JPH06102046A - Oscillation gyrosensor - Google Patents

Abstract

PURPOSE:To obtain a general purpose sensor by performing drift correction of an oscillation gyrosensor not through sofware processing but through an electric circuit built in the sensor. CONSTITUTION:When the variation rate per a predetermined time of sensor output, obtained by subjecting the output from piezoelectric elements 2, 3 fixed to an oscillator 1 to amplitude correction, differential amplification, synchronous detection, and DC amplification, settles below a predetermined level, a drift correction voltage is generated for sustaining the sensor output at that point or time during steady state interval. A drift correction voltage for setting the sensor output at a predetermined reference voltage Vref is also generated upon turn ON of power for an oscillation gyrosensor 22. This constitution allows drift correction for aging or environmental variation not through software processing but through electric circuit built in the sensor thus realizing a general purpose sensor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gyro sensor used for determining turning of an automobile and detecting a rotational angular velocity, and more particularly to a regular triangular prismatic vibrating gyro sensor.

[0002]

2. Description of the Related Art A vibrating gyro sensor can directly detect the rotational angular velocity applied to the sensor with high accuracy. Therefore, when mounted on a vehicle, it is possible to detect the turning direction of the vehicle and the yaw rate during turning. Becomes These detection results are very useful for navigation systems, four-wheel steering systems, antilock brake control systems, etc.,
Employment is being actively studied.

However, in the case of the regular triangular prism type vibrating gyro sensor, for example, a piezoelectric element such as so-called PZT is attached to a regular triangular prism vibrator made of a constant elastic material. Therefore, there are many mechanical parts, and due to variations in materials and manufacturing tolerances,
After the signal processing, it is necessary to correct the zero-point voltage which is an intermediate value of the fluctuation range of the sensor output voltage and which is the output voltage when the rotational angular velocity is not input. Further, there is a problem in that drift may occur due to changes over time and environmental changes due to temperature and the like due to differences in thermoelastic coefficients of the components.

In order to correct such drift, for example, the following method has been proposed.

When mounted on a vehicle, it is possible to determine whether or not the vehicle is traveling steadily by another sensor, so the sensor output during steady traveling is corrected by software processing.

The sensor signal is subjected to high-speed analog / digital conversion, and the frequency component of the sensor signal is analyzed by the so-called FFT method or the like, whereby the low-frequency sensor output component and the extremely low-frequency drift component are discriminated and drifted. Only the components are removed by calculation.

The sensor signal is AC-coupled to block the DC component, and the drift component of extremely low frequency is electrically removed.

[0008]

In the above method, it is necessary to input the detection results of the steering sensor, the left and right wheel speed sensors, etc. to the correction circuit, which requires a large scale configuration and requires software processing. Since,
The gyro sensor alone is extremely inferior in versatility. In addition, when the drift is large, the zero-point voltage is largely deviated from the center of the dynamic range of the sensor, and the dynamic range of the sensor cannot be fully utilized.

The above method requires a digital signal processor or the like having a high-speed arithmetic function, which makes the configuration large and lacks versatility of the sensor.

The above method has a relatively simple structure, and therefore such a drift correction circuit can be built in the sensor, and is excellent in versatility. However, if a constant rotational angular velocity is continuously input,
The sensor output changes to the zero-point voltage, which is the output when the rotational angular velocity is not input, and even though the rotational angular velocity is applied, only the same output as when it is not applied is obtained. There is a problem that it ends up.

An object of the present invention is to provide a vibrating gyro sensor which has a versatile and simple structure and is capable of compensating for drift due to changes over time and environmental changes.

[0012]

According to the present invention, there is provided a vibrating gyro having a signal processing circuit for deriving an output voltage corresponding to a rotational angular velocity from a component due to a Coriolis force in an output voltage of a piezoelectric element formed on a side surface of a vibrator. In the sensor, a reset circuit that outputs a correction permission signal for a predetermined time from the time when the power supply to the gyro sensor is started,
In response to the correction permission signal from the reset circuit, a predetermined voltage is stored as a target voltage, and a correction voltage such that the output voltage becomes equal to the target voltage during the predetermined time, and the predetermined time is set. The vibration gyro sensor is provided with a drift correction circuit including a correction voltage generation circuit that holds the correction voltage and supplies the signal to the signal processing circuit when it exceeds.

