WO2005103618A1

WO2005103618A1 - Gyroscope device

Info

Publication number: WO2005103618A1
Application number: PCT/JP2005/007125
Authority: WO
Inventors: Akira Mori; Iku Nagai; Kazushige Sawada; Makoto Narita
Original assignee: Murata Manufacturing Co., Ltd.; Asahi Kasei Microsystems Co., Ltd.
Priority date: 2004-04-20
Filing date: 2005-04-13
Publication date: 2005-11-03
Also published as: JP2007255890A

Abstract

A gyroscope device capable of detecting an angular velocity more accurately than before by preventing the occurrence of a ripple in an angular velocity detection signal after temperature compensation while removing the effect of the temperature drift of an angular velocity detection signal. The gyroscope device comprises an angular velocity detector (100), a temperature sensor (65) for detecting temperatures and outputting them in analogue values, a memory (66) for storing a correction factor that corrects the temperature gradient of a detected output from the temperature sensor (65), a temperature drift correction signal producing circuit (643) for regulating the detected output from the temperature sensor (65) based on a correction factor stored in the memory (66) and producing the regulated detected output as a temperature drift correction signal, and an adding/subtracting circuit (646) for adding a temperature drift correction signal produced by the temperature drift correction signal producing circuit (643) to an angular velocity detection signal output from the angular velocity detector (100) or for subtracting a temperature drift correction signal produced by the temperature drift correction signal producing circuit (643) from an angular velocity detection signal output from the angular velocity detector (100).

Description

Specification

Gyro device

Technical field

The present invention relates to a gyro device used for detecting an angular velocity and a rotation direction thereof.

Background art

In recent years, gyro devices have been used as means for detecting the attitude of a vehicle, detecting the traveling direction of a navigation device, correcting camera shake, performing virtual reality operations, and the like.

[0003] In this gyro device, when a constant angular velocity is applied, an angular velocity detecting section including an angular velocity detecting element composed of a vibrator or the like generates an angular velocity detection signal having a voltage level corresponding to the angular velocity. Is output. Then, by determining the magnitude of the DC voltage level of the angular velocity detection signal, the magnitude of the angular velocity and the rotation direction can be detected.

[0004] By the way, as described above, the voltage level of the angular velocity detection signal output from the angular velocity detector may change due to factors other than the magnitude of the angular velocity. That is, when the ambient temperature of the gyro device changes, the voltage level during non-rotation fluctuates, that is, a so-called temperature drift may occur. Also, the sensitivity of the angular velocity detecting element and its peripheral circuits may change due to a change in the ambient temperature.

[0005] As described above, when the voltage level of the angular velocity detection signal output from the angular velocity detection section fluctuates due to the influence of the temperature drift and the change in detection sensitivity caused by the ambient temperature change, the magnitude of the angular velocity can be accurately determined. It becomes difficult to detect well. Therefore, in order to accurately detect the angular velocity, it is necessary to eliminate such error factors.

Therefore, in the related art, for example, regarding a temperature drift, a temperature correction value set for each predetermined relatively narrow temperature interval is stored in a memory, and based on the output of the temperature sensor, The temperature correction value corresponding to each temperature is read from

Digital / Analog) converters have been proposed in which the voltage level of the angular velocity detection signal is corrected by adding it to the angular velocity detection signal after analog conversion. For example, see Japanese Utility Model Registration No. 2577760 (Patent Document 1).

[0007] Further, in the related art, a temperature correction value set for each predetermined relatively wide temperature interval is stored in a memory, and stored in the memory. A temperature correction value corresponding to that temperature is obtained by interpolation processing from the temperature correction values existing before and after, and the output level of the angular velocity detection signal is corrected in the same manner as described above by the temperature correction value obtained by this interpolation processing. Some have been proposed (for example, see Japanese Patent Application Laid-Open No. 2000-258162 (Patent Document 2)).

Patent Document 1: Utility Model Registration No. 2577760

Patent Document 2: JP-A-2000-258162

Disclosure of the invention

Problems to be solved by the invention

[0008] In the meantime, the former conventional technique described in Patent Document 1 has the following problems. For example, assume that the angular velocity detection signal has caused a temperature drift as shown in FIG. 12A with respect to a temperature change. At this time, since the temperature correction values corresponding to each temperature stored in the memory are discrete data, when this temperature correction value is analogized by a DZA converter, the temperature is corrected as shown in FIG. 12B. It shows a characteristic that changes stepwise in response to the change.

Accordingly, an angular velocity detection signal obtained by correcting an angular velocity detection signal that causes a temperature drift as shown in FIG. 12A with a temperature correction value having a characteristic as shown in FIG. 12B includes, as shown in FIG. 12C, Thus, a so-called ripple that changes in a sawtooth waveform with respect to a temperature change is generated. For this reason, the SZN (Signal / Noise) ratio of the angular velocity detection signal deteriorates, and it becomes difficult to detect a minute angular velocity.

[0010] To prevent the occurrence of ripples in the angular velocity detection signal after the temperature drift correction, it is conceivable to store the temperature correction value in a memory at small temperature intervals. However, in this case, conversely, a large memory capacity is required, which leads to an increase in cost, which is not an advantage.

[0011] In the latter conventional technique as described in Patent Document 2, a temperature correction value that is insufficient for each temperature is obtained by interpolation processing, and therefore, a memory that stores the temperature correction value. Has a relatively small capacity.

[0012] However, even in this case, even in this case, the temperature correction value obtained by the interpolation processing is analogized by a DZA converter and added to the angular velocity detection signal, which is the same as the former related art. Therefore, discontinuities in converting discrete digital values to analog values are inevitable. Therefore, as shown in FIG. 12C, ripples still occur in the angular velocity detection signal after the temperature drift is corrected by the temperature correction value converted to analog by the DZA converter, as shown in FIG. 12C.

[0013] The present invention has been made to solve the above-described problem, and has high accuracy with respect to a temperature drift and a change in detection sensitivity caused by an ambient temperature change of an angular velocity detection signal output from an angular velocity detection element. It is an object of the present invention to provide a gyro device capable of performing temperature compensation by using the gyro apparatus and detecting an angular velocity with higher accuracy than before by preventing a ripple from being generated in the angular velocity detection signal after the temperature compensation.

