JP2004012203A - Optical inclination angle detecting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize at least one from among improvement of measuring precision, reduction of time necessary for measurement and that measuring precision is not affected by temperature, as compared with a conventional optical inclination angle detecting device. <P>SOLUTION: The inclination angle detecting device includes a unit to be projected including two or more kinds of materials, a light projecting unit for projecting a light to the unit to be projected, a light receiving part which receives a light containing a light which is projected from the projecting unit to the unit to be projected, and optically affected by the unit to be projected, converts the light to an electronic signal and outputs it, and a processing part which inputs the signal from the light receiving part, and calculates an inclination angle to the gravity direction, on the basis of the signal. The two or more kinds of materials accommodated in a vessel contain a part making a planar boundary vertical to the gravity at least in the case of inclination angle measurement. The inclination angle to the gravity direction is calculated by detecting the inclination of the boundary surface with the light receiving part. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical inclination angle detecting device.
[0002]
2. Description of the Related Art In Japanese Patent Application Laid-Open No. 60-183516, as specified in the tenth line from the upper left of page 2 of the specification, the inclination angle of a structure in which a light source and a one-dimensional image sensor are opposed to each other with a communicating pipe interposed therebetween. A detection device is disclosed. An opaque fluid is sealed in the communication pipe. However, when an opaque liquid is used as the enclosed fluid, there are two drawbacks: the inclination direction cannot be determined, and the output of the inclination angle detection device has a time delay. The following description is based on the assumption that an opaque liquid is used as the opaque fluid while air is also sealed in the communication tube.
[0003]
First, a three-dimensional coordinate system and an angle are defined in FIG. In the x, y, and z axes, respectively, a perpendicular line 104 from the origin 43 to the surface 44 and an xy plane are formed with respect to a surface 44 having an intercept of a 'indicated by 40, b' indicated by 41, and c 'indicated by 42. The angle 101 is defined as θ. The x-axis component of θ is defined as + θx, and the y-axis component is defined as + θy. FIG. 11 is a conceptual diagram of the apparatus disclosed in Japanese Patent Application Laid-Open No. 60-183516. The relationship between the coordinates indicated by 2 in FIG. 11 and the angles θ, + θx, + θy is as shown in FIG. In FIG. 11, the distance 61 between the one-dimensional image sensors 45 and 46 is d. ₁ The distance 114 in the z-axis direction between the boundary positions 68 and 69 between the air 9 and the opaque liquid 49 at the position of the one-dimensional image sensor is represented by d. ₂ Then, the inclination angle in the θy direction is tan ^-1 (D ₂ / D ₁ ). Suppose that it is inclined in the -θx direction in FIG. This is shown in FIG. Of the light emitted from the surface light source 50, the light below the light 52 is blocked by the opaque liquid 49 and does not reach the one-dimensional image sensor 45. Therefore, assuming that the output of a pixel irradiated with light on the one-dimensional image sensor 45 is “1” and the output of a non-irradiated pixel portion is “0”, the output of a pixel below the light beam 52 in FIG. , While the output of the pixels above the light ray 52 is “1”. FIG. 14A shows an output state of the one-dimensional image sensor. Next, it is assumed that the inclination angle detecting device in FIG. 11 is inclined in the + θx direction. This is shown in FIG. In this case, similarly to the case of FIG. 12 inclined in the −θx direction, the light below the light beam 52 in FIG. 13 is shielded by the opaque liquid 49, so that the output of the pixel below the light beam 52 is “0”, Pixel outputs of 52 or more are "1". FIG. 14B shows the state of pixel output in this case. 14A and 14B, the vertical axis is a position number when the pixels of the one-dimensional line sensor 45 are counted from above. The horizontal axis is the output of each pixel, which is "1" or "0". Comparing FIG. 14A and FIG. 14B, when the tilt angle detecting device disclosed in JP-A-60-183516 is tilted by the same amount in the + θx direction and the −θx direction, the one-dimensional image sensor 45 is detected. Are completely the same, and it can be seen that the difference in the inclination direction cannot be determined.
