JPH03123813A - Angular speed detecting device - Google Patents

Abstract

PURPOSE:To accurately detect an angular speed even when a travel state continues for a long time by stopping a sensor driving part at specific intervals of timing, inputting angular speed information when the sensor driving part is in the stop state as angular speed correction data, and correcting the angular speed. CONSTITUTION:The angular speed detecting device 10 drives a gyro-sensor 2 according to a driving signal outputted by the sensor driving part 1 to detect the angular speed. Then a sensor driving part stopping means (a) stops the driving part 1 at specific intervals of timing. A correction data fetch means (b) inputs the angular speed information when the driving part 1 is in the stop state as the angular speed correction data. Further, a correcting means (c) corrects the angular speed according to the angular speed correction data. Therefore, even when the travel state continues for a long time, the angular speed can accurately be detected.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an angular velocity detection device.

(Prior art) As a conventional angular velocity detection device, for example, Japanese Patent Application Laid-Open No. 55-1
A method described in Publication No. 5505 is known, in which when a measurement error occurs due to drift while the vehicle is running, the angular velocity when the vehicle is stopped, when no angular velocity should be generated, is detected, and this angular velocity data is used to transfer the angular velocity data to the device at that time. This was used as correction data for subsequent drift correction.

(Problem to be Solved by the Invention) However, in the conventional device as described above, correction data is obtained only when the vehicle is stopped, so if the vehicle runs for a long time without stopping, the correction data is not available. There was a problem in that the angular velocity could not be detected with high precision during that time.

This invention was made in view of the above-mentioned problems.
It is an object of the present invention to provide an angular velocity detection device that can calculate a drift correction value at fixed timings even while a vehicle is running, and can always detect angular velocity with high accuracy.

(Means for Solving the Problems) In order to solve the above problems, the present invention is configured as shown in FIG. Gyro sensor 2
drive and detect the angular velocity.

The sensor drive unit stopping means a stops the sensor drive unit 1 at every predetermined timing.

In addition, the correction data importing means also includes the sensor drive unit 1.
Angular velocity information when the is in a stopped state is taken in as angular velocity correction data.

Furthermore, the correction means C corrects the angular velocity based on the angular velocity correction data.

(Function) Based on the above-mentioned means, the sensor drive section is stopped every predetermined period of time, and the angular velocity information when the sensor drive section is in the stopped state is captured as angular velocity correction data, and this correction data Since the angular velocity correction coefficient is calculated based on , the angular velocity is automatically corrected at each predetermined timing.

(Explanation of Examples) Embodiments of the present invention will be described below based on the drawings.

FIG. 2 is an overall configuration diagram of an embodiment to which the present invention is applied, in which the angular velocity detection device 10 is mounted on a vehicle and used to detect the traveling direction for route guidance of the vehicle, etc.

In the figure, reference numeral 1 denotes a sensor drive unit that turns on an oscillator 11 that outputs a predetermined frequency signal and the output of the oscillator 11;
It includes a switch 12 that turns off.

Further, reference numeral 2 denotes a vibration type gyro sensor for detecting angular velocity, and a drive element 13.1 consisting of a pair of piezoelectric bimorphs is driven by the oscillator 11 when the switch 12 is in the ON state.
3, and the same (composed of a pair of sensing elements 14, 14 made of piezoelectric bimorphs).

Furthermore, 3 is an amplifier that amplifies the output of the detection element 14.14.

4 is a signal processing section, which is composed of a synchronous detection circuit 15 and an amplifier 16 into which the sensor signal amplified by the amplifier 3 and the oscillation signal of the oscillator 11 are input; It is configured so that it can detect the angular velocity that is generated.

On the other hand, 5 receives the output of the signal processing unit 4, and
This calculation unit 5 outputs ON/OFF signals for the switch 12, and calculates an angular velocity correction coefficient as described later.

