JPH09288124A - Acceleration detection apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an acceleration detection apparatus by which the direction and the magnitude of an acceleration in a space can be detected by one integrated detector and in which the adjustment between three axes is not required. SOLUTION: An acceleration detection apparatus is provided with a container 2 which contains a spherical body 1 at the inside and which has a spherical space whose diameter is larger than that of the spherical body 1, with an elastic body 19 which is situated in a space generated between the container 2 and the spherical body 1 and which weightlessly holds the spherical body 1 in the central point of the spherical space and with a plurality of position detection means 3 to 8 which are installed in positions corresponding to contacts between a cube coming ino external contact with the spherical space at the container 2 and the spherical space. Then, the deviation amount of the central position of the spherical body 1 is measured by the position detection means 3 to 8, and acceleration is detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acceleration detecting device used for underwater and aerial vehicles, industrial machines, consumer machines and the like.

[0002]

2. Description of the Related Art Conventionally, in order to detect an acceleration in space, it has been necessary to dispose a plurality of acceleration detection devices for each of the X, Y and Z axes and to calculate them from the outputs thereof. .

[0003]

However, it is troublesome to arrange a plurality of acceleration detecting devices at a right angle, and in addition, the occupied volume becomes large. SUMMARY OF THE INVENTION It is an object of the present invention to solve such a problem and enable one acceleration detecting device to detect the direction and magnitude of acceleration in space.

[0004]

SUMMARY OF THE INVENTION An acceleration detecting device of the present invention made to solve the above problems is a sphere, a container having the sphere therein and having a spherical space having a diameter larger than that of the sphere, and the container. And a spherical body in a space generated between the spherical body and the elastic body for holding the spherical body at the center point of the spherical space, and a position corresponding to the contact point between the cube and the spherical space circumscribing the spherical space of the container. Is provided with a plurality of position detecting means.

In the acceleration detecting device of the present invention, the sphere in the container having the spherical space is subjected to acceleration, whereby the force corresponding to the product of the mass of the sphere and the received acceleration and the repulsive force of the elastic body are displaced to each other.

The distances from the plurality of position detecting means surrounding it are determined accordingly, and the signals detected by the respective position detecting means are also determined.

Then, from the signals detected by the plurality of position detecting means, X of the acceleration vector on the Cartesian coordinates of the space is calculated.
The axis, Y axis, and Z axis components are known. As described above, the acceleration of the space can be detected by one acceleration detecting device.

Further, the second invention is such that a sphere made of a magnetic material, a container made of a non-magnetic material which contains the sphere and has a spherical space having a diameter larger than that of the sphere, and between the container and the sphere. An elastic body that holds the sphere at the center point of the spherical space in a weightless state in the space where it occurs, and six pieces provided at the position corresponding to the contact point between the cube and the spherical space that circumscribes the spherical space of the container. A magnetic pole and two sets of windings wound around the magnetic poles, one of which is an excitation side, and an alternating current for excitation is commonly applied to each magnetic pole winding, and the other of which is a detection side and faces each other. It is characterized in that the windings of the same magnetic pole are differentially connected and that a yoke made of a magnetic material that connects the outsides of the magnetic poles is provided. It is easy to wind the windings of the same wire diameter and the same material on the facing magnetic poles the same number of times, and apply an alternating current from the same oscillator to each excitation side,
If the induced voltage on the detection side of each magnetic pole is measured when the magnetic body approaches the magnetic pole, it is possible to obtain one with extremely close characteristics.

Further, since the moving range of the magnetic body is limited to the space between both magnetic poles, only the portion having good linearity can be used by reducing the distance between the magnetic poles.

When the detection side windings of the facing magnetic poles are differentially connected so that the phases are opposite to each other and the position of the magnetic body between the magnetic poles is measured, when the magnetic body is equidistant from both magnetic poles, The output on the detection side has the same voltage and cancels each other out to zero.

Further, even with respect to the temperature drift, the signals from the detection windings of the respective magnetic poles are shifted by the same amount, but since the signals are different, they are canceled and the influence on the accuracy can be suppressed. .

Since the above-mentioned characteristics are the same for the three pairs of magnetic poles, the position of the sphere is used as the X-axis, Y-axis, and Z-axis components on the Cartesian coordinates of the space without any special adjustment. Each can be taken out accurately.