[0004]
Next, the occurrence of a time delay in the output of the tilt angle detection device disclosed in Japanese Patent Application Laid-Open No. 60-183516 will be described. It is assumed that the detection device has changed from the state shown in FIG. 13, that is, the state inclined in the + θx direction, to an angle state of 0 in the + θx direction. In this case, a very thin film of the opaque liquid remains on the wall surface of the communication tube, and blocks light from the light source. The opaque liquid remaining on the wall flows downward with time and eventually disappears. This is the cause of the time delay. FIG. 16A shows the output of the one-dimensional image sensor 45 in a state of being inclined in the + θx direction. FIGS. 15B, 15C, and 15D show a state where the state of the liquid changes over time when the inclination in the + θx direction is 0. FIGS. 16 (a), (b), (c) and (d) show outputs in the states of FIGS. 15 (a), (b), (c) and (d), respectively. FIG. 15B shows a state in which the time elapses from the state in which the angle is inclined in the + θx direction to the state in which the angle is 0, and the time lapse is short. A thin opaque film remains on the inner surface of the communication tube, and the light beam is remarkably blocked by the film. Even in the same horizontal state, the output varies with the passage as shown in FIGS. 16 (b), (c) and (d). Since the value of the tilt angle calculated in FIG. 15D is a desired measurement value, accurate tilt angle measurement is impossible when the above-described film remains, and the tilt angle in FIG. I have to wait until the state. That is, depending on the change in the tilt angle, it may take time to measure the tilt angle with high accuracy.
[0005]
As a simple type of tilt angle detecting device, a device using a bubble tube has been widely used. In a bubble tube in which a liquid and bubbles are sealed, the upper portion of the bubble tube has a convex surface or a concave surface, and bubbles contained therein are shifted from the center by the inclination angle. In the tilt angle detection device described in Japanese Patent Publication No. 6-48194, a light beam is emitted from above or below, a light receiving element is arranged on the opposite side of the bubble tube from the light source, and light transmitted and refracted from the bubble tube is received by the light receiving device. receive. The amount of light received is converted into an electronic signal by the light receiving element, and information on the shift of the bubbles in the bubble tube is obtained from the electronic signal by calculation, whereby the inclination angle with respect to the direction of gravity can be known. In the tilt angle detecting device described in Japanese Patent Application Laid-Open No. H07-146142, an electrolytic solution is used as the liquid in the bubble tube. The bubble position shifts according to the tilt angle. At this time, the shift of the bubble position causes a change in the ratio of the bubble and the electrolyte contacting the electrodes, and changes the impedance between the electrodes. The inclination angle is calculated by detecting the impedance. However, in the case of using a bubble tube, an error occurs due to expansion and contraction of bubbles sealed in a liquid caused by a change in temperature. In the case of the tilt angle detection device described in Japanese Patent Publication No. 6-48194, the area of the bubble shadow on the light receiving element changes due to the change in the size of the bubble, and therefore, the electronic signal from the light receiving element changes. . Further, in the tilt angle detecting device described in Japanese Patent Application Laid-Open No. H07-146142, the impedance between the electrodes changes when the area of the bubble contacting the electrodes increases.
[0006]
As disclosed in Japanese Patent Application No. 8-59186, there is a method for detecting a tilt angle between a plurality of electrodes by changing an impedance by filling a closed container with an electrolytic solution as a tilt angle detecting device. A disadvantage of this type of tilt angle detection device is that the use period of the detection device is limited due to deterioration of the electrolytic solution. Patents relating to this type of tilt angle detecting device also disclose several patents relating to prolonging the life of an electrolytic solution. For example, in Japanese Patent Application No. 7-146142, the amount of electrolysis is reduced by enlarging the area of the electrode in contact with the electrolyte and suppressing the current density flowing in the electrolyte. However, in any case, this method causes deterioration of the electrolytic solution due to electrolysis or the like, and limits the use period of the detection device.
[0007]
Problems to be Solved by the Invention, Means for Solving Problems, and Effects
The present invention is based on the above circumstances, and achieves at least one of improvement of measurement accuracy of a tilt angle measuring device, reduction of time required for measurement, and prevention of measurement accuracy from being affected by temperature. The objective is to obtain an optical tilt angle detecting device of each of the following embodiments. As in the claims, each aspect is divided into sections, and each section is numbered from (1) to (9), and if necessary, is described in a form in which the numbers of other sections are cited. This is merely for the purpose of facilitating the understanding of the present invention, and the technical features and combinations thereof described first in the present invention should not be construed as being limited to those described in the following sections. Further, when a plurality of items are described in one section, it is not always necessary to adopt the plurality of items together, and it is also possible to take out and adopt only some of the items.
