JPS62257014A - Angular velocity sensor - Google Patents

Abstract

PURPOSE:To enhance detection accuracy, by constituting an angular velocity sensor so that one axis of an elastomer is compressed and stretched to generate linear reciprocating motion in the direction crossing the other axis thereof at a right angle. CONSTITUTION:The detection pieces 24, 25 on a Y-axis performs linear reciptocating motion by stretching and compressing a spring 21 in the direction (Y-axis direction) crossing the compressing and stretching direction (X-axis direction) of the spring 21 at a right angle and, therefore, the force applied to the leading ends of the detection pieces 24, 25 in a velocity direction is limited only to the direction crossing a rotary shaft at a right angle and the electric signals outputted from piezoelectric elements 26, 27 for detection become proportional to Corioli's force incurring no error. Therefore, by increasing only the speeds of the leading ends of the detection pieces 24, 25, the detection accuracy of angular velocity is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Applications> The present invention relates to an angular velocity sensor with improved detection accuracy.

(Conventional technology and its problems) As a conventional angular velocity sensor,
1C) There are some as described in the Q publication. Third
To explain with the drawings, two driving piezoelectric elements 1a, 1b arranged facing each other, and each driving piezoelectric element 1a, I
One end 3a, 3b in the longitudinal direction of b is fixed, and the other end 4a, 4
Detection pressure Ifi elements 2a and 2b are fixed at right angles to drive pressure Ifi elements 1a and Ib. Distortion occurs in the driving piezoelectric elements 1a and 1b due to an electric signal applied from the outside. Utilizing this property, when an AC signal is applied, the driving piezoelectric element 18.1b generates vibration. When vibration occurs, when the angular velocity changes around the longitudinal axis of each piezoelectric element, that is, around the l-axis, the detection piezoelectric elements 2a and 2b generate a Coriolis wave proportional to the angular velocity in a direction perpendicular to the rotation axis and the vibration direction. Force acts. This Rioli force causes distortion in the detection piezoelectric elements 2a and 2b, and electric charge t3 is detected as a change in charge.

However, in such a conventional angular velocity sensor, in order to improve the sensitivity of the detection piezoelectric elements 2*, 2b, a relatively good T [spinners 2a, 2b are used, and the drive piezoelectric element 1a is , 1b with one end 3a, 3b as the fulcrum) Since it connects to the end and A, when electric signal 0 is applied, the ends 1, 1 of the detection 1 mo electric cable 2a, 2b, straight t1 Not backward movement, driving JIl: -vA3 of electric elements 1a, 1b
8.3beQ point Toshi performs circular arc-like reciprocating motion. Due to the speed of vibration, the direction of the force applied to the tip of the detection piezoelectric element deviates from the direction perpendicular to the rotating X-axis, and force is applied in the X-axis direction in addition to the direction perpendicular to lf.
Since it is combined with the Coriolis force, there is a problem that detection accuracy deteriorates.

(Object of the Invention) An object of the present invention is to solve these conventional problems and provide an angular velocity sensor with improved accuracy.

(Structure of the Invention) The angular velocity hinge of the present invention includes an elastic body, a vibrator that compresses and stretches the elastic body along one axial direction, and an axial direction perpendicular to the stretching and compression direction of the elastic body. In addition, it was constructed with a stress detector that moves back and forth in a linear manner.

(Examples shown in ') Below, the present invention will be explained with reference to the drawings. Fig. 1 shows the following:
FIG. 1 is a diagram showing an embodiment of the present invention. First, the configuration will be described. Reference numeral 21 denotes a spring as an elliptical elastic body. The short axis direction of the ellipse is the X axis, and the long axis direction perpendicular to the short axis is the Y axis. Reference numerals 22 and 23 designate electromagnetic actuators that are placed between the spring 21 on the X-axis and compress and expand the spring 21 on the X-axis 1. is spring 2101
F contraction and extension are synchronized. 30.31 is the base of the electromagnetic actuator 22.23. The stress detector consists of a detection piece 24, 25 and an ffm element 26.27.

