JPS62274211A - Tilt angle detecting sensor - Google Patents

Abstract

PURPOSE:To improve measuring accuracy and to obtain a stable tilt angle sensor by measuring an interval between two images of a slit arranged in a focal plane and detecting the tilt angle of a vessel and preventing a measuring error due to temperature variation, etc. CONSTITUTION:When the vessel 2 is tilted by an angle theta in the direction of the gravity, an angle made by a horizontal plane 11 and a plane mirror 1 is made to 90 deg.+ or -theta. When a refractive index of a liquid and a focal distance of a condenser lens 4' are denoted as (n) and (f) respectively, in case theta is small, the interval (d) between two images of the slit 6 made by two optical paths is indicated as (d)=4(n)theta(f). In other words, since the interval (d) is proportional to an angle which is subtracted 90 deg. from the angle made by the plane mirror 1 and the horizontal plane 11, namely, the tilt angle theta of the vessel 2, the tilt angle can be calculated by measuring the interval (d). Since the interval (d) is directly given by the tilt angle theta on one photodetector, any error due to the characteristic variation, the relative position variation, etc., of the photodetector due to the temperature variation, etc., is not brought in.

Description

[Detailed description of the invention]

3. 1Iv = Detailed Description of the Invention (Industrial Application Field) The present invention is composed of a virtual plane mirror that sprays the liquid onto the horizontal surface and one side of the container to adjust the inclination angle of the container containing the liquid to the direction of gravity. Two pieces 4! ! The present invention relates to a photoelectric tilt angle detection sensor that converts the reflected light beam into a change in the reflection direction to obtain an output signal corresponding to the tilt angle. (Prior Art) Conventionally, a tilt angle sensor has been put into practical use that detects the tilt of a liquid by utilizing the fact that the liquid always presents a horizontal surface due to the action of gravity. The path of the reflected light from this horizontal surface changes depending on the shape of the container, so we can find the angle of inclination by photoelectrically detecting the change in the path of the reflected light when it is tilted compared to the standard path. That is. At this time, the path of the reflected light is detected by the light receiving detector, but due to changes in the zero point of the light receiving detector due to changes in temperature, fluctuations in sensitivity, fluctuations in relative position, etc. Because the output fluctuates, it is inevitable that there will be errors in tilt angle detection. (Problems to be Solved by the Invention) This invention was made to eliminate the measurement PA difference caused by temperature changes, etc., which is seen in the conventional tilt angle sensor as described above, and improves measurement accuracy and makes it more stable. The purpose of the present invention is to provide a tilt angle sensor. (Means for Solving the Problems) The inclination angle detection sensor of the present invention has a water i′ in FIG.
A container 2 containing a liquid 3't exhibiting F-11 is provided with a plane mirror 1 on its I II surface, and the light from a slit 6 arranged at its focal plane is collimated. This collimated light is transferred to the horizontal surface 11 of the liquid 3 and the plane mirror 1.
A collimating system 4 is fixedly arranged with respect to the container 2 so as to simultaneously make the light incident on both reflecting surfaces of a two-panel mirror consisting of and a condensing system 4' fixedly disposed relative to the container 2 so as to focus the two slits of the slit 6 on the light-receiving detector 7 disposed at its focal plane. There is. (Function) When the angle detection sensor of the present invention is configured in this way, as shown in FIG. They are connected at a distance of d, and since the distance d is proportional to about 1 f + ceramic θ, the inclination θ of the container 2 can be detected by measuring the distance d with the light receiving detector 7. (Actual Case) A first embodiment of the present invention will be described with reference to FIG. 1 and FIG. 2. As shown in FIG. 1, a positive mirror 1 is provided on this side of a transparent container 52 whose Ijr surface makes an angle of approximately 45 with respect to one of the side surfaces, and a transparent liquid contained in the container 2 &C is provided. Container 2'f so that the water iF-11 and the plane mirror 1 are approximately perpendicular to t! : Placed relative to the object to be measured (not shown). The optical axis 9 of the collimator optical system 20 is aligned with the moth surface 1 and the horizontal surface 11.
The light source 5, the collimator lens 4 (which also serves as a condensing lens 4'), the slit 6, the light receiving detector 7, and the half mirror 8 are located on the i-axis, which is approximately directly connected to the intersection line 10 with The collimator optical system 20 is fixed to the container 2 so as to be located in a plane including the plane mirror 9 and the plane mirror 1 and the water IP 11. Since the slit 6 and the light receiving detector 7 are placed vertically on the focal plane of the collimator lens 4, the light H/% of the light source 5 emitted from the slit 6 - Fumiter 8
The light is reflected by the beam and is collimated by the collimator lens 4 to become a beam of light, which passes through the bottom of the container 2 and enters the liquid 3. This sub-beam light is reflected in the order of (1) horizontal plane 1 plane boundary 1 with the plane including the intersection line 10 and parallel to the optical axis 9 as the boundary.
, (2) It is divided into two optical paths: a mirror F and a mirror 11. Then, each reflected light is collected by a condensing lens 4' (also a collimator lens 4) into an I-7 mirror 8.
The light beam passes through the slit 6 and forms images of the two members of the slit 6 (obstructions corresponding to the two optical paths described above) on the light receiving detector 7 placed on the focal plane thereof. In the case of FIG. 11, the plane 'a1 and the horizontal plane 11 are i! Since they form an angle, the images of the slit 6 formed by the two nine reflected lights overlap each other to form one peak. Against this