[0008]
(1) A light projecting unit including a container containing two or more types of substances, a light projecting unit that projects light to the projecting unit, and a projecting unit that projects light from the projecting unit to the projecting unit. A light receiving unit that receives light including light that has been optically affected, converts the light into an electronic signal, and outputs the electronic signal; and inputs an electronic signal from the light receiving unit, and calculates a tilt angle based on the electronic signal. An optical tilt angle detection device that includes a processing unit, and detects a tilt angle of a light-projected portion with respect to the direction of gravity from a position state of a substance in a container.
An advantage of optically detecting the inclination angle is that the degree of deterioration in the characteristics of the light-receiving portion and the light-receiving portion is extremely small even when used for a long period of time.
[0009]
(2) The processing unit transfers the whole or a part of the boundary position formed between the different types of substances to the light receiving unit, among the positional information of the substances contained in the container constituting the light receiving unit. The optical inclination angle detection device according to (1), wherein the inclination angle with respect to the direction of gravity is calculated by the processing unit. The container constituting the light-projected portion of the optical tilt angle detecting device may or may not be sealed. When two or more types of substances are accommodated in the closed container that constitutes the projected part, a boundary surface is formed between the substances, and the position of the boundary surface changes due to the effect of gravity, and the entire position of the boundary surface is changed. Alternatively, as long as the portion can be detected by the light receiving section, the substance in the container can be in any state of gas, liquid, and solid.
In addition to the light projecting unit, the light projecting unit, the light receiving unit, and the processing unit as components of the optical inclination angle detecting device, light emitted from the light projecting unit or light receiving unit for the purpose of improving the inclination angle detection characteristics. It is possible to provide a filter, a reflection plate, a slit, a lens, a shielding plate, and the like that limit or change the properties of light that has been optically affected in the light projecting unit. At this time, the position where the filter, the reflection plate, the slit, the lens, the shielding plate, etc. are disposed may be in the optical path from the light receiving section to the light receiving section, in the optical path from the light receiving section to the light receiving section, or in the light receiving section. Inside.
An advantage of deriving the tilt angle based on information on the boundary between different substances in the container constituting the light-projected portion is that it is inexpensive and easy to realize a high-precision optical tilt angle detection device.
[0010]
(3) The substance contained in the container is a transparent or translucent liquid and a transparent or translucent gas, or a plurality of types of transparent or translucent liquids, and different types of substances formed in the container. The optical tilt angle detecting device according to (2), wherein the whole or a part of the position of the boundary surface between the substances is detected by the light receiving unit, and the processing unit calculates the tilt angle. In Japanese Patent Application Laid-Open No. 60-183516, a transparent gas and an opaque liquid are put in a container, light is irradiated to the container, and a light transmitted through the gas and liquid in the closed container and the inside thereof is detected by a one-dimensional image sensor. An inclination angle detection device that detects an inclination angle based on information on a liquid level in a closed container included in a light beam is disclosed.
If an opaque substance is used as the substance contained in the container, a case may occur in which the opaque substance itself conceals boundary information. That is, the range of the tilt angle that can be detected is limited because the optical path to the light receiving unit is limited, or the relative positional relationship between the shape of the container constituting the light receiving unit, the light transmitting unit, the light receiving unit, and the light receiving unit. Will be limited.
For example, in FIG. 7, a transparent or translucent closed container 29 having a triangular pyramid shape, and a light-receiving portion in which a mixed liquid 7 of alcohol and water and air 9 are accommodated in the container 29 as a transparent or translucent liquid, Light is emitted from the electroluminescent device 5 as a light projecting unit for projecting light to the container, and the camera 19 having a two-dimensional array of charge-coupled elements as a light receiving unit facing the light projecting unit with the light projecting unit interposed therebetween. In an inclination angle detecting device for detecting the position of the boundary 11 between the liquid and the air formed on the side surface of the container constituting the light receiving portion, it is not appropriate to use an opaque liquid instead of a transparent or translucent solution. This is because when the boundary position 11 between the different substances in FIG. 8, which is an example of the image of the light-projected portion obtained by the camera 19 in FIG. 7, is in the state shown in FIG. In such a case, the boundary position 11 between the different substances cannot be obtained. However, as shown in FIGS. 7 and 8, if a transparent or translucent solution and a transparent or translucent gas are used as the substances to be contained in the container and the container shape is known, for example, a triangular pyramid shape The ratio of the lengths 94, 95, 96 occupied by the air and the lengths 97, 98, 99 occupied by the liquid on each side of the container 29 specifies at least three non-linear three-dimensional positions. Therefore, both the inclination angles θ and φ of the coordinate 2 shown in FIG. 7 can be calculated.
