JP2766725B2 - Displacement detector - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a displacement detection device for detecting a rotation angle, that is, an angular displacement.

[Conventional technology]

In recent years, compass and other gyro devices have been developed as displacement detecting devices for detecting angular displacement. Especially for gyro devices such as mechanical gyro and laser gyro,
Various schemes or mechanisms are under consideration.

[Problems to be solved by the invention]

However, there has been no conventional compass of small size and high precision. Further, in the conventional gyro apparatus, although the accuracy is high, the mechanism and structure are complicated, adjustment and the like are not easy, and attention is required for handling. Further, the gyro apparatus itself is large, difficult to handle, has a limited use, and is very expensive.

In view of the above circumstances, an object of the present invention is to provide a displacement detection device having a very simple structure, small size and light weight, and high accuracy.

[Means for solving the problem]

In order to achieve the above object, in the displacement detection device according to the present invention, (a) the displacement detection member is provided so as to be rotatable around a predetermined rotation axis set on a displacement detection member whose displacement is to be detected. A movable member that maintains a fixed direction,
(B) a support member that supports the movable member and is rotatable around the predetermined rotation axis; and (c) that is provided on the support member and that the movable member rotates relative to the support member. (D) a power supply for operating the deviation detecting means, which detects and outputs information relating to the direction of the relative rotation; A first coupling means for supplying, and (e) provided on the displacement detection member side, and when the relative rotation of the movable member with respect to the support member is detected, the support member is moved around the predetermined rotation axis. A driving means for rotating in the same rotation direction as the movable member,
(F) second coupling means for temporarily converting the output from the displacement detecting means to an optical signal and transmitting the signal from the displacement detecting means side to the driving means side; (g) a displacement detection member; And a displacement amount detecting means for detecting a relative rotation amount between them.

According to a preferred embodiment of the displacement detection device according to the present invention, the displacement amount detection means determines a relative rotational displacement amount between the displacement detection member and the support member based on the drive direction and the drive amount of the drive means. To detect.

[Action]

In the displacement detection device according to the present invention, even when the displacement detection member rotates along the predetermined rotation axis, the movable member maintains a constant direction with respect to the outside world according to the inertial force or the external force.
For example, when the displacement detection member rotates and the movable member relatively rotates with respect to the support member, the displacement detection means detects the occurrence of the relative rotation and the direction of the rotation. The driving means is
Immediately, the support member is rotated so as to follow the relative rotation of the movable member, and an attempt is made to return the relative positional relationship between the support member and the movable member to the state before the occurrence of the displacement. Therefore, the relative positional relationship between the support member and the movable member is kept substantially constant. The displacement amount detecting means detects a relative rotation amount of the support member with respect to the displacement detection member.
This amount of rotation corresponds to the amount of rotational displacement of the displacement detection member, that is, the displacement detection device itself.

In this case, the relative positional relationship between the support member and the movable member is kept macroscopically constant, although the vibration is repeated microscopically near the original positional relationship. Therefore, the support means is driven while constantly canceling out the frictional resistance and other stresses directly or indirectly acting between the support means and the movable member in the positive and negative directions. Errors can be minimized.

Also, by providing the first coupling means,
Means such as mechanical contacts for supplying power to the displacement detection means provided on the support means are not required. Further, the provision of the second coupling means eliminates the need for a means such as a mechanical contact for transmitting the output from the above-described displacement detecting means to the driving means.

In a preferred embodiment of the displacement detecting device according to the present invention, the driving means keeps the relative positional relationship between the support means and the movable member constant as needed, and at the same time, the displacement amount detecting means The driving direction and the driving amount are monitored. Therefore, if this driving amount is integrated in consideration of the driving direction of the driving unit, the relative rotation amount of the supporting unit with respect to the displacement detection member can be detected. The rotational displacement of the displacement detection member itself is obtained by replacing the detected rotation amount of the support means with the sign.

〔Example〕

Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

FIG. 1 illustrates the configuration of a horizontal displacement detecting device according to one embodiment of the present invention.

Inside the outer box 1 which is a member to be displaced, a container 4 as a support member, a servomotor 2 as a driving means, and the like are accommodated. The servomotor 2 is fixed to a fixed point 3 provided at one end of the outer box 1. The cylindrical plastic container 4 is connected to the servomotor 2 via the shaft 7 and the coupling 5,
It is rotatable around an axis 7, the rotation of which is controlled by the servomotor 2.