[7] As shown in Fig. 2, when the container 2 is tilted at an angle θ with respect to the direction of the stuttering force, the angle formed by the horizontal plane 11 and the plane mirror 1 is t14 degrees ti90 + θ (in the case of Fig. 2, it is positive). . Assuming that the refractive index of the liquid 30 is n and the focal length t-f of the focusing lens 4', when θ is small, riSdi between the two holes of the slit 6 formed by the above two optical paths.
t. It is expressed as d = 4 n 19 f . That is, the distance dFi is the angular change obtained by subtracting 90 from the angle formed by the plane mirror l and the horizontal surface 11. Since the distance is proportional to the inclination angle θ of the container 2, the inclination angle can be determined by measuring the distance d. FIG. 3 shows the relationship between the inclination angle θ and the distance d. As is clear from the above explanation, the distance d is given by the II contact slope 040 on one light receiving detector, so it is different from the conventional one. Characteristic fluctuations of the photodetector due to temperature fluctuations due to isobaric changes. No errors due to relative position fluctuations etc. are introduced. When a slit having a pure gap shape as shown in the fourth part is used as the slit 6, if there is an inclination, a law as shown in the fifth part will be formed on the light reception detection D7. If a CCD, license sensor, or the like is used as the light receiving detector 7, the interval d between the peaks can be measured digitally, and the inclination angle θ can be determined based on this. Figures 6 and 7 show the slit 6 (Figure 6) for measuring the image interval d in an analog manner and the light receiving detection 87 (vJ7).
Another example of the shape of figure t- is shown. The slit 6 has an isosceles triangular part 21 whose light intensity decreases symmetrically from the center line of the slit in order to measure the interval d, and a ninth part which keeps the light intensity constant. It is divided into a part 22 with a certain width,
The images are formed on the fluorescent parts 23 and 24 of the light receiving detector 7, respectively. FIG. 8 shows the relationship between the slit iron and each light-receiving part of the light-receiving detector when there is an inclination. Two images of the slit portion 21 formed by the two optical paths are shown by solid lines and dotted lines. The relationship is as shown in FIG. 9 with respect to the output Fi of the light receiving section 23 and the inclination angle θ.
It will be proportional to. Here, a' and %vX of such a slit are as follows: If the light receiving part 23 is located at any position within the range where the two parts of the slit part 21 intersect, the slit covering the light receiving part 23 is The area of the two l's of the portion 21 is the area t of the light receiving part 23.
Since it is constant regardless of v-, the intensity of the detected light is not affected by fluctuations in the position of the light receiving detector due to temperature fluctuations or the like. Note that the shape of the slit portion 21 is not limited to the above-mentioned one; for example, the shape of the slit portion 21 may be such that the light intensity increases symmetrically outward from the center line. The output of the corresponding light receiving section 24 is used to control the emission intensity of the light source 5, keeping the light intensity if of the slit 21 constant, and eliminating measurement errors due to changes in light intensity. Figures 10 and 11 show a side view and a KF plane view of an embodiment in which a half mirror is not used in the frimeter optical system.
The slit 6 and the light receiving detector 7 are the collimator lens 4
(The condensing lens 4 can also be covered) is placed in a symmetrical position with respect to a thousand planes (thousand planes perpendicular to plane M in Figure 11) that include an optical axis of 9 feet and intersect with 10 lines of intersection. . By arranging the optical system in this way, the slope of the embodiment shown in FIGS. 1 and 2 is 1! ! The tilt angle can be determined in the same way as the detection sensor. FIG. 12 shows the elegance of an embodiment in which the collimator lens 4 of the light transmitting system and the condensing lens 4' of the light receiving system are constructed with separate lenses, and similarly a half mirror is not used.
is arranged at the focal plane of the collimator lens 4, and the light receiving detector 7 is arranged at the focal plane of the condensing lens 4'. The operation is similar to that of each of the embodiments shown above. In each of the above embodiments, it is not possible to determine the direction of inclination, that is, the sign of the inclination angle θ. If it is necessary to determine this sign, use the inclination angle detection sensor of the present invention only on the + side or the + side of the inclination angle θ on the characteristic diagram shown in Fig. 3 or Fig. 9. When spraying onto the object to be measured, either adjust the position or spray the collimator lens 4 and slit 6 in the plane including the line 0, which roughly intersects the optical axis 9, as shown in FIGS. It is preferable to use an opaque cutting board 25 or the like placed between the two. This kind of cutting board 2
5, the sign of the inclination θ that can be detected is only on the + side. In the above embodiment, the collimated light from the collimator lens 4 is transmitted from inside the liquid to the plane mirror 1 and the horizontal surface 1.
If the horizontal surface 11 of the liquid 3 is reflective, the collimated light may be made to enter the liquid 3 from above. It will be apparent to those skilled in the art that various modifications can be made to the pond. (Effects of the Invention) As described above, according to the present invention, the mole beam 1@ is divided into two optical paths by the two mirrors configured such that the mole surface firing and the liquid horizontal plane are generally orthogonal to each other. It is reflected, and in the condensing system, the reflected light of each optical path is disturbed and the two of the friend slits are
Since the tilt angle is detected by measuring the interval between the two irons, it is possible to provide a highly accurate tilt angle detection sensor that is not affected by fluctuations in precision or the like. This tilt Ml* output sensor can detect the tilt of an object with high precision, and it is possible to apply feedback to the tilt of the object or the pond object it is related to by using the 9-ton air signal, and the automatic side It can be used for remote control, etc.

