnecessary vibration called the quadrature error, Δω is the difference in the resonance angular frequencies of the two vibration axes, and E is the vibration energy. According to formula (1), in the Hall angle mode, due to the frequency error of the vibrator called Angle Dependent Bias and the error of the time constant depending on the Q value, an error occurs in the measured angle. Also, taking the two vibration axes of the vibrator as the x-axis and the y-axis, due to processing errors of the vibrator, 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 occur. Therefore, these gain errors become factors of the error in the measured angle in the Hall angle mode.

[0008] In view of the above points, an object of the present disclosure is to provide a gyro sensor that is controlled in the Hall angle mode and can reduce the error in the measured angle caused by the gain error of the drive signal and the gain error of the detection signal of the vibration between the two vibration axes of the vibrator, and a control method thereof.

Means for Solving the Problems

[0009] According to one aspect of the present disclosure, the gyro sensor includes a vibrator (2) having a first vibration mode and a second vibration mode with different resonance angular frequencies, a mounting substrate (3) having a plurality of electrodes (51) facing the vibrator, a control unit (10) that executes drive control of the vibrator, and is provided with Taking a virtual 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, in the radial direction, the direction along the vibration direction of the first vibration mode is taken as the x-axis, and the direction along the vibration direction of the second vibration mode is taken as the y-axis, the control unit PLLs (140, 141) for resonantly driving the vibrator in two axes of the first vibration mode and the second vibration mode, A detection gain ratio (G pxy ) which is a ratio between the gain of a first detection signal from a first detection electrode that detects vibration of the vibrator on the x-axis among a plurality of electrodes and the gain of a second detection signal from a second detection electrode that detects vibration of the vibrator on the y-axis among the plurality of electrodes, and a detection gain ratio correction unit (106) that corrects the ratio; A first coordinate conversion unit (105) that converts a signal from a detection electrode from a real coordinate axis to a coordinate axis for calculation, using a plane coordinate axis formed in the radial direction as the real coordinate axis; A drive gain ratio (G fxy ) which is a ratio between the gain of a first drive signal to a first drive electrode for vibrating the vibrator in a first vibration mode among a plurality of electrodes and the gain of a second drive signal to a second drive electrode for vibrating the vibrator in a second vibration mode among the plurality of electrodes, and a drive gain ratio correction unit (153) that corrects the ratio; A second coordinate conversion unit (154) that converts a signal corrected by the drive gain ratio correction unit from a coordinate axis for calculation to a real coordinate axis; A first demodulation block (110) that performs calculation of a first demodulation output (V Xi1 , V Xq1 ) based on the first detection signal and the first drive signal, and a second demodulation output (V Xi2 , V Xq2 ) based on the first detection signal and the second drive signal; A second demodulation block (120) that performs calculation of a third demodulation output (V Yi1 , V Yq1 ) based on the second detection signal and the first drive signal, and a fourth demodulation output (V Yi2 , V Yq2 ) based on the second detection signal and the second drive signal; An AGC (130, 131) that performs calculation of a drive output for maintaining the vibration amplitudes of the vibrator in the first vibration mode and the second vibration mode; An angle feedback unit (180) that, after correction of the detection gain ratio and the drive gain ratio, has an integration circuit (182) that calculates a rotation angle by integrating the angular velocity based on the angular velocity information input from the AGC, and feeds back the calculated rotation angle to the first coordinate conversion unit and the second coordinate conversion unit.

[0010] This gyro sensor has two independent PLLs and AGCs, and while the vibrator is resonantly driven in each of the two vibration modes, four demodulation outputs are calculated by a combination of one of the detection signals of the two vibration modes and one of the drive signals by two demodulation blocks. Further, based on the demodulation output, this gyro sensor corrects the gain ratios of the detection signals and drive signals of the x-axis and y-axis of the vibrator by a detection gain ratio correction unit and a drive gain ratio correction unit, and reduces the influence of the gain ratio of the drive / detection signals of the vibrator on the x-axis and y-axis. Therefore, this gyro sensor is controlled in the hall angle mode, and the error in the measured angle due to the gain ratio of the detection signal and the gain ratio of the drive signal is reduced.

[0011] According to another aspect of the present disclosure, a method for controlling a gyro sensor is a method for controlling a gyro sensor in which a vibrator (2) having a first vibration mode and a second vibration mode with different resonance angular frequencies is mounted on a mounting substrate (3) having a plurality of electrodes (51) facing the vibrator, resonantly driving the vibrator in two axes of the first vibration mode and the second vibration mode by two independent PLLs (140, 141) and AGCs (130, 131); a detection gain ratio (G pxy ) which is the ratio of the gain of the first detection signal from the first detection electrode that detects the vibration of the vibrator in the x-axis among the plurality of electrodes to the gain of the second detection signal from the second detection electrode that detects the vibration of the vibrator in the y-axis among the plurality of electrodes, is calculated and determined, a drive gain ratio (G fxy ) which is the ratio of the gain of the first drive signal to the first drive electrode for vibrating the vibrator in the x-axis among the plurality of electrodes to the gain of the second drive signal to the second drive electrode for vibrating the vibrator in the y-axis among the plurality of electrodes, is calculated and determined, The demodulation blocks (110, 120) perform operations on the demodulation outputs (V Xi1 , V Xq1 ) based on the first detection signal and the first drive signal, the demodulation outputs (V Xi2 , V Xq2 ) based on the first detection signal and the second drive signal, the demodulation outputs (V Yi1 , V Yq1 ) based on the second detection signal and the first drive signal, and the demodulation outputs (V Yi2 , V Yq2 ) based on the second detection signal and the second drive signal, and Taking the x-axis and y-axis as the vibration axes, a direction along the radial direction with a virtual straight line passing through the center of the region surrounded by a plurality of electrodes and along the thickness direction of the mounting substrate as the axis, and taking the direction along the drive electrodes for resonantly driving in the first vibration mode and the second vibration mode among the plurality of electrodes as the electrode axes (X, Y), after determining the detection gain ratio, based on the result calculated in the demodulation block, calculate the deviation angle (θ ω ), which is the angle formed by the vibration axis of the vibrator and the electrode axis, and perform feedback control of the deviation angle, and After the feedback control of the deviation angle, based on the frequency signals corresponding to the first vibration mode and the second vibration mode output from the PLL, calculate Δf, which is the difference between the resonance frequencies of the first vibration mode and the second vibration mode, and perform feedback control of Δf, and After the feedback control of Δf and the determination of the drive gain ratio, calculate the rotation angle of the gyro sensor by integrating the angular velocity, and feedback the calculated rotation angle to the calculation of the rotation angle in the detection direction and the drive direction of the vibration of the vibrator, and After the feedback of the rotation angle, measure the angle and angular velocity of the gyro sensor, including.

[0012] The control method of this gyro sensor resonantly drives the vibrator in two independent PLLs and AGCs in two vibration modes respectively, and calculates four demodulation outputs by combining one of the detection signals of the two vibration modes and one of the drive signals by two demodulation blocks. Further, the control method of this gyro sensor, based on the demodulation output, calculates the detection gain ratio, which is the gain ratio of the detection signals of the x-axis and y-axis of the vibrator, by calculation, then calculates the deviation angle between the vibration axis and the electrode axis of the vibrator, and performs feedback of the deviation angle. Further, the control method of this gyro sensor calculates and performs feedback on the difference Δf in resonance frequency based on the two drive signals corresponding to the two vibration modes from the two PLLs, and calculates and determines the drive gain ratio, which is the gain ratio of the drive signals of the x-axis and y-axis. After executing the above processing, the control method of this gyro sensor executes the calculation of the angle and the angular velocity, thereby obtaining the effect of reducing the measurement angle error caused by the gain ratio of the x-axis and y-axis of the detection signal and the drive signal.

[0013] Note that the reference signs with parentheses attached to each component etc. show an example of the correspondence relationship between the component etc. and the specific components etc. described in the embodiments described later.

Brief Description of Drawings

[0014]

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Embodiments for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In each of the following embodiments, parts that are the same or equivalent to each other will be denoted by the same reference numerals and described.

[0016] (First Embodiment) The gyro sensor 1 of the first embodiment will be described with reference to the drawings.

[0017] 〔Basic Configuration〕 The gyro sensor 1 of this embodiment has, for example, as shown in FIG. 1, a vibrator 2 and a mounting substrate 3, and includes a sensor element in which the vibrator 2 is mounted on the mounting substrate 3. The gyro sensor 1 can detect the angular velocity and the rotated angle applied to the gyro sensor 1 based on the change in capacitance between a part of the thin vibrator 2 that can vibrate in the first vibration mode and the second vibration mode and a plurality of first electrode portions 51 of the mounting substrate 3. The gyro sensor 1 is controlled, for example, in the hall angle mode by a control unit 10 described later, and correction and feedback processing for reducing the error of the measured angle are executed.

[0018] The vibrator 2 is, for example, as shown in FIG. 2, a three-dimensional substantially symmetric micro-vibrator including a curved surface portion 21 having an outer shape of a substantially hemispherical three-dimensional curved surface, and a mounting portion 22 extending from the vertex side of the virtual hemisphere formed by the curved surface portion 21 toward the center side of the hemisphere. The vibrator 2 has, for example, conductive films (not shown) formed on both the front and back surfaces, and voltage can be applied from the mounting substrate 3. And the vibrator 2 has, for example, a rim 23 which is an end portion of the curved surface portion 21 opposite to the mounting portion 22 facing a plurality of first electrode portions 51, and the rim 23 vibrates in a resonance mode by the electrostatic force generated between the first electrode portion 51 and the rim 23.