24.25 is a rectangular parallelepiped detection 11 that is integrated with the C spring 21 and extends in the Y-axis direction outside the spring 21 at two locations on the Y-axis of the spring 21, and its detection J+2
A piezoelectric element 26, 27 is glued to 4.251. ,
:Detection piece 2 due to Coriolis force 41.42.43.44
4.25 is subjected to a specific ff of the detection piece 24.25.
Since the stress is concentrated at the f position, the piezoelectric elements 26 and 27 are bonded to the positions of the detection pieces 24 and 25 where stress is concentrated. and,
28.29 are lead wires for deriving the electrical signals generated in the piezoelectric circuit 26.27. The elliptical spring 21 and the detection piece 24.2 can be constructed by joining two pieces of spring material 61.62 as shown in FIG. Also, in place of the piezoelectric elements 26 and 27, a strain gauge or other device for detecting stress can be used.

Next, the effect will be explained. FIG. 2 is a diagram showing the driving state of the spring 21. FIG. 2(a) shows the electromagnetic actuator 22, 23 extending the elliptical spring 21. FIG. 2fb) shows the spring 21 being compressed. When the detection piece 24.25 and the spring 21 are compressed and expanded,
．． A reciprocating motion is performed linearly on the same frequency cY@ as the driving frequency of 23. While this 1■ return motion is being performed, if an angular velocity occurs around Z@ shown in Figure 4,
Detection) "j2A, detecting piece 24 in the 41 direction perpendicular to the surface of 2b
．． 25's movement speed and detection piece 24.25's question and own speed 1α
A Coriolis angle of 41.42°43.44 is generated which is proportional to the product of . Cori A-Rica 41.44 has spring 21 I
It occurs when the spring 21 is compressed, and Coriolica 42.43C occurs when the spring 21 is expanded. Coriolis 41, 42, 43° 44 generates stress in the detection piece 24, 25, and the generated stress causes the piezoelectric element 26 to
．． 27, distortion occurs. The distortion results in a change in the amount of electricity, and
An electrical signal proportional to the angular velocity around the axis is output through the leads '028.29.

As described above, by extending and compressing the spring 21 in a direction perpendicular to the direction of compression and extension (X-axis direction) (Y @ force direction), the detection piece 24°25 on the Y-axis becomes linear t.
Since it performs a backward motion, the force in the speed direction applied to the tips of the detection plates 24 and 25 is only in the direction orthogonal to the rotation axis, and the electrical signals output from the detection piezoelectric elements 26 and 27 do not include the difference a. It is proportional to the force of the sled A. Therefore, the effect of improving the detection accuracy of the angular velocity can be obtained by simply increasing the speed of the tip of the detection piece 24.degree. 25 by L.

Further, the height in the direction of the rotation axis can be configured to be low. FIG. 5 shows a means for compressing and expanding the spring 21.
This is another embodiment using a piezoelectric actuator 51, 52, in which a cantilever-shaped piezoelectric actuator 51, 52 configured in a unimorph or bi-rufa type is mounted on the short axis of an elliptical spring 21. Compress by sandwiching 21,
Perform extension. By using the IF electronic type actuator 50, the shape in the direction of the detection axis can be further changed to an a-type configuration.

In this embodiment, an elliptical spring 21 is used, but a rhombic or polygonal spring that linearly reciprocates in a direction perpendicular to the direction in which it is compressed and expanded by the camera may also be used.

(Effects of the Invention) As explained above, according to the present invention, by compressing and expanding one axis of the elastic body, linear reciprocating motion is generated in the direction of the other orthogonal axis. Because of this structure, the force applied to the tip of the stress detector due to the reciprocating motion is a stiffness force that does not include an error, and by increasing the speed of the reciprocating motion of the stress detector, the detection accuracy is improved. Furthermore, it has the great effect of being able to reduce the height in the direction of the rotation axis.

[Brief explanation of drawings]

FIG. 1 is a diagram of an angular velocity sensor according to an embodiment of the present invention. FIG. 2(a) is a diagram showing a state in which the spring is expanded. FIG. 2(b) is a diagram showing a state in which the spring is compressed. FIG. 3 is a diagram of a conventional angular velocity lens. FIG. 4 is a diagram explaining the operation of this embodiment. FIG. 5 is a diagram showing another embodiment of the present invention. 6th
The figure shows the configuration of the spring used in this example. 21... Elastic body, 22.23... Camera element, 24°2
5.26.27... Stress detection piece. Patent applicant: Kousan Automatic Wipes Co., Ltd. No. 2rXI Figure 4A

Claims (1)

[Claims] It is composed of an elastic body, a vibrator that compresses and stretches the elastic body along one axial direction, and a stress detector that linearly reciprocates in an axial direction perpendicular to the direction of compression and expansion of the elastic body. An angular velocity sensor characterized by: