JPH10122858A - Inclination measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure the inclination of a container accurately and inexpensively by detecting a reflection pulse signal reflected by a plurality of liquid level positions in the container and obtaining its propagation delay time difference. SOLUTION: The ultra-short pulse signal of a pulse generation means 1 is propagated in the longitudinal directions of pulse signal propagation means 3a and 3b. The propagation means 3a and 3b are made of, for example, a rod-shaped metal, the dielectric constant of a liquid for dipping a part that is lower than air where an upper part contacts is high, and they have different impedances. Therefore, impedance mismatching occurs at the position of the a liquid level 4 and a pulse signal is reflected on the liquid level 4, and a pulse signal is reflected similarly at the lower edge part, thus detecting 5a and 5b each reflection pulse signal, where the liquid level position on the propagation means 3a and 3b changes according to the inclination of a container, and delay time detection parts 6a and 6b measure the difference in each propagation time from the detected reflection pulse signals 5a and 5b. An operation part 7 obtains the inclination of the liquid level 4 for the container according to the delay time difference of both, thus eliminating the need for measuring a capacitance or the need for a light-emitting element.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tilt measuring device for measuring the tilt of an object, and more particularly to a tilt measuring device utilizing the level of a liquid stored in a container.

[0002]

2. Description of the Related Art Hitherto, various tilt measuring apparatuses have been proposed which utilize a property that a liquid is stored in a container and the liquid level is always maintained in a horizontal direction.

[0003] For example, there is one that utilizes optical reflection or refraction on a liquid surface as represented by Japanese Patent Publication No. 3-45322. This inclination measuring device irradiates the liquid surface with light at a predetermined angle with respect to the container, and changes the refraction or reflection of light generated on the liquid surface with a change in the inclination of the container, the amount of light or the spot position of light, The inclination of the container is measured by detecting the change in the image position.

Further, as another method, for example,
As described in Japanese Patent No. 47475/1992, there is one using capacitance. In this method, a liquid and a gas, or different liquids are sealed in a sealed container, and the inclination of the container is measured by electrically detecting a change in capacitance caused by a change in inclination.

[0005]

However, in the above-described conventional tilt measuring apparatus, when the former optical means is used, expensive parts such as a light emitting element and a light receiving element are required, and the entire measuring apparatus is expensive. When using the latter change in capacitance, the absolute value of the detected change in capacitance is small, so very precise measurement is required, and it is susceptible to temperature changes and noise. Have a problem.

Accordingly, an object of the present invention is to provide a completely new tilt measuring device which solves the above-mentioned problems of the conventional tilt measuring device.

It is a further object of the present invention to provide a new tilt measuring device with high accuracy and low cost.

[0008]

According to the present invention, there is provided a pulse generating means for generating a short pulse signal, a container for storing a liquid therein, and a predetermined distance within the container. Disposed, each upper end is connected to the pulse generation means, each lower end is immersed in the liquid, at least a plurality of pulse signal propagation means having a predetermined length in the vertical direction, and the pulse signal propagation means A liquid level reflection pulse signal reflected at the position of the liquid level of the pulse signal propagation means is connected, and the inclination of the container is measured based on a difference in propagation delay time of the liquid level reflection pulse signal. This is achieved by providing a tilt measuring device having tilt detecting means.

[0009] More specifically, the inclination detecting means includes:
Detecting a time difference between an upper end reflection pulse signal reflected at an upper end portion of the pulse signal propagation means and the liquid level reflection pulse signal, and tilting the container from the relationship of the time difference obtained from the plurality of pulse signal propagation means; Is measured.

Further, as another specific example, the inclination detecting means detects a time difference between a lower end reflected pulse signal reflected at a lower end of the pulse signal transmitting means and the liquid level reflected pulse signal, The inclination of the container is measured from the relationship between the time differences obtained from the plurality of pulse signal propagation means.

By transmitting the ultrashort pulse signal to the propagation means partially immersed in the liquid, the delay time of the reflected pulse signal on the liquid surface can be detected, and the inclination between the liquid surface and the container can be detected. .

Further, the present invention relates to a tilt measuring device which is mounted on a container to be measured which contains a liquid therein and measures a tilt of the container to be measured, a pulse generating means for generating a short pulse signal, and the container to be measured. Are arranged at a predetermined distance from each other, and each upper end is connected to the pulse generation means,
At least a plurality of pulse signal propagation means each having a lower end immersed in the liquid and having a predetermined length in a vertical direction, respectively connected to the pulse signal propagation means, and a position of the liquid surface of the pulse signal propagation means. And an inclination detecting means for detecting an inclination of the container to be measured based on a difference in propagation delay time of the liquid surface reflection pulse signal.