[0019] Note that the vibrator 2 can be manufactured, for example, by preparing a plate material made of an arbitrary reflow material such as quartz and a mold having a bowl-shaped recess and a support portion located at the center of the recess, setting the plate material in the mold, and heating and softening the recess while reducing the pressure.

[0020] Further, the vibrator 2 may have a substantially disc shape having, for example, as shown in FIG. 3, a disc-shaped portion and a columnar connection portion joined to the mounting substrate 3 at the center of the portion. In this case, the vibrator 2 has a rim 23 at the end of the hollow disc-shaped portion, and the portion is surrounded by a plurality of first electrode portions 51. Thus, the vibrator 2 only needs to be a structure that can vibrate in the first vibration mode and the second vibration mode by a driving electrode among the plurality of first electrode portions 51, and in addition to the above structure, other known structures may be used.

[0021] As shown in, for example, FIGS. 1 and 2, the mounting substrate 3 includes a lower substrate 4 and an upper substrate 5, and these are joined together. For example, the mounting substrate 3 is obtained by performing wiring film formation or the like on a lower substrate 4 made of borosilicate glass as an insulating material, and then anodically joining an upper substrate 5 made of silicon as a semiconductor material to the lower substrate 4 and performing patterning. The mounting substrate 3 has, for example, a plurality of first electrode portions 51 and second electrode portions 52 formed by performing dry etching such as DRIE (Deep Reactive Ion Etching) on the upper substrate 5 after anodic bonding. Also, when the vibrator 2 has the bird bath shape shown in FIG. 2, for example, an annular groove (not shown) along the rim 23 may be formed in the lower substrate 4 as necessary so as not to contact the rim 23.

[0022] The plurality of first electrode portions 51 are arranged at equal intervals and separated from each other so as to draw one ring on the plane of the mounting substrate while surrounding the rim 23 of the vibrator 2, and electrode films (not shown) are formed on their upper surfaces. The plurality of first electrode portions 51 are connected to external circuit boards or the like through wires (not shown) connected to the electrode films (not shown), enabling control of their potentials. All of the plurality of first electrode portions 51 are spaced apart from the rim 23 of the vibrator 2 by a predetermined distance, and each forms a capacitor with the vibrator 2, enabling detection of the capacitance between the vibrator 2 and the first electrode portions 51. A part of the plurality of first electrode portions 51 serves as detection electrodes for detecting capacitance, and another part serves as drive electrodes for applying electrostatic force to the rim 23 of the vibrator 2.

[0023] As shown in FIG. 1, for example, the second electrode portion 52 has a frame shape surrounding the plurality of first electrode portions 51. An electrode film (not shown) is formed on the upper surface, and a wire (not shown) is connected to the electrode film (not shown). The second electrode portion 52 is connected to a conductive film (not shown) of the vibrator 2 through wiring or the like (not shown), and is configured to be able to apply a voltage.

[0024] Hereinafter, for convenience of explanation, a sensor element composed of the vibrator 2 and the mounting substrate 3, and a circuit (such as a current-voltage conversion circuit) (not shown) used for applying a voltage to the plurality of first electrode portions 51 may be collectively referred to as a "sensor unit".

[0025] When viewed from the normal direction with respect to the plane formed by the mounting substrate 3 (hereinafter referred to as "top view") of the vibrator 2, for example, as shown in FIG. 4, by applying a voltage to a part of the first electrode portion 51, the number of bellies and nodes in the vibration amplitude of the outer contour of the rim 23 becomes 2n each, and a resonance state is obtained. n is an integer of 2 or more, and such a resonance state of the vibrator 2 is called a "wine glass mode". In FIG. 4, a resonance mode of n = 2 in the wine glass mode, in which the vibration axes x and y described later coincide with the electrode axes X and Y, is shown as a representative example. However, the vibrator 2 can also be vibrated in a higher-order wine glass mode of n = 3 or more.

[0026] Hereinafter, for convenience of explanation, as shown in FIG. 4, with the center position of the rim 23 in the top view as the center C, the radial direction with the straight line along the thickness direction of the mounting substrate 3 passing through the center C as the axis is referred to as the "substrate radial direction", and the circumferential direction with the straight line as the axis is referred to as the "substrate circumferential direction". Further, among the directions along the substrate radial direction, the direction passing through the belly position of the vibration of the rim 23 of the vibrator 2 in the first vibration mode (resonance angular frequency ω1) is referred to as the "vibration axis x", and the direction passing through the node position is referred to as the "vibration axis y". At this time, in the wine glass mode of 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 of n = 2, the angle formed by the vibration axis x and the vibration axis y is 45°.

[0027] The plurality of first electrode portions 51 are arranged, for example, along the substrate circumferential direction so as to be separated from each other and at substantially the same distance from the non-vibrating rim 23. Hereinafter, for convenience, for example, as shown in FIG. 4, one direction on the actual plane on which the plurality of first electrode portions 51 are arranged is the "X r direction", and the direction orthogonal to the X r direction on the same plane is the "Y r direction", and the Xr Direction and Y r The plane to which the direction belongs is the "X r Y r plane". And, X r Y r One direction in the X r Y r plane is defined as the "electrode axis X", and the direction in which the electrode axis X points when rotated counterclockwise by (360 / 4k)° along the circumferential direction of the substrate on the X

[0028] At this time, in a top view, the sensor unit has, for example, as shown in FIG. 5, two springs with spring constants k x 、k y connected to two objects with damping coefficients C x 、C y and can be regarded as an oscillator of a two-degree-of-freedom system that vibrates in a two-dimensional plane. Note that FIG. 5 and FIG. 10 described later show the vibration axes x, y and the electrode axes X, Y in the X r Y r plane converted into a rectangular coordinate system, and the origin of the vibration axes x, y and the origin of the electrode axes X, Y are made to coincide. The above-converted rectangular coordinate system corresponds to the coordinate axes for calculation in the control unit 10. The vibration axes x, y may also be referred to as spring axes. Hereinafter, the vibration axes x, y may be simply referred to as the "x-axis" and the "y-axis", respectively.

[0029] The spring constants k x 、k y are the spring constants for the respective vibration axes x, y, and the damping coefficients C x 、C y are the damping coefficients of the vibration for the respective vibration axes x, y. θ ω is the angle between the electrode axes X, Y and the vibration axes x, y which are the spring axes in the rectangular coordinate system shown in FIG. 5, that is, the misalignment angle, and θ τ is the angle between the electrode axes X, Y and the damping axis along the direction in which the vibration decays in the same rectangular coordinate system. Unless special processing or the like is performed, the sensor unit usually has θ ω ≠0.

[0030] The above is the basic configuration of the sensor portion of the gyro sensor 1 of the present embodiment. The details of the control unit 10 that executes the drive control of the gyro sensor 1 will be described next.

[0031] In FIG. 1, the case where the mounting substrate 3 has 16 first electrode portions 51 and one frame-shaped second electrode portion 52 is shown as a representative example, but the present invention is not limited thereto. For the first electrode portion 51 and the second electrode portion 52 of the mounting substrate 3, for example, the number, arrangement, shape, etc. may be appropriately changed.

[0032] 〔Control Unit〕 Next, the control unit 10 of the gyro sensor 1 will be described.

[0033] The control unit 10 is, for example, an electronic control unit in which various electronic components such as a CPU, a ROM, and a RAM are mounted on a circuit board (not shown), and which executes drive control in the gyro sensor 1. The CPU is an abbreviation for Central Processing Unit, the ROM is an abbreviation for Read Only Memory, and the RAM is an abbreviation for Random Access Memory.

[0034] As shown in FIG. 6, for example, the control unit 10 includes detection circuits 101 and 102 that detect the vibrations of the vibrator 2 in the x-axis and y-axis directions, and ADCs 103 and 104 that convert the analog signals of the detection circuits 101 and 102 into digital signals. The ADC is an abbreviation for Analog to Digital Converter. For example, the detection circuit 101 detects a signal from a detection electrode that detects the vibration in the x-axis direction among a plurality of first electrode portions 51. The detection circuit 102 detects a signal from a detection electrode that detects the vibration in the vibration axis y direction among a 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.

[0035] The control unit 10 includes, for example, a first coordinate conversion unit 105 to which signals from the ADCs 103 and 104 are input, a detection gain ratio correction unit 106, a first demodulation block 110, and a second demodulation block 120.

[0036] The first coordinate conversion unit 105 performs, for example, a rotation matrix operation that converts the input signals from the ADCs 103 and 104 to coordinates on a coordinate axis for calculation in which the electrode axes X and Y are orthogonal and the vibration axes x and y are orthogonal. Note that this rotation matrix operation is the same matrix operation as the operation of equation (5) that converts the electrode axes X and Y to the vibration axes x and y, which will be described later. The control unit 10 executes, for example, the arithmetic processing in the second coordinate conversion unit 154 from the first coordinate conversion unit 105 on the above-converted coordinate axes. The first coordinate conversion unit 105, for example, corrects the detection gain ratio G pxy , performs feedback control of θ ω , and performs feedback control of Δf in this order, and then feedback of the rotation angle θ is performed from the angle feedback unit 180, which will be described later. The rotation angle θ here refers to the azimuth formed by the current vibration direction of the vibrator 2 on the vibration axes x and y of the converted coordinates. The detection gain ratio G pxy and calculation, θ ω and the feedback control of Δf will be described later.

