JP3399221B2 - Angular velocity sensor - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an angular velocity sensor having a self-diagnosis function.

[0002]

2. Description of the Related Art For example, a tuning fork type angular velocity sensor is provided with a detection plate at the tip of both drive plates of a tuning fork type drive section in a direction orthogonal to the driving plates, and the angular velocity is kept constant while the drive plates are constantly driven. When added, the angular velocity is detected by the output from the detection plate which vibrates in the opposite directions in response thereto.

[0003]

A problem with the conventional angular velocity sensor is that, after the sensor is activated, when a failure occurs in a component, the failure is notified to the outside or a criterion for determining the failure from the outside. It was not equipped with the function to have the information that becomes.

An object of the present invention is to enable the use of a highly reliable angular velocity sensor by enabling external detection of a state in which a part of it is damaged and normal detection operation is not possible. It is what

[0005]

In order to achieve this object, an angular velocity sensor according to the present invention supplies a drive signal to a sensor element having a vibrating section and a detecting section for detecting angular velocity, and a vibrating section of the sensor element. And a monitor circuit to which a monitor signal from the sensor element is added. By adding the output of the monitor circuit to the driver circuit via an AGC circuit, the vibrating portion of the sensor element is stably driven and vibrates. Driving means, a charge amplifier to which the output from the detection unit of the sensor element is added, and a synchronous detector to which the output of the charge amplifier is added via a bandpass filter, and the output of the bandpass filter is driven. Detecting means for detecting an angular velocity signal in synchronism with the drive signal from the means and outputting a signal synchronized with the drive signal of the drive means. Self diagnosis means for outputting a self diagnosis signal detects an abnormality of said sensor element by applying the preceding stage from the synchronous detector composing means output, said self-diagnostic manual
Switching means for switching the stage to the operating / non-operating state
And the signal level of the detection means during the non-operation of the self-diagnosis.
To detect abnormalities in the sensor element at all times
And a logic output of the judging device as the judging means.
On the other hand, the switching logic value of the switch as the switching means is reversed.
The input terminal of the drive signal of the switch and the determination
It is electrically connected to the output terminal of
It is configured so that the switch does not malfunction due to force .

With the above structure, the sensor is always supplied from the outside.
Not only can abnormality be detected, but external diagnosis
Failure can be detected even when there is a disconnection signal .

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention includes a sensor element having a vibrating section and a detecting section for detecting an angular velocity, and a driver circuit for supplying a drive signal to the vibrating section of the sensor element. A monitor circuit to which a monitor signal from the sensor element is added.
Driving means for stably driving and vibrating the vibrating portion of the sensor element by applying it to the driver circuit via the GC circuit, charge amplifier to which output from the detecting portion of the sensor element is added, and output of this charge amplifier And a synchronous detector added via a bandpass filter,
A detector that detects the output of the band-pass filter in synchronization with the drive signal from the drive unit and outputs an angular velocity signal, and a synchronous detector that configures the signal synchronized with the drive signal of the drive unit. Self-diagnosis means for detecting abnormality of the sensor element and outputting a self-diagnosis signal by adding to the preceding stage, and operating / non-operation state of the self-diagnosis means.
And a switching means for switching the self-diagnosis
During the operation, the signal level of the detection means is detected to detect the sensor element.
And a judging means for constantly judging abnormality of the child.
As the switching means for the logical output of the judging device as a stage
All the switches must be reversed so that the switching logic values of the switches are reversed.
Electrically connect the drive signal input terminal and the output terminal of the judging device.
, The logic output of the decision device causes the switch to malfunction.
Since it is configured not to operate, the sensor is always external
Not only can it detect abnormalities from outside, but
It has the function of being able to detect a failure even when there is a diagnostic signal from the above .

According to a second aspect of the invention, the vibrating portion and the angular velocity are
A sensor element having a detection unit for detecting, and the sensor element
The driver circuit that supplies a drive signal to the vibration part of the child
Monitor circuit to which the monitor signal from the sensor element is added.
The output of the monitor circuit via the AGC circuit.
Vibration of the sensor element when applied to the driver circuit
Drive means for stably driving and vibrating the part, and the sensor element.
A charge amplifier to which the output from the child detector is added
The output of the charge amplifier via the bandpass filter
And a bandpass filter including:
Data output in synchronization with the drive signal from the drive means.
Detecting means for outputting an angular velocity signal and driving of the driving means.
A signal synchronized with the motion signal is detected by the synchronization detection which constitutes the detection means.
Abnormality of the above-mentioned sensor element by adding in the previous stage from the wave
A self-diagnosis means for detecting and outputting a self-diagnosis signal;
Switch the self-diagnosis means to the operating / non-operating state
The switching means and the detecting means during the non-operation of the self-diagnosis.
Detects the signal level and always judges the abnormality of the sensor element
And a determination means as the determination means.
Switching logic of the switch as the switching means for the physical output
Input terminal for the drive signal of the switch so that the values are equal
And the output terminal of the judging device are electrically coupled,
The logic output of the switch will force the switch to operate
Since it is configured to enter self-diagnosis mode,
Error detection status until a reset signal is applied from the
It has the effect of continuing to hold .