Means for solving the problem

[0014] In order to solve the above problems, a gyro device according to an aspect of the present invention includes an angular velocity detection unit, a temperature sensor that detects a temperature and outputs an analog value, and a temperature gradient of a detection output of the temperature sensor. A memory for storing a correction coefficient to be corrected; and a temperature drift correction signal for adjusting a detection output of the temperature sensor based on the correction coefficient stored in the memory and generating the adjusted detection output as a temperature drift correction signal. Generating circuit and angular velocity detection section force Addition of the temperature drift correction signal generated by the temperature drift correction signal generation circuit to the output angular velocity detection signal or angular velocity detection section force Output angular velocity detection signal power Temperature drift correction An addition / subtraction circuit for subtracting the temperature drift correction signal generated by the signal generation circuit.

[0015] Preferably, the temperature drift correction signal generation circuit uses the correction coefficient read from the memory or the force multiplied by the detection output of the temperature sensor and the correction coefficient read from the memory. Includes a multiplication / division circuit for division.

[0016] Preferably, the correction coefficient stored in the memory is set to an individual value for each of the plurality of temperature regions.

[0017] More preferably, the gyro device further compares a detection output of the temperature sensor with a reference voltage. A temperature drift correction signal generation circuit that adjusts the detection output of the temperature sensor based on the correction coefficient corresponding to the determined current temperature region, and performs the adjusted detection. An output is generated as a temperature drift correction signal.

A gyro device according to still another aspect of the present invention includes an angular velocity detecting unit, a temperature sensor that detects a temperature and outputs an analog value, and a correction coefficient that corrects a temperature gradient of a detection output of the temperature sensor. A memory for storing, a sensitivity temperature correction signal generation circuit for adjusting the detection output of the temperature sensor based on the correction coefficient stored in the memory, and generating the adjusted detection output as a sensitivity temperature correction signal; The angular velocity detection signal output from the angular velocity detection section is multiplied by the sensitivity temperature correction signal generated by the sensitivity temperature correction signal generation circuit, or the angular velocity detection signal output from the angular velocity detection section is multiplied by the sensitivity temperature correction signal generation circuit. And a multiplication / division circuit for dividing by the sensitivity temperature correction signal generated in the step (c).

Preferably, the sensitivity correction signal generation circuit divides a force for multiplying a detection output of the temperature sensor by a correction coefficient read from the memory or a detection output of the temperature sensor by a correction coefficient read from the memory. Includes multiplication / division circuit.

[0020] Preferably, the correction coefficient stored in the memory is set to an individual value for each of the plurality of temperature regions.

[0021] More preferably, the gyro device further includes a comparator for comparing a detection output of the temperature sensor with a reference voltage to determine a current temperature region, and the sensitivity temperature correction signal generation circuit includes The detection output of the temperature sensor is adjusted on the basis of the correction coefficient corresponding to the temperature region, and the adjusted detection output is generated as a sensitivity temperature correction signal.

A gyro device according to still another aspect of the present invention includes an angular velocity detection unit, a temperature sensor that detects a temperature and outputs an analog value, and a first sensor that corrects a temperature gradient of a detection output of the temperature sensor. A memory for storing a correction coefficient and a second correction coefficient, and a detection output of the temperature sensor is adjusted based on the first correction coefficient stored in the memory, and the adjusted detection output is generated as a temperature drift correction signal. The temperature drift correction signal generation circuit and the force for adding the temperature drift correction signal generated by the temperature drift correction signal generation circuit to the angular velocity detection signal output from the angular velocity detection unit or the angular velocity detection signal power output Subtract the temperature drift correction signal generated by the temperature drift correction signal generation circuit And a sensitivity temperature correction signal generation circuit that adjusts the detection output of the temperature sensor based on the second correction coefficient stored in the memory and generates the adjusted detection output as a sensitivity temperature correction signal. Multiplied by the angular velocity detection signal output from the addition / subtraction circuit and the sensitivity temperature correction signal generated by the sensitivity temperature correction signal generation circuit, or the added or subtracted angular velocity detection signal is generated by the sensitivity temperature correction signal generation circuit And a multiplication / division circuit for dividing by the sensitivity temperature correction signal.

The invention's effect

According to the first aspect of the present invention, when the angular velocity detection signal output from the angular velocity detection unit has caused a temperature drift due to a change in ambient temperature, a temperature drift correction signal is added or Since the influence of the temperature drift is offset by subtraction, temperature compensation can be performed with high accuracy.

[0024] The temperature drift correction signal used at that time is not an output of the DZA converter, but is basically an analog signal generated by processing the detection output itself of the temperature sensor. The signal changes continuously. For this reason, a ripple does not occur in the angular velocity detection signal after temperature compensation by the temperature drift compensation signal. Therefore, the SZN ratio is improved as compared with the related art, and the angular velocity can be detected with higher accuracy.

[0025] In addition, since it is only necessary to store the correction coefficient in the memory, it is not necessary to store the temperature drift correction value individually corresponding to each temperature as in the related art. The cost required for the memory can be reduced.

According to the invention described in claim 2, the temperature drift correction signal generation circuit includes a multiplication / division circuit that multiplies or divides the detection output of the temperature sensor by the correction coefficient read from the memory. With this configuration, an appropriate temperature drift correction signal can be generated.

According to the third aspect of the present invention, since the memory has the individual correction coefficient set for each of the plurality of temperature regions, when the temperature change of the temperature drift indicates a function value of second order or higher, Appropriate measures can be taken with V ヽ.

[0028] According to the inventions set forth in claims 4 and 8, since a comparator for judging the current temperature region by comparing the detection output of the temperature sensor with the reference voltage is provided, the present invention has a simple configuration. The current temperature region can be determined.

[0029] According to the invention of claim 5, when the detection sensitivity of the angular velocity detecting element fluctuates due to the influence of the ambient temperature change, the detection sensitivity fluctuation is multiplied or divided by the sensitivity temperature correction signal. Since the effects are offset, temperature compensation can be performed with high accuracy.