[0037] The detection gain ratio correction unit 106 corrects, for example, the gain ratio of the detection signals on 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 and 131 and the PLLs 140 and 141, which will be described later, are operated. The detection gain ratio G pxy calculated by the detection gain ratio correction unit 106 or the demodulation output calculation unit 113 is used for the feedback control of θ ω .

[0038] The first demodulation block 110 performs, for example, the calculation of the demodulation output related to the vibration axis x based on the input signal from the detection gain ratio correction unit 106. Also, the first demodulation block 110 outputs, for example, an amplitude component in phase with the frequency signal and an amplitude component with a 90° phase shift from the frequency signal, based on the frequency signal for 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.

[0039] The first demodulation unit 111 calculates, for example, the demodulation outputs V X and V Xi1 based on the first drive signal for resonantly driving the vibrator 2 in the first vibration mode with the resonance angular frequency ω1 and the detection signal V Xq1 from the detection electrodes of the vibration in the first vibration mode. The demodulation outputs V Xi1 and 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 and V Xi2 based on the second drive signal for resonantly driving the vibrator 2 in the second vibration mode with the resonance angular frequency ω2 and the detection signal V Xq2 . This is possible because, in a system where the resonance driving of the resonance angular frequencies ω1 and ω2 of the vibrator 2 is maintained by two independent PLLs 140 and 141 described later, the detection signal V X contains information about the vibration amplitude in the vibration axis y direction of the second vibration mode. The demodulation outputs V Xi2 and 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, V Xi1 , V Xq1 , V Xi2 , and V Xq2Based on this, the amplitude and phase of the first vibration mode of the vibrator 2 are calculated. Note that the first drive signal and the second drive signal respectively correspond to the frequency signal about the vibration axis x and the frequency signal about the vibration axis y, and are input from the PLL140 to the demodulation blocks 110 and 120.

[0040] The second demodulation block 120 performs, for example, an operation of demodulation output regarding the vibration axis y based on the input signal from the detection gain ratio correction unit 106. Also, the second demodulation block 120 outputs, for example, an amplitude component in phase with the frequency signal and an amplitude component with a 90° phase shift from the frequency signal based on the frequency signal about the vibration axis y from the PLL141 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.

[0041] The first demodulation unit 121 calculates, for example, the demodulation outputs V Y and V Yi2 based on the second drive signal and the detection signal V Yq2 from the detection electrode of the vibration of the second vibration mode. The demodulation outputs V Yi2 and V Yq2 are, for example, 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 second demodulation unit 122 calculates, for example, the demodulation outputs V Y and V Yi1 based on the first drive signal and the detection signal V Yq1 . The demodulation by the second demodulation unit 122 is possible because the detection signal V Y includes information about the vibration amplitude in the x direction of the vibration axis of the first vibration mode. The demodulation outputs V Yi1 and V Yq1 are, for example, 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 demodulation output calculation unit 113 calculates, for example, V Yi1 , V Yq1 , V Yi2 , V Yq2Based on this, the amplitude and phase of the second vibration mode of the vibrator 2 are calculated. Note that the calculation of each of the above-described demodulation outputs will be described later.

[0042] The control unit 10 includes an AGC 130 and a PLL 140 for resonantly driving the vibrator 2 in the first vibration mode and maintaining this state, and an AGC 131 and a PLL 141 for resonantly driving the vibrator 2 in the second driving mode vibration mode and maintaining the resonance mode. AGC is an abbreviation for Automatic Gain Control and is also referred to as automatic gain control. PLL is an abbreviation for Phase Locked Loop and is also referred to as a phase-locked loop.

[0043] For example, amplitude information in the x direction of the vibration axis of the first vibration mode of the vibrator 2 is input from the first demodulation block 110 to the AGC 130, and the AGC 130 performs calculations and signal outputs for controlling the amplitude in the first vibration mode to a predetermined constant value based on the amplitude information. For example, the AGC 130 outputs a control signal for amplitude fixation to the modulation unit 151 and outputs a signal for angular velocity calculation to the angular velocity calculation unit 191.

[0044] For example, amplitude information in the y direction of the vibration axis of the second vibration mode of the vibrator 2 is input from the second demodulation block 120 to the AGC 131, and the AGC 131 performs calculations and signal outputs for controlling the amplitude in the second vibration mode to a predetermined constant value based on the amplitude information. For example, the AGC 131 outputs a control signal for amplitude fixation to the modulation unit 152 and outputs a signal for angular velocity calculation to the angular velocity calculation unit 191.

[0045] For example, phase information about the first vibration mode of the vibrator 2 is input from the first demodulation block 110 to the PLL 140, and the PLL 140 performs frequency control and signal output of a first drive signal for resonantly driving the vibrator 2 in the first vibration mode at a resonance angular frequency ω1. The PLL 140 includes, for example, a PI circuit and an NCO circuit (not shown), and the demodulated output V Xq1The PI circuit corrects the signal of , and based on the corrected signal, the NCO circuit outputs a first drive signal of a predetermined frequency. PI is an abbreviation for Proportional Integral. 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. PLL140 outputs signals to the demodulation blocks 110, 120, and the modulation unit 151.

[0046] For example, PLL141 receives phase information about the second vibration mode of the vibrator 2 from the second demodulation block 120, and performs frequency control and signal output of a second drive signal for resonantly driving the vibrator 2 at the resonant angular frequency ω2. PLL141 has, for example, the same configuration as PLL140, and the demodulated output V Yq2 of the signal is corrected by the PI circuit, and based on the corrected signal, the NCO circuit outputs a second drive signal of a predetermined frequency. PLL141 outputs signals to the demodulation blocks 110, 120, and the modulation unit 152.

[0047] The control unit 10 includes, for example, a modulation unit 151 to which output signals from the AGC130 and PLL140 are input, and a modulation unit 152 to which output signals from the AGC131 and PLL141 are input. For example, the modulation unit 151 superimposes the frequency signal f x from the PLL140 on the amplitude control signal input from the AGC130, and outputs the superimposed signal to the drive gain ratio correction unit 153. For example, the modulation unit 152 superimposes the frequency signal f y from the PLL141 on the amplitude signal input from the AGC131, and outputs the superimposed signal to the drive gain ratio correction unit 153.

[0048] 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.

[0049] 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, based on the input signals from the modulation units 151 and 152 when the AGCs 130, 131, and the PLLs 140, 141 are operating. fxy The drive gain ratio correction unit 153 calculates the drive gain ratio G pxy after the setting of the detection 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.

[0050] 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 converted coordinates converted by the first coordinate conversion unit 105 to the X r Y r coordinates shown in FIG. 4, that is, the actual coordinates. The second coordinate conversion unit 154 receives, for example, a feedback of the rotation angle θ from the angle feedback unit 180 described later. The second coordinate conversion unit 154 outputs signals corresponding to the rotation angles of the calculated drive directions of the x-axis and y-axis to the DACs 155 and 156, for example. The drive gain ratio G fxy and its calculation will be described later.

[0051] The DACs 155 and 156 convert, for example, the digital signals for driving the vibrator 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.

[0052] 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, respectively, to vibrate the vibrator 2 in the resonance mode and output them to the drive electrodes among the plurality of first electrode portions 51. As a result, a force F x due to electrostatic force acts on the vibrator 2 in the x-axis direction, and a force F y due to electrostatic force acts on the vibrator 2 in the y-axis direction, respectively, and vibration control is performed.

[0053] The control unit 10 further includes, for example, a deviation angle correction unit 160, a mode match control unit 170, an angle feedback unit 180, an angle calculation unit 190, and an angular velocity calculation unit 191.

[0054] The deviation angle correction unit 160 performs a deviation angle correction to make zero the angle θ (hereinafter referred to as "deviation angle") formed by the vibration axes x and y and the electrode axes X and Y, based on, for example, either one of D x and D y calculated by the demodulation blocks 110 and 120. The deviation angle correction unit 160 outputs, for example, a control signal Vθ ω to the sensor unit to control the control signal Vθ x and D y so that either one of them becomes zero, and controls the state where the vibration axes x and y overlap the electrode axes X and Y, that is, the state where θ ω = 0. The deviation angle correction unit 160 has, for example, two independent PIs 161 and 162 as shown in FIG. 7. A signal corresponding to D ω from the first demodulation block 110 is input to the PI 161, and a signal corresponding to D x from the second demodulation block 120 is input to the PI 162. Then, the deviation angle correction unit 160 outputs, for example, a control signal Vθ y to the sensor unit to control so that D x = 0 or D y = 0. The calculation of D ω and D x and D y will be described later.

[0055] The mode match control unit 170 performs mode match control 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, for example, after the feedback control of θ ω = 0 is performed by the deviation angle correction unit 160. The mode match control unit 170 has, for example, a PI 171 as shown in FIG. 8, and frequency signals f x and f yA signal corresponding to the frequency difference Δf obtained based on this is input to PI171. The mode match control unit 170 outputs a control signal VΔf to the sensor unit for controlling so that the frequency difference Δf = 0.