Further, the present invention provides a vibration gyro sensor having a signal processing circuit for deriving an output voltage corresponding to a rotational angular velocity from a component due to Coriolis force in an output voltage of a piezoelectric element formed on a side surface of a vibrator. It is determined whether or not it is in a steady state from the amount of change in voltage per time, and in the steady state, a steady determination circuit that outputs a correction permission signal, and in response to the correction permission signal from the steady determination circuit, The output voltage at the time when it is determined to be in a steady state is stored as a target voltage, and a correction voltage such that the output voltage becomes equal to the target voltage during the steady state is defined as a non-steady state. In this case, a vibration gyro sensor is provided, which is provided with a drift correction circuit including a correction voltage generation circuit which holds the correction voltage and gives it to the signal processing circuit. A.

Furthermore, the present invention provides a vibration gyro sensor having a signal processing circuit for deriving an output voltage corresponding to a rotational angular velocity from a component due to a Coriolis force in an output voltage of a piezoelectric element formed on a side surface of a vibrator. A reset circuit that outputs a first correction permission signal for a predetermined time from the time when the power supply to the gyro sensor is started, and a change amount of the output voltage per a predetermined time is used to determine whether or not it is in a steady state. However, a steady-state determination circuit that outputs the second correction permission signal when in the steady state, and a predetermined voltage that is stored as the first target voltage when the first correction permission signal is input from the reset circuit, and the steady-state determination circuit When the second correction permission signal is input from, the output voltage of the piezoelectric element at that time is stored as the second target voltage, and the first or second correction is performed. A correction that holds a correction voltage such that the output voltage becomes the first or second target voltage when a valid signal is input, and holds the correction voltage when the first or second correction permission signal is not input. A voltage generating circuit, a correction voltage based on the first target voltage,
The vibration gyro sensor is provided with a drift correction circuit including a compensation circuit for compensating a level difference at the time of switching with a correction voltage based on a second target voltage and giving the correction voltage to a signal processing circuit.

[0015]

According to the present invention, the drift correction including the reset circuit and the correction voltage generation circuit in the signal processing circuit for extracting the output voltage corresponding to the rotational angular velocity from the output voltage of the piezoelectric element formed on the side surface of the vibrator. Provide a circuit. The drift voltage due to the change with time of the output voltage of the piezoelectric element attached to the vibrator is already superposed at the start of energization of the vibration gyro sensor, that is, when the ignition key switch is turned on when the vibration gyro sensor is mounted on the vehicle. Therefore, the reset circuit outputs the correction permission signal in a predetermined time from the time when the power supply to the gyro sensor is started, that is, in the steady state in which the vehicle is stopped.

During the time when the correction permission signal is input, the correction voltage generation circuit stores a predetermined voltage, for example, a voltage near the middle of the dynamic range of the output voltage of the piezoelectric element as the target voltage, and the piezoelectric element outputs the voltage. A correction voltage is supplied to the signal processing circuit so that its output voltage becomes equal to the target voltage. Further, the signal processing circuit adds the held correction voltage to the output voltage of the piezoelectric element which fluctuates after the lapse of the time, and outputs the vibration gyro sensor output. Therefore, the zero point correction is performed every time the power supply is started. Therefore, fine adjustment at the time of manufacturing is unnecessary, and the process can be simplified. Further, the drift correction can be performed with a simple configuration without using software processing.

According to the invention, the signal processing circuit for processing the output voltage of the piezoelectric element is provided with the drift correction circuit having the steady state determination circuit and the correction voltage generation circuit. The steady state determination circuit determines whether or not the output voltage of the piezoelectric element is in a steady state from a predetermined amount of change per unit time, that is, the change rate of the output voltage, and is in a steady state in which the rotational angular velocity is not applied. Sometimes a correction permission signal is output to the correction voltage generation circuit.

When the correction permission signal is input, the correction voltage generating circuit stores the output voltage of the piezoelectric element at that time as the target voltage, and the output voltage is stored during the period in which the steady state continues. The signal processing circuit is provided with a correction voltage that is equal to the target voltage. Further, in the non-steady state, the correction voltage immediately before the non-steady state is held and given to the signal processing circuit. The signal processing circuit adds the correction voltage to the output voltage of the piezoelectric element and derives it as an output signal of the vibration gyro sensor. Therefore, drift correction can be performed with a simple structure without providing a special sensor or the like for steady determination.