[0030] The sensitivity temperature correction signal used at that time is not an output of the DZA converter but an analog signal generated basically by detecting the output of the temperature sensor itself. The signal changes continuously with the change. Therefore, no ripple occurs when the sensitivity of the angular velocity detection signal is temperature-corrected by the sensitivity temperature correction signal. Therefore, the SZN ratio is higher than before, and it is possible to detect angular velocity with higher accuracy.

[0031] Further, since it is not necessary to store the sensitivity temperature correction value corresponding to each temperature just by storing the correction coefficient in the memory, it is possible to cope with a small memory capacity. The cost required for memory can be reduced.

[0032] According to the invention described in claim 6, the sensitivity correction signal generation circuit includes a multiplication / division circuit that multiplies or divides the detection output of the temperature sensor by the correction coefficient read from the memory. Thus, an appropriate sensitivity temperature correction signal can be generated.

According to the invention described in claim 7, since the memory has the individual correction coefficient set for each of the plurality of temperature regions, it is suitable even when the temperature change of the sensitivity indicates a function value of second order or higher. Response can be taken.

According to the ninth aspect of the present invention, since both the temperature drift correction signal generation circuit and the addition / subtraction circuit, and the sensitivity temperature correction signal generation circuit and the multiplication / division circuit are provided, the temperature with respect to the temperature drift of the angular velocity detection signal is obtained. Since the compensation and the temperature compensation for the fluctuation of the detection sensitivity of the angular velocity detecting element can be performed together, the angular velocity can be detected with higher accuracy.

Brief Description of Drawings

FIG. 1 is a plan view showing a structure of a vibrator of a gyro device according to an embodiment of the present invention.

[FIG. 2] A part of a state where a vibrator substrate and a protective substrate constituting the gyro device of FIG. 1 are joined together FIG.

FIG. 3 is a block diagram showing the overall circuit configuration of the gyro device.

FIG. 4 is a circuit diagram illustrating an example of a [4A] CV conversion circuit.

FIG. 4 is a circuit diagram illustrating an example of a [4B] CV conversion circuit.

FIG. 5 is a block diagram showing details of an output adjustment circuit.

[6A] A waveform diagram of a drive signal applied to the drive electrode of the vibrator.

FIG. 6B is a waveform diagram of a drive signal applied to the drive electrode of the vibrator.

FIG. 7 (a) is an explanatory diagram of a vibration state of a vibrator. (B) is an explanatory diagram of the vibration state of the vibrator. [8] An explanatory diagram showing the relationship between the driving vibration direction of the vibrator and the vibration direction of Coriolis.

[9A] is an explanatory diagram of a processing operation when correcting a temperature drift occurring in an angular velocity detection signal with a temperature drift correction signal.

[9B] FIG. 9 is an explanatory diagram of a processing operation in a case where a temperature drift generated in an angular velocity detection signal is corrected by a temperature drift correction signal.

[9C] is an explanatory diagram of a processing operation when correcting a temperature drift generated in the angular velocity detection signal by a temperature drift correction signal.

[9D] is an explanatory diagram of a processing operation when correcting a temperature drift generated in an angular velocity detection signal by a temperature drift correction signal.

[FIG. 10A] is an explanatory diagram of a processing operation in the case where a temperature change in sensitivity occurring in an angular velocity detection signal is corrected by a sensitivity temperature correction signal.

[FIG. 10B] is an explanatory diagram of a processing operation in the case where a temperature change in sensitivity occurring in an angular velocity detection signal is corrected by a sensitivity temperature correction signal.

[10C] is an explanatory diagram of a processing operation in a case where a temperature change in sensitivity occurring in an angular velocity detection signal is corrected by a sensitivity temperature correction signal.

FIG. 10D is an explanatory diagram of a processing operation in the case where a temperature change in sensitivity that occurs in the angular velocity detection signal is corrected using a sensitivity temperature correction signal.

[11A] Correct the temperature drift that occurs in the angular velocity detection signal with the temperature drift correction signal FIG. 14 is an explanatory diagram of another processing operation in the case.

FIG. 11B is an explanatory diagram of another processing operation when correcting a temperature drift generated in the angular velocity detection signal using a temperature drift correction signal.

FIG. 11C is an explanatory diagram of another processing operation when correcting a temperature drift generated in the angular velocity detection signal using a temperature drift correction signal.

FIG. 11D is an explanatory diagram of another processing operation in a case where a temperature drift generated in the angular velocity detection signal is corrected using the temperature drift correction signal.

FIG. 12A is an explanatory diagram of a processing operation when a temperature drift generated in an angular velocity detection signal is corrected by a temperature drift correction signal in a conventional technique.

FIG. 12B is an explanatory diagram of a processing operation in a case where a temperature drift generated in an angular velocity detection signal is corrected by a temperature drift correction signal in the related art.

FIG. 12C is an explanatory diagram of a processing operation when a temperature drift generated in an angular velocity detection signal is corrected by a temperature drift correction signal in the related art.

Explanation of symbols

[0036] 1 oscillator, 64 output adjustment circuit, 64A comparator, 64B offset voltage adjustment section, 64C temperature drift correction section, 64D sensitivity temperature correction section, 64E sensitivity adjustment section, 65 temperature sensor, 66 memory, 643 temperature drift correction Signal generation circuit, 645 1st temperature gradient adjustment circuit (multiplication / division circuit), 646 1st addition circuit (addition / subtraction circuit), 647 sensitivity temperature correction signal generation circuit, 649 2nd temperature gradient adjustment circuit (multiplication / division circuit), 650 1st multiplication circuit (multiplication / division circuit), 100 angular velocity detector.

BEST MODE FOR CARRYING OUT THE INVENTION

In this embodiment, a case will be described in which the present invention is applied to a gyro device using a vibrator as an angular velocity detecting element.

FIG. 1 is a plan view showing the structure of a vibrator used in the gyro device according to the present embodiment. FIG. 2 shows a part of a state in which a vibrator substrate and a protection substrate constituting the gyro device are joined. FIG.