Since the position of the sphere in the spherical space is determined by the direction and magnitude of the acceleration, the vector of the position of the sphere with the center of the spherical space as the origin indicates the magnitude and direction of the acceleration.

As described above, it is possible to easily obtain an acceleration detecting device having better linearity and accuracy.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 is a sectional view of an acceleration detector showing an embodiment of the present invention, and FIG. 2 is a block diagram of a signal processing unit connected to the acceleration detector of FIG.

In FIG. 1, reference numeral 1 denotes a sphere, for example, an iron ball is used. Reference numeral 2 denotes a container having a spherical space that encloses the spherical body 1, and is made of, for example, synthetic resin. It should be noted that the container 2 can be moved so that the sphere 1 can move inside the container
The diameter of the spherical space is larger than the diameter of the spherical body 1.

In the space formed between the container 2 and the spherical body 1, an elastic body 19 is inserted so as to hold the spherical body at the center point of the spherical space in a weightless state. Rubber is used for the elastic body, for example. In addition, when attaching the elastic body,
In order to temporarily install the sphere in the center of the container, insert three thin positioning pins, which are set at 120 ° in the horizontal plane and 45 ° with respect to the vertical plane, into the lower part of the container and support it by this. Attach the rubber and then pull it out.

The container 2 is provided with a total of six position detecting means 3, 4, 5, 6, 7, 8 at the positions corresponding to the contact points between the cube circumscribing the spherical space and the spherical space. For example, a proximity sensor is used as the position detecting means. That is, X, Y, whose origin is the center of the spherical space of the container 2,
Considering the Z orthogonal coordinates, two position detecting means are installed on each coordinate axis so as to face each other.

By taking the difference between the signals of the two position detecting means facing each other, the component of the position of the sphere 1 in the spherical space in each coordinate axis direction can be detected.

The operation when acceleration is applied to the acceleration detecting device of the present invention will be described with reference to FIG. In FIG. 7, the origin O of the coordinates is the center position of the spherical space of the container 2.

When no acceleration is applied, the spherical body 1 is supported by the elastic body 19 and the center of the spherical body 1 is at the origin O.
In the state of being accelerated, a force F as shown by the following equation is generated on the spherical body 1.

F = m · a F: Force that pushes the elastic body 19 when the spherical body 1 receives acceleration m: Mass of the spherical body 1 a: Acceleration Since the spherical body is surrounded by the elastic body 19, the spherical body 1 is subject to acceleration. The force F and the repulsive force Fs of the elastic body 19 generated due to the movement of the sphere 1 move to a position where they are in balance. When the position of the sphere 1 in space is detected, the moving distance p from the origin O is proportional to the magnitude of the acceleration, and the direction from the origin is the direction opposite to the acceleration. Therefore, if the position of the sphere seen from the origin is detected, the direction and magnitude of the acceleration in space can be measured.

FIG. 2 shows a block diagram of the signal processing section. The position detecting means 3, 4, 5, 6, 7, 8 outputs a voltage according to the distance when the sphere 1 approaches. In each position detecting means, 3, 4 are X-axis, 5 and 6 are Y-axis,
7 and 8 are arranged to detect the position of the sphere in the Z-axis direction. The output signals from the position detecting means 3 and 4 are subtracted by the differential amplifier 9 and become a voltage signal Vx as information about the X axis of the position of the sphere 1. Similarly, the output signals from the position detecting means 5 and 6 are subtracted by the differential amplifier 10, and the voltage signal Vy as information on the Y axis of the position of the sphere 1 and the signals from the position detecting means 7 and 8 are differential. The difference is taken by the amplifier 11 and becomes a voltage signal Vz as information on the Z axis of the position of the sphere 1. The axis voltage signals Vx, Vy, Vz are converted into digital signals by the A / D converter 12.

The digitized signal is sent to the CPU 13 and RAM by the program written in the ROM 14.
The output as a parallel signal is output from the parallel output port 16, the output as a serial signal is output from the serial port 17, and the output as an analog voltage is output from the D / A converter 18.

Next, an outline of signal processing by a program will be described. A process of multiplying Vx, Vy, and Vz, which means the component of each coordinate axis in the orthogonal coordinates of the space, with each axis component of the acceleration vector is performed. If necessary, it is possible to convert the space orthogonal coordinate system to the polar coordinate system by arithmetic processing.