Furthermore, according to the present invention, the signal processing circuit for extracting the voltage corresponding to the rotational angular velocity from the output voltage of the piezoelectric element includes a reset circuit, a steady state determination circuit, a correction voltage generation circuit, and a compensation circuit. A drift correction circuit is provided. The reset circuit outputs the first correction permission signal for a predetermined time from the time when the power supply to the gyro sensor is started. Further, the steady state determination circuit determines whether or not the steady state is based on a change amount of the output voltage of the piezoelectric element per predetermined time, and outputs the second correction permission signal when the steady state is present.

The first and second correction permission signals are input to the correction voltage generation circuit, and the correction voltage generation circuit receives a predetermined voltage when the first correction permission signal is input, that is, at the start of power energization. For example, a voltage that is approximately the intermediate value of the dynamic range of the output voltage of the piezoelectric element is stored as the first target voltage, and when the second correction permission signal is input, the output voltage of the piezoelectric element at that time is set to the second target voltage. Memorize as.

The correction voltage generation circuit outputs a correction voltage such that the output voltage of the piezoelectric element becomes the first or second target voltage, respectively, when these first or second correction permission signals are input. Further, when the first and second correction permission signals are not input, the first or second correction
The correction voltage at the time when the correction permission signal is input is held and output. The correction voltage is input to a compensation circuit, and the compensation circuit compensates a level difference at the time of switching between the correction voltage based on the first target voltage and the correction voltage based on the second target voltage, that is, the level thereof. A voltage corresponding to the difference is added to the correction voltage and then applied to the signal processing circuit.

[0022]

1 is a block diagram showing an electrical configuration of a vibration gyro sensor 22 having a drift correction circuit 21 according to an embodiment of the present invention. This vibration gyro sensor 22
Uses an equilateral triangular prism-shaped vibrator 1, a left and right piezoelectric elements 2 and 3 for driving are provided on two sides of the vibrator 1, and a remaining one side is used for feedback. A piezoelectric element 4 is provided. A drive signal of, for example, 8 kHz from the oscillation circuit 5 is applied to the piezoelectric elements 2 and 3 through the phase correction circuit 6 with the phase thereof being deviated by 90 ° to excite the vibrator 1. When the vibrator 1 is rotated in the direction of arrow 7 in this state, the voltage generated by the Coriolis force proportional to the rotation angular velocity is superimposed on the drive signal, and the outputs indicated by reference numerals 8a and 9a on the lines 8 and 9 respectively. The voltage is derived. The output voltage also includes a drift component.

The output voltage from the piezoelectric elements 2 and 3 is amplitude-corrected by the amplitude correction circuit 10, and the differential amplifier circuit 1
When differential amplification is performed at 1, the drive signal from the phase correction circuit 6 is canceled out, and only the voltage component due to the Coriolis force and drift is extracted from the differential amplification circuit 11 to the line 12 as indicated by reference numeral 12a. can do. When the output from the differential amplifier circuit 11 is half-wave rectified in the synchronous detection circuit 13 in synchronization with the drive signal from the oscillation circuit 5,
The reference numeral 14a indicates the direct current amplifier circuit 15 through the line 14.
The output is given by. By smoothing this output by the DC amplifier circuit 15, an output proportional to the rotational angular velocity as indicated by reference numeral 16a is derived from the line 16.

The output from the DC amplification circuit 15 is given to a navigation device, an antilock brake control device, etc. as a sensor output of the vibration gyro sensor 22 and used for turning determination and yaw rate calculation. This sensor output is also given to the drift correction circuit 21, and from this drift correction circuit 21, a drift correction voltage created as described later is applied to the line 17
Is supplied to the DC amplifying circuit 15 via, and the sensor output from the DC amplifying circuit 15 becomes an output voltage from which the drift component is removed and which corresponds only to the rotational angular velocity.

A high level voltage Vcc is applied to the drift correction circuit 21 via a line 24 from a power supply circuit 23 which supplies electric power to the circuits 5, 11, 13 and the like, and a line 25 is also applied. A reference voltage Vref that is ½ of the voltage Vcc is applied via the above. Further, a drive signal from the oscillation circuit 5 is given via the line 26.

FIG. 2 is a block diagram showing an electrical configuration of the drift correction circuit 21. When the ignition key switch of the automobile is connected to the Acc or IG contact, power supply from the power supply circuit 23 to each part of the vibration gyro sensor 22 is started. As a result, the reset circuit 31 outputs the first correction permission signal to the target voltage setting circuit 33 via the line 32 at the rising timing of the voltage Vcc. In response to this, the target voltage setting circuit 33
Derives the reference voltage Vref input from the power supply circuit 23 via the line 25 as a target voltage to the line 34, and correspondingly, from the level shift circuit 35,
The drift correction voltage is fed back to the DC amplification circuit 15 via the line 17.

