JPS63309812A - Inclinometer - Google Patents

Abstract

PURPOSE:To obtain a small-sized, inexpensive sensor with improved measurement accuracy by allowing a photodetecting element which detects the intensity of a light beam reflected by plural reflectors provided so that they are horizontal at all times. CONSTITUTION:An incident light beam 22 emitted by a light source 26 is stopped down by a slit 25 narrowly and incident on a 1st reflector 20 to become a 1st reflected light beam 23 which varies in intensity according to the dependency of the reflection factor on the angle of incidence. Then the light beam 23 is incident on a 2nd reflector 21 and reflected for the 2nd time to become a 2nd reflected light beam 24. At this point of time, the light beam 24 becomes parallel to the light beam 22 and this relation is maintained even when a body 30 to be measured slants. The light beam 24 is, therefore, made incident on the photodetecting element 28 at a constant angle at all times and converted here into an electric signal. Then the deviation from the electric signal at a reference angle is calibrated to detect the tilt angle of the body 30 to be measured continuously. Further, the deviation signal based upon the reference angle is supplied to equipment and an operation terminal is operates so as to cancel the deviation, thereby controlling the attitude to the body 30 to be measured.

Description

[Detailed description of the invention] [Industrial application field] This invention is applicable to architecture, industrial robots, and airplanes.

This invention relates to an inclination sensor used for horizontal detection of automobiles, ships, etc.

[Conventional technology]

Figure 3 is an example of "1 Sensor Practical Encyclopedia" supervised by Toyoaki Oshiki, p.
8. This is a principle diagram showing the conventional tilt sensor described in Fujikai Techno System (1986), and in the figure (1)
is the reflector, (2) is the incident ray that enters the reflector (1), (3) is the primary reflected ray when the incident ray (2) is reflected by the reflector (1), (4) is the incident ray from the light source (
(2) is a position detection element for detecting the position of the primary reflected light beam (3).

FIG. 4 is a configuration diagram of a tilt sensor using the principle diagram of FIG.
is a case that is attached to the object to be measured (9), and inside this case (8) are a light source (7), a position detection element (6), and a reflector (10) that is always maintained horizontally with respect to the fulcrum (10) K.
) are stored.

Explain the operation to Ash. Even when the object to be measured (9) is tilted, the reflector (1) always remains horizontal, so the angle of incidence of the incident light beam (2) on the reflector (1) changes. Accordingly, as shown in Fig. 3, the primary reflected ray (
Since the reflection angle of 3) also changes, the primary reflected ray (3)
The position of incidence on the position detection element (6) changes. The inclination angle of the object to be measured (9) can be determined from the magnitude of this change in position.

[Problem that the invention seeks to solve]

Since the conventional tilt sensor is configured as described above, in order to improve measurement accuracy, it is necessary to increase the distance (L) between the reflector (1) and the position detection element (6), and accordingly Therefore, a large position detection element (6) must be used, which poses a problem in that the entire tilt sensor becomes large.

The present invention has been made to solve the above-mentioned problems, and aims to provide an inexpensive tilt sensor that improves measurement precision, can be made smaller, and is also inexpensive.

[Means for solving problems]

The inclination sensor according to the present invention includes a case attached to a tilting object to be measured, a light source installed in the case, and a light source installed in the case so as to be always parallel to each other to reflect light from the light source. It is equipped with a plurality of reflectors and a light-receiving element that is attached inside the case and detects the intensity of the reflected light beam reflected by the reflectors.

[For production]

In the tilt sensor of this invention, when an incident light beam that enters a reflector is reflected by multiple reflectors, the intensity of the reflected light changes depending on the angle of incidence, and the light receiving element detects the intensity, which converts it into an electrical signal. By processing the electrical signals, the inclination angle of the object to be measured can be determined.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention, (2
0) is the first reflector made of a glass plate, and (21) is the first reflector.
A second reflector provided parallel to the reflector (20) of (
22) is the incident light beam incident on the first reflector (20);
(23) is the primary reflected ray reflected by the first reflector (20), (24) is the secondary reflected ray reflected by the second reflector (21), and (25) is the incident ray (22) is a slit for narrowing the light, (26) is a light emitting diode (LED).
), a light source consisting of a light emitting element such as a laser diode (LD), (27) is a first reflector (20), a second reflector (
21) is always supported horizontally, (28) is a photodiode that receives the secondary reflected light beam (24), and (28) is a photodiode that receives the secondary reflected light beam (24).
9) is a case that is attached to the object to be measured (30), and inside this case (29) are the above-mentioned members (20) and (21).
, (25).

