JPH0560562A - Vibrating gyroscope - Google Patents

Abstract

PURPOSE:To provide a vibrating gyroscope in which the relation in phase between the output voltage of a driving piezoelectric element and a driving AC voltage is stabilzed so that sensitivity toward angular velocities is stablized by feeding back the output voltage of the driving piezoelectric element itself. CONSTITUTION:A vibrator 5 comprises piezoelectric elements 9, 10 stuck to at least two adjacent side faces of a vibrator 1 having a polygonal cross section. The two fixed terminals of a variable resistor 6 are connected to the piezoelectric elements 9, 10 stuck to adjacent side faces of the vibrator 1 and are used as terminals for feedback and for detection and the movable terminal of the variable resistor 6 is used as a drive terminal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibrating gyro, and more particularly to a non-rotating mechanical vibrating gyro for detecting angular velocity.

[0002]

2. Description of the Related Art Conventionally, this type of vibrating gyro is a mechanical vibrating gyro that does not have a rotating element peculiar to the gyro, for example, there is one shown in FIG. That is, this vibrating gyro includes a vibrator 5 in which driving piezoelectric elements 2 and 3 and a returning piezoelectric element 4 are attached to three side surfaces of a vibrating body 1 having a triangular cross section. Both fixed terminals of the variable resistor 6 are connected to the driving piezoelectric elements 2 and 3, and the driving AC voltage is applied to the movable terminal of the variable resistor 6 from the driving circuit 7 and the output voltage of the feedback piezoelectric element 4 is applied. Drive circuit 7
To generate a self-excited vibration by keeping the phase relationship between the driving AC voltage and the output voltage of the feedback piezoelectric element 4 constant.

When the vibrator 5 rotates itself during vibration, a Coriolis force is generated in a direction orthogonal to both the vibration direction and the rotation direction. Therefore, this force is displaced, strained or changed in capacitance. The rotational angular velocity can be measured by detecting as.

Therefore, when the Coriolis force is generated,
Since a voltage difference is generated between the driving piezoelectric elements 2 and 3,
The angular velocity can be measured by means such as connecting the voltages of the driving piezoelectric elements 2 and 3 to the detection circuit 8 and making a differential, and there is a difference in the electrostatic capacitance values of the driving piezoelectric elements 2 and 3. In this case, and when there is a difference in the resonance frequency in the directions orthogonal to the two side surfaces of the vibrator 1 to which the piezoelectric elements 2 and 3 for driving are attached, the voltage between the piezoelectric elements 2 and 3 for driving is different. Since a phase shift occurs and it becomes difficult to measure the angular velocity accurately, the resistance value connected to the driving piezoelectric elements 2 and 3 is adjusted by the variable resistor 6 so that the output voltages have the same phase. is doing.

[0005]

However, in the vibrating gyroscope having the above-mentioned structure, the piezoelectric element 4 for feedback is composed of another piezoelectric element independent of the piezoelectric elements 2 and 3 for driving. When a difference occurs in the impedance change of each piezoelectric element 2 and 3 due to a change or the like, the phase relationship between the driving AC voltage and the output voltage of the feedback piezoelectric element 4 changes, and the condition of the self-excited vibration of the vibrator 5 is changed. However, there is a defect that the sensitivity to angular velocity changes. Also, since it is necessary to attach at least three piezoelectric elements,
Assembly work is troublesome.

An object of the present invention is to feed back the output voltage of the driving piezoelectric element itself so that the output voltage of the piezoelectric element and the driving AC voltage are different from each other even if a difference in impedance change of the piezoelectric element occurs due to a temperature change or the like. It is an object of the present invention to provide a vibration gyro of the type described above, which stabilizes the phase relationship and the sensitivity to angular velocity.

Another object of the present invention is to provide a vibrating gyro of the above-mentioned type in which a vibrating body is constituted by a vibrator with a minimum of two piezoelectric elements and the assembly process can be simplified. is there.