On the other hand, the sensor output from the DC amplification circuit 15 via the line 16 is supplied from the follower circuit 36 via the switches SW1 and SW2 to the two hold circuits 37,
38, respectively. The switch SW1 receives the timing from the timing signal generation circuit 41 during a period in which the second correction permission signal from the steady state determination circuit 39, which will be described later, is inverted by the inversion buffer 40, and thus the second correction permission signal is not output. Signal is AND gate 4
It is inputted via 2 and performs a switching operation.

To the timing signal generating circuit 41, the frequency divider circuit 43, which is realized by a so-called gate IC, receives the drive signal from the oscillation circuit 5 via the line 26.
For example, it is input after being divided by 256. Therefore, in response to the drive signal of 8 kHz, the timing signal shown in FIG. 2C is derived from the timing signal generation circuit 41 to the switch SW1 every 128 msec, and the hold value of the hold circuit 37 is updated. Further, the timing signal generating circuit 41 shifts by a half cycle from the timing signal of the switch SW1, that is, 64 ms.
The timing signal shown in FIG. 2 (4) is derived to the switch SW2 with a shift of ec. Therefore, when the second correction permission signal is not derived from the steady state determination circuit 39, the two hold circuits 37 and 38 are deviated from each other by a half cycle and the sensor output from the DC amplification circuit 15 is updated and held. ing.

The hold values of the hold circuits 37 and 38 are stored in the differential amplification and comparison circuit 4 of the steady state judgment circuit 39.
4 and the differential amplification and comparison circuit 44
When the amount of change in the hold value of both hold circuits 37 and 38 is within ± 5 [mV] per 64 msec, for example, it is determined that the vehicle is stationary or the vehicle is traveling straight ahead, and the filter circuit The second correction permission signal is output to the lines 18 and 19 via 45. The filter circuit 45, when the hold value of the hold circuits 37 and 38 that fluctuates in the unsteady state accidentally falls within the voltage 5 [mV] even for a moment,
The delay circuit is, for example, about 2 seconds in order to prevent erroneous steady determination.

When the second correction permission signal is derived, the timing signal from the timing signal generating circuit 41 to the switch SW1 is blocked by the AND gate 42, and the hold value of the hold circuit 37 becomes an unsteady state. It is held at the value immediately before. The second correction permission signal is also applied to the target voltage setting circuit 33, and the target voltage setting circuit 33 also receives the second correction permission signal by the hold circuit 37 which is input via the line 46. The hold value is set to the target voltage, and the value is led to the level shift circuit 35 via the line 34.

The first and second parts shown in FIG. 2 (2).
The correction permission signal is also given to the switch SW3 via the OR gate 47. The switch SW3 gives the output of the follower circuit 36 to the integration circuit 48 during the period in which the first and second correction permission signals are derived. The target voltage setting circuit 33 also applies a target voltage to the integrator circuit 48. Therefore, the integrator circuit 48 generates a correction voltage such that the output of the follower circuit 36 approaches the target voltage. The signal is fed back from the line 17 via the level shift circuit 35 to the DC amplification circuit 15 as a drift correction voltage, and thus the drift correction is performed.

Therefore, when the power supply is started from time t1 in FIG. 2 and the sensor output for which drift correction is not performed changes as indicated by reference numeral α1 in FIG. 2 (1), drift correction is performed. And a sensor output indicated by reference numeral α2 is obtained.

FIG. 4 is an electric circuit diagram showing a specific structure of the drift correction circuit 21, and the same reference numerals are given to the portions corresponding to those in FIGS. 1 and 2 described above. The frequency dividing circuit 43
Is configured to include an integrated circuit 43a for frequency division,
The parallel outputs from the integrated circuit 43a are respectively applied to the gate ICs 41a and 41b in the timing signal generating circuit 41, and the drive signal is divided by 256 as described above, and the switches SW1 and SW2 are alternately timed every 64 msec. The signal is output.

