JPS63204111A - Angle-of-inclination sensor - Google Patents

Abstract

PURPOSE:To achieve miniaturization and wt. reduction and to perform accurate measurement, by forming a container enclosing an electrode, a conductive liquid and gas into a shape generating no lateral sensitivity and using fixed resistors as the resistors constituting a bridge circuit. CONSTITUTION:A container 5 is formed into such a shape that the cross-sectional area of the conductive liquid 10 in the container 5 at each part between electrodes does not substantially vary by the rotation of the container 5 in the direction crossing a measuring direction at a right angle and an electrode 7 for applying voltage is provided at the center in the container 5 and opposed electrodes 6, 8 for detecting an angle-of-inclination signal are provided in the vicinity of both ends of said container, and the conductive liquid 10 and gas 11 changing electric resistance or impedance are sealed between the electrode 7 and the electrodes 6, 8. Further, auxiliary fixed resistors 13, 14 correcting the unbalance of the initial electric resistances between the electrodes 6, 7 and the electrodes 7, 8 are added to the opposed electrodes 6, 8 of a sensor 1 and constitute a bridge circuit for measuring an angle of inclination along with fixed resistors 15, 16.

Description

[Detailed description of the invention] Jj4: f [Industrial application field J “-ru.

[Prior Art] The present inventors first provided a counter electrode for applying a voltage and a counter electrode for detecting a tilt angle signal inside an annular container, and sealed a conductive liquid inside the container. The authors also proposed a tilt angle sensor that detects resistance or impedance between electrodes that changes as the bubble moves as the container tilts.

The above-mentioned inclination angle sensor has four electrodes inserted into the container, and a bridge is formed between each of the electrodes with a resistor element f.
When there are air bubbles around two electrodes, if the air bubble moves due to the tilt of the container, the resistance of one of the left and right resistance elements will increase and the resistance of the other will decrease. ).

However, since there are two resistance elements that are not involved in bubbles at all, the two resistance elements could be replaced with solid resistance.

-]゛1゛Also, in the above sensor ΣN-ゝ°, which contains air bubbles in an annular container, there is no distortion of the air bubbles when the air bubbles move in the circumferential direction (rotate around the axis of the wheel shaft). However, when the arc is tilted in the direction of inclination with the horizontal diameter direction as its axis, the cross-sectional shape of the container in which bubbles are formed changes, resulting in so-called lateral sensitivity. Furthermore, extension to in-plane (two-dimensional) tilt angle sensors has manufacturing difficulties.

[Problems to be Solved by the Present Invention] When a conductive liquid and a gas are sealed in a container into which electrodes are inserted, when the container is tilted, the relative displacement of the liquid or gas to the container wall causes electricity between the internal electrodes to decrease. When a resistance change occurs or the minimum unit for obtaining this electrical resistance change is one resistive element of two electrodes, the other two resistive elements are fixed resistors, making the container significantly lighter. Can be made compact
become capable.

In addition, by appropriately selecting the shape of the container based on the above-mentioned three-electrode, two-resistance elements arranged in series, output fluctuations due to rotation of the container in a direction perpendicular to the inclination direction to be measured in the plane, that is, lateral sensitivity, will not occur. Taking the shape of a container becomes N'f ability. Furthermore, this container shape facilitates expansion into a sensor that detects inclination angles in a plane (two dimensions).

An object of the present invention is to obtain a tilt angle sensor that solves the above-mentioned problems.

[Means for Solving the Problems] In order to achieve the above object, the tilt angle sensor of the present invention has an electrode for voltage application at least in the center of the inside of the container, and electrodes for detecting tilt angle signals near both ends of the container. A counter electrode is provided in the container, and there is an electrical resistance between the central electrode and the end electrode according to the inclination of the counter electrode, and the cross-sectional area of the liquid in the container at each part between the electrodes does not substantially change. 2 to form a bridge circuit for tilt color measurement on the counter electrode.
Two fixed resistors are connected.

[Function] In the above-mentioned tilt angle sensor, when a tilt is given to the container, the conductive liquid inside flows relative to the container wall while maintaining the surface level, so the conductance between each electrode changes. A mutual variation occurs in the contributing cross-sectional area of the liquid and the surface area of the electrodes, and this variation causes a change in the impedance slope due to DC resistance, capacitance, inductance, etc. between each electrode for signal detection. Therefore, the inclination angle of the signal detection counter electrode or device around one axis or around two orthogonal axes in a plane is measured.

In this case, the container is formed so that the cross-sectional area of the liquid in the container at each part between the electrodes does not substantially change when the container is rotated in a direction perpendicular to the direction in which the inclination is measured. No output fluctuations due to directional rotation, ie no lateral sensitivity.