The gyro device according to the present embodiment includes a vibrator 1 as an angular velocity detecting element. The vibrator 1 is of an electrostatic drive Z-capacitance detection type, for example, a single crystal or a polycrystal. A vibrator substrate 2 made of a low-resistance silicon material that forms a crystal, and a protective substrate 3 made of a high-resistance silicon material, a glass material, or the like provided on the main surface and the back surface of the vibrator substrate 2. And The two substrates 2 and 3 are integrally joined by a joining method such as anodic joining, for example, except for a portion where a cavity 4 for securing a movable portion of the vibrator substrate 2 is formed. Also, the cavity 4 is kept in a vacuum state or a low pressure state to reduce vibration damping! / ピング.

The vibrator substrate 2 is subjected to fine processing such as etching, so that the first to fourth mass portions 71 to 74, the driving beam 8, the first and second monitor electrodes 91 and 92, The first to fourth drive electrodes 101 to 104, the first to fourth detection electrodes 161 to 164, and the ground electrodes 181 and 182 are formed. Here, in FIG. 1, when the longitudinal direction of the vibrator 1 is the Y-axis direction, the transverse direction perpendicular to the Y-axis direction is the X-axis direction, and the direction perpendicular to the paper plane perpendicular to both axes is the Z-axis direction, The first to fourth mass parts 71 to 74 are supported in series along the Y-axis direction by a driving beam 8 partially connected to the ground electrodes 181, 182, whereby the first to fourth mass parts 71 to 74 are supported. Each of the mass parts 71 to 74 of 4 is in a state capable of vibrating along the X-axis direction. That is, the first to fourth mass parts 71 to 74 and the drive beam 8 are movable parts, and the first and second monitor electrodes 91 and 92, the first to fourth drive electrodes 101 to 104, and the ground are provided. Electrodes 181, 182 are fixed parts

The first mass section 71 is a comb-shaped movable member formed to project right and left so as to face the comb-shaped portions of the first monitor electrode 91 and the first and second drive electrodes 101 and 102. Side electrodes 11 la, 111 b, 111 c are provided.

The second mass section 72 is formed by connecting a square first drive frame 121 supported by the drive beam 8 and two squares supported by the upper and lower first detection beams 131 inside the first drive frame 121. And a first detection frame 141 having a rectangular shape. Outside the first drive frame 121, comb-shaped movable electrodes 151a and 151b are provided in proximity to the first mass portion 71 and opposed to the comb-shaped portions of the first and second drive electrodes 101 and 102. Is formed. Further, inside the two quadrangular portions of the first detection frame 141, a comb-shaped movable side electrode 171 is formed to face the first and second comb-shaped detection electrodes 161, 162, respectively. As a result, the first detection frame 141 and the movable side electrode 171 can be vibrated along the Y-axis direction by the first detection beam 131. The fourth mass part 74 is a comb-shaped movable member that is formed to project right and left so as to face the comb-shaped part of the second monitor electrode 92 and the third and fourth drive electrodes 103 and 104. Side electrodes 112a, 112b, 112c are provided.

The third mass part 73 is formed by connecting a square second drive frame 122 supported by the drive beam 8 and two squares supported by the upper and lower second detection beams 132 inside the second drive frame 122. And a second detection frame 142 in the shape of a circle. Outside the second drive frame 122, comb-shaped movable electrodes 152a and 152b are disposed adjacent to the fourth mass portion 74 and opposed to the comb-shaped portions of the third and fourth drive electrodes 103 and 104. Is formed. Further, inside the quadrangular portion of the second detection frame 142, a comb-shaped movable electrode 172 is formed opposite to the comb-shaped third and fourth detection electrodes 163, 164, respectively. As a result, the second detection frame 142 can be vibrated along the Y-axis direction by the second detection beam 132 together with the movable-side electrode 172.

[0045] The first and second monitor electrodes 91 and 92, the first to fourth drive electrodes 101 to 104, the first to fourth detection electrodes 161 to 164, and the ground electrodes 181 and 182 are connected to the vibrator substrate. It is formed on the joint with the protective substrate 3 on 2 and is fixed. Each of the electrodes 91, 92, 101-104, 161-164, 181, 182 on the fixed side is individually connected to each electrode node 5 as shown in FIG. Electrical connection to an external electric circuit described later via 5 is enabled. The movable part of the vibrator 1 is mechanically and electrically connected to the ground electrodes 181 and 182 via the driving beam 8, and is kept at the ground potential.

[0047] The angular velocity detection unit 100 includes an oscillator 1, an inverting circuit 21, an AGC (Auto Gain Control) circuit 22, a first phase adjusting circuit 23, first and second CV converting circuits 31, 32, The first differential amplification circuit 41, the filter circuit 51, the third and fourth CV conversion circuits 33 and 34, the second differential amplification circuit 42, the filter circuit 52, and the second phase adjustment circuit 60 are synchronized with each other. It includes a detection circuit 61, a smoothing circuit 62, and an amplification circuit 63. The angular velocity detector 100 preferably includes a filter circuit 51, a filter circuit 52, and an amplifier circuit 63, but may have a configuration that does not include these.

The first monitor electrode 91 is connected to the first CV conversion circuit 31, and the second monitor electrode 92 is connected to the second CV conversion circuit 32. The first and second CV conversion circuits 31, 32 are both the first differential amplifier The first differential amplifier circuit 41 is connected to the AGC circuit 22 via the filter circuit 51 and the first phase adjustment circuit 23. Further, the first differential amplifier circuit 41 is connected to a second phase adjustment circuit 60 described later via a filter circuit 51. The output section of the AGC circuit 22 is directly connected to the second drive electrode 102 and the third drive electrode 103, and is also connected to the first drive electrode 101 and the fourth drive electrode 104 via the inversion circuit 21. ing.

On the other hand, the first detection electrode 161 and the third detection electrode 163 are both connected to the third CV conversion circuit 33, and the second detection electrode 162 and the fourth detection electrode 164 are both connected to the fourth CV conversion circuit 34 Has been done. The third and fourth CV conversion circuits 33 and 34 are both connected to the second differential amplifier circuit 42. Further, the second differential amplifier circuit 42 is connected to a synchronous detection circuit 61 via a filter circuit 52.