The differential amplification / comparison circuit 44 of the steady-state determination circuit 39 includes a differential amplifier 44a and a window comparator 44b, and the differential amplifier 44a holds the hold values of the hold circuits 37 and 38. The output corresponding to the difference is amplified by, for example, a gain of 20 and derived to the window comparator 44b. The window comparator 44b includes a pair of comparators 44m and 44n and voltage dividing resistors R1 to R3, and resistors R1 to R3.
3 is a line 24 of voltage Vcc and a line 49 of ground level
It is interposed in series between and. Therefore, the output voltage of the differential amplifier 44a is the voltage Vref ± 100 [mV] generated by the voltage division of the resistors R1 to R3.
When the voltage is within the two reference voltages V1 and V2, a high level output is derived from the comparators 44m and 44n to the filter circuit 45.

The filter circuit 45 includes two differential amplifiers 4
5a and 45b and a capacitor C3, and the inverting input terminals of the differential amplifiers 45a and 45b are
Via line 25 to line 53, the reference voltage Vref
Is given. The differential amplifier 45a derives an output corresponding to the difference between the differential amplifier 44a and the reference voltage of the window comparator 44b, and charges and discharges the capacitor C3. The differential amplifier 45b receives the charging voltage of the capacitor C3 and the reference voltage Vr from the line 25 to the line 53.
ef is compared, and when the charging voltage of the capacitor C3 is high, that is, when there is no fluctuation in the input to the hold circuits 37 and 38, the second correction permission signal is output to the lines 18 and 19.

The reset circuit 31 includes a capacitor C4
And two inverting buffers 31a and 31b are included. When the power is turned on as described above, the charging of the capacitor C4 is started, and the voltage drop between the terminals of the capacitor C4 becomes a predetermined level. Up to the switch SW from the inverting buffers 31a and 31b through the line 32.
A high-level first correction permission signal is derived at 3. Also, the switch SW3 is turned on by the second correction permission signal via the line 19. While the switch SW3 is conducting in this way, the integration circuit 48
Outputs to the level shift circuit 35 an output such that the deviation between the sensor output input via the switch SW3 and the target voltage input from the target voltage setting circuit 33 via the line 34 becomes zero. .

On the other hand, in the target value setting circuit 33, when the second correction permission signal is input from the line 19, the switch SW5 is turned on and the switch SW4 is turned off via the inversion buffer 51, and the integration circuit 48 is turned on. Is input as a target voltage after the hold value of the hold circuit 37 via the line 46 is corrected as described later. When the high level first correction permission signal is derived from the reset circuit 31 via the line 52, the switch S
W5 is cut off, switch SW4 is turned on, and the line 2
The reference voltage Vref via 5 is input to the integration circuit 48 as a target voltage.

However, when such switching of the target voltage is performed, the integrating circuit 48 is corresponding to the difference between the target voltages.
The output of will also change. Therefore, in the level shift circuit 35 which is a compensation circuit, when the switch SW4 is conducting, the switch SW7 is conducting and the line 5
The output voltage of the integrating circuit 48 is added to the reference voltage Vref via 3 and then amplified by the differential amplifier 35a to create the drift correction voltage. On the other hand, the switch S
When W5 is conducting, the voltage of the integrating circuit 48 is added to the voltage obtained by amplifying the difference between the reference voltage Vref and the output voltage of the target value setting circuit 33 by the differential amplifier 35b, and then the operational amplifier 35. A drift correction voltage is generated via. In this way, the output transition of the integrating circuit 48 at the time of switching the target voltage can be absorbed.

The sensor output input via the line 16 and the sensor output held by the hold circuit 37 are stored in the line 4
There may be a slight difference between the voltage VA derived at 6 and the voltage VA due to the offset of the follower circuit 36 and the hold circuit 37. Therefore, if drift correction is performed with this deviation still occurring, a deviation will occur in the sensor output, so that the deviation will be accumulated if the steady state and the non-steady state are repeated.

In order to eliminate such a problem, in the present embodiment, a correction circuit 55 is provided in the target voltage setting circuit 33. The correction circuit 55 includes two differential amplifiers 55a and 55b. When the hold value VA of the hold circuit 37 is larger than the reference voltage Vref, the voltage Vc at the point 56 is slightly determined by the resistor RA. The voltage Vr increases. Therefore, the comparator 5
The output voltage VB of 5 is VA-Vr. On the other hand, when the voltage VA is smaller than the reference voltage Vref, V
B = VA + Vr. The correction circuit 55 may be deleted when the offset values of the follower circuit 36 and the hold circuit 37 are matched.