Inside the container 4, a disk-shaped float 8 which is a movable member is stored together with water. The float 8 is supported by bearings 9 and 10 and a support shaft 11 so as to be rotatable around a rotation axis that is an extension of the shaft 7.

A pair of LEs that generate infrared light are provided on the upper end surface of the container 4.
D light sources 12a and 12b are provided. Light detectors 14a and 14b are provided on the lower end surface of the container 4 so as to face the two LED light sources. One LED light source 12a and one light detector 14a constitute a set of sensors, and the other LED light source 12a
The light source 12b and the other light detector 14b also form a set of sensors. As will be described in detail below, it is possible to detect the deviation of the relative positional relationship between the container 4 and the float 8 and the direction thereof based on the outputs of the pair of sensors.

Note that power for operating the LED light source 12 and the photodetector 14 is supplied by a first coupling unit in which the incandescent lamp 15a and the solar cell 15b are combined.

The output from the light detector 14 is converted into a digital signal by an A / D conversion circuit 16 provided on the side surface of the container 4, and is output as a light signal from a light emitting unit 17a such as an LED.
The light signal from the light emitting means 17a is detected by the light receiving means 17b.
Here, the light receiving means 17b is composed of a light receiving element group such as a PD having an annular light receiving surface around the axis 7. Light receiving means
17b itself is fixed to the outer box 1 side by means not shown.

FIG. 2 shows the container 4 when the displacement detecting device is in the operating state.
And the positional relationship of the float 8.

A magnetic needle 8c is provided on the upper surface of the float 8. The float 8 receives a force from the magnetic needle 8c or maintains its direction with respect to the outside world due to its inertia. In this case, the specific gravity of the float 8 is made equal to the specific gravity of the water in the container 4, thereby reducing the friction between the bearings 9, 10 and the support shaft 11. As a result, the float 8 accurately maintains a constant direction with respect to the outside world.

Half of the disk-shaped float 8 is a transparent portion 8a, and the other half is an opaque portion 8b. At the time of operation of the displacement detecting device, as shown in FIG.
The LED light source 12a and the light detector 14a provided on the side face each other so as to sandwich the boundary between the portions 8a and 8b of the float 8. The LED light source 12b and the photodetector 14b also face each other with the boundary of the float 8 interposed therebetween. In other words, LED light source 1
The 2a, 12b, the photodetectors 14a, 14b, and the boundaries are in substantially the same plane. In the following description, the relative position of the float 8 in the illustrated state with respect to the container 4 will be referred to as a reference position for convenience.

When the float 8 is at the reference position, the light detector 14a
The light signal received from the LED light source 12a from the LED light source 12a is blocked by the opaque portion 8b of the float 8 and is about half of the maximum. The same applies to the case of the optical detector 14b. If the float 8 in FIG. 2 is slightly rotated clockwise from this state, the amount of light reaching the light detector 14a from the LED light source 12a decreases, and the light amount from the LED light source 12b to the light detector 14b is reduced.
Is increased. Conversely, if the float 8 rotates slightly counterclockwise, the amount of light reaching the light detector 14a from the LED light source 12a increases, and the amount of light reaching the light detector 14b from the LED light source 12b decreases. That is, by detecting the differential outputs of the optical detectors 14a and 14b, the float 8 is shifted from the reference position,
The direction of the shift can be detected.

FIG. 3 shows a circuit configuration of the control circuit 16 and the like shown in FIG.

The LED light sources 12a and 12b are supplied with power from the control circuit 18 and generate infrared light. The light detectors 14a and 14b generate a voltage or a current in response to infrared light from the LED light source. The control circuit 18 adjusts the output voltage at the point A to be zero when the amounts of light incident on the photodetectors 14a and 14b are substantially equal. That is, when the outputs from both light detectors are unbalanced, the servo motor 2 is driven to rotate the container 4. In this case, the rotation direction of the container 4 is set to a direction for canceling the imbalance of the outputs from the two photodetectors. As a result, even if the float 8 is displaced with respect to the container 4, the positional relationship between the float 8 and the container 4 is immediately returned to the original state (state of the reference position) by the control circuit 18 and the servomotor 2.

The rotation angle of the container 4 is detected by a posi- nometer 19, which is a displacement detecting means, and displayed on an angle display 20. In this case, the main body of the potentiometer 19 is fixed to the outer case 1 by means not shown, and the brush inside the potentiometer 19 is fixed to the shaft 7 side.

 The operation of the displacement detection device shown in FIG. 1 will be described below.

The illustrated displacement detection device is attached to an object on which the displacement detection device is to be mounted, for example, a vehicle or the like, which is required to detect angular displacement from vertical.