Further, for example, FIGS. 24 and 25 show a case where an opaque liquid and air are sealed in a rectangular parallelepiped transparent container as the light-projected portion, and a boundary line on a side surface is detected by a camera. It is difficult to distinguish between the 25 states. This is due to the reason described in the section “0003” of “Prior Art” in the present specification. On the other hand, as shown in FIGS. 22 and 23, as the light-projected portion, a transparent or translucent liquid and air as a transparent or translucent gas are sealed in a rectangular parallelepiped transparent container. When the detection is performed by the camera 85, it is possible to obtain a boundary position 88 on a plane close to the camera 19 and a boundary position 89 on a plane far from the camera 19 by changing the focus position of the camera 85. It is possible to do. Further, the detection of the boundary position on both the near surface and the far surface and the distinction thereof can be performed by providing an imaging lens in the optical path of the light-receiving portion and the light-receiving portion as shown in FIG. When the imaging lens is not provided as shown in FIGS. 18 and 19, the contrast of the light amount distribution at the boundary position on the surface close to the sensor is larger than the contrast on the distant surface. It is possible.
By measuring the mutual width of the boundary lines generated on the two surfaces, the inclination in the direction perpendicular to the surfaces can be obtained. For example, in FIG. 18, the height of the boundary indicated by 91 is p, and the height of the boundary indicated by 92 is q. The length of one side of the container indicated by 116 in FIG. 18 is represented by c. At this time, when p and q are measured by the one-dimensional photoelectric conversion element 75, the inclination angle of the coordinate 2 in FIG.
tan ^-1 It can be calculated from ((p−q) / c). The relationship between coordinate 2 and θx in FIG. 18 is as shown in FIG.
That is, by making the substance contained in the container a transparent or translucent substance, more information on the boundary between different kinds of substances can be obtained.
When an opaque liquid is used as the substance contained in the container, one of the drawbacks is that the response time is slow. This is because when the liquid level inside the closed container drops, the opaque liquid remains on the wall of the closed container and must wait until the liquid moves to the correct liquid level position. The detection of the boundary position requires a long time. This is as described in the section "0004" of the "prior art" of the present specification.
In order to solve the problem of the response time, it is effective to make the liquid contained in the container constituting the light-projected portion transparent or translucent. As a result, the light beam is not blocked or refracted significantly due to the small amount of liquid remaining on the wall of the closed container, and the trace amount of liquid remaining on the wall higher than the current liquid level is a cause. This is because light rays are interrupted and a position higher than the actual liquid level is not detected. Therefore, even when the liquid level is lowered due to a change in the tilt angle, it is not necessary to wait until a small amount of liquid remaining on the wall surface falls to the current liquid level, and the time required for measurement is reduced. Referring to FIG. 17, a transparent or semi-transparent liquid 6 containing a transparent or translucent liquid 6 and an air 9 as a transparent or translucent gas is contained as a light projecting part as shown in FIG. Includes a transparent rectangular parallelepiped container 111, includes one-dimensional photoelectric conversion element arrays 75 and 76 as light-receiving parts, sandwiches a light-receiving part, and is arranged so that the light-receiving part and the light-receiving part face each other. Consider an angle detection device. Here, the relationship between the coordinates indicated by 2 in FIG. 17 and the inclination angles θx and θy is as shown in FIG. The light receiving units 75 and 76 detect the boundary positions 77 and 78 of the boundary surface 107 between different substances on the surface of the inner wall of the container close to the light receiving unit, respectively. Here, the heights of the boundary positions 77 and 78 between the different materials from the bottom of the container are a and b, respectively, and the distance between the centers of the one-dimensional photoelectric conversion element arrays 75 and 76 is c. Θy is determined by the height of the detected boundary position between the different substances and the center-to-center distance of the one-dimensional photoelectric conversion element array.