The gyro sensor 2 used in this embodiment is a vibrating gyro sensor called a piezo gyro that uses mechanical vibration of a piezoelectric body, and the oscillator 11 drives the drive elements 13 and 13, thereby causing the detection element 1
4.14 is vibrated and, for example, when an angular velocity in the direction of arrow W is applied to the gyro sensor 2, a Coriolis force in the A direction is generated within the sensor, so the two sensing elements 14.14 are also bent in the A direction. As a result, an electrical signal proportional to the angular velocity W is output. In addition,
The configuration of the gyro sensor 2 itself is not related to the gist of this embodiment, so it will not be described in further detail.

Incidentally, when the switch 12 is in the ON state and the sensor drive unit 1 is sending a drive signal to the gyro sensor 2, drift occurs in the following parts of the entire device.

In other words, if we list these in descending order of drift amount,
It is as follows.

(1) A signal detection circuit section including both the amplifier 3 and the signal processing section 4.

(2) A piezoelectric system portion including a driving element 13.13 and a sensing element 14.14, which are electrical components within the gyro sensor 2.

(3) Mechanical components of the gyro sensor 2 main body.

Therefore, in order to eliminate the influence of drift, the above (1),
It would be sufficient to eliminate the influence of drift occurring in each part of (2) and (3), but since the gyro sensor 2 is not driven when the sensor drive section 1 is stopped, - (1) above and ( Only the amount of drift occurring in part 2) is output.

Therefore, every predetermined period of time (or every time after traveling a predetermined distance)
By turning off the switch 12, the sensor drive unit 1 is stopped at regular intervals, and the amount of drift occurring in the above portions (1) and (2) where the amount of drift is relatively large is detected, and the drift in this case is detected. This embodiment attempts to minimize the influence of drift and detect the angular velocity with high accuracy by using the amount as a correction coefficient.

Hereinafter, the angular velocity detection processing procedure executed by the calculation unit 5 will be explained as follows.
This will be explained based on the flowchart shown in the figure.

When the program is started in the figure, first, initial settings are performed to set various constants used in subsequent processing and to reset a correction timing counter to be described later (step 100).

By the way, as already mentioned, in this embodiment, the calculation of the angular velocity correction coefficient is performed every predetermined period of time, regardless of whether the vehicle is running or stopped.

Therefore, in the subsequent step 110, it is checked whether the next correction time has arrived, but since the correction timing counter is initially reset to 0, the process proceeds to step 120.

Then, in step 120, the uncorrected angular velocity data output from the signal processing section 4 is taken in.

Next, the process proceeds to step 130, where the data captured in step 120 is corrected using the latest correction coefficient calculated up to that point.

In this case, the correction will be performed using the following equation (4).

Corrected angular velocity = corrected surface angular velocity - correction coefficient (4) Next, the process proceeds to step 140, where the corrected data is output as angular velocity data. Then, in the subsequent step 150, the correction timing counter is counted up by 1, and the process returns to step 110 again.

If it is determined in step 110 that the correction period has arrived (YES in step 110), the process proceeds to step 160,
It is checked whether the corrected data value obtained in the process of step 140 during the previous process is less than or equal to the specified value α1.

Here, if α0 or more (NO in step 160),
Considering that the angle is in the middle of a rapid change, the process returns to step 120 to continue measurement.

On the other hand, if it is determined that it is within α1, (Y in step 160
ES), a correction coefficient calculation process is performed below, and first, in step 170, initial processing for correction coefficient calculation is performed.

That is, the switch 12 is turned off to stop the drive signal output from the sensor drive section 1, and further the correction data counter is reset.

Next, the process proceeds to step 180, where the correction data is set to a specified number α
It can be checked whether only 2 have been collected.

In this case, since the predetermined number α2 has not been reached at first, the process proceeds to step 190, and correction data is fetched from the signal processing section 4.

By the way, during normal output when the switch 12 is in the ON state,
Since the sensor drive unit number is output from the sensor drive unit 1 to the gyro sensor 2, the output of the signal processing unit 4 includes the above-mentioned (1), (
The drift part that occurs in parts 2) and (3) is included.

On the other hand, in the data captured in the process of step 190, the switch 12 is turned OFF and the output of the drive signal from the sensor drive section 1 to the gyro sensor 2 is stopped, so the output of the signal processing section 4 is the original one. Angular velocity and above (
The drift generated in the portion 3) is excluded, and only the drift generated in the portions (1) and (2) above, where the amount of drift is relatively large, is included.