[Effects of the Invention] The inclination angle sensor of the present invention has a simple structure in which the electrode, conductive liquid, and gas are housed in a container, and other resistors necessary for the bridge circuit are fixed resistors. ,
The sensor itself can be made extremely small, lightweight, and low in cost. Moreover, since the above-mentioned lateral sensitivity does not occur, not only accurate measurement is possible, but also it can be easily extended to a sensor that detects inclination angles in a plane (two-dimensional).

Various signal processing formats can be adopted by considering the magnitude of the applied voltage, how to construct a circuit for detecting and outputting resistance/impedance, and calibrating the detection signal.

Therefore, it can be effectively used, for example, as a spirit level, an inclinometer, or an attitude sensor for people and machines.

[Embodiment] The embodiment of the present invention shown in FIG. 1 includes a tilt angle sensor 1 and a detection circuit 2 connected to the tilt angle sensor 1 for detecting a rotation angle about an axis perpendicular to the plane of the paper. There is.

More specifically, the sensor 1 has a lead wire shaped like a spheroid made of a hard electrically insulating material and led out of the container 5. The central electrode 7 is for applying voltage, and the counter electrodes 6 and 8 at both ends are for detecting changes in voltage corresponding to the angle of inclination of the container 5 from the horizontal plane.

Further, a conductive liquid lO and a gas 11 are sealed in the container 5 to provide an electrical resistance R or an impedance Z between the electrodes 6, 7 and the electrode 7°8. The liquid 10 and the gas 11 move relative to the container 5, and the resistance R or impedance Z
is configured so that it changes.

Auxiliary fixed resistors 13 and 14 are added to the counter electrodes 6° 8 at both ends of the sensor 1 to correct the unbalance of the initial electric resistance between the electrodes 6 and 7 and between the electrodes 7 and 8. Together with the two connected fixed resistors 15 and 16, a bridge circuit for measuring the tilt angle is configured.

A liquid solution, a colloid liquid such as a soap solution, or a powder mixture containing dielectric material, piezoelectric powder, etc. can be used.

It should be noted that the shape of the electrode provided in the container 5 is not limited to the needle-like shape shown in the figure, and for example, a plate-like shape, a mesh-like shape, etc. can be used.

A detection circuit 2 is connected to the sensor 1 for detecting the amount of inclination from a change in resistance or impedance between the electrodes. The detection circuit 2 has a power supply 17 connected between the connection point between the fixed resistors 15 and 16 and the central electrode 7,
The power source 17 is configured to apply a reference alternating voltage or -1 voltage directly between the connection point and the electrode 7. Furthermore, a differential amplifier D detects and amplifies changes in resistance or impedance between the 12 pairs of electrodes 6 and 8, and removes noise components superimposed on the output signal from the differential amplifier. band pass filter BP
F and an amplifier A that amplifies its output are connected.

The tilt angle detection sensor having the above configuration is configured such that the container 5 is held horizontally and a reference alternating voltage is applied by the power source I7, and when the container 5 is tilted from this state, the flow of the conductive liquid lO in the container 5 As a result, the resistance R or impedance Z between the electrodes 6 and 7 and between the electrodes 7 and 8 in the bridge circuit changes, and this change is detected by a differential amplifier. The detection signal increases as the angle of inclination of the container 5 increases, and as the direction of inclination is reversed left and right, the sign of the output signal is also reversed. Therefore, it is conceivable to pair the tilt angle and the differential potential detected according to the amount of change in resistance or impedance.

FIGS. 2(a) to 2(C) show another embodiment of the uniaxial tilt angle sensor, and FIG. 2(a) shows its longitudinal section. This tilt angle sensor, like the embodiment shown in FIG.
1, 22, and 23 are installed. Of course, the central electrode 22
is for applying voltage, and electrodes 21 and 23 at both ends are for detecting voltage corresponding to the tilt angle. The cross-sectional shape of the container 18 can be square as shown in FIG. 2(b), or circular as shown in FIG. 2(C).

Moreover, FIGS. 3(a) and 3(b) show the conductive liquid 26 and the gas 2.
The container 25 enclosing the electrode 7 is shaped like a ξ-shaped container 25 as shown in FIGS. 2(a) and 2(b), and its bottom surface is curved concavely to form an electrode.

FIG. 4(a) shows an embodiment of a sensor that can measure the tilt angle two-dimensionally. In this case, the container 31 is formed into a Shinji shape, electrodes 32, 33, 34, 35, and 36 are inserted into the center and each protrusion, and the conductive liquid 37 and gas 38 are sealed in the container 31. ing. This two-dimensional tilt angle sensor is a combination of a uniaxial sensor using electrodes 32, 33, 34 and a multi-axis sensor using electrodes 8i32, 35, 36. FIG. 4(b) shows the connection relationship between the above-mentioned tilt angle sensor, fixed resistors 41, 42, 43, 44, power supply 45, and differential amplifiers D1 and D2, and shows the connection relationship between the above-mentioned uniaxial sensor and other It is an equivalent circuit diagram in which the phase car interference of the shaft sensor is assumed to be small and its influence is ignored. Each differential amplifier D I, D 2 is connected to two independent parallel bridges, by means of which the tilt angles about both axes are detected.