[0056] The angle feedback unit 180, for example, based on the angular velocity information input from the AGCs 130 and 131 after correction of the detection gain ratio G pxy calculates the rotation angle θ by integrating the angular velocity. The angle feedback unit 180 outputs a signal corresponding to the rotation angle θ obtained by the calculation to the first coordinate conversion unit 105 and the second coordinate conversion unit 154. The angle feedback unit 180 includes, for example, as shown in FIG. 9, a PI181 to which angular velocity information is input from the AGCs 130 and 131, and an integration circuit 182. PI181 corrects the information on the angular velocity 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 PI181, and calculates an angle at which the angular velocity becomes zero (hereinafter referred to as "zero angle"). 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.

[0057] The angle calculation unit 190 calculates the angle of the gyro sensor 1 based on, for example, the information on the zero angle from the angle feedback unit 180 and a scale factor measured in advance.

[0058] The angular velocity calculation unit 191, for example, based on the input signals V Ω+ 、V Ω- from the AGCs 130 and 131, divides the value obtained by subtracting these signals by a scale factor measured in advance to calculate the angular velocity externally applied to the gyro sensor 1.

[0059] The above is the basic configuration of the control unit 10.

[0060] 〔Calculation of Demodulation Output〕 Next, the calculation of the demodulation output in the demodulation blocks 110 and 120 will be described. Here, the case of n = 2 in the wineglass mode is described as a representative example, and the description of the higher-order cases of n = 3 or more is omitted because it is basically the same.

[0061] When the resonator 2 is resonantly driven in both the first vibration mode and the second vibration mode of the resonance mode with n = 2, for example, as shown in FIG. 10, it vibrates along two orthogonal vibration axes x and y. Let the vibration amplitude and the resonance angular frequency on the vibration axis x be A and ω1, respectively, and the vibration amplitude and the resonance angular frequency on the vibration axis y be B and ω2, respectively, and the angle formed by the vibration axis x and the electrode axis X be θ. ω Then, the vibration amplitudes of the vibration axes x and y at time t are represented by the following equations (2) and (3).

[0062] x = A sin(ω1t + φ1) ··· (2) y = B sin(ω2t + φ2) ··· (3)

[0063] φ1 in equation (2) and φ2 in equation (3) are the phases with respect to the external forces applied from each direction. Let the components of the vibration with amplitude A on the electrode axes X and Y be a X , a Y , and let the components of the vibration with amplitude B on the electrode axes X and Y be b X , b Y . Then, the deviation angle θ ω between the vibration axis x and the electrode axis X is represented by the following equation (4) from the orthogonality of the vibration axes x and y.

[0064]

Equation

[0065]

Equation

[0066] X = a X sin(ω1t + φ1) + b X sin(ω2t + φ2) ··· (6) Y = a Y sin(ω1t + φ1) + b Y sin(ω2t + φ2) ··· (7) Note that in equations (6) and (7), each component a X , b X , a Y , b Y is, in the example shown in FIG. 7, a X = Acosθ ω , b X = -Bsinθ ω , a Y = Asinθ ω , b Y = Bcosθ ω . Also, assuming the conversion coefficients from the amplitudes to the voltages according to the detection method are ξ X , ξ Y , the voltages V XP , V YP at the detection electrodes on the electrode axes X and Y respectively are expressed by the following equations (8) and (9).

[0067] V XP = ξ X {a X sin(ω1t + φ1) + b X sin(ω2t + φ2)} ··· (8) V YP = ξ Y {a Y sin(ω1t + φ1) + b Y sin(ω2t + φ2)} ··· (9) The first demodulation unit 111 performs the calculation of the demodulation outputs V XP for the external forces on the vibration axes x and y based on the voltage V Xi1 , V Xq1 in equation (8). The demodulation output V Xi1is calculated by multiplying the voltage V with sinω1t as represented by the following equation (10), and passing it through a low-pass filter as represented by the equation (11) to eliminate the terms of the second harmonic and the frequency sum through an operation. XP

[0068]

Equation

[0069]

Equation

[0070] |f(t)| in the equation (11) LPF means the operation of eliminating the terms of the second harmonic and the frequency sum that have passed through the above-mentioned low-pass filter. The same applies to the following equations (13), (15), and (17).

[0071] The demodulated output V Xq1 is calculated by multiplying the voltage V with cosω1t as represented by the following equation (12), and passing it through a low-pass filter as represented by the equation (13) to eliminate unnecessary terms through an operation. XP

[0072]

Equation

[0073]

Equation

[0074] V XP sin(ω2t + Δφ) = ξ X {a X sin(ω1t + φ1) + b X sin(ω2t + φ2)}sin(ω2t + Δφ) ··· (14)

[0075]

Number

[0076] V XP cos(ω2t + Δφ) = ξ X {a X sin(ω1t + φ1) + b X sin(ω2t + φ2)}cos(ω2t + Δφ) ··· (16)

[0077]

Number

[0078] Demodulation output V Xi1 V Xq1 V Xi2 V Xq2 V Yi1 V Yq1 V Yi2 V Yq2 is output to, for example, the demodulation output arithmetic units 113, 123, etc., and is used for calculating the amplitudes of the first and second oscillation modes and the phase difference. Hereinafter, for simplicity 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".

[0079] 〔Calculation of Amplitude and Phase Using Demodulation Output〕 Next, the calculation of the amplitude and phase of the oscillation mode using each demodulation output will be described.

[0080] For example, the demodulation output arithmetic units 113, 123 are configured to include 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 between the respective demodulation outputs.

[0081] The demodulation output arithmetic unit 113, for example, calculates |ξ Xi1 V Xq1 by performing a sum-of-squares operation that adds the squares of the demodulation outputs V X b X| is calculated. The demodulation output calculation unit 113, for example, calculates |ξ Xi2 by performing a sum-of-squares calculation in the calculation unit based on the demodulation output V Xq2 after passing through the HPF. Also, the demodulation output calculation unit 113, for example, calculates the phase difference Δφ X a X based on the demodulation output V Xi1 after passing through the HPF, and calculates the phase difference Δφ Xi2 based on the demodulation output V Xi after passing through the HPF, and calculates the phase difference Δφ Xq1 respectively. Xq2 Similarly, the demodulation output calculation unit 123 calculates |ξ Xq by performing a sum-of-squares calculation based on the demodulation output V

[0082] after passing through the HPF, and calculates |ξ Yi1 based on the demodulation output V Yq1 by performing a sum-of-squares calculation. Also, the demodulation output calculation unit 123 calculates the phase difference Δφ Y b Y based on the demodulation output V Yi2 and calculates the phase difference Δφ Yq2 based on the demodulation output V Y a Y respectively. Similarly, the demodulation output calculation unit 123 calculates the phase difference Δφ Yi1 based on the demodulation output V Yi2 and calculates the phase difference Δφ Yi based on V Yq1 and calculates the phase difference Δφ Yq2 based on the demodulation output V Yq respectively.

[0083] The demodulation blocks 110 and 120 can obtain the amplitude information of the resonance mode through the above calculations of |ξ X a X |, |ξ Y a Y |, |ξ X b X |, |ξ Y b Y |, and can obtain the phase information of the resonance mode through the above calculations of the phase differences Δφ Xi Δφ Xq Δφ Yi Δφ Yq respectively.

[0084] Hereinafter, for simplicity of explanation, the operation of |ξ X a X |, |ξ Y a Y |, |ξ X b X |, |ξ Y b Y | for calculating the above amplitude is simply referred to as "amplitude operation". Also, the demodulation output V Xi1 , V Xq1 calculated by the first demodulation unit 111 is referred to as "the first demodulation output", and the demodulation output V Yi2 , V Yq2 calculated by the first demodulation unit 121 is referred to as "the second demodulation output", respectively. Also, the demodulation output V Xi2 , V Xq2 calculated by the second demodulation unit 112 is referred to as "the third demodulation output", and the demodulation output V Yi1 , V Yq1 calculated by the second demodulation unit 122 is referred to as "the fourth demodulation output", respectively.

[0085] 〔Feedback control of θ ω 〕 Next, the calculation of θ ω by the deviation angle correction unit 160 and its feedback control will be described.

[0086] The control unit 10 is configured such that the first demodulation output calculation unit 113 performs calculations based on the first demodulation output and the third demodulation output, and the second demodulation output calculation unit 123 performs calculations based on the second demodulation output and the fourth demodulation output.

[0087] Here, the angle formed by the vibration axes x and y and the electrode axes X and Y, that is, the deviation angle θ ω can be calculated by the following equation (18) or (19).

[0088]

Equation

[0089]

Equation

[0090] D in equations (18) and (19) X and D Y are collectively denoted as D k Then, D k is represented by the following equation (20).

[0091] D k = |ξ k 2 a k b k | (k = X, Y) ··· (20) Based on the demodulation outputs calculated by the demodulation units 111, 112, 121, and 122, the control unit 10 applies a control voltage from the deviation angle correction unit 160 to the sensor unit so that |θ ω | = 0. |θ ω | = 0 when D X = 0 or D Y = 0 is satisfied according to equations (18) and (19).