[0008]

In a vibrating gyroscope according to the present invention, a piezoelectric element is attached to at least two adjacent side surfaces of a vibrating body having a polygonal cross section to form a vibrating body. The two fixed terminals of the variable resistor are respectively connected to the piezoelectric elements attached to the adjacent side surfaces of the variable resistor, and the two fixed terminals of the variable resistor are used as the feedback and detection terminals.
The movable terminal of this variable resistor is used as a driving terminal.

In another vibrating gyroscope according to the present invention, a piezoelectric element is attached to at least two non-parallel side surfaces of a vibrating body having a polygonal cross section to form a vibrating element, and the vibrating elements are parallel to each other. Common to a set of piezoelectric elements attached to different side surfaces, one end of two fixed terminals of the variable resistor is connected, and the other end of these fixed terminals is not parallel to the parallel side surfaces, but is parallel to each other. Connected in common to a set of piezoelectric elements attached to the variable resistor, the movable terminal of the variable resistor is used as a driving terminal, and the two fixed terminals of the variable resistor are used as feedback and detection terminals. It is characterized by.

[0010]

In the present invention, the vibrating body 1 having a polygonal transverse cross section, for example, a triangle or a quadrangle, has at least two adjacent vibrating bodies 1.
The piezoelectric elements 9 and 10 are attached to the side surfaces to form the vibrator 5, and the two fixed terminals of the variable resistor 6 are attached to the piezoelectric elements 9 and 10 attached to the adjacent side surfaces of the vibrating body 1. The variable resistors 6 are connected to each other, and the two fixed terminals of the variable resistor 6 are used as feedback and detection terminals, and the movable terminal of the variable resistor 6 is used as a driving terminal.

Further, in the present invention, the piezoelectric element (9, 10; 13, 14) is attached to at least two non-parallel side surfaces of the vibrating body 1 having a polygonal cross section to form the vibrator 5, One end of two fixed terminals of the variable resistor is connected in common to the set of piezoelectric elements (9, 13) attached to the parallel side surfaces of the vibrating body 1, and the other end of the fixed terminals is connected to the parallel side. Although not parallel to the side surface, they are commonly connected to a set of piezoelectric elements (10, 14) attached to the other side surfaces that are parallel to each other, and the movable terminal of the variable resistor 6 is used as a driving terminal, Two fixed terminals of the variable resistor are used as a feedback terminal and a detection terminal.

According to the vibrating gyroscope of the present invention constructed as described above, the output voltage itself of the piezoelectric elements (9, 10, 13, 14) whose phases are matched by adjusting the variable resistor 6 is used for feedback and Since it is used for detection, it is possible to realize self-excited vibration in which the phase relationship between the driving AC voltage and the voltage to be fed back is kept constant, and it is possible to suppress the change in sensitivity with respect to the angular velocity due to temperature change.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an embodiment of a vibrating gyroscope according to the present invention. In the figure, the same parts as those described in the prior art shown in FIG. 4 are designated by the same reference numerals. The piezoelectric element 9 is attached to the side surface of the vibrating body 1 having a quadrangular cross section, and the piezoelectric element 10 is further attached to the side surface adjacent thereto to form the vibrator 5. Both fixed terminals of the variable resistor 6 are connected to the piezoelectric elements 9 and 10, and a driving AC voltage is applied from the drive circuit 11 to the movable terminal of the variable resistor 6. And
The output voltage at the connection between the piezoelectric elements 9 and 10 and both fixed terminals of the variable resistor 6 is fed back to the drive circuit 11 to keep the phase relationship between the drive AC voltage and the output voltage constant and self-excited. Try to generate vibration. At this time, the movable terminal of the variable resistor 6 is adjusted so that the phases of the two output voltages match. Further, the output voltage at the connection between the piezoelectric elements 9 and 10 and both fixed terminals of the variable resistor 6 is supplied to the detection circuit 12, and the difference between the output voltages is measured as the angular velocity.