In this example, the inclination of the tank can be measured by mounting the inclination measuring apparatus of the present invention on a huge tank for storing oil.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. However, the technical scope of the present invention is not limited to the embodiment.

FIG. 1 is an overall configuration diagram of an embodiment of the present invention. 1 is a pulse signal generating means for generating an ultrashort pulse signal, and 2 is a container containing a liquid 4 having a dielectric constant larger than air, such as water or oil, and at least two pulse signal transmitting means 3a in the container 2. , 3b are fixed so that the lower ends thereof are immersed in the liquid with a predetermined distance therebetween. Therefore, the liquid surface positions of the pulse signal propagation means 3a and 3b relatively change according to the change in the inclination of the container. When two pulse signal propagation means 3a and 3b are provided, a one-dimensional inclination is obtained, and when three or more pulse signal propagation means are provided, a two-dimensional inclination (surface inclination) is obtained.

The upper ends of the pulse signal propagation means 3a and 3b are connected to the pulse signal generation means 1 and supplied with the generated ultrashort pulse signal. Further, the pulse signal propagation means 3
The upper ends of a and 3b are also connected to pulse signal receiving units 5a and 5b for detecting pulse signals propagating and reflected therein. Then, each pulse signal receiving unit 5
a and 5b further include pulse signal time difference measuring units 6a and 6b.
Is also connected. Then, the time difference measuring units 6a and 6b
Is supplied to the calculation unit 7 and converted into information on the inclination angle, and is output from the display output unit 8 to the outside.

The pulse generating means 1 is, for example, 200 picoseconds.
A pulse signal having a pulse width of about ec can be generated, and an electromagnetic wave generated by the generated pulse signal is propagated in the longitudinal direction of the pulse signal propagation means 3a, 3b.

FIG. 2 is a diagram for explaining the state of propagation of the pulse signal in the pulse signal propagation means 3a, 3b.
The ultrashort pulse signal supplied from the pulse generation means 1 reflects due to impedance mismatch at the upper end 31 which is a connection with the pulse signal propagation means 3a. By appropriately selecting the connection structure at the upper end portion 31, the reflected pulse signal at the upper end propagates to the pulse detector 5a side.

The pulse signal propagation means 3a has an impedance different from that of the connection conductor to the pulse generation means 1, and is formed of, for example, a rod-shaped conductor made of metal. Then, the upper part of the rod-shaped conductor in contact with air and the liquid 4
The liquid and the lower part immersed in the liquid have different impedances because the liquid has a higher dielectric constant than the air. Therefore, impedance mismatch exists at the position 32 on the liquid surface, and reflection of the pulse signal also occurs on the liquid surface. The pulse signal is similarly reflected at the lower end of the rod-shaped conductor. Thus, the reflected pulse signal at the liquid surface and the reflected pulse signal at the lower end are supplied to the pulse detector 5a.

As described above, the position of the liquid surface on the pulse signal propagation units 3a and 3b changes according to the change in the inclination of the container. Therefore, by detecting the time when the reflected pulse signal propagates on the liquid surface, the inclination angle of the container can be accurately detected.

FIG. 3 is a diagram showing the relationship between the detected reflected pulse signals. As described above, the upper-end reflection pulse signal P31, the liquid-surface reflection pulse signal P32, and the lower-end reflection pulse signal P33 are detected by the pulse receiving units 5a and 5b. (1) and (2) in FIG.
This is an example where a and 3b have the same length. Basically, they are provided at the same height in the container. However, even if the heights are slightly different, it is possible to adjust them at the signal processing stage.

When the reflected pulses shown in FIGS. 3A and 3B are detected, the time difference measuring sections 6a and 6b, for example, detect the liquid level reflected pulse signal P32 and the lower end reflected pulse signal P.
The delay times t _a and t _b between the container 33 and the container 33 are measured, and the calculation unit 7 calculates the inclination of the liquid level with respect to the container according to the delay times t _a and t _b .