Note that, as the first to fourth CV conversion circuits 31 to 34, for example, a charge amplification circuit as shown in FIG. 4A or an impedance conversion circuit as shown in FIG. 4B is applied. As the first and second differential amplifier circuits 41 and 42, for example, an operational amplifier is applied.

The second phase adjustment circuit 60 shifts the phase of the monitor signal output from the first differential amplifier circuit 41 via the filter circuit 51 by 90 ° and outputs the same as the detection reference signal S4. Also, the synchronous detection circuit 61 synchronizes the detection reference signal S4 output from the second phase adjustment circuit 60 with the angular velocity detection signal S3 supplied from the second differential amplifier circuit 42 via the filter circuit 52. It performs phase detection. The synchronous detection circuit 61 is connected to an output adjustment circuit 64 via a smoothing circuit 62 and an amplification circuit 63. Further, a temperature sensor 65, a memory 66, and a reference voltage generator 67 are connected to the output adjustment circuit 64, respectively.

The temperature sensor 65 detects the temperature of the entire gyro device including the angular velocity detecting element 1 as an analog value, and is, for example, a thermistor. In the memory 66, for example, a ROM (Read Only Memory) is used, and a correction coefficient for correcting a temperature gradient of a detection output of the temperature sensor 65 is set and stored individually for each of a plurality of temperature regions. That is, in this example, a correction coefficient used for temperature drift correction (hereinafter referred to as a temperature drift correction coefficient) and a correction coefficient used for sensitivity temperature correction for two regions, a low temperature region and a high temperature region, respectively. (Hereinafter referred to as “sensitivity temperature correction coefficient”) are stored separately. . Further, the memory 66 stores an offset voltage adjustment value and a sensitivity adjustment value in advance.

As shown in FIG. 5, the output adjustment circuit 64 also includes a comparator 64A, an offset voltage adjustment unit 64B, a temperature drift correction unit 64C, a sensitivity temperature correction unit 64D, and a sensitivity adjustment unit 64E.

The comparator 64A compares the detection output of the temperature sensor with the reference voltage given from the reference voltage generator 67 to determine the current temperature range. For example, a noisy level signal is output.

[0055] The offset voltage adjustment unit 64B stores the voltage so that the voltage level of the angular velocity detection signal always becomes a constant offset value (for example, +2.5 V) at normal temperature and when the angular velocity is not applied to the vibrator 1. It is adjusted by the offset voltage adjustment value given from 66 and comprises a DZA converter 641 and a first addition circuit 642.

The temperature drift correction unit 64C adjusts the detection output of the temperature sensor 65 based on the temperature drift correction coefficient stored in the memory 66, and generates this as a temperature drift correction signal. 643 and a second addition circuit 646 that adds the temperature drift correction signal generated by the temperature drift correction signal generation circuit 643 to the angular velocity detection signal after the offset voltage adjustment.

The temperature drift correction signal generating circuit 643 includes a first selection circuit 644 for selecting a temperature drift correction coefficient given from the memory 66, and a temperature drift correction coefficient selected by the first selection circuit 644. And a first temperature gradient adjusting circuit 645 composed of a multiplying circuit for multiplying the detection output of the temperature sensor 65.

[0058] The sensitivity temperature correction unit 64D adjusts the detection output of the temperature sensor 65 based on the sensitivity temperature correction coefficient stored in the memory 66 and generates a sensitivity temperature correction signal as a sensitivity temperature correction signal. A correction signal generation circuit 647 and a first multiplication circuit 650 for multiplying the angular velocity detection signal after temperature drift correction by the sensitivity temperature correction signal generated by the sensitivity temperature correction signal generation circuit 647 are provided.

[0059] The sensitivity correction signal generation circuit 647 includes a second selection circuit 648 that selects a sensitivity temperature correction coefficient given from the memory 66, and a sensitivity temperature correction coefficient selected by the second selection circuit 648 as a temperature. It consists of a multiplication circuit that multiplies the detection output of sensor 65. And a second temperature gradient adjusting circuit 649.

The sensitivity adjuster 64E is provided from the memory 66 because the sensitivity of the angular velocity detection signal at room temperature may differ due to variations in characteristics such as detection performance of the vibrator 1 that are not related to the temperature characteristics of the vibrator 1. It is provided to adjust the gain by the sensitivity adjustment value.

, A DZA converter 651 and a second multiplication circuit 652.

Next, the operation of the gyro device having the above configuration will be described.

[0062] The drive signal S12 obtained by inverting the level of the drive signal S11 output from the AGC circuit 22 by the inverting circuit 21 is applied to the first and fourth drive electrodes 101 and 104. The drive signal S11 output from the AGC circuit 22 is directly applied to the second and third drive electrodes 102 and 103. In this case, as shown in FIG. 6A and FIG. 6B, both drive signals Sl 1 and S12 are AC signals whose levels are in an inverting relationship with each other with reference to an offset potential of, for example, +2.5 V with respect to the ground potential.

[0063] Therefore, for example, when one drive signal S12 is at a high level and the other drive signal S11 is at a single level, the first and fourth drive electrodes 101, 104 and the electrodes 101, 104 are opposed to each other. The electrostatic attraction of the movable electrodes 111a, 151a and 112b, 152b becomes "strong", while the second and third drive electrodes 102, 103 and the movable electrode 1 facing the electrodes 102, 103 The electrostatic attraction of l ib, 151b and 112a, 152a is in a "weak" state. Naturally, if the levels of the two signals S12 and S11 are opposite, the state is reversed. Therefore, as shown in FIG. 7A, the first to fourth mass portions 71 to 74 are driven in opposite phases in the X-axis direction and vibrate due to the difference in electrostatic attraction.

[0064] Depending on this vibration, the capacitance between the movable electrode 11lc and the first monitor electrode 91 provided on the first mass portion 71 and the movable electrode provided on the fourth mass portion 74 are provided. The capacitance between 112c and the second monitor electrode 92 changes.