In the above embodiment, six position detecting means are used to improve the accuracy to take the difference between the axes, but the acceleration can be detected in the same manner even if the differential amplifier is omitted with one axis.

FIG. 3 is a sectional view of an acceleration detector which is another embodiment of the present invention. In FIG. 3, reference numeral 21 denotes a magnetic spherical body, for example, an iron ball is used. Reference numeral 22 denotes a container made of a non-magnetic material having a spherical space that encloses the spherical body 21 and is made of, for example, synthetic resin. The diameter of the spherical space of the container 22 is set larger than the diameter of the sphere 21 so that the sphere 21 can move within the container.

In the space formed between the container 22 and the sphere 21, an elastic body 19 is inserted so as to hold the sphere at the center point of the spherical space in a weightless state. Rubber is used for the elastic body, for example.

The container 22 is provided with a total of six magnetic poles 23, 24, 25, 26, 27, 28 at the positions corresponding to the contact points between the cube circumscribing the spherical space and the spherical space. That is, considering X, Y, and Z orthogonal coordinates with the origin of the center of the spherical space of the container 22, two magnetic poles are respectively installed on each coordinate axis so as to face each other. These magnetic poles 23, 24, 25, 26, 27, 28
Windings 33, 34, 35, 36, 37, 38 are wound around the. There are two sets of each winding, and one side is an excitation side and an alternating current is passed through. The other is the detection side, each magnetic pole 2
The induced voltage increases as the spherical body 21 made of a magnetic material approaches 3 to 28. Each of the magnetic poles 23 to 28 is connected to a yoke 30 made of a magnetic material. The yoke 30 covers the whole and also serves as a magnetic shield.

Since the position of the sphere in the spherical space is determined by the direction and magnitude of the acceleration, the vector of the position of the sphere with the center of the spherical space as the origin indicates the magnitude and direction of the acceleration.

FIG. 4 shows a block diagram of a signal processing unit of the acceleration detector shown in FIG. For each magnetic pole, 23 and 24 are X
Axis 2, 25 and 26 are Y-axis, 27 and 28 are Z-axis spheres 2
It is arranged to detect the position of No. 1, and the windings 33, 34, 35, 36, 37, 38 of the respective magnetic poles on the detection side are 33 and 34, 35 and 36, and 37 and 38, respectively. Connected.

An alternating exciting current is supplied from the exciting oscillation circuit 29 to the exciting side of each winding. The signal from the detection side of the windings 33 and 34 passes through the detector 40, and the filter 4
Pass 1 As a result of the above operation, information about the X axis of the position of the sphere 21 is obtained as the voltage signal Vx. Similarly, the signal from the detection side of the windings 35 and 36 passes through the detector 42 and the filter 43 and becomes a voltage signal Vy as information on the Y axis of the position of the sphere 21, and the signal from the detection side of the windings 37 and 38. Passes through the detector 44 and the filter 45 and becomes a voltage signal Vz as information about the Z axis of the position of the sphere 21.

Each axis voltage signal Vx, Vy, Vz is A / D
Each of them is converted into a digital signal by the converter 46.
The digitized signal is processed by the CPU 39 and the RAM 32 by the program written in the ROM 31, and the parallel signal is output as the parallel output port 4.
7. The serial signal output is the serial port 48,
The output as an analog voltage is output from the D / A converter 49. The signal processing by the program is the same as in the above embodiment.

In the above embodiment, two sets of windings are used for each magnetic pole, and the detection windings of the facing magnetic poles are differentially connected and used as a differential transformer. The acceleration can be similarly detected by using a magnetic detection element fixed to the tip of the magnetic pole instead. A Hall element or a magnetoresistive element is used as the magnetic detection element. Since these elements are generally well known, the description will be made assuming that a bias circuit and the like are included, and that the output is obtained by voltage.

FIG. 5 shows a sectional view of the embodiment in this case, and FIG. 6 shows a block diagram of the signal processing section. Since most of the operating principle is the same as that of the above-mentioned embodiment, it will be omitted and only different parts will be described.