tan ^-1 It is determined from ((ab) / c). Here, in this device configuration, it is assumed that the state shown in FIG. 19, that is, the state tilted + θx in the + x direction, has changed to the state shown in FIG. 20, that is, the state of 0 in the + x direction. In this case, as shown in FIGS. 26 (b), (c), and (d), a transparent or translucent liquid film remains on the wall surface of the container, flows downward with time, and finally disappears. (A), (b), (c), and (d) of FIG. 27 are one-dimensional figures of FIG. 26 in the states of (a), (b), (c), and (d) of FIG. 26, respectively. The output of the photoelectric conversion element array 87 is shown. Even in a state where this film remains, that is, in the states of FIGS. 26 (b) and (c), it is possible to detect the boundary position indicated by 73 in FIGS. 26 (b) and (c) from the light quantity distribution. The inclination angle in the θx direction can be calculated without waiting until the state shown in FIG.
[0011]
(4) The boundary between the two substances contained in the container includes the light-projected portion having a structure including a plane or a planar shape perpendicular to the direction of gravity, and the boundary between the different kinds of substances in the container. The optical inclination angle detecting device according to the above mode (2), wherein the inclination angle is calculated based on the direction of the surface. (Claim 1)
In the description of any paragraph including this paragraph, when the shape of the boundary between different kinds of substances is described as a plane, the part of the boundary between the different kinds of substances that contacts the inner wall of the container slightly deviates from the plane due to surface tension or the like. However, in such a case, the boundary shall be regarded as forming a plane.
In this case, two upper and lower boundary lines usually appear due to surface tension. In such a case, processing such as setting the middle position between the upper and lower boundary lines as a boundary is performed. Also, the image of the line may become a thick line due to the influence of focus. In this case, the center of the line may be adopted, or the upper and lower ends of the line may be used.
As the optical tilt angle detecting device, a device using a bubble tube has been widely used. In a bubble tube enclosing a liquid and bubbles and having a convex or concave upper shape, the bubbles contained therein are shifted from the center according to the inclination angle. In Japanese Patent Publication No. 6-48194, a light beam is emitted from an upper or lower light source, and a light receiving element facing the light source with a bubble tube interposed receives light transmitted and refracted from the bubble tube. The amount of light received is converted into an electronic signal by the light receiving element, and information on the shift of the bubbles in the bubble tube is obtained from the electronic signal by calculation, whereby the inclination angle with respect to the direction of gravity can be known. In Japanese Patent Application Laid-Open No. 7-146142, the liquid in the bubble tube is used as the electrolyte, and the shift of the bubbles in the bubble tube appears as an impedance change between the electrodes corresponding to the ratio of the bubbles in contact with the electrodes and the electrolyte. The inclination angle is calculated from this information. However, in the case of using a bubble tube, an error occurs because bubbles surrounded by the liquid expand and contract due to a change in temperature.
In the present invention, the inclination angle is calculated from the inclination of the boundary surface formed by the two substances enclosed in the container forming the light-projected portion. Does not.
For example, in the state where the inclination angle is the same in FIG. 17, the boundary position between different materials indicated by 108 is the boundary surface after changing from the boundary position between different materials indicated by 107 due to expansion and contraction of the material. The moving distance of the boundary position between the different materials in the one-dimensional photoelectric conversion element arrays 75 and 76 has the same value α. Here, the heights from the bottom surface of the container at the boundary between the different substances, indicated by 107 before movement, detected at 75 and 76, are denoted by e and f, respectively. The distance 81 between the centers of the one-dimensional photoelectric conversion element arrays 75 and 76 is g. Even if the tilt angle is calculated in the state of being moved by expansion and contraction, the tilt angle in the θy direction is
tan ^-1 ((E + α-f-α) / g)
= Tan ^-1 From ((ef) / g), the same value tan as before the movement is obtained. ^-1 ((Ef) / g) will be obtained.
In the case where the inclination angle is detected based on the boundary position information between different types of materials in the container that constitutes the light-projected portion, the boundary between the different materials in the container that constitutes the light-projected portion is positioned with respect to the direction of gravity. When detecting the inclination angle from a shape that is close to a plane that is close to a vertical plane or a shape that is close to a plane that is perpendicular to the direction of gravity and that is close to a plane that is perpendicular to the direction of gravity, two lines that are not parallel Alternatively, by detecting one line segment and one point that is not on a straight line including the line segment, or three points that are not on the same straight line, the inclination angles in two directions can be known.