(26L (28) is stored under nitrogen gas.

Figure 2 is a diagram showing the dependence of the reflectance from the glass surface on the angle of incidence, where Rs is the electric vector of the incident light and the reflectance of the component perpendicular to the plane of incidence, and Rp is the electric vector of the incident light. This is the reflectance of the component parallel to the plane of incidence. Here, the plane of incidence refers to a plane consisting of the incident light and the normal to the boundary surface. The average of both components is the intensity of light that is commonly used.

In the tilt sensor configured as described above, the incident light beam (22) emitted from the light source (26) is
(25), enters the first reflector (20), and becomes a primary reflected light beam (23) whose intensity changes according to the dependence of the reflectance on the angle of incidence as shown in FIG.

This primary reflected ray (23) then passes through a second reflector (
21) and undergoes a second reflection, resulting in the second reflected ray (
24). At this point, the secondary reflected light beam (24) becomes parallel to the incident light beam (22), and this relationship always holds even when the object to be measured (30) is tilted.

Therefore, the secondary reflected light beam (24) is transmitted to the light receiving element (28).
) at a constant angle, where it is converted into an electrical signal. If the deviation from the electrical signal at the reference angle is calibrated with respect to the angle, the inclination angle of the object to be measured (30) can be continuously detected. Furthermore, by connecting a deviation signal from the reference angle to the device and operating the operating end to cancel the deviation, the attitude of the object to be measured (30) can be controlled.

Note that in the above embodiment, the incident light beam (22) is reflected by the first reflector (20) and the second reflector (21), and the change in light intensity is magnified to a square ratio, and the first reflector (20) and the second reflector (21) (20) and the second reflector (21) are arranged in parallel, so the angle of incidence of the secondary reflected light beam (24) on the light receiving element (28) is always constant, making the tilt measurement accurate. will improve.

Also, in the above embodiment, the first and second reflectors (20) for the incident light beam (22) and the primary reflected light beam (23).

As can be seen from Figure 2, the angle of incidence on (21) is set to 70° or more, at which the reflectance changes significantly, and the light receiving element (28) detects only the Rp acid component, so it is possible to measure the inclination. Accuracy is further improved.

Furthermore, the inside of the case (29) is filled with electrical gas to prevent deterioration, so the light source (26) and light receiving element (28)
It is used with the cap removed, and the light source (26
) and the first reflector (20), the distance between the second reflector (20)
The distance between 1) and the light receiving element (28) can be reduced, and the overall shape of the tilt sensor can be reduced.

〔Effect of the invention〕

As described above, in the tilt sensor of the present invention, the light receiving element detects the light intensity of the reflected light rays reflected by the plurality of reflectors provided so as to be always horizontal to each other, so the reflectance This has the effect of amplifying changes and allowing the reflected light to always be incident on the light receiving element at a constant angle, improving measurement accuracy and making it possible to downsize.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a tilt sensor according to an embodiment of the present invention, FIG. 2 is a diagram showing the dependence of the reflectance of glass on the angle of incidence for explaining the invention in detail, and FIG. FIG. 4 is a principle diagram showing an example of a conventional tilt sensor. FIG. 4 is a configuration diagram showing an example of a conventional tilt sensor. In the figure, (20) is the first reflector, and (21) is the second reflector.
reflector, (26) is a light source, (28) is a light receiving element, (2
9) is a case, and (30) is an object to be measured. In each figure, the same reference numerals indicate the same or corresponding parts. 30: Nederata II 4 Sadai Himself Shooting Mountain ψ

Claims (1)

[Claims] a case attached to an inclined object to be measured; a light source attached in the case; a plurality of reflectors provided in the case so as to be always horizontal to each other and reflect light from the light sources; A tilt sensor comprising: a light-receiving element that is mounted inside a case and detects the intensity of the reflected light beam reflected by the reflector.