Next, another example of the vibrating gyroscope according to the present invention is shown in FIG. This example is different from the example shown in FIG. 1 in the following points. That is, the piezoelectric element 9 is attached to the side surface of the vibrating body 1 having a quadrangular cross-sectional shape, the piezoelectric element 13 is attached to the side surface parallel to the same, and further to the side surface adjacent to and not parallel to these piezoelectric elements. The piezoelectric element 10 is attached, and the piezoelectric element 14 is attached to the side surface parallel to the piezoelectric element 10 to form the vibrator 5. The other points are the same as those shown in FIG. That is, one end of the fixed terminal of the variable resistor 6 is connected to the piezoelectric element 9 and
13 and the other ends of the fixed terminals are connected to the piezoelectric elements 10 and 14, respectively, and self-excited vibration is generated as in the example shown in FIG. 1, whereby the angular velocity is detected.

Still another example of the vibrating gyroscope according to the present invention is shown in FIG. In this example, the piezoelectric elements 9 and 10 are attached to the side surfaces of the vibrating body 1 having a triangular cross-sectional shape adjacent to each other as in the example shown in FIG. 1, and both the variable resistors 6 are fixed to these piezoelectric elements. The terminals are connected, and a driving AC voltage is supplied to the variable terminals from the driving circuit 11 to cause the vibrator 5 to self-oscillate, thereby detecting the angular velocity. As described above, this example is exactly the same as the example shown in FIG. 1 except that the cross-sectional shape of the vibrating body 1 is different, and therefore a detailed description thereof will be omitted.

[0016]

According to the present invention having the above-mentioned structure, the output voltage of the driving piezoelectric element itself is fed back even if the impedance change of the piezoelectric element is changed due to temperature change or the like. The phase relationship of is stable,
The sensitivity to angular velocity can be significantly stabilized. Further, since the vibrator can be constituted by at least two piezoelectric elements for the vibrating body, the assembling process can be simplified. Further, when the number of piezoelectric elements to be attached is increased, all the piezoelectric elements can be driven, so that the amplitude of vibration is increased and the detection sensitivity can be improved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration of an embodiment of a vibrating gyroscope of the present invention.

FIG. 2 is an explanatory diagram showing the configuration of another embodiment of the vibration gyro of the present invention.

FIG. 3 is an explanatory view showing the constitution of still another embodiment of the vibration gyro of the present invention.

FIG. 4 is an explanatory diagram showing an example of a conventional vibrating gyro.

[Explanation of symbols]

 1 Vibrating body 2, 3 Driving piezoelectric element 4 Feedback piezoelectric element 5 Transducer 6 Variable resistor 7 Driving circuit 8 Detection circuit 9, 10, 13, 14 Piezoelectric element 11 Driving circuit 12 Detection circuit

Claims (2)

[Claims] 1. A vibrator is constructed by attaching piezoelectric elements to at least two adjacent side surfaces of a vibrating body having a polygonal cross section, and the piezoelectric element is attached to each of the adjacent side surfaces of the vibrating body. Two fixed terminals of the resistor are respectively connected, the two fixed terminals of the variable resistor are used as feedback and detection terminals, and the movable terminal of the variable resistor is used as a driving terminal. A vibrating gyro. 2. A vibrating body having a polygonal transverse cross section, wherein piezoelectric elements are attached to at least two non-parallel side surfaces of the vibrating body to form a vibrator, and a set of piezoelectric elements attached to the respective parallel side surfaces of the vibrating body. Is connected to one end of two fixed terminals of the variable resistor, and the other end of the fixed terminal is not parallel to the parallel side surfaces, but is connected to a pair of piezoelectric elements attached to the parallel side surfaces. A vibrating gyro, which is connected in common, wherein a movable terminal of the variable resistor is used as a driving terminal and two fixed terminals of the variable resistor are used as a feedback terminal and a detection terminal.