Consider the case where the object on which the displacement detection device is mounted rotates and the displacement detection device rotates around an arbitrary axis parallel to the axis 7. In this case, since the rotation of the container 4 is controlled only by the servomotor 2, the container 4 is
, And there is no change in the positional relationship between the container 4 and the outer box 1. On the other hand, the float 8 maintains its original orientation or position due to its inertia or the like. Since the water is also an inertial body, the float 8 does not receive the resistance of the water.
As a result, the float 8 rotates relatively to the container 4 and the outer box 1. Assuming that the float 8 is at the reference position in advance, the float 8 will be shifted from the reference position.

For example, if the float 8 in FIG. 1 rotates clockwise as viewed from above (in reality, the outer box 1 and the container 4
Has rotated counterclockwise. ), Light detector
The amount of light detected by 14a increases, and the amount of light detected by photodetector 14b decreases. When the output difference from the light detector exceeds a predetermined value, the control circuit 18 drives the servomotor 2 to rotate the container 4 in the direction in which the float 8 is shifted (in this case, clockwise as viewed from the upper side in FIG. 1). . When the output difference from the light detector becomes equal to or less than a predetermined value, the control circuit 18 stops the servomotor 2 and stops the rotation of the container 4. As a result, the float 8 returns to the reference position with respect to the container 4 again.

The above operation is for the case where the float 8 is rotated clockwise with respect to the container 4, but the same is true when the float 8 is rotated counterclockwise, and the float 8 is maintained at the reference position. Is done. Here, if the rotation amount of the container 4 is monitored as a resistance value detected by the potentiometer 19, the rotation displacement amount of the entire displacement detection device, that is, the angular displacement can be detected.

An actual displacement detection device generally rotates continuously in an arbitrary direction. Therefore, it is desirable that the container 4 also rotates smoothly and accurately so as to cancel the rotation. For this purpose, it is desirable to operate the servomotor 2 even if the output difference from the optical detector is slight. Further, it is desirable that the rotation of the servomotor 2 is smooth and the response is good.

Various modifications are possible for the first embodiment of FIG.

For example, the inside of the container 4 may be coated with Teflon or the like in order to reduce the contact resistance with water.

In addition, a liquid other than water can be used as the liquid contained in the container 4. However, needless to say, a liquid having a low viscosity is desirable. This is for reducing the contact resistance with the container 4. Furthermore, in actual use, it is desirable to use a liquid that is transparent to the light of the light source, has a low melting point, and a large specific gravity.

Further, for example, a buffer made of a hollow tube may be provided inside the side surface of the container 4. Since this buffer expands and contracts in accordance with the pressure of the liquid in the container, it can absorb a change in volume of water due to a change in temperature and can prevent generation of bubbles.

Further, as the light emitting means, a light source such as an LD other than the LED may be used. Although infrared light is used as signal light so as not to receive outside light in the visible region as noise, it goes without saying that signal light of various wavelengths can be used. Further, a combination of an ultrasonic wave transmission source and a receiver may be used as the deviation detecting means. Further, a magnetic / electrostatic position detecting device may be provided on the float 8 and the container 4, and this may be used as a displacement detecting means.

Furthermore, in the case of this embodiment, two sets of sensors were used,
A shift detecting unit may be configured from the pair of LED light sources and the light detector. In this case, when the float 8 and the container 4 are in a predetermined positional relationship, an optical signal from the LED light source to the light detector is blocked. For example, if the point where the intermittent switching of the optical signal is switched is set as the reference position of the float 8,
Except for this switching point, the float 8 is shifted from the reference position. Further, the direction in which the detected optical signal is shifted from the reference position is determined by the state of the intermittent light signal.

Further, water inside the container 4 may be removed or the pressure inside the container 4 may be reduced. In this case, the float 8 receives no resistance from the surrounding water, but the load applied to the bearings 9, 10 and the like increases. However, since the relative positional relationship between the container 4 and the float 8 is maintained in the state shown in FIG. 2 while repeating the vibration, the resistance force applied to the float 8 is almost canceled in the positive and negative directions. More precisely float 8
It is desirable to use, for example, a bearing utilizing magnetic levitation instead of the bearings 9 and 10 in order to operate.

FIG. 4 is a view for explaining a displacement detecting device according to a second embodiment of the present invention.