FIG. 1 shows an embodiment of the present invention .
~ It demonstrates using FIG .

One end of metallic drive plates 11 and 12 is fixed to both sides of the support pin 8 and 9 of the substrate 10, and plate-shaped piezoelectric elements 11a and 12a are fixed to the surfaces of the drive plates 11 and 12, respectively. A tuning fork type drive unit is formed. The other end of the drive plates 11 and 12 as shown in FIG. 1, the piezoelectric element 11a, bent in a direction perpendicular to the 12a portion,
After that, the plate-shaped piezoelectric elements 13a and 14a are fixed to the detection plates 13 and 14 which are formed to be extended, and thereby the detection unit is configured.

A tuning fork type angular velocity sensor element is formed by the drive section and the detection section. In the control circuit of the same angular velocity sensor element shown in FIG. 1 , the piezoelectric element 1 of the drive plate 11
1a from driver 15 to about 1VP-P, 1.5KHz
AC signal is applied. Thereby, the drive plates 11, 1
2 starts tuning fork vibration inward and outward with respect to the support pin 9. The piezoelectric element 12a of the driving plate 12 is induced voltage proportional to the applied signal by the tuning fork vibration, it passes through the current amplifier 16, a band-pass filter 17, and outputs a monitor signal as shown in FIG. 3 to the point A. This is next full wave rectifier 1
8. The AGC control of the drive signal is performed so that the signal is fed back to the driver 15 via the AGC circuit 19 and the signal amplitude at the point A is always constant. In the detector, the signals of the piezoelectric elements 13a and 14a are combined at point D and input to the charge amplifier 20. Further, the monitor signal synchronized with the tuning fork vibration from the point A is attenuated by the attenuator 32 and is applied to the non-inverting input terminal of the charge amplifier 20 via the injector 30. The output of the charge amplifier 20 is output from the output terminal 24 via the bandpass filter 21, the synchronous detector 22, and the lowpass filter 23.

[0012] monitor signal A at point A as shown in FIG. 3 is added to the attenuated injector 30 as shown in waveform I of FIG. 3 in the attenuator 32. Injector 30 is composed of, for example, a capacitor and a resistor or the like as shown in FIG. 2, the non-inverting input terminal here made to have a phase shift with respect to the monitor signal A as the waveform H of Figure 3 the charge amplifier 20 Added to. Here, since the inverting and non-inverting inputs of the charge amplifier 20 is in virtually the same potential, the non-inverted input signal from the injector 30 which is applied to the terminal the reversal of the charge amplifier 20 as shown in a waveform D in FIG. 3 It also appears on the input terminal.

Further , in FIG. 1, a signal from the attenuator 32 can be opened / closed by the switch 31 so as to open / close the input to the injector 30 from the outside. The specific circuit is shown in Fig. 2 .
Operation waveform is shown in FIG.

Since the monitor signal I attenuated by the attenuator 32 is normally cut by the switch 31, it is not transmitted to the injector 30, so that the sensor output also remains normal.

Further , in FIG. 1, the input terminal from the outside of the switch 31 is shared with the output terminal of the other judging device 28. The determiner 28 is, for example, the charge amplifier 2
The output E of 0 is monitored to detect an abnormal voltage generated by, for example, an abnormal impact or vibration applied to the tuning fork, and the abnormality is output from the terminal 29 to the outside. Here, the input of the switch 31 is shared with the terminal 29, but the switch 31 is set so that the logic value of the switch 31 is opposite to the logic output of the determiner 28. Therefore, when the switch 31 is not normally operated, an abnormal voltage generated by an abnormal external impact or vibration applied to the tuning fork is detected and the abnormality is notified to the outside. On the other hand, at the time of checking the sensor, a check signal is input from the terminal 29 and the sensor output of the terminal 24 is monitored, so that multi-function failure diagnosis can be performed by one terminal and high cost performance is realized.

Further, when the switching logic value of the switch 31 is set to be equal to the logical output of the judging device 28, the switching device 31 is forcibly forced by the logical output of the judging device 28. It can be operated to shift to the self-diagnosis mode, and the output of the signal as the abnormality detection state can be continuously maintained at the terminal 29 until the external self-diagnosis reset signal is applied.

Here, an actual example for knowing the operating state of the sensor using the monitor signal has been described, but the same circuit configuration enables the offset adjustment of the sensor output.
At this time, the attenuation amount may be adjusted by the attenuator 32 or the phase shift amount may be adjusted by the injector 30 to perform a desired offset adjustment. If the attenuation amount and the phase shift are changed by the temperature using the temperature sensitive element, the temperature of the sensor output can be corrected.

The same applies when the output of the injector 30 is added to the bandpass filter 21 and the synchronous detector 22.