[Brief explanation of the drawing]

Fig. 1 is a side view of a cry angle sensor according to an embodiment of the present invention, Fig. 2 is an explanatory diagram when there is an inclination, the third figure is a characteristic diagram of the inclination angle versus image distance, and Fig. 4 is Figure 5 is a front view of an example of the slit shape, Figure 5 is a front view of the slit shape I, Figure 6 is a front view of the f width side of the slit shape, and Figure 7 is the front view of the slit shape. Front view of the light receiving detector corresponding to the slit in the figure, No. 8
The figure is an explanatory diagram showing the relationship between the slit obstruction in Figure 6 and the photodetector in Figure 7, Figure 9 is a tilt angle vs. output characteristic diagram in the case of Figure 8, and Figures 10 and 11 are FIG. 12 is a front view and a front view of an embodiment in which the half mirror 1 is not used, and FIG. : Container 3: Liquid 4: Collimator lens 4': Condensing lens 5: Light source 6: Slit 7: Light receiving detector 8: Half mirror 9: Optical axis 10: Line of intersection 1
1: Horizontal surface of liquid 20: Collimator optical system 21: Slit for measuring inclination angle 22: Slit for controlling light intensity 23: Light receiving part for measuring inclination angle 24: Light receiving part for controlling light intensity 25: Shikiri plate patent applicant Atom type Business measurement machine
Patent attorney Fumi Sato (and 2 others)
First name) Ward Hase-ji 4
Figure Po 5 Figure Bo 6 1' Sekisu 8 Figure Leather Port Book 11 Figure 112 Procedural Amendment (Voluntary) 1985 June 233 Commissioner of the Patent Office Uga Michibe 1, Indication of Case 1988 Patent Application No. 117575 2, Name of the invention Inclination angle detection sensor 3, Relationship to the case of the person making the amendment Patent applicant address 1-1-1 Tomigaya, Shibuya-ku, Tokyo Name Sokkisha Co., Ltd. Representative Kogako Parti 4. Agent 5, Subject of amendment Column 6 of “Detailed Description of the Invention” of the specification, Contents of amendment -) Correct the 19th line of the same page, "Focusing lens 4'" to "Condensing lens 4".
’”. 3) Change “on the plane of Figure 11” to “1st line” on page 10, line 15 of the same page.
1 on the page of the paper.

Claims (7)

[Claims] (1) A container containing a liquid exhibiting a horizontal surface and having a plane mirror on one side, collimating light from a slit placed at its focal plane, and collimating the collimated light between the horizontal plane of the liquid and the plane mirror. A collimating system is fixedly arranged with respect to the container so that the light is simultaneously incident on both reflecting surfaces of the two mirrors, and the collimated light reflected twice by the two mirrors is collected and collected. a condensing system fixedly disposed relative to the container so as to form two images of the slit on a light-receiving detector disposed in a focal plane; An inclination angle detection sensor, characterized in that the inclination angle of the container is detected by measuring the interval between. (2) The slit is in the shape of a slit, and the light receiving detector is configured to measure the distance between two images of the slit in the slit shape. An inclination angle detection sensor according to scope 1. (3) The slit has a shape such that the light intensity distribution of the slit image changes continuously and symmetrically from the center line of the slit, and the light receiving detector is located within the intersection range of the two images of the slit. 2. The tilt angle detection sensor according to claim 1, wherein the sensor is configured to measure the total light intensity of a predetermined width in the center line direction. (4) The tilt angle detection sensor according to any one of claims 1 to 3, wherein the collimating system and the condensing system are constituted by one imaging system. (5) Any one of claims 1 to 4, characterized in that a partition plate is provided between the collimating system and the slit and between the light collecting system and the light receiving detector. Tilt angle detection sensor described in . (6) According to any one of claims 1 to 5, the collimated light from the collimating system is arranged so as to be incident on the horizontal surface of the liquid and the plane mirror from below the horizontal surface. The tilt angle detection sensor described. (7) According to any one of claims 1 to 5, the collimated light from the collimating system is arranged so as to be incident on the horizontal surface of the liquid and the plane mirror from above the horizontal surface. The tilt angle detection sensor described.