[0092] The first demodulation output calculation unit 113 calculates the value of |ξ Xi1 and V Xq1 by performing a sum-of-squares operation of squaring each of the demodulation outputs V X b X | at, for example, φ1 = φ2 = Δφ = 0. The second demodulation output calculation unit 123 calculates the value of |ξ Yi2 and V Yq2 by performing a sum-of-squares operation of squaring each of the demodulation outputs V Y b Y | at, for example, φ1 = φ2 = Δφ = 0. These calculation results are output to, for example, the control circuit 150 and are used for feedback control such that D X = 0 or D Y = 0, that is, |θ ω | = 0.

[0093] Note that the deviation angle correction unit 160 is based on |θ ωIn the feedback control with |=0, for example, based on the calculation of the phase information by the demodulation blocks 110 and 120, it is determined whether to rotate the vibration axes x and y in the clockwise or counterclockwise direction. The deviation angle correction unit 160, for example, as shown in FIG. 12, based on the calculated phase difference, the demodulated output V Xi , V Xq of the output waveform and the demodulated output V Yi , V Yq of the output waveform are discriminated whether they are in-phase or out-of-phase. The polarity "+" of θ ω in FIG. 12 means that the vibration axis is deviated counterclockwise with respect to the electrode axis, and the polarity "-" of θ ω means that the vibration axis is deviated clockwise with respect to the electrode axis. The deviation angle correction unit 160 determines the rotation direction of the vibration axis in the direction opposite to the deviation direction according to the polarity of θ ω , and outputs the determined control signal Vθ ω to a part of the first electrode unit 51.

[0094] [Calculation of Detection Gain Ratio, Driving Gain Ratio, and Attenuation Coefficient] Next, the detection gain ratio and its calculation will be described.

[0095] For example, in a system that inputs a driving force to the vibrator 2 as shown in FIG. 6, the case where the ratio of the non-ideal gains of the x-axis and the y-axis exists as the detection gain ratio G pxy will be considered. In this case, for x and y of the vibration information of the vibrator 2, the voltages input to each axis are V x , V y , and the voltages V x , V y and the detection gain ratio G pxy are expressed by the following equation (21).

[0096] [Equation]

[0097] In order to cancel the non-ideal detection gain ratio G pxy in the equation (21), the detection gain ratio G pxyCalculate it and multiply the determinant of the following equation (22) by the equation (21).

[0098]

Number

[0099] 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 pxy is represented by the following equation (23).

[0100]

Number

[0101] D in the equation (23) x 、D yis calculated by operations shown in FIGS. 13 and 14, for example. Specifically, for example, as shown in FIG. 13, the first demodulation block 110 performs an amplitude operation based on the demodulated output V Xi1 and an amplitude operation based on the demodulated output V Xq1 , calculates a first addition value obtained by adding two values obtained by each amplitude operation. Further, for example, the first demodulation block 110 performs an amplitude operation based on the demodulated output V Xi2 and an amplitude operation based on the demodulated output V Xq2 , calculates a second addition value obtained by adding two values obtained by each amplitude operation. Then, for example, the first demodulation block 110 multiplies the first addition value and the second addition value to calculate the operation value D x .

[0102] The second demodulation block 120, for example, as shown in FIG. 14, performs amplitude operations based on the demodulated outputs V Yi1 and V Yq1 respectively, adds the two obtained values to calculate a third addition value. Further, for example, the second demodulation block 120 performs amplitude operations based on the demodulated outputs V Yi2 and V Yq2 respectively, calculates a fourth addition value obtained by adding two values obtained by each amplitude operation, and then multiplies the third and fourth addition values to calculate the operation value D y .

[0103] Then, the detection gain ratio correction unit 106, for example, as shown in FIG. 15, performs 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 a detection gain ratio correction value represented by the formula (22) based on the detection gain ratio G pxy , and corrects the detection gain ratio by multiplying this by the formula (21).

[0104] Next, in a system in which driving forces F x and F y are input to the oscillator 2, the ratio of the non-ideal gains of the driving forces F x and F y is the driving gain ratio Gfxy Consider the case where it exists. The output signal from DAC155 on the x-axis and the output signal from DAC156 on the y-axis are respectively VF x、 VF y As the driving force F applied to the vibrator 2 based on the driving signals from the driving circuits 157 and 158 x 、F y is expressed by the following equation (24) including the driving gain ratio G fxy .

[0105]

Equation

[0106] To cancel the non-ideal driving gain ratio G in equation (24) fxy , some means can be used to calculate the driving gain ratio G fxy and multiply the determinant of the following equation (25) by equation (24).

[0107]

Equation

[0108]

Equation

[0109] 〔Measurement error reduction process〕 Next, an example of the processing operation for reducing errors in the measurement of the angle or angular velocity in the gyro sensor 1 will be described.

[0110] The control unit 10 starts the control flow shown in FIG. 17 when a predetermined start condition is satisfied, for example, when the external power supply for driving the gyro sensor 1 is turned on.

[0111] In step S100, the control unit 10, for example, turns on the PLLs 140 and 141 and starts the frequency control of the first and second drive signals to vibrate the vibrator 2 in the first and second vibration modes.

[0112] In step S110, the control unit 10, for example, turns on the AGCs 130 and 131 and starts controlling the amplitude of vibration in the first vibration mode and the second vibration mode of the vibrator 2. This causes the vibrator 2 to be maintained in two vibration states, for example, a vibration mode with a resonant angular frequency ω1 and a predetermined amplitude A and a vibration mode with a resonant angular frequency ω2 and a predetermined amplitude B.

[0113] In step S120, the control unit 10 acquires detection signals from the first detection electrodes for detecting vibrations in the x-axis and the second detection electrodes for detecting vibrations in the y-axis among the plurality of first electrode units 51. Then, the detection gain ratio correction unit 106 calculates the detection gain ratio G pxy The calculation, i.e., identification, is performed.

[0114] In step S130, the detection gain ratio correction unit 106 calculates, for example, the inverse number 1 / G pxy The detection gain ratio is set, i.e., correction is performed, by the above matrix calculation of multiplying a matrix having the following formula: where x=y, y=y, y=y. This reduces the effect of measurement error in the gyro sensor 1 due to the gain ratio of the detection signal between the x-axis and the y-axis. Note that the control unit 10 executes the processes of steps S120 and S130 in a state where the rotation angle feedback by the angle feedback unit 180 is turned off or the zene of the output signal of the PI 181 is set to zero, i.e., in an offline state.

[0115] In step S140, for example, the drive gain ratio correction unit 153 performs the above-mentioned calculation 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 to obtain the drive gain ratio G fxy The calculation, i.e., identification, is performed.

[0116] In step S150, for example, the drive gain ratio correction unit 153 calculates the inverse number 1 / G fxyThe above matrix operation of multiplying a matrix having [the relevant elements] is performed to set, i.e., correct, the drive gain ratio. Thereby, the influence of the measurement error in the gyro sensor 1 due to the gain ratio of the drive signals between the x-axis and the y-axis is reduced.

[0117] In step S160, for example, the deviation angle correction unit 160 controls the control signal Vθ x , D y such that one of them becomes zero and outputs it to the sensor unit. Thereby, the vibrator 2 is controlled to a state where the vibration axes x, y and the electrode axes X, Y substantially coincide. Note that in order to perform the Δf feedback control, it is necessary that θ ω ω is minimized, so this θ ω control is executed before the Δf feedback control.

[0118] 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 PLLs 140, 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, in the vibrator 2, for example, an electric spring effect is generated by the electrostatic force between the rim 23 and a part of the plurality of first electrode portions 51, and one or both of the resonance angular frequencies ω1, ω2 of the first and second vibration modes having the higher frequency are controlled, and it is controlled to Δf = 0.

[0119] In step S180, the control unit 10 turns on the angle feedback unit 180, drives the PI 181 and the integration circuit 182 based on the input signals from the AGCs 130, 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, and performs feedback of the rotation angle.

[0120] ​Finally, in step S190, the control unit 10 executes calculations of the angular velocity and angle applied to the gyro sensor 1 by the angle calculation unit 190 and the angular velocity calculation unit 191. As a result, the influence of the detection gain ratio G pxy and the drive gain ratio G fxy is reduced, and after the θ ω control, Δf feedback control is performed, and the accuracy of the Δf feedback is improved, so that the error of the measured angle is reduced.

[0121] The above is an example of the process for reducing the error of the measured angle in the gyro sensor 1. This process for reducing the error of the measured angle includes at least correction of the detection gain ratio G pxy , θ ω control, and Δf feedback control, which are executed in this order, and after the correction of the detection gain ratio G pxy , the correction of the drive gain ratio G fxy is executed. Therefore, for the correction of the drive gain ratio G fxy , it may be between the θ ω control and the Δf feedback control, or it may be after the Δf feedback control. That is, the correction of the gain ratio of the detection signal and the gain ratio of the drive signal, that is, the gain mismatch correction, may be such that the process immediately after the correction of the detection gain ratio G pxy is the correction of the drive gain ratio G fxy , or the correction of the drive gain ratio G fxy may be executed with other processes in between.