Therefore, the following processing is performed using the drift amount taken in in the process of step 190 as correction data for calculating the correction coefficient.

In the process of step 200, step 19
Stores the data captured in process 0.

Next, the process proceeds to step 210, increments the correction data counter by one, and returns to step 180 again.

If it is determined in the process of step 180 that the number of correction data exceeds the specified number α2 (YES in step 180), the process proceeds to step 220 and the switch 12 is turned on because the data for calculating the correction data has been collected. Turn it on and start outputting the drive signal again.

Next, the process proceeds to step 230 and subsequent steps, and a correction coefficient calculation process is performed based on the correction data collected up to that point. First, in step 230, the correction data stored in the process of step 200 is changed from the maximum value to the minimum value. , and remove a specified number of β1 pieces of data from the largest value to the smallest value, and remove a specified number of β4 pieces of data from the smallest value to the largest value. Then, the remaining data is selected as data to be used for calculating the correction coefficient. Therefore, for example step 2
If β correction data are stored in the process of 00, (β−2β1) correction data will be selected.

Next, the process proceeds to step 240, and the correction data value selected in the process of step 230 is added.

Then, in step 250, the total value added in the process of step 240 is divided by the number of selected data pieces, and the resulting value is used as a correction coefficient.

Next, the process advances to step 260, where the correction timing counter is reset, and the process returns to step 110 again.

Thereafter, a new correction coefficient will be calculated every predetermined period of time regardless of whether the vehicle is running or stopped.

As explained above, in this embodiment, when calculating the correction coefficient, first, the sensor drive unit 1 is set to a stopped state, and the output value when the gyro sensor 2 is not driven is used as correction data due to drift. Detected as. In this case, the signal detection circuit system including the amplifier 3 and the signal processing section 4, the drive element 13.13, and the detection element 14.1
This means that the amount of drift of the piezoelectric system portion No. 4 is detected as correction data. On the other hand, during normal output, in addition to the above drift, drift due to the mechanical components of the gyro sensor 2 body is also included, but compared to the amount of drift in the signal detection circuit system and piezoelectric system, the amount of drift is much greater. It's small. Therefore, the output value when the sensor drive unit 1 is in a stopped state is used as the drift correction data of this device, and this correction data is processed according to a predetermined processing procedure to be used as a correction coefficient.

Therefore, in this embodiment, it is possible to automatically calculate the correction coefficient by bringing the sensor drive unit 1 into a stopped state every predetermined time period, regardless of whether the vehicle is running or stopped. Therefore, angular velocity can be detected with much higher accuracy than conventional devices of this type.

(Effects of the Invention) As described above, the angular velocity detection device according to the present invention stops the sensor drive unit at predetermined timings to distinguish between a vehicle running and a stop, and furthermore, the sensor drive unit stops. Since the angular velocity information in the current state is captured as angular velocity correction data and the angular velocity is corrected based on this correction data, the angular velocity can always be detected accurately even when the vehicle has been running for a long time. has.

[Brief explanation of drawings]

FIG. 1 is a claim correspondence diagram of the present invention, FIG. 2 is an overall configuration diagram of an embodiment device to which the present invention is applied, and FIG. 3 is a flowchart showing the processing procedure of the embodiment device to which the present invention is applied. . 1...Sensor drive unit 2...Gyro sensor 3...Amplifier 4...Signal processing unit 5...Calculation unit 10... ... Angular velocity detection device 11 ... Oscillator 12 ... Switch 13 ... Drive element 14 ... Detection element 15 ... Synchronous detection circuit 16...Amplifier

Claims (1)

[Claims] 1. In an angular velocity detection device that detects angular velocity by driving a gyro sensor based on a drive signal output from a sensor drive unit, the sensor drive unit stops the sensor drive unit at every predetermined timing. A stop means; a correction data import means for taking in angular velocity information when the sensor drive unit is in a stopped state as angular velocity correction data; and a correction means for correcting the angular velocity based on the angular velocity correction data. Angular velocity detection device.