5(a) to 5(e) are two-axis diagrams similar to FIG. 4(a), and the container 46 in the sensor in FIG. electrodes 47.4B at the center and at each end.

49, 50, and 51 are provided, and a conductive liquid 52 and a gas 53 are sealed inside.

In addition, the container 54 shown in FIG. 5B has a shape in which cylindrical tubes are orthogonal to each other, and the container 55 shown in FIG. The container 56 shown in FIG. 3(d) has a radial partition wall provided in the thick disk-shaped container except for the central part, and the container 57 shown in FIG. The rectangular containers shown in a) and ('b) with gate-shaped bottoms are crossed at right angles. It goes without saying that electrodes are provided at the center and at each end of each of these containers, and a conductive liquid and gas are sealed inside.

(a) shows the case of the tilt angle sensor shown in Fig. 1, (b) shows the case of the sensor shown in Fig. 2 (a), and Fig. 4 (c) shows the case of the two-vehicle tilt sensor shown in Fig. 4. There is. In FIG. 6(c), chi is the measurement result for the uniaxial sensor using electrodes 32, 33.34, and ch2 is the measurement result for the uniaxial sensor using electrodes 8i32, 35.36.
This figure shows the measurement results for a multi-axis sensor using the .

According to these experimental results, in any case,
It can be seen that there is no lateral sensitivity or that it is very small.

Note that Figures 6 (a) to (c) only show the measurement results when tilted in one direction, but when tilted in the other direction, the phase is reversed and the output is adjusted according to the tilt angle. Obtainable.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of an actual example of the present invention showing the main parts in cross section, Figures 2 (a) to (C) and Figure 3 ('a' and (b) are Another different embodiment of the angle sensor is shown in FIG.
5(a) to 5(e) are perspective views showing other embodiments of the two-axis tilt angle sensor; Figure 6 (a)
-(C) are diagrams showing an example of the measurement results of the tilt angle according to the embodiment of the present invention. 5.18, 25, 31, 46. 54-57・e container, 6
~8,21~23.28~30.32~36.47~5
1. Electrode, 10. 19, 26, 37, 52. Fist conductive liquid, 11. 20, 27, 38, 53. Fist gas, 15.
16.41~44...Fixed resistance. To the designated agent, Director of Product Science Research Institute, Agency of Industrial Science and Technology, Q. Ko Takahashi! 5pK (A 4C,)J! ) 0
1 ':'U (~4yn actual) cl''+! Procedural amendment C method) September 3rd, 1939 (1:, Indication of the case, 11 1989 Patent Application No. 189345 2, Title of the invention Inclined Angle sensor 3, relationship with the case of the person making the correction Patent applicant address: 1-3-1 Kasumigaseki, Chiyoda-ku, Tokyo (114)
Name Kozo Iizuka, Director of the Agency of Industrial Science and Technology, Designated Agent 305 Address 1-1-4 Tsukuba South East, Ibaraki Prefecture (19861)
(Due to the administrative division change on January 30th) 6. Drawings subject to amendment 7. Contents of amendment The drawing numbers of Drawings 5 and 6 of the drawings are marked in red on the attached copy of the drawing, respectively, as "Fig. 6". , corrected as "Fig. 5". (-11C, e) (11C] Cow Apology) &'+?

Claims (2)

[Claims] 1. At least an electrode for voltage application is placed in the center of the inside of the container.
Further, counter electrodes for detecting tilt angle signals are provided near both ends of the container, and a conductive liquid is contained in the container that changes the electrical resistance or impedance between the center electrode and the end electrodes in accordance with the tilt of the container. and a gas, and the container has a shape in which the cross-sectional area of the liquid in the container at each part between the electrodes does not substantially change when the container is rotated in a direction perpendicular to the direction in which the inclination in the plane is to be measured, A tilt angle sensor characterized in that two fixed resistors for configuring a bridge circuit for tilt angle measurement are connected to the counter electrode. 2. The container is formed into a two-dimensional shape, and an electrode for applying a common voltage is provided at the center of the container, and counter electrodes for detecting tilt angle signals are provided near the four peripheries of the container, and counter electrodes at opposing positions are provided. 2. The tilt angle sensor according to claim 1, wherein fixed resistors are connected to each of the bridge circuits for forming a bridge circuit for measuring the tilt angle.