The configurations of the outer case 1, the motor 2, the control circuit 18, the angle display 18, and the like are the same as those in FIG. The container 4 is basically the same as that in FIG. However, a band-shaped solar cell 105b is formed around the container 4. Therefore, the incandescent lamp
105a is arranged at a position to illuminate the side surface of the container 4. The power from the solar cell 105b is supplied to the LED light sources 12a and 12b and the A / D conversion circuit 16
And used to work. A light signal digitized by the A / D conversion circuit 16 is output from the light emitting means 107a provided above the A / D conversion circuit 16. Light emitting means
The optical signal from 107a is detected by the light receiving means 107b provided on the side of the outer box 1 opposite thereto. The output of the light receiving means 107b is processed by the control circuit 18 to drive the servomotor 2. The rotation amount of the servomotor 2 is detected by a rotary encoder 109 attached to the servomotor 2 and displayed on an angle display 20. Note that the LED light sources 12a and 12b and the light detectors 14a and 14b
Are the same as those in FIG. 1, although the upper and lower positions are interchanged.

The present invention is not limited to the embodiment shown in FIGS. 1 and 4, and various modifications are possible.

For example, the displacement detecting device shown in FIGS. 1 and 4 may be placed horizontally. The horizontal arrangement makes it possible to detect the rotation angle around the axis 7 arranged in the horizontal plane. However, the magnetic needle 8c for giving the action of the external magnetic field to the float 8 becomes unnecessary. A weight may be used instead of the magnetic needle 8c. That is, by providing a weight around a part of the float 8, the float 8 can be kept in a constant state with respect to the gravitational field.

In addition, the shape of the float 8 can be arbitrary. For example, a float having a non-rotational target shape may be used. Further, when the displacement detecting device is set horizontally, a float whose center of gravity is removed from the support shaft 11 may be used.

Further, the container 4 shown in FIGS. 1 and 4 may be omitted, and the inside of the outer box 1 containing the displacement detecting device itself may be depressurized.

〔The invention's effect〕

As described above, according to the present invention, since the support member is rotated together with the movable member, the structure is simple, and the device is a small and lightweight displacement detection device. A possible displacement detection device can be provided.

Further, since transmission and reception of signals and the like are enabled by using the first and second coupling means, frictional resistance due to contact can be reduced, and errors in angular displacement detection can be reduced.

Further, according to the displacement detecting device of the preferred embodiment, the angular displacement can be easily detected based on the driving direction and the driving amount of the driving unit.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing a configuration of a first embodiment of a displacement detection device according to the present invention, and FIG. 2 is a view showing an arrangement of a container and a float of the displacement detection device of FIG. FIG. 3 is a diagram showing a circuit configuration of a control circuit of the displacement detecting device of FIG. 1, and FIG.
It is a figure showing the displacement detector of an example. 2 ... driving means, 4 ... supporting means, 8 ... movable members, 12a, 12b, 14a, 14b ... shift detecting means, 15a, 15b ... first coupling means, 17a, 17b ... second Coupling means of 19, displacement amount detecting means.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Toshihiko Suzuki 1126-1, Nomachi, Hamamatsu-shi, Shizuoka Prefecture Inside Hamamatsu Photonics Co., Ltd. 71115 (JP, A) JP-T-62-502913 (JP, A) JP-T-49-24694 (JP, B1) (58) Fields investigated (Int. Cl. ⁶ , DB name) G01C 17/04-17 / 26 G01C 9/00-9/36 G01B 11/26 G01P 9/00

Claims (2)

(57) [Claims] An object is provided so as to be rotatable around a predetermined rotation axis set on a displacement detection member whose displacement is to be detected,
A movable member that maintains a fixed direction with respect to the outside world; a support member that supports the movable member and that is rotatable around the predetermined rotation axis; A displacement detecting means for detecting and outputting information about the relative rotation with respect to the member and the direction of the relative rotation, and a power supply for operating the displacement detecting means, which is once converted into light energy and A first coupling unit that supplies the displacement detection member from the displacement detection member side, and a first coupling unit that is provided on the displacement detection member side and that detects relative rotation of the movable member with respect to the support member. Driving means for rotating the support member in the same rotational direction as the movable member around the predetermined rotation axis; and temporarily converting the output from the deviation detecting means into an optical signal. Second transmitting to the driving unit side from said shift detecting means side and
A displacement detecting device comprising: coupling means; and displacement amount detecting means for detecting a relative rotation amount between the displacement detection member and the support member. 2. The apparatus according to claim 1, wherein said displacement detecting means detects a relative rotational displacement between said displacement detection member and said support member based on a driving direction and a driving amount of said driving means. The displacement detection device according to claim 1.