[0122] According to this embodiment, the gyro sensor 1 has the detection gain ratio G of the x-axis and y-axis of the vibrator 2 pxy and the drive gain ratio G fxyGain mismatch correction to be corrected is performed, and the influence on the angle measurement due to the gain ratio of the detection signal and the drive signal is reduced. The gyro sensor 1 performs frequency control of the drive signals of two independent vibration modes by the PLLs 140 and 141, and amplitude control in the two independent vibration modes by the AGCs 130 and 131. Further, the gyro sensor 1 includes a first demodulation unit 111, 121 that demodulates based on one of the detection signals and its drive signal in the first and second vibration modes, and a second demodulation unit 112, 122 that demodulates based on one of the detection signals and the other drive signal in the two vibration modes. Further, the gyro sensor 1 includes a first demodulation block 110 having the first demodulation unit 111 and the second demodulation unit 112, and a second demodulation block 120 having the first demodulation unit 121 and the second demodulation unit 122. Therefore, the gyro sensor 1 calculates the operation value D x , D y , the detection gain ratio G pxy , the drive gain ratio G fxy , θ ω , Δf. Then, the gyro sensor 1 performs θ ω control by the deviation angle correction unit 160, Δf control by the mode match control unit 170, and various feedbacks of the rotation angle by the angle feedback unit 180, thereby reducing the error in the measurement of the angle or the angular velocity.

[0123] (1) Based on the calculation results of the demodulation blocks 110 and 120, the gyro sensor 1 multiplies the matrix of the formula (22) including the reciprocal 1 / G pxy of the detection gain ratio by the determinant of the formula (21). Thereby, the gyro sensor 1 performs matrix operation to cancel the non-ideal detection gain ratio G pxy between the x-axis and the y-axis, and reduces the error in the measurement of the angle and the angular velocity due to the influence of the detection gain ratio G pxy .

[0124] (2) The gyro sensor 1 has the reciprocal 1 / G of the drive gain ratio by the drive gain ratio correction unit 153 fxyMultiply the matrix of formula (25) including it by the determinant of formula (24). As a result, the gyro sensor 1 performs a matrix operation that cancels out the non-ideal drive gain ratio G between the x-axis and the y-axis, and reduces the error in the measurement of the angle and the angular velocity due to the influence of the drive gain ratio G. fxy and the error in the measurement of the angle and the angular velocity due to the influence of the drive gain ratio G is reduced. fxy

[0125] (3) The first demodulation block 110 includes a first demodulation unit 111 that performs operations on the demodulation outputs V Xi1 , V Xq1 , and a second demodulation unit 112 that performs operations on the demodulation outputs V Xi2 , V Xq2 based on the first detection signal and the first drive signal. The second demodulation block includes a first demodulation unit 121 that performs operations on the demodulation outputs V Yi2 , V Yq2 based on the second detection signal and the second drive signal, and a second demodulation unit 122 that performs operations on the demodulation outputs V Yi1 , V Yq1 based on the second detection signal and the first drive signal. And the control unit 10 has a deviation angle correction unit 160 that calculates the deviation angle θ ω in the vibrator 2 based on the calculated values D x , D y calculated by the demodulation blocks 110 and 120, and outputs a control signal Vθ ω for the deviation angle θ ω . As a result, the deviation angle θ ω can be minimized, and the accuracy in the control of Δf, that is, the mode matching control, can be improved. Xi1 、V Xq1 of the first detection signal and the first drive signal, and a second demodulation unit 112 that performs operations on the demodulation outputs V Xi2 , V Xq2 based on the first detection signal and the second drive signal. The second demodulation block includes a first demodulation unit 121 that performs operations on the demodulation outputs V Yi2 , V Yq2 based on the second detection signal and the second drive signal, and a second demodulation unit 122 that performs operations on the demodulation outputs V Yi1 , V Yq1 based on the second detection signal and the first drive signal. And the control unit 10 has a deviation angle correction unit 160 that calculates the deviation angle θ ω in the vibrator 2 based on the calculated values D x , D y calculated by the demodulation blocks 110 and 120, and outputs a control signal Vθ ω for the deviation angle θ ω . As a result, the deviation angle θ ω can be minimized, and the accuracy in the control of Δf, that is, the mode matching control, can be improved. Xi2 、V Xq2 of the first detection signal and the second drive signal. The second demodulation block includes a first demodulation unit 121 that performs operations on the demodulation outputs V Yi2 , V Yq2 based on the second detection signal and the second drive signal, and a second demodulation unit 122 that performs operations on the demodulation outputs V Yi1 , V Yq1 based on the second detection signal and the first drive signal. And the control unit 10 has a deviation angle correction unit 160 that calculates the deviation angle θ ω in the vibrator 2 based on the calculated values D x , D y calculated by the demodulation blocks 110 and 120, and outputs a control signal Vθ ω for the deviation angle θ ω . As a result, the deviation angle θ ω can be minimized, and the accuracy in the control of Δf, that is, the mode matching control, can be improved. Yi2 、V Yq2 of the second detection signal and the second drive signal, and a second demodulation unit 122 that performs operations on the demodulation outputs V Yi1 , V Yq1 based on the second detection signal and the first drive signal. And the control unit 10 has a deviation angle correction unit 160 that calculates the deviation angle θ ω in the vibrator 2 based on the calculated values D x , D y calculated by the demodulation blocks 110 and 120, and outputs a control signal Vθ ω for the deviation angle θ ω . As a result, the deviation angle θ ω can be minimized, and the accuracy in the control of Δf, that is, the mode matching control, can be improved. Yi1 、V Yq1 of the second detection signal and the first drive signal. And the control unit 10 has a deviation angle correction unit 160 that calculates the deviation angle θ ω in the vibrator 2 based on the calculated values D x , D y calculated by the demodulation blocks 110 and 120, and outputs a control signal Vθ ω for the deviation angle θ ω . As a result, the deviation angle θ ω can be minimized, and the accuracy in the control of Δf, that is, the mode matching control, can be improved. x 、D y based on the calculated values D x , D y calculated by the demodulation blocks 110 and 120, calculates the deviation angle θ ω in the vibrator 2, and has a deviation angle correction unit 160 that outputs a control signal Vθ ω for the deviation angle θ ω . As a result, the deviation angle θ ω can be minimized, and the accuracy in the control of Δf, that is, the mode matching control, can be improved. ω in the vibrator 2, and outputs a control signal Vθ ω for the deviation angle θ ω . As a result, the deviation angle θ ω can be minimized, and the accuracy in the control of Δf, that is, the mode matching control, can be improved. ω And the control unit 10 has a deviation angle correction unit 160 that calculates the deviation angle θ ω in the vibrator 2 based on the calculated values D x , D y calculated by the demodulation blocks 110 and 120, and outputs a control signal Vθ ω for the deviation angle θ ω . As a result, the deviation angle θ ω can be minimized, and the accuracy in the control of Δf, that is, the mode matching control, can be improved. ω for the deviation angle θ ω . As a result, the deviation angle θ ω can be minimized, and the accuracy in the control of Δf, that is, the mode matching control, can be improved. ω As a result, the deviation angle θ ω can be minimized, and the accuracy in the control of Δf, that is, the mode matching control, can be improved.

[0126] (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. As a result, the mode matching control of the vibrator 2 becomes possible, and the accuracy of the measurement of the angle and the angular velocity is improved.

[0127] (5) In the gyro sensor 1 of this embodiment, measurement errors of angles and angular velocities are reduced by a control method including the following first to eighth steps. The first step is to resonate and drive the vibrator 2 on two axes in the first and second vibration modes by two independent PLLs 140, 141 and AGCs 130, 131. The second step is to calculate a detection gain ratio G pxy The third step is to calculate and determine a drive gain ratio G, which is the ratio between the gain of the first drive signal for vibrating the transducer 2 on the x-axis and the gain of the second drive signal for vibrating the transducer 2 on the y-axis. fxy The fourth step is to calculate and determine the demodulated output V Xi1 , V Xq1、 V Xi2 , V Xq2 , V Yi1 , V Yq1 , V Yi2 , V Yq2 The fifth step is to calculate the detection gain ratio G pxy After the determination, the deviation angle θ of the transducer 2 is calculated based on the calculation results in the demodulation blocks 110 and 120. ω Calculate the deviation angle θ ω The sixth step is to perform feedback control of the deviation angle θ ω After the feedback control, the difference Δf between the resonance frequencies of the first and second vibration modes is calculated based on the frequency signals corresponding to these vibration modes output from the PLL 140, and feedback control of Δf is performed. fxy After the determination, the rotation angle of the gyro sensor 1 is calculated by integrating the angular velocity, and the calculated rotation angle is fed back to the calculation of the rotation angle of the vibration detection direction and the drive direction of the vibrator 2. The eighth step is to measure the angle and angular velocity of the gyro sensor 1 after the feedback of the rotation angle.

[0128] (6) Detection gain ratio G pxyIn the determination, the demodulation blocks 110 and 120 calculate the detection gain ratio G pxy and multiply by a matrix including 1 / G pxy to perform matrix operations that cancel out the detection gain ratio. As a result, the non-ideal detection gain ratio G pxy on the vibration axes x and y of the vibrator 2 is canceled out, and the errors in the measurement of the angle and angular velocity due to the influence of the detection gain ratio G pxy are reduced.

[0129] (7) Drive gain ratio G fxy In the determination, multiply by a matrix including the reciprocal 1 / G fxy of the drive gain ratio to perform matrix operations that cancel out the drive gain ratio G fxy As a result, the non-ideal drive gain ratio G fxy on the vibration axes x and y of the vibrator 2 is canceled out, and the errors in the measurement of the angle and angular velocity due to the influence of the drive gain ratio G fxy are reduced.