In the above embodiment, two sets of windings are used for each magnetic pole, and the detection windings of the facing magnetic poles are differentially connected and used as a differential transformer. However, in this embodiment, the detection windings are used. Magnetic detection element 5 fixed to the tip of the magnetic pole instead of the wire
1, 52, 53, 54, 55, 56 are used. The output signals of the magnetic detection elements 51 and 52 are passed through the detector 61 and the filter 64 after being subtracted by the differential amplifier 58. As a result of the above operation, information about the X axis of the position of the sphere 21 is the voltage signal Vx.
Is obtained as Similarly, the signals from the magnetic detection elements 53 and 54 are subtracted by the differential amplifier 59, passed through the detector 62 and the filter 65, and the voltage signal Vy as information about the Y axis at the position of the sphere 21 and the magnetic detection element 55. The signals from and 56 are taken out by the differential amplifier 60, passed through the detector 63 and the filter 66, and become a voltage signal Vz as information on the Z axis at the position of the sphere 21.

[0037]

According to the acceleration detecting device of the present invention, since the direction and magnitude of the acceleration in space can be detected by one acceleration detecting device, there is no need to attach a plurality of acceleration detecting devices at a relatively right angle. It does not take, and the occupied volume can be reduced.

Since they are integrated, there is also a feature that adjustment of each axis is not required at the time of assembly.

In the second invention, in addition to the above characteristics, detection can be performed with good linearity on each coordinate axis and with uniform characteristics, and the zero point can be adjusted by the differential connection of the position detecting means with uniform characteristics. It is unnecessary and can suppress the influence on temperature drift. Furthermore, since it is magnetically shielded by surrounding the whole with a yoke, it is less susceptible to the external magnetic field.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an acceleration detecting device according to an embodiment of the present invention, in which (a) is a CC ′ cross section, (b) is an AA ′ cross section, and (c) is a BB ′ cross section. Is.

FIG. 2 is a block diagram of a signal processing unit of the acceleration detection device of FIG.

3A and 3B are cross-sectional views of an acceleration detecting device according to another embodiment of the present invention, in which FIG. 3A is a FF ′ cross section, and FIG.
D'section, (c) is an EE 'section.

FIG. 4 is a block diagram of a signal processing unit of the acceleration detection device in FIG.

5A and 5B are cross-sectional views of an acceleration detecting device according to an embodiment of the present invention, in which FIG. 5A is an II ′ cross section, FIG. 5B is a GG ′ cross section, and FIG. Is.

6 is a block diagram of a signal processing unit of the acceleration detection device in FIG.

FIG. 7 is an explanatory diagram of the operation of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1: Sphere 2: Container 3, 4: X-axis direction position detecting means 5, 6: Y-axis direction position detecting means 7, 8: Z-axis direction position detecting means 19: Elastic body 21: Sphere (magnetic body) 22: container (non-magnetic body) 23, 24: magnetic pole in X-axis direction 25, 26: magnetic pole in Y-axis direction 27, 28: magnetic pole in Z-axis direction 29: excitation oscillation circuit 30: yoke 33, 34: X Axial magnetic pole winding 35, 36: Y-axis magnetic pole winding 37, 38: Z-axis magnetic pole winding 51, 52: X-axis magnetic detecting element 53, 54: Y-axis magnetic detecting element 55, 56: Z-axis magnetic detection element

Claims (2)

[Claims] 1. A sphere, a container containing the sphere and having a spherical space having a diameter larger than that of the sphere, and a center point of the spherical space in a space generated between the container and the sphere in a gravity-free state. An acceleration detecting device comprising: an elastic body for holding the sphere; and a plurality of position detecting means provided at a position corresponding to a contact point between a cube and a spherical space circumscribing the spherical space of the container. 2. A sphere made of a magnetic material, a container made of a non-magnetic material which contains the sphere and has a spherical space having a diameter larger than that of the sphere, and a space formed between the container and the sphere has no gravity. An elastic body for holding the sphere at the center point of the spherical space in a state, six magnetic poles provided at positions corresponding to the contact points of the cube and the spherical space circumscribing the spherical space of the container, and the magnetic poles. Each of the two windings is wound on one side, and one side is the excitation side, and an alternating current for excitation is commonly applied to each magnetic pole winding, and the other side is the detection side. An acceleration detecting device comprising a differentially connected yoke and a yoke made of a magnetic material that connects the outsides of the magnetic poles.