JPH02187622A - Vehicle - Google Patents

Abstract

PURPOSE:To reduce an influence of oscillation of a vehicle upon the Coriolis force detection output of a gyro and to stabilize this output by setting the oscillation frequency of the oscillatory gyro mounted on the vehicle to a value higher than the frequency of oscillation generated during stop and running. CONSTITUTION:When a current flows to driving piezoelectric elements 4, vibrating reeds 3 of an oscillator 2 are oscillated in the Y direction. When an angular speed around the Z axis is applied to an oscillatory gyro 1 by curvilinear motion of the vehicle, the Coriolis force in the direction X orthogonal to the oscillation direction Y is generated to bend vibrating reeds 3 in the X direction. This bend is detected by detecting piezoelectric elements 5, and the applied angular speed is detected by the Coriolis force detection output. Though oscillation of the vehicle is transmitted from a supporting shaft 6, an influence upon the Coriolis force detection output is reduced to obtain the stable output because the resonance frequency of the oscillator 2 is sufficiently high. There is not a fear that the amplitude is increased by the resonance of the oscillator 2 to break the gyro 1.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to vehicles such as automobiles.

[Prior art] A vibrating gyroscope vibrates the vibrator at its resonant frequency by driving a piezoelectric element attached to the vibrator, and applies the Coriolis force generated when angular velocity is applied to the vibrator to the vibrator. It detects the deformation that occurs and detects the applied angular velocity, but in conventional vibrating gyroscopes, the resonant frequency of the vibrator was set as low as, for example, 600 Hz in order to generate a large Coriolis force. .

[Problems to be Solved by the Invention] By the way, it is conceivable that a vibrating gyroscope could be installed in a car to detect and detect the angular velocity during driving, and be used to detect the trajectory of the car by calculating the integral. When a vibrating gyroscope is installed in a car, the vibration of the car causes the entire vibrating gyroscope to vibrate, and the vibration of the vibrating gyroscope as a whole affects the vibration of the vibrator, which in turn affects the Coriolis detection output, making the output unstable. There is a problem with becoming.

The present invention has been made in view of the above circumstances, and an object of the present invention is to prevent the output of the vibrating gyroscope from being affected by vibrations of the vehicle when the vibrating gyroscope is mounted on a vehicle.

[Means for Solving the Problems] The present invention, which solves the above problems, is equipped with a vibrating gyroscope, and sets the resonant frequency of the vibrator of the vibrating gyroscope to be higher than the frequency of vibrations generated when the vehicle is stopped and running. This vehicle is characterized by:

[Operation] Since the resonant frequency of the vibrator is higher than the frequency of vibrations generated when the vehicle is stopped and running, the vibrations of the vehicle have little effect on the vibrations of the vibrator. Therefore, the influence of vehicle vibration on the Coriolis detection output of the mounted vibration gyroscope is small, and a stable Coriolis detection output can be obtained.

Furthermore, there is no fear that the vibrator will resonate with the vibrations of the vehicle and the amplitude of the vibrations will increase significantly, causing damage to the vibrating gyroscope.

[Example] FIG. 1 shows a vibrating gyroscope 1 in a perspective view. Although not shown, this vibrating gyroscope 1 is mounted on a vehicle such as an automobile. To explain the details of this vibrating gyroscope 1, drive piezoelectric elements 4 are pasted on the front and back sides of the four vibrating pieces 3 of the H-shaped vibrator 2 in the X direction, respectively, and the thin plate-shaped portion on the tip side of each vibrating piece 3 is In this structure, a detection piezoelectric element 5 is attached to each outer surface in the X direction, and the vibrator 2 is supported by a support shaft 6 that is fixed and passes through the center of gravity of the vibrator 2 in the X direction. Support shaft 6
Both ends are fixed to a case (not shown) or the like, and the case is attached to an appropriate location of a vehicle (not shown).

In the present invention, the resonant frequency of the vibrator 2 is set to be sufficiently higher than the frequency of vibrations generated when the automobile is stopped and running. The frequency of vibration during normal driving of a car is 200H.
z, and under rough road conditions such as gravel roads, it exists up to about 800 Hz, although it is very small. Therefore, it is sufficient that the resonant frequency of the vibrator is a certain distance from about 8.800 Hz, but it is preferable to set it to a sufficiently high frequency, such as 7000 Hz, which is far away.

The operation of the vibrating gyroscope 1 will be explained. When a driving current is applied to the driving piezoelectric element 4, each vibrating piece 3 of the vibrator 2 vibrates back and forth in the X direction. When an angular velocity around the Z-axis is applied to the vibrating gyro 1, that is, the vibrator 2, as a result of a car driving around a curved part of the road, the angular velocity around the Z-axis is applied to the vibration direction of the drive (X direction) and the direction (X direction) A Coriolis force is generated, the vibrating element 3 is deflected in the X direction by this Coriolis force, and the detection piezoelectric element 5 detects this deflection to detect the Coriolis force.
The angular velocity added from the output of the Coriolis detection is detected.

In the Coriolis detection operation described above, when the vehicle vibrates, the vibration of the vehicle is transmitted via the support shaft 6, but the resonance frequency of the vibrator 2 is sufficiently higher than the frequency of vibrations that occur when the vehicle is stopped and running. Therefore, the vibration of the vehicle has little influence on the vibration of the vibrator 2. Therefore, the influence of vehicle vibration on the Coriolis detection output of the mounted vibrating gyroscope 1 is small, and a stable Coriolis detection output can be obtained.

Furthermore, there is no fear that the vibrator 2 will resonate with the vibrations of the vehicle, the amplitude of the vibrations will increase significantly, and the vibrating gyroscope 1 will be damaged.

Although the embodiment is applied to a vibrating gyroscope having an H-shaped vibrator, the present invention is not limited thereto, and can of course be applied to a vibrating gyroscope having a tuning fork-shaped or vibrating piece-shaped vibrator.

The present invention, configured as described above, has the following effects.

The resonant frequency of the vibrator of the mounted vibrating gyroscope is higher than the frequency of vibrations that occur when the vehicle is stopped and running, so vehicle vibration has little effect on the vibration of the vibrator. A stable Coriolis detection output is obtained.

Furthermore, there is no fear that the vibrator will resonate with the vibrations of the vehicle and the amplitude of the vibrations will increase significantly, causing damage to the vibrating gyroscope.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of a vibrating gyroscope mounted on a vehicle. DESCRIPTION OF SYMBOLS 1... Vibrating gyro, 2... Vibrator, 4... Piezoelectric element for drive, 5 Piezoelectric element for detection, 6... Support shaft. Applicant: NEC Home Electronics Co., Ltd. [Effects of the invention]

Claims (1)

[Claims] A vehicle is equipped with a vibrating gyroscope, and the resonant frequency of the vibrator of the vibrating gyroscope is set higher than the frequency of vibrations generated when the vehicle is stopped and running.