[0130] (Other embodiments) Although the present disclosure has been described based on examples, it should be understood that the present disclosure is not limited to such examples and structures. The present disclosure also includes various modifications and modifications within the equivalent range. In addition, various combinations and forms, and further other combinations and forms including only one of these elements, more, or less, are within the scope and spirit of the present disclosure.

[0131] In addition, as a representative example, the sensor element has been described with a configuration in which the vibrator 2 has a substantially hemispherical shape or a substantially disc shape, and a plurality of first electrode portions 51 are arranged so as to surround it. However, the present disclosure is not limited to such forms. For example, if the gyro sensor 1 can be regarded as a vibrator of a two-degree-of-freedom system shown in FIG. 5, the above control by the control unit 10 is possible. Therefore, the forms and arrangements of the vibrator 2 and the electrode portions 51 and 52 may be other known ones.

[0132] The control unit 10 and its method described in the present disclosure may be implemented by a dedicated computer provided by configuring a processor and a memory programmed to execute one or more functions embodied by a computer program. Alternatively, the control unit 10 and its method described in the present disclosure may be implemented by a dedicated computer provided by configuring a processor with one or more dedicated hardware logic circuits. Or, the control unit 10 and its method described in the present disclosure may be implemented by one or more dedicated computers configured by a combination of a processor programmed to execute one or more functions and a memory and a processor configured by one or more hardware logic circuits. Further, the computer program may be stored in a computer-readable non-transitory tangible recording medium as instructions executable by a computer.

[0133] In addition, in each of the above embodiments, it goes without saying that the elements constituting the embodiment are not necessarily essential except when it is explicitly stated that they are particularly essential or when they are considered to be clearly essential in principle. Also, in each of the above embodiments, when numerical values such as the number, numerical value, quantity, range, etc. of the components of the embodiment are mentioned, they are not limited to that specific number except when it is explicitly stated that they are particularly essential or when they are clearly limited to a specific number in principle. Further, in each of the above embodiments, when referring to the shape, positional relationship, etc. of components, etc., they are not limited to that shape, positional relationship, etc. except when it is explicitly stated or when they are clearly limited to a specific shape, positional relationship, etc. in principle.

[0134] (From the perspective of the present disclosure) The above-described present disclosure can be understood, for example, from the following perspectives.

[0135] [First perspective] A gyro sensor, A vibrator (2) having a first vibration mode and a second vibration mode with different resonance angular frequencies, A mounting substrate (3) having a plurality of electrodes (51) facing the vibrator, and a control unit (10) that executes drive control of the vibrator. Taking a virtual 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, in the radial direction, the direction along the vibration direction of the first vibration mode is defined as the x-axis, and the direction along the vibration direction of the second vibration mode is defined as the y-axis, the control unit includes PLLs (140, 141) for resonantly driving the vibrator in two axes of the first vibration mode and the second vibration mode, a detection gain ratio correction unit (106) that corrects a detection gain ratio (G pxy ) which is the ratio of the gain of a first detection signal from a first detection electrode that detects vibration of the vibrator in the x-axis among the plurality of electrodes to the gain of a second detection signal from a second detection electrode that detects vibration of the vibrator in the y-axis among the plurality of electrodes, a first coordinate conversion unit (105) that converts a signal from a detection electrode from the actual coordinate axes to coordinate axes for calculation with the plane coordinate axes formed by the radial direction as the actual coordinate axes, a drive gain ratio correction unit (153) that corrects a drive gain ratio (G fxy ) which is the ratio of the gain of a first drive signal to a first drive electrode for vibrating the vibrator in the first vibration mode among the plurality of electrodes to the gain of a second drive signal to a second drive electrode for vibrating the vibrator in the second vibration mode among the plurality of electrodes, a second coordinate conversion unit (154) that converts the signal corrected by the drive gain ratio correction unit from the coordinate axes for calculation to the actual coordinate axes, a first demodulation block (110) that performs calculation of demodulation outputs (V Xi1 , V Xq1 , V Xi2 , V Xq2 ) used for calculation of the detection gain ratio based on the first detection signal, a second demodulation block that performs calculation of demodulation outputs (V Yi1 , V Yq1 , V Yi2 based on the second detection signal and used for calculation of the detection gain ratio,Yq2 ) to perform an operation of a second demodulation block (120), an AGC (130, 131) that performs an operation of a drive output for maintaining vibration amplitudes in the first vibration mode and the second vibration mode of the oscillator, after correction of the detection gain ratio and the drive gain ratio, based on the angular velocity information input from the AGC, an integration circuit (182) that calculates a rotation angle by integrating the angular velocity, and an angle feedback unit (180) that feeds back the calculated rotation angle to the first coordinate conversion unit and the second coordinate conversion unit. [Second aspect] The detection gain ratio correction unit multiplies a matrix including 1 / G x , D y ), which is the reciprocal of the detection gain ratio, and performs a matrix operation to cancel the detection gain ratio, for the gyro sensor according to the first aspect. pxy [Third aspect] The drive gain ratio correction unit multiplies a matrix including 1 / G fxy ), which is the reciprocal of the drive gain ratio, and performs a matrix operation to cancel the drive gain ratio, for the gyro sensor according to the first or second aspect. [Fourth aspect] The first demodulation block includes a first demodulation unit (111) that performs an operation of a demodulation output (V Xi1 , V Xq1 ) based on the first detection signal and the first drive signal, and a second demodulation unit (112) that performs an operation of a demodulation output (V Xi2 , V Xq2 ) based on the first detection signal and the second drive signal. The second demodulation block includes a third demodulation unit (121) that performs an operation of a demodulation output (V Yi2 , V Yq2 ) based on the second detection signal and the second drive signal, and a fourth demodulation unit (122) that performs an operation of a demodulation output (V Yi1 , V Yq1 ) based on the second detection signal and the first drive signal. Using the x-axis and the y-axis as vibration axes, and taking the direction along the radial direction and along the drive electrodes for resonantly driving in the first vibration mode and the second vibration mode among the plurality of electrodes as the electrode axes (X, Y), The control unit is based on the calculation values (D x , D y ) calculated by the first demodulation block and the second demodulation block, calculates the deviation angle (θ ω ) which is the angle formed by the vibration axis and the electrode axis of the vibrator, and further has a deviation angle correction unit (160) that outputs a control signal for the deviation angle. The gyro sensor according to any one of the first to third aspects. [Fifth aspect] The control unit calculates Δf which is the difference in resonance frequencies 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 further has a mode match control unit (170) that outputs a signal for controlling the Δf. The gyro sensor according to any one of the first to fourth aspects. [Sixth aspect] A control method for a gyro sensor in which a vibrator (2) having a first vibration mode and a second vibration mode with different resonance angular frequencies is mounted on a mounting substrate (3) having a plurality of electrodes (51) facing the vibrator, Resonantly driving the vibrator in two axes of the first vibration mode and the second vibration mode by two independent PLLs (140, 141) and AGCs (130, 131), Taking the radial direction 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, taking the direction along the vibration direction of the first vibration mode as the x-axis, and taking the direction along the vibration direction of the second vibration mode as the y-axis, calculating and determining the detection gain ratio (G pxy ) which is the ratio between the gain of the first detection signal from the first detection electrode for detecting the vibration of the vibrator on the x-axis among the plurality of electrodes and the gain of the second detection signal from the second detection electrode for detecting the vibration of the vibrator on the y-axis among the plurality of electrodes, The drive gain ratio (G fxy ), which is the ratio of the gain of the first drive signal to the first drive electrode for vibrating the vibrator along the x-axis among the plurality of the electrodes, and the gain of the second drive signal to the second drive electrode for vibrating the vibrator along the y-axis among the plurality of the electrodes, is calculated and determined. The demodulation blocks (110, 120) perform demodulation outputs (V Xi1 , V Xq1 ) based on the first detection signal and the first drive signal, demodulation outputs (V Xi2 , V Xq2 ) based on the first detection signal and the second drive signal, demodulation outputs (V Yi1 , V Yq1 ) based on the second detection signal and the first drive signal, and demodulation outputs (V Yi2 , V Yq2 ) based on the second detection signal and the second drive signal. Using the x-axis and the y-axis as vibration axes, with a virtual straight line passing through the center of the region surrounded by the plurality of the electrodes and along the thickness direction of the mounting substrate as an axis, in the radial direction along the direction along the drive electrodes for resonantly driving the first vibration mode and the second vibration mode among the plurality of the electrodes as the electrode axes (X, Y), after determining the detection gain ratio, based on the result calculated in the demodulation block, the deviation angle (θ ω ), which is the angle formed by the vibration axis and the electrode axis of the vibrator, is calculated, and feedback control of the deviation angle is performed. After the feedback control of the deviation 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, Δf, which is the difference in the resonance frequencies of the first vibration mode and the second vibration mode, is calculated, and feedback control of Δf is performed. After the feedback control of Δf and the determination of the drive gain ratio, the rotation angle of the gyro sensor is calculated by integral operation of the angular velocity, and the calculated rotation angle is fed back to the calculation of the rotation angle in the detection direction and the drive direction of the vibration of the vibrator. A control method for a gyro sensor, including performing measurement of the angle and angular velocity of the gyro sensor after feedback of the rotation angle. [Seventh aspect] In determining the detection gain ratio, the detection gain ratio is calculated by the demodulation block, and a matrix including 1 / G which is the reciprocal of the detection gain ratio is multiplied to perform matrix operation for canceling the detection gain ratio, the control method for a gyro sensor according to the sixth aspect. pxy [Eighth aspect] In determining the drive gain ratio, a matrix including 1 / G which is the reciprocal of the drive gain ratio is multiplied to perform matrix operation for canceling the drive gain ratio, the control method for a gyro sensor according to the sixth or seventh aspect. fxy