As described above, in the drift correction circuit 21 according to the present invention, the zero-point voltage can be set to the reference voltage Vref when the power is turned on, and the fine adjustment at the time of manufacturing the vibrating gyro sensor 22 is unnecessary, and the process is simplified. can do. Further, not only time-dependent changes due to the zero-point voltage correction but also environmental changes such as temperature changes are corrected according to the sensor output during steady state, so drift correction can be performed with a simple configuration without software processing. It can be performed. Furthermore, even if the material does not have excellent temperature characteristics, the mechanical strength can be preferentially used, and the reliability such as impact resistance can be improved. Furthermore, the drift correction circuit 21 according to the present invention is composed of a group of basic circuits such as a gate IC, a differential amplifier circuit, or an analog switch, and therefore a so-called custom I circuit.
It is easy to make C, downsizing and cost reduction can be achieved, and the versatility can be improved by integrating with the sensor.

[0042]

As described above, according to the present invention, it is possible to correct drifts caused by variations in vibrators and piezoelectric elements and their changes over time and environmental changes with a simple configuration without software processing. be able to. Therefore, it is possible to improve the versatility by integrating these correction circuits on the sensor side. Further, the adjustment at the time of manufacturing can be simplified, and even if the temperature characteristic is not necessarily good, a part having good mechanical strength can be used, and reliability such as impact resistance can be improved. .

[Brief description of drawings]

FIG. 1 is a block diagram showing an electrical configuration of a vibration gyro sensor 22 including a drift correction circuit 21 according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an electrical configuration of a drift correction circuit 21.

FIG. 3 is a waveform diagram for explaining the operation of the drift correction circuit 21.

FIG. 4 is an electric circuit diagram showing a specific configuration of the drift correction circuit 21.

[Explanation of symbols]

 1 Vibrator 2-4 Piezoelectric element 21 Drift correction circuit 22 Vibration gyro sensor 31 Reset circuit 33 Target voltage setting circuit 35 Level shift circuit 36 Follower circuit 37, 38 Hold circuit 39 Steady state judgment circuit 44 Differential amplification and comparison circuit 45 Filter circuit 48 integrating circuit

Claims (3)

[Claims] 1. A vibrating gyrosensor having a signal processing circuit for deriving an output voltage corresponding to a rotational angular velocity from a component due to a Coriolis force in an output voltage of a piezoelectric element formed on a side surface of a vibrator. A reset circuit that outputs a correction permission signal only for a predetermined time from the time when power energization is started, and a preset voltage is stored as a target voltage in response to the correction permission signal from the reset circuit, and during the predetermined time. Is a drift correction circuit having a correction voltage for making the output voltage equal to the target voltage, and a correction voltage generation circuit for holding the correction voltage and giving it to the signal processing circuit when the predetermined time is exceeded. A vibration gyro sensor characterized in that 2. A vibrating gyrosensor having a signal processing circuit for deriving an output voltage corresponding to a rotational angular velocity from a component due to Coriolis force in an output voltage of a piezoelectric element formed on a side surface of a vibrator. It determines whether or not it is in a steady state from the amount of change per unit time set, and outputs a correction permission signal when it is in a steady state, and in response to the correction permission signal from the steady determination circuit, The output voltage at the time when it is determined to be present is stored as a target voltage, and a correction voltage that makes the output voltage equal to the target voltage during the steady state period and the correction voltage when the non-steady state occurs A vibration gyro sensor, comprising: a drift correction circuit including a correction voltage generation circuit that holds a voltage and applies the voltage to the signal processing circuit. 3. A vibrating gyrosensor having a signal processing circuit for deriving an output voltage corresponding to a rotational angular velocity from a component due to Coriolis force in an output voltage of a piezoelectric element formed on a side surface of a vibrator. A reset circuit that outputs the first correction permission signal for a predetermined time from the time when the power energization is started, and a steady state is determined based on a change amount of the output voltage per predetermined time, and a steady state is determined. Second when
A steady-state determination circuit that outputs a correction permission signal and a predetermined voltage when the first correction permission signal is input from the reset circuit is stored as a first target voltage, and a second correction permission signal is input from the steady-state determination circuit. In this case, the output voltage of the piezoelectric element at that time is stored as the second target voltage, and when the first or second correction permission signal is input, the output voltage becomes the first or second target voltage, respectively. A correction voltage generating circuit that holds the correction voltage when the first or second correction permission signal is not input, a correction voltage based on the first target voltage, and a correction voltage based on the second target voltage A drift correction circuit provided with a compensating circuit for compensating for a level difference at the time of switching between the signal processing circuit and the signal processing circuit. Gyro sensor.