[0019]

As described above, according to the present invention , the vibration part and the angular velocity are
A sensor element having a detection unit for detecting, and the sensor element
The driver circuit that supplies a drive signal to the vibration part of the child
Monitor circuit to which the monitor signal from the sensor element is added.
The output of the monitor circuit via the AGC circuit.
Vibration of the sensor element when applied to the driver circuit
Drive means for stably driving and vibrating the part, and the sensor element.
A charge amplifier to which the output from the child detector is added
The output of the charge amplifier via the bandpass filter
And a bandpass filter including:
Data output in synchronization with the drive signal from the drive means.
Detecting means for outputting an angular velocity signal and driving of the driving means.
A signal synchronized with the motion signal is detected by the synchronization detection which constitutes the detection means.
Abnormality of the above-mentioned sensor element by adding in the previous stage from the wave
A self-diagnosis means for detecting and outputting a self-diagnosis signal;
Switch the self-diagnosis means to the operating / non-operating state
The switching means and the detecting means during the non-operation of the self-diagnosis.
Detects the signal level and always judges the abnormality of the sensor element
And a determination means as the determination means.
Switching logic of the switch as the switching means for the physical output
With the input terminal of the drive signal of the switch so that the value is reversed
The decision unit is electrically coupled to the output terminal of the decision unit.
Configured so that the switch does not malfunction due to the logical output of
Therefore, the abnormality is always detected from outside the sensor.
Not only can Ukoto, when there is a cross-sectional signal only from the outside
In addition, it is possible to realize a highly reliable angular velocity sensor capable of detecting a failure .

[Brief description of drawings]

FIG. 1 is a circuit block diagram showing an embodiment of an angular velocity sensor of the present invention.

FIG. 2 is a circuit diagram showing a circuit configuration of a main part of the sensor .

FIG. 3 is an operation waveform diagram of each part of the sensor .

[Explanation of symbols]

11,12 Drive plate 11a, 12a, 13a, 14a Piezoelectric element 13,14 Detection plate 15 Driver circuit 16 Current amplifier 17,21 bandpass filter 18 full wave rectifier 19 AGC circuit 20 charge amplifier 22 Synchronous detector 23 Low-pass filter 30 injectors 31 switch 32 attenuator

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-3-226620 (JP, A) JP-A-6-207946 (JP, A) JP-A-4-215017 (JP, A) JP-A-7- 77538 (JP, A) European patent application publication 702207 (EP, A 1) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01C 19/56 G01P 9/04

Claims (2)

(57) [Claims] 1. A sensor element having a vibrating section and a detecting section for detecting an angular velocity, a driver circuit for supplying a drive signal to the vibrating section of the sensor element, and a monitor circuit to which a monitor signal from the sensor element is added. A driving means for stably driving and vibrating the vibrating portion of the sensor element by applying the output of the monitor circuit to the driver circuit via the AGC circuit, and the charge to which the output from the detecting portion of the sensor element is added. A detection unit that includes an amplifier and a synchronous detector to which the output of the charge amplifier is added via a bandpass filter, and detects the output of the bandpass filter in synchronization with the drive signal from the drive unit to output an angular velocity signal. And a signal synchronized with the drive signal of the drive means is added to the stage before the synchronous detector constituting the detection means. Self diagnosis means for detecting an abnormality of the service element and outputs the self-diagnosis signal, and operation of the self-diagnosis unit
Switching means for switching to a non-operating state, and
Before detecting the signal level of the detection means during the non-operation of diagnosis
And a determination means for constantly determining abnormality of the sensor element,
The switching of the logical output of the judging device as the judging means is performed.
Before switching the switching logic value of the switch as a replacement means
The input terminal of the drive signal of the switch and the output terminal of the judgment device
And are electrically coupled, and the logical output of the judging device
An angular velocity sensor configured to prevent the switch from malfunctioning . 2. A vibration unit and a detection unit for detecting angular velocity are provided.
Drive signal to the sensor element and the vibration part of the sensor element.
Driver circuit for supplying power and monitor from the sensor element
A monitor circuit to which a signal is applied, the monitor circuit
Output of the above is added to the driver circuit through the AGC circuit.
By virtue of this, the vibration part of the sensor element is stably driven and vibrates.
Driving means for driving and output from the detection part of the sensor element
Is added to the charge amplifier and the output of this charge amplifier.
Synchronous detector with force applied via bandpass filter
The output of the bandpass filter including the
The angular velocity signal is output in synchronization with the drive signal from the stage.
Detection means and a signal synchronized with the drive signal of the drive means
Is added before the synchronous detector that constitutes the detection means.
By detecting the abnormality of the sensor element, the self-diagnosis signal
And self-diagnosis means for outputting
Switching means for switching to a non-operating state, and
Before detecting the signal level of the detection means during the non-operation of diagnosis
And a determination means for constantly determining abnormality of the sensor element,
The switching of the logical output of the judging device as the judging means is performed.
To make the switching logic values of switches as replacement means equal
Input terminal of the drive signal of the switch and output terminal of the determiner
It is electrically coupled to the child and
Switch to the self-diagnosis mode by forcibly operating the switch.
Angular velocity sensor configured to .