When the metal is used as the material for the pulse signal propagation means 3a and 3b as described above, the propagation speed of the short pulse signal propagating through the metal is about 200,000 km per second. Therefore,
The wavelength of the pulse signal of 200 picosec is about 40 mm, and the delay time between the liquid surface reflection pulse P31 and the lower end reflection pulse P33 is about 1 nsec when the length of the rod-shaped conductor is about 0.2 m. . Therefore, if the delay times t _a and t _b are of such _{a level} , the detection can be made relatively accurately.

FIG. 3C shows an example in which the pulse signal propagation means 3b is longer than 3a. In this case, for example, the relationship of the delay time when the container is kept in a horizontal state is measured in advance, and stored as calibration data in the arithmetic unit 7, so that the delay time t according to the inclination at the time of measurement is obtained. _a , t _b '
The inclination can be obtained based on

In FIG. 3, the upper end reflected pulse signal P31
It is also possible to calculate the delay time between the pulse signal P32 and the liquid surface reflection pulse signal P32, and compare the two delay times to obtain the slope.

The position of the liquid-surface reflection pulse signal P32 in FIG. 3 moves right and left in accordance with the inclination of the container. The movement is detected by a delay time, and the delay times are compared to obtain the inclination. Can be requested.

The circuit of the pulse generating means 1 can be a known circuit used for a radar, for example.

In the above-described embodiment, an example has been described in which the measuring apparatus uses a container containing a liquid as a constituent element. However, it can also be used as a device for measuring the inclination of a container such as a huge oil tank. In that case, for example, in FIG.
3b is mounted on the inner wall at a fixed height from the edge of the container, and detects the tilt of the tank itself by detecting the electromagnetic wave pulse signal that propagates to the liquid surface and reflects in the pulse signal transmitting means. You can also. Therefore, in that case, the measuring device does not include a tank containing oil.

[0029]

As described above, according to the present invention, there is no need to use a light-emitting element or a light-receiving element, and there is no need to measure a capacitance which is difficult to detect. A tilt measurement can be performed. Further, since the above-mentioned ultrashort pulse generation means can be realized without using particularly expensive components, the cost can be reduced as a whole.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an embodiment of the present invention.

FIG. 2 is a diagram for explaining a state of propagation of a pulse signal in pulse signal propagation means 3a and 3b.

FIG. 3 is a diagram illustrating a relationship between detected reflected pulse signals.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pulse signal generation means 2 Container 3 Pulse signal propagation means 4 Liquid 5 Pulse detection unit 6 Delay time detection unit P31 Upper reflection pulse signal P32 Liquid surface reflection pulse signal P33 Lower reflection pulse signal

Claims (4)

[Claims] 1. A pulse generating means for generating a short pulse signal; a container for storing a liquid therein; a container disposed at a predetermined distance in the container, each upper end connected to the pulse generating means; At least a plurality of pulse signal propagation means each having a lower end immersed in the liquid and having a predetermined length in the vertical direction, respectively connected to the pulse signal propagation means, and a position of the liquid surface of the pulse signal propagation means And a tilt detecting means for detecting a liquid level reflection pulse signal reflected by the liquid crystal panel and measuring a tilt of the container based on a difference in propagation delay time of the liquid level reflection pulse signal. 2. A tilt measuring device which is mounted on a container to be measured for storing a liquid therein and measures a tilt of the container to be measured, comprising: pulse generating means for generating a short pulse signal; At least a plurality of pulse signal propagation means having a predetermined length in the vertical direction, wherein each of the plurality of pulse signal transmission means is disposed at a distance, and each upper end is connected to the pulse generation means, and each lower end is immersed in the liquid and has a predetermined length in the vertical direction; The pulse signal transmitting means is connected to each of the signal transmitting means, detects a liquid surface reflected pulse signal reflected at the position of the liquid surface of the pulse signal transmitting means, and detects the measured signal based on a difference in propagation delay time of the liquid surface reflected pulse signal. A tilt measuring device having a tilt detecting means for measuring the tilt of the container. 3. The tilt measuring device according to claim 1, wherein said tilt detecting means includes a time difference between an upper end reflected pulse signal reflected at an upper end of said pulse signal transmitting means and said liquid level reflected pulse signal. And a tilt measuring device for measuring the tilt of the container from the relationship of the time differences obtained from the plurality of pulse signal propagation means. 4. The tilt measuring device according to claim 1, wherein said tilt detecting means includes a time difference between a lower end reflected pulse signal reflected at a lower end of said pulse signal transmitting means and said liquid level reflected pulse signal. And a tilt measuring device for measuring the tilt of the container from the relationship of the time differences obtained from the plurality of pulse signal propagation means.