JPH04236322A - Angular velocity detecting apparatus - Google Patents

Abstract

PURPOSE:To provide an angular velocity detecting apparatus which is hard to be affected by vibration noises from outside, and compact-size. CONSTITUTION:This angular velocity detecting apparatus is comprised of an angular velocity sensor 1, a circuit board 7 having a-circuit part to drive the angular velocity sensor 1 and process output signals, and a casing 10 which houses the angular velocity sensor 1 and the circuit board 7 altogether. The angular velocity sensor 1 is supported from both ends on the detecting shaft and fixed to the circuit board 7.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an angular velocity detection device used for attitude control of ships, vehicles, etc.

0002

2. Description of the Related Art As a conventional technique, a vibration type angular velocity sensor with a tuning fork structure will be described.

Conventionally, as an inertial navigation device using a gyroscope, a mechanical rotary gyro has been mainly used as a means for determining the direction of a moving object such as an airplane or a ship.

[0004] Although this method provides a stable orientation, since it is mechanical, the device is large-scale and costly, and it is difficult to apply it to equipment that is desired to be miniaturized.

On the other hand, there is a vibration-type angular velocity sensor that detects "Coriolis force" by vibrating an object without using rotational force and using a vibrated sensing element. Many of these structures employ piezoelectric and electromagnetic mechanisms. In these cases, the mass that makes up the gyro does not move at a constant speed, but instead vibrates. Therefore, when an angular velocity is applied, the Coriolis force occurs as a vibration torque with a frequency equal to the frequency of the mass. The principle of a vibration-type angular velocity sensor is to measure angular velocity by detecting vibrations caused by this torque, and many sensors using piezoelectric materials have been devised (Journal of the Japan Society for Aeronautics and Astronautics, Vol. 23, No. 25).
7, pp. 339-350).

A conventional tuning fork structure vibration type angular velocity sensor will be explained with reference to FIGS. 4 to 6. The angular velocity sensor has a structure as shown in FIG. 4, and is mainly composed of a drive element consisting of four piezoelectric bimorphs, a monitor element, and first and second detection elements, including a drive element 101 and a first detection element 103.
The first vibration unit 10 is orthogonally joined at the joining part 105.
9 and a second vibration unit 110 in which the monitor element 102 and the second detection element 104 are orthogonally joined at the joint 106 are connected by a connecting plate 107, and this connecting plate 107 is connected to the support rod 1.
It has a tuning fork structure supported at one point at 08.

When a sinusoidal voltage signal is applied to the drive element 101, the first vibration unit 109 starts to vibrate due to the inverse piezoelectric effect, and the second vibration unit 110 also starts to vibrate due to the tuning fork vibration. Therefore, the charge generated on the surface of the monitor element 102 due to the piezoelectric effect is proportional to the sinusoidal voltage signal applied to the drive element 101. By detecting the charge generated in the monitor element 102 and controlling the sinusoidal voltage signal applied to the drive element 101 so that the charge has a constant amplitude, stable tuning fork vibration can be obtained. The mechanism by which this sensor generates an output proportional to angular velocity will be explained using FIGS. 5 and 7.

FIG. 5 shows the angular velocity sensor shown in FIG. 4 viewed from above. When rotation at an angular velocity ω is applied to the sensing element 103, which is vibrating at a speed v, a "Coriolis force" is applied to the sensing element 103. arise. This "Coriolis force" is perpendicular to the velocity v and has a magnitude of 2 mvω (m is the equivalent mass of the tip of the sensing element 103). Since the sensing element 103 is vibrating like a tuning fork, if the sensing element 103 is vibrating at a speed v at a certain point, the sensing element 104 is vibrating at a speed -v, and the "Coriolis force" is -2mvω. It is. Therefore, the sensing elements 103 and 104 exert "Coriolis force" on each other as shown in FIG.
deforms in the direction in which it acts, and charges are generated on the element surface due to the piezoelectric effect. Here, v is the motion caused by the vibration of the tuning fork, and the vibration of the tuning fork is v=a・sinω0t
a: Amplitude of tuning fork vibration

ω0: If it is the period of tuning fork vibration, the “Coriolis force” is Fc=a・ω・sinω0t, which is proportional to the angular velocity ω and the tuning fork amplitude a, and is a force that deforms the sensing elements 103 and 104 in the plane direction. becomes. Therefore, the amount of surface charge Q of the sensing elements 103 and 104 is Q
∝a・ω・sinω0t, and if the tuning fork amplitude a is controlled to be constant, then Q∝ω・sinω0t, which is the amount of surface charge Q generated on the sensing elements 103 and 104.
is obtained as an output proportional to the angular velocity ω, and this signal is expressed as ω
If synchronous detection is performed at 0t, a DC signal proportional to the angular velocity ω can be obtained. Note that even if a translational motion other than angular velocity is applied to this sensor, charges of the same polarity are generated on the surfaces of the two sensing elements 103 and 104, so when converting to a DC signal,
They cancel each other out so that no output is produced.

[0009]

[Problems to be Solved by the Invention] However, if the angular velocity sensor is simply fixed to a storage case to form an angular velocity detection device, as in the structure of a conventional angular velocity sensor, the angular velocity sensor, including the circuit section, cannot be used externally. The sensor was affected by vibration noise, resulting in false detections and an inability to obtain a stable output signal.

[0010] Therefore, the angular velocity sensor has to be fixed at a mounting location that is less affected by external vibrations, etc., separately from the circuit section. With this configuration, it was not possible to realize a compact angular velocity detection device.