The capacitance change at the first and second monitor electrodes 91 and 92 for monitoring the driving vibration state of the vibrator 1 in the X-axis direction corresponds to each capacitance change by the first and second CV conversion circuits 31 and 32. It is converted into monitor signals S21 and S22 having the obtained voltage levels. In this case, since both monitor signals S21 and S22 are signals having phases opposite to each other, they are amplified and converted into one monitor signal S2 by the first differential amplifier circuit 41 in the next stage. [0066] The monitor signal S2 is input to the AGC circuit 22 after unnecessary noise components are removed by the filter circuit 51 and the first phase adjustment circuit 23 performs phase adjustment required for self-excited oscillation. It is. The AGC circuit 22 automatically adjusts the amplification factor so that the input signal amplitude becomes constant. Therefore, the first to fourth driving electrodes 101 to 104 are always supplied with the driving signals Sll and S12 having appropriate amplitudes.

[0067] In this way, the drive signals Sll and S12 are generated from the monitor signals S2 obtained at the first and second monitor electrodes 91 and 92, respectively, and the respective drive signals Sll and S12 are converted to the first to fourth signals. By applying a voltage to the drive electrodes, a closed-loop self-excited oscillation circuit is formed, and the vibrator 1 continues to vibrate at the same resonance frequency as the drive signals Sl1, S12.

In this state, when a rotational angular velocity about the Z axis as a central axis is applied to the vibrator 1, Corioliska is generated in each of the mass portions 71 to 74 in the Y axis direction orthogonal to the vibration direction. The first and second detection frames 141 and 142 supported by the first and second detection beams 131 and 132 are driven by Coriolisers in directions opposite to each other in the Y-axis direction, as shown in FIG. And vibrates at the same frequency as the drive vibration in the X-axis direction. The capacitance between the movable electrodes 171 and 172 provided in the first and second detection frames 141 and 142 and the first to fourth detection electrodes 161 to 164 respectively changes depending on the vibration. In FIG. 7 (b), the vibration of the mass parts 71 to 74 in the X-axis direction is omitted.

[0069] Coriolis F generated when an angular velocity is applied is given by the following equation.

F = 2M ov

Here, M is the mass of the entire first to fourth mass parts 71 to 74, ω is the angular velocity, and V is the driving vibration velocity of the entire first to fourth mass parts 71 to 74.

Here, when the vibrator 1 is a non-resonant type, the structural resonance frequency of the vibrator 1 in the Υ-axis direction is sufficiently different from the vibration frequency when driven in the X-axis direction by the drive signals Sl l and S12. Therefore, there is a 90 ° phase difference between the の -axis vibration caused by Coriolis and the X-axis drive vibration driven by the drive signals Sl 1 and S12. For this reason, if vibration occurs in the Υ-axis direction while driving vibration occurs in the X-axis direction, the first to fourth mass portions 71 to 74 perform elliptical motion as shown in FIG. Therefore, the capacitance change generated in the first and second monitor electrodes 91 and 92 due to the drive vibration, and each detection electrode 161 due to the vibration due to the Corioliska. The change in capacitance occurring at 164164 results in a phase difference of 90 °.

On the other hand, the capacitance change generated in the first and third detection electrodes 161 and 163 due to the vibration by Coriolis is converted by the third CV conversion circuit 33 into an angular velocity detection signal S 31 having a voltage level corresponding to the capacitance change. You. Similarly, the capacitance change generated in the second and fourth detection electrodes 162 and 164 due to the vibration by Coriolis is converted by the fourth CV conversion circuit 34 into an angular velocity detection signal S32 having a voltage level corresponding to the capacitance change. .

In this case, since the angular velocity detection signals S31 and S32 output from the third and fourth CV conversion circuits 33 and 34 are signals having phases opposite to each other with respect to the components that depend on Coriolis, the second difference in the next stage is used. The dynamic amplification circuit 42 amplifies and converts the signal into one angular velocity detection signal S3. The angular velocity detection signal S3 is input to a synchronous detection circuit 61 after unnecessary noise components are removed by a filter circuit 52.

The monitor signal S 2 output from the first differential amplifier circuit 41 is input to the second phase adjustment circuit 60 after unnecessary noise components are removed by the filter circuit 51. The filter circuits 51 and 52 are designed in advance so that the phase rotation amounts are the same. The second phase adjustment circuit 60 shifts the phase of the output signal of the filter circuit 51 by 90 ° and outputs the result as the detection reference signal S4. As described above, in the non-resonant type vibrator 1, the monitor signal S2 and the angular velocity detection signal S3 are originally output with a phase difference of 90 °. Further, the phase rotation of the filter circuit 51 and the phase rotation of the filter circuit 52 are designed to be the same. Therefore, the detection reference signal S4 output from the second phase adjustment circuit 60 has the same phase (or opposite phase) as the Coriolis component of the signal output from the filter circuit 52, and this detection reference signal S4 is used as the synchronous detection circuit 6. Entered into 1.

The synchronous detection circuit 61 synchronously detects the angular velocity detection signal S3 using the detection reference signal S4. In this case, since the two signals S3 and S4 are in phase (or opposite phase), the angular velocity detection signal S5 after synchronous detection by the synchronous detection circuit 61 has a half-wave rectified form, which is further smoothed. By being smoothed by the circuit 62, an angular velocity detection signal S6 having a DC voltage level corresponding to the angular velocity is obtained. Then, this angular velocity detection signal S6 is amplified by a next-stage amplifier circuit 63, and is then supplied to an output adjustment circuit 64.

[0075] The offset voltage adjustment value stored in the memory 66 is determined by the D of the offset voltage adjustment unit 64B. After the analog signal is converted by the ZA converter 641, the signal is supplied to the first adding circuit 642. The first calorie calculation circuit 642 adds the offset voltage adjustment value to the angular velocity detection signal, so that the angular velocity is applied to the vibrator 1, and the voltage level of the angular velocity detection signal at room temperature in a normal case is always constant. It is adjusted so that it becomes the offset value (for example, + 2.5V).

Further, the detection output of the temperature sensor 65 is applied to a comparator 64A and is also supplied to first and second temperature gradient adjusting circuits 645 and 649, respectively. The comparator 64A compares the detection output of the temperature sensor 65 with the reference voltage provided from the reference voltage generator 67 to determine the current temperature region, and a signal corresponding to the current temperature region, for example, a low signal in a low temperature region. A high-level signal is output in a high-temperature region.

[0077] In the temperature drift correction unit 64C, for example, when the output signal of the comparator 64A is at a low level because the current temperature is included in the low temperature region, the first selection circuit 644 sets the temperature having a value of ml. Select the drift correction coefficient. Further, when the output signal of the comparator 64A is at the high level because the current temperature is included in the high temperature region, the temperature drift correction coefficient having the value of m2 is selected.

The temperature drift correction coefficient ml or m2 selected by the first selection circuit 644 as described above is supplied to the first temperature gradient adjustment circuit 645. The first temperature gradient adjustment circuit 645 multiplies the detection output of the temperature sensor 65 by the temperature drift correction coefficient ml or m2 selected by the first selection circuit 644, and uses this as a temperature drift correction signal for a second addition. Give to circuit 646. The second addition circuit 646 adds the temperature drift correction signal output from the first temperature gradient adjustment circuit 645 to the angular velocity detection signal.

Accordingly, for example, the angular velocity detection signal S6 input to the output adjustment circuit 64 causes a temperature drift as shown in FIG. 9A, while the detection output of the temperature sensor 65 changes to a linear detection characteristic curve as shown in FIG. 9B. In this case, the detection output itself of the temperature sensor 65 cannot be used as a temperature drift correction signal for the angular velocity detection signal. Therefore, by multiplying the detection output of the temperature sensor 65 by the appropriate temperature drift correction coefficients ml and m2 for the high temperature region and the low temperature region, a temperature drift correction signal having temperature characteristics as shown in FIG. 9C is obtained. Can be Then, by adding this temperature drift correction signal to the angular velocity detection signal, the angular velocity detection signal after the addition is, as shown in FIG. It is corrected so as to have a substantially flat characteristic that does not cause a shift. In this case, however, since the temperature drift correction signal is a continuous analog signal generated based on the detection output of the temperature sensor 65, the angular velocity detection signal after the temperature drift correction has a conventional ripple. Does not occur.

[0080] The angular velocity detection signal subjected to the temperature drift correction is input to the sensitivity temperature correction unit 64D in the next stage. In the sensitivity temperature correction unit 64D, for example, when the output signal of the comparator 64A is at a low level because the current temperature is included in the low temperature region, the second selection circuit 648 has a sensitivity temperature correction value of nl. Select a coefficient. When the output signal of the comparator 64A is at a high level because the current temperature is included in the high temperature region, the sensitivity temperature correction coefficient having the value of n2 is selected.

The sensitivity temperature correction coefficient nl or n2 selected by the second selection circuit 648 as described above is given to the second temperature gradient adjustment circuit 649. The second temperature gradient adjustment circuit 649 multiplies the detection output of the temperature sensor 65 by the sensitivity temperature correction coefficient nl or n2 selected by the second selection circuit 648, and uses this as a sensitivity temperature correction signal in a first multiplication circuit. Give to 650. The first multiplication circuit 650 multiplies the angular velocity detection signal by the sensitivity temperature correction signal output from the second temperature gradient adjustment circuit 649.

Therefore, for example, when the sensitivity of the angular velocity detection signal input to the output adjustment circuit 64 causes a temperature change as shown in FIG. 10A, the detection output of the temperature sensor 65 is different between the high temperature region and the low temperature region. By multiplying the appropriate sensitivity temperature correction coefficients nl and n2, a sensitivity temperature correction signal having a temperature characteristic as shown in FIG. 10C is obtained. Then, by multiplying the angular velocity detection signal by the sensitivity temperature correction signal, the sensitivity of the angular velocity detection signal after the multiplication is corrected so as to have a substantially flat characteristic unaffected by the temperature change as shown in FIG.10D. . In this case, since the sensitivity temperature correction signal is a continuous analog signal generated based on the detection output of the temperature sensor 65 in this case, no ripple occurs during the sensitivity correction of the angular velocity detection signal.

The angular velocity detection signal corrected for the sensitivity temperature is input to the sensitivity adjustment unit 64E at the next stage. The sensitivity adjustment value stored in the memory 66 is converted into an analog signal by the DZA converter 651 of the sensitivity adjustment unit 64E, and is provided to the second multiplication circuit 652. The second multiplier 652 By multiplying the angular velocity detection signal after the sensitivity temperature correction by the degree adjustment value, gain adjustment is performed when the level of the angular velocity detection signal is different due to variation in characteristics such as the detection performance of the vibrator 1. Then, based on the angular velocity detection signal S7 after the gain adjustment, the magnitude of the actual angular velocity and its rotation direction are calculated by a subsequent processing circuit (not shown).

In the above embodiment, the temperature drift correction coefficients ml and m2 and the sensitivity temperature correction coefficients nl and n2 are set for the two regions of the low-temperature region and the high-temperature region, respectively. An appropriate temperature drift correction coefficient and sensitivity temperature correction coefficient can be set according to the force and the temperature range, respectively.

Further, as shown in FIG. 11A, when the temperature drift characteristic of the angular velocity detection signal changes linearly, a single temperature drift correction coefficient m3 is used without distinguishing the temperature region. A temperature drift correction signal having a temperature characteristic as shown in FIG. 11C may be generated by multiplying the detection output of the temperature sensor 65 shown in FIG. 11B by the temperature drift correction coefficient m3. Similarly, when the sensitivity of the angular velocity detection signal changes linearly according to the temperature change, a single sensitivity temperature correction coefficient can be used.

[0086] Furthermore, in the above embodiment, the first temperature gradient adjustment circuit 645 constituting the temperature drift correction unit 64C is configured by a multiplication circuit, but may be a division circuit depending on the content of the temperature correction. You can also. That is, the first temperature gradient adjusting circuit 645 performs the division using the temperature drift correction coefficient ml or m2 selected by the first selecting circuit 644 as a divisor and the detection output of the temperature sensor 65 as a dividend, and performs the division. To the second adder circuit 646 as a temperature drift correction signal.

[0087] Also, the second addition circuit 646 can be configured by a subtraction circuit depending on the content of the temperature drift. That is, the subtraction circuit that replaces the second addition circuit 646 also subtracts the angular drift detection signal strength from the temperature drift correction signal output from the first temperature gradient adjustment circuit 645, and outputs the subtraction result to the first multiplication circuit 650.