Explanation of symbols

[0136] 2... Vibrator, 3... Mounting substrate, 10... Control unit, 51... First electrode unit, 105... First coordinate conversion unit, 106... Detection gain ratio correction unit, 110... First demodulation block, 111, 121... First demodulation unit, 112, 122... Second demodulation unit, 120... Second demodulation block, 130, 131... AGC, 140, 141... PLL, 153... Drive gain ratio correction unit 153... Second coordinate conversion unit, 160... Deviation angle correction unit, 170... Mode match control unit, 180... Angle feedback unit, 182... Integrating circuit, 191... Angular velocity calculation unit, G fxy ... Drive gain ratio, G pxy ... Detection gain ratio, V Xi1 、V Xq1 、V Xi2 、V Xq2 、V Yi1 、V Yq1 、V Yi2 、V Yq2 … Demodulation output, X, Y... Electrode axes, θ ω … Deviation angle

Claims

1. A gyro sensor, comprising: a vibrator (2) having a first vibration mode and a second vibration mode with different resonance angular frequencies; a mounting substrate (3) having a plurality of electrodes (51) facing the vibrator; a control unit (10) for executing drive control of the vibrator, a radial direction passing through the center of the region surrounded by the plurality of electrodes and along the thickness direction of the mounting substrate, with the direction along the vibration direction of the first vibration mode as the x-axis and the direction along the vibration direction of the second vibration mode as the y-axis, wherein the control unit includes PLLs (140, 141) for resonantly driving the vibrator in two axes of the first vibration mode and the second vibration mode; A detection gain ratio (G), which is a ratio between a gain of a first detection signal from a first detection electrode that detects vibration of the vibrator in the x-axis among the plurality of electrodes, and a gain of a second detection signal from a second detection electrode that detects vibration of the vibrator in the y-axis among the plurality of electrodes. ｐｘｙ A detection gain ratio correction unit (106) that corrects (). a first coordinate conversion unit (105) for converting a signal from a detection electrode from the real coordinate axes to coordinate axes for calculation with the radial plane coordinate axes as the real coordinate axes; The drive gain ratio (G), which is the ratio of the gain of the first drive signal to the first drive electrode for vibrating the vibrator in the first vibration mode among the plurality of the electrodes, and the gain of the second drive signal to the second drive electrode for vibrating the vibrator in the second vibration mode among the plurality of the electrodes ｆｘｙ A drive gain ratio correction unit (153) that corrects the drive gain ratio (G a second coordinate conversion unit (154) for converting the signal corrected by the drive gain ratio correction unit from the coordinate axes for calculation to the real coordinate axes; Based on the first detection signal, a first demodulation block (110) that performs an operation on the demodulated output (V Ｘｉ１ , V Ｘｑ１ , V Ｘｉ２ , V Ｘｑ２ ) used for calculating the detection gain ratio, Based on the second detection signal, a second demodulation block (120) that performs an operation on the demodulated output (V Ｙｉ１ , V Ｙｑ１ , V Ｙｉ２ , V Ｙｑ２ ) used for calculating the detection gain ratio, AGCs (130, 131) for calculating a drive output for maintaining the vibration amplitudes of the vibrator in the first vibration mode and the second vibration mode; and an integration circuit (182) for calculating a rotation angle by integrating the angular velocity based on the information of the angular velocity input from the AGC after correction of the detection gain ratio and the drive gain ratio, and an angle feedback unit (180) for feeding back the calculated rotation angle to the first coordinate conversion unit and the second coordinate conversion unit.

2. The detection gain ratio correction unit multiplies a matrix including 1 / G ｘ , D ｙ ), which is the reciprocal of the detection gain ratio, based on the calculated values (D ｐｘｙ ) calculated by the first demodulation block and the second demodulation block, and performs a matrix operation to cancel the detection gain ratio. The gyro sensor according to claim 1.

3. The drive gain ratio correction unit multiplies a matrix including 1 / G which is the reciprocal of the drive gain ratio, and performs a matrix operation for canceling the drive gain ratio. The gyro sensor according to claim 1 ｆｘｙ which performs a matrix operation for canceling the drive gain ratio by multiplying a matrix including 1 / G which is the reciprocal of the drive gain ratio.

4. The first demodulation block performs demodulation output (V Ｘｉ１ , V Ｘｑ１ ) based on the first detection signal and the first drive signal, and a first demodulation unit (111) that performs an operation of the demodulation output (V Ｘｉ２ , V Ｘｑ２ ) based on the first detection signal and the second drive signal, and has a second demodulation unit (112) that performs an operation of The second demodulation block includes a third demodulation unit (121) that performs an operation on a demodulation output (V Ｙｉ２ , V Ｙｑ２ ) based on the second detection signal and the second drive signal, and a fourth demodulation unit (122) that performs an operation on a demodulation output (V Ｙｉ１ , V Ｙｑ１ ) based on the second detection signal and the first drive signal. With the x-axis and the y-axis as vibration axes, and the direction along the radial direction and along the drive electrodes for resonantly driving in the first vibration mode and the second vibration mode among the plurality of electrodes as the electrode axes (X, Y), The control unit further has an offset angle correction unit (160) that calculates an offset angle (θ ｘ , D ｙ ) which is an angle formed by the vibration axis and the electrode axis of the vibrator based on calculation values (D ω ) calculated by the first demodulation block and the second demodulation block, and outputs a control signal for the offset angle. The gyro sensor according to claim 1.

5. The control unit further includes a mode match control unit (170) for calculating Δf, which is the difference between the resonance frequencies of 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 outputting a signal for controlling the Δf. The gyro sensor according to any one of Claims 1 to 4.

6. A control method for a gyro sensor, wherein an oscillator (2) having a first vibration mode and a second vibration mode with different resonance angular frequencies is mounted on a mounting substrate (3) having a plurality of electrodes (51) facing the oscillator, resonantly driving the oscillator in two axes of the first vibration mode and the second vibration mode by two independent PLLs (140, 141) and AGCs (130, 131); A radial direction with a virtual 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, with the direction along the vibration direction of the first vibration mode as the x-axis and the direction along the vibration direction of the second vibration mode as the y-axis. The gain of the first detection signal from the first detection electrode that detects the vibration of the vibrator on the x-axis among the plurality of electrodes is compared with the gain of the second detection signal from the second detection electrode that detects the vibration of the vibrator on the y-axis among the plurality of electrodes. The detection gain ratio (G ｐｘｙ ) is calculated and determined, The drive gain ratio (G ｆｘｙ ), which is the ratio of the gain of the first drive signal to the first drive electrode for vibrating the vibrator in the x-axis among the plurality of the electrodes, and the gain of the second drive signal to the second drive electrode for vibrating the vibrator in the y-axis among the plurality of the electrodes, is calculated and determined. The demodulation blocks (110, 120) perform operations on the demodulation outputs (V Ｘｉ１ , V Ｘｑ１ ) based on the first detection signal and the first drive signal, the demodulation outputs (V Ｘｉ２ , V Ｘｑ２ ) based on the first detection signal and the second drive signal, the demodulation outputs (V Ｙｉ１ , V Ｙｑ１ ) based on the second detection signal and the first drive signal, and the demodulation outputs (V Ｙｉ２ , V Ｙｑ２ ) based on the second detection signal and the second drive signal, and Using the x-axis and the y-axis as vibration axes, in the direction along the radial direction with a virtual 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, and taking the direction along the drive electrodes for resonantly driving the plurality of electrodes in the first vibration mode and the second vibration mode as the electrode axes (X, Y), after determining the detection gain ratio, based on the result calculated in the demodulation block, the deviation angle (θ ω ), which is the angle formed by the vibration axis and the electrode axis of the vibrator, is calculated, and feedback control of the deviation angle is performed. after the feedback control of the deviation angle, calculating Δf, which is the difference in resonance frequencies 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 performing feedback control of the Δf; after the feedback control of the Δf and the determination of 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 the calculation of the rotation angle in the detection direction and the rotation angle in the drive direction of the vibration of the oscillator; after the feedback of the rotation angle, measuring the angle and angular velocity of the gyro sensor. A control method for a gyro sensor including these steps.

7. In determining the detection gain ratio, the demodulation block calculates the detection gain ratio, and multiplies by a matrix including 1 / G which is the reciprocal of the detection gain ratio, and performs matrix operation to cancel the detection gain ratio. ｐｘｙ The method for controlling a gyro sensor according to claim 6.

8. In determining the drive gain ratio, a matrix multiplication including 1 / G which is the reciprocal of the drive gain ratio is performed, and a matrix operation for canceling the drive gain ratio is carried out. The method for controlling a gyro sensor according to claim 6 or 7. ｆｘｙ ​

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