[0011] The present invention solves the above-mentioned problems, and aims to provide a compact angular velocity detection device that is less susceptible to vibration noise from the outside.

0012

[Means for Solving the Problems] In order to achieve this object, the angular velocity detecting device of the present invention comprises: an angular velocity sensor; a circuit board having a circuit section for driving the angular velocity sensor and processing an output signal; The angular velocity sensor is comprised of a case that collectively houses the sensor and the circuit board, and the angular velocity sensor is supported from both ends on the angular velocity detection axis and fixed to the circuit board.

[0013]

[Function] With this configuration, the angular velocity detection device can compactly store the angular velocity sensor and the circuit section all at once, and at the same time provide a shielding effect that reduces vibration noise from the outside, providing extremely high performance. An angular velocity detection device can be provided.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a partially cutaway perspective view of an angular velocity detecting device according to an embodiment of the present invention. Figure 2(a)
is a front view of the same angular velocity detection device from the X direction, FIG. 2(b)
is a side view of the same angular velocity detection device from the Y direction, FIG. 2(c)
is a top view of the same angular velocity detection device from the Z direction.

The angular velocity sensor 1, which is inserted and held and fixed in a cylindrical weight member 2, is attached to angles 4a and 4b through shock absorbing materials 3a and 3b such as polyurethane and silicone rubber at both ends and the lead pin side, respectively. It is held hollow by The angles 4a and 4b are fixed to a large circuit board 7 with screws or the like, and this large circuit board 7 is fixed to a base 9 made of die-cast aluminum or the like with screws or the like.

The lead pins of the angular velocity sensor 1 are attached to a small circuit board 5, and are further connected to a large circuit board 7 via lead wires 6a, 6b, 6c, 6d, and 6e from above the small circuit board 1.
electrically connected to. The input and output signals of the angular velocity sensor 1 are connected to lead wires 8a and 8 connected to the large circuit board 7.
b, 8c, and these lead wires 8a, 8b, 8
c are used for input, output, and ground, respectively.

Reference numeral 10 denotes a case that houses these and is fixed to the base 9. The operation of the angular velocity detection device of this embodiment configured as described above will be described below.

When the angular velocity sensor 1 receives an angular velocity, a charge corresponding to the angular velocity is generated. This charge is subjected to signal processing via the large circuit board 7, and a voltage is output from the lead pins. The principle by which the angular velocity sensor 1 detects angular velocity is based on a conventional example of a tuning fork structure vibration type angular velocity sensor, where the velocity generated by tuning fork vibration is v and an output proportional to the angular velocity generated in the detection piezoelectric element is obtained. This is the same as shown in , so it will be omitted.

Since the angular velocity sensor 1 and the circuit are susceptible to vibration noise from the outside world, holding the angular velocity sensor 1 requires a structure that absorbs the vibration impact before it is transmitted to the angular velocity sensor. Therefore, a weight member 2 is attached to the angular velocity sensor 1, and shock absorbers 3a are attached to both ends.
By fixing it to the substrate via 3b, a stable angular velocity detection device that is resistant to external vibrations was realized.

To fix the angular velocity sensor 1, it is possible to support it from the cylindrical side surface with the shock absorbing material 3c (see FIG. 3(b)), but it is more stable to support it in the axial direction. This was confirmed by experiment. The experimental data is shown in FIG. Here, in FIG. 3(a), the shaft-side holding refers to the configuration of this embodiment, and the side-side holding refers to the configuration shown in FIG. 3(b).

[0022]

As described above, the present invention provides an angular velocity sensor, a circuit board equipped with a circuit section for driving the angular velocity sensor and processing an output signal, and a case that collectively houses the angular velocity sensor and the circuit board. The angular velocity sensor is supported from both ends on the angular velocity detection axis and fixed to the circuit board, so that the angular velocity sensor and the circuit section can be housed compactly together, and at the same time, vibrations from the outside can be prevented. It is possible to provide an extremely high performance and highly stable angular velocity detection device that can have a shielding effect that absorbs and reduces noise.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view of an angular velocity detection device according to an embodiment of the present invention.

[Figure 2] (a) is a front view of the same example from the X direction (b)
is a side view of the same example from the Y direction (c) is a side view of the same example from the Z direction.
Top view from the direction

[Figure 3] (a) is a characteristic diagram comparing the holding states of the angular velocity sensor (b) is a perspective view showing the holding state of a comparative example

[Figure 4] Perspective view of tuning fork structure vibration type angular velocity sensor

[Figure 5] Diagram explaining the operation of the tuning fork structure vibration type angular velocity sensor

[Figure 6] Diagram explaining the operation of the tuning fork structure vibration type angular velocity sensor

[Explanation of symbols]

1 Angular velocity sensor 2 Weight members 3a, 3b Shock absorbing material 4a, 4b Angle 5 Small circuit board 6a, 6b, 6c, 6d, 6e Lead wire 7 Large circuit board 8a, 8b, 8c Lead wire 9 Base 10 Case

Claims (3)

[Claims] 1. The angular velocity sensor comprises an angular velocity sensor, a circuit board having a circuit section for driving the angular velocity sensor and processing an output signal, and a case that collectively houses the angular velocity sensor and the circuit board, the angular velocity sensor An angular velocity detection device characterized in that it is supported from both ends on an angular velocity detection axis and fixed to a circuit board. 2. Claim 1, wherein the angular velocity sensor is supported at both ends while being inserted into the weight member.
The angular velocity detection device described. 3. The angular velocity detection device according to claim 1, wherein the angular velocity sensor is supported at both ends via a shock absorbing material.