Further, the second temperature gradient adjustment circuit 649 constituting the sensitivity temperature correction unit 64D is configured by a multiplication circuit, but may be a division circuit depending on the content of the correction. That is, the second temperature gradient adjusting circuit 649 performs the division with the sensitivity temperature correction coefficient nl or n2 selected by the second selection circuit 648 as a divisor and the detection output of the temperature sensor 65 as a dividend. Then, the result of the division is given to the first multiplier circuit 650 as a sensitivity temperature correction signal.

Further, the first multiplication circuit 650 can also be configured by a division circuit depending on the content of the change in the temperature sensitivity. That is, the division circuit that replaces the first multiplication circuit 650 performs the division with the sensitivity temperature correction signal output from the second temperature gradient adjustment circuit 649 as a divisor and the angular velocity detection signal as a dividend.

In the above-described embodiment, a case has been described in which the gyro device is applied to a vibrating gyro including the vibrator 1 of the electrostatic drive Z-capacitance detection type, but the present invention is not limited to this. For example, a vibrating gyroscope having a resonator element made of a piezoelectric material or a single crystal as an angular velocity detecting element, a vibrating gyroscope having a tuning fork vibrator as an angular velocity detecting element, and other types of gyro devices. Can be widely applied

Claims

The scope of the claims

[1] an angular velocity detector (100),

A temperature sensor (65) that detects temperature and outputs an analog value;

A memory (66) for storing a correction coefficient for correcting a temperature gradient of a detection output of the temperature sensor (65),

A temperature drift correction signal generation circuit that adjusts a detection output of the temperature sensor (65) based on the correction coefficient stored in the memory (66) and generates the adjusted detection output as a temperature drift correction signal. (643),

The temperature drift correction signal generated by the temperature drift correction signal generation circuit (643) is added to the angular velocity detection signal output from the angular velocity detection section (100), or the angular drift detection signal is output from the angular velocity detection section (100). A gyro device comprising: an addition / subtraction circuit (646) for subtracting the temperature drift correction signal generated by the temperature drift correction signal generation circuit (643) from the angular velocity detection signal.

[2] The temperature drift correction signal generation circuit (643) includes: a force multiplied by a detection output of the temperature sensor (65) and a force read out from the memory (66) or the temperature sensor (65) The gyro apparatus according to claim 1, further comprising a multiplication / division circuit (645) for dividing the detection output of the memory by the correction coefficient read out by the memory (66).

3. The gyro device according to claim 1, wherein the correction coefficient stored in the memory (66) is set to an individual value for each of a plurality of temperature regions.

[4] The gyro device further comprises:

A comparator (64A) for comparing a detection output of the temperature sensor (65) with a reference voltage to determine a current temperature region;

The temperature drift correction signal generation circuit (643) adjusts a detection output of the temperature sensor (65) based on the correction coefficient corresponding to the determined current temperature region, and outputs the adjusted detection output to a temperature. The gyro device according to claim 3, wherein the gyro device is generated as a drift correction signal.

[5] angular velocity detector (100),

A temperature sensor (65) that detects temperature and outputs an analog value; A memory (66) for storing a correction coefficient for correcting a temperature gradient of a detection output of the temperature sensor (65),

A sensitivity temperature correction signal generation circuit (A) that adjusts a detection output of the temperature sensor (65) based on the correction coefficient stored in the memory (66) and generates the adjusted detection output as a sensitivity temperature correction signal. 647),

The angular velocity detection signal output from the angular velocity detection section (100) is multiplied by the sensitivity temperature correction signal generated by the sensitivity temperature correction signal generation circuit (647), or the angular velocity detection signal is output from the angular velocity detection section (100). A gyro device comprising: a multiplication / division circuit (650) for dividing the output angular velocity detection signal by the sensitivity temperature correction signal generated by the sensitivity temperature correction signal generation circuit (647).

[6] The sensitivity correction signal generation circuit outputs a force multiplied by a detection coefficient of the temperature sensor (65) and a correction coefficient from which a force of the memory (66) is read or a detection output of the temperature sensor (65). The gyro device according to claim 5, further comprising a multiplication / division circuit (649) for dividing by the correction coefficient read from the memory (66).

[7] The gyro device according to claim 5, wherein the correction coefficient stored in the memory (66) is set to an individual value for each of a plurality of temperature regions.

[8] The gyro device further comprises:

The sensitivity temperature correction signal generation circuit (647) adjusts the detection output of the temperature sensor (65) based on the correction coefficient corresponding to the determined current temperature region, and adjusts the adjusted detection output. 8. The gyro device according to claim 7, wherein the gyro device generates the sensitivity temperature correction signal.

[9] angular velocity detector (100),

A temperature sensor (65) that detects temperature and outputs an analog value;

A memory (66) for storing a first correction coefficient and a second correction coefficient for correcting a temperature gradient of a detection output of the temperature sensor (65);

The temperature sensor based on the first correction coefficient stored in the memory (66); A temperature drift correction signal generation circuit (643) for adjusting the detection output of (65) and generating the adjusted detection output as a temperature drift correction signal;

The temperature drift correction signal generated by the temperature drift correction signal generation circuit (643) is added to the angular velocity detection signal output from the angular velocity detection section (100), or the angular velocity detection signal is output from the angular velocity detection section (100). An addition / subtraction circuit (646) for subtracting the temperature drift correction signal generated by the temperature drift correction signal generation circuit (643) from the angular velocity detection signal; and the second correction coefficient stored in the memory (66) A sensitivity temperature correction signal generation circuit (647) that adjusts a detection output of the temperature sensor (65) based on the detection output, and generates the adjusted detection output as a sensitivity temperature correction signal.

The angular velocity detection signal output from the addition / subtraction circuit (646) is multiplied by the sensitivity temperature correction signal generated by the sensitivity temperature correction signal generation circuit (647), or the added or subtracted angular velocity detection signal is calculated. A gyro device comprising: a multiplication / division circuit for dividing by the sensitivity temperature correction signal generated by the sensitivity temperature correction signal generation circuit (647).