For example, referring to the drawings, when the three points on the surface 34 in FIG. 9 are detected to determine the inclination angle of the surface 34, the position of the point 35, the position of the point 36, and the position of the point 37 are detected. , Θ can be calculated. Here, the φ direction is an inclination angle around the z axis, and the θ direction is an inclination angle around the x axis. Only by detecting the position of the point 36, the position of the point 37, and the position of the point 38, the inclination angle in the φ direction can be calculated and the inclination angle in the θ direction cannot be calculated. When one line segment position and one point position on the plane 34 in FIG. 9 are detected and the inclination angle of the plane 34 is obtained, the line segment position connecting the points 36 and 37 and the position of the point 35 are detected. The inclination angles in the φ direction and the θ direction can be calculated. For example, when detecting the position of the line segment connecting the points 36 and 37 and the position of the point 38, the inclination angle in the φ direction alone can be calculated, and the inclination angle in the θ direction cannot be calculated. When the position of two line segments on the plane 34 in FIG. 9 is detected and the inclination angle of the plane 34 is obtained, for example, the position of the line segment connecting the points 35 and 36 and the position of the line segment connecting the points 36 and 37 are detected. Then, the inclination angles in the φ direction and the θ direction can be calculated. Further, for example, if only the position of the line segment connecting the points 36 and 37 and the position of the line segment connecting the points 37 and 38 are detected, the inclination angle in the φ direction can be calculated. It is impossible. Generally speaking, if at least two non-parallel line segments on one plane, or one point not on a straight line including one line segment and that line segment, or three points not on a straight line, are obtained, The expression ax + by + cz = d representing the plane is obtained. If the equation is obtained, the inclination angles φ and θ in FIG.
φ = tan ^-1 (-A / b),
θ = tan ^-1 (−c / b).
As can be seen from the above example, to obtain information including two non-parallel line segments, or one line segment and one point not on a straight line including the line segment, or three points not on a straight line, By combining the following terms including this term, it is possible to detect inclination angles in two independent directions.
[0012]
(5) The light receiving unit includes a one-dimensional array of photoelectric conversion elements, and the light receiving unit detects the position of the boundary surface at two or more positions, and the processing unit detects a relative positional relationship between the two or more positions. The optical inclination angle detecting device according to the above mode (4), wherein the inclination angle of the planar boundary surface is calculated. (Claim 2)
As an advantage of the optical tilt angle detecting device according to the present invention, the position of a portion forming a plane perpendicular to gravity in the boundary between different kinds of substances is detected at two or more points, and the inclination of a line segment connecting the points is detected. Is calculated by calculating the inclination angle, the change in the liquid level due to the change in the volume ratio of the substance contained in the container due to the expansion and contraction of the substance due to the temperature change, etc., affects the detection accuracy. I will not.
Since the substance contained in the container is a combination of a transparent or translucent gas and a transparent or translucent liquid, or a combination of a plurality of types of transparent or translucent liquids, a one-dimensional array of photoelectric conversion elements Accordingly, it is possible to obtain a light amount distribution near the boundary surface between the different substances on the inner wall of the container, and to detect the boundary position between the different substances from the light amount distribution with subpixel accuracy of the photoelectric conversion element array. Thus, it is possible to detect the tilt angle with high accuracy. The one-dimensional array of photoelectric conversion elements is also advantageous in that it is small and lightweight, and contributes to the realization of a small and highly accurate tilt angle detection device.
Further, in the apparatus according to the present mode, when three points that are not on the same straight line of a portion forming a plane perpendicular to the gravitational direction in the boundary between the heterogeneous substances are detected, The position of the portion forming the vertical plane can be specified. Therefore, it is possible to detect the inclination angles in two directions.
[0013]
(6) The light receiving section includes a two-dimensional array of photoelectric conversion elements, the light receiving section detects the whole or a part of the position of the boundary plane between different kinds of substances, and calculates an inclination angle from the position of the boundary plane (3). Item 4. The optical tilt angle detecting device according to any one of Items 1 to 4.
Conventionally, in a tilt angle detection device that calculates a tilt angle by detecting the position of a bubble in a bubble tube or the position of a spherical pendulum in a concave container, photoelectric conversion in which four photoelectric conversion elements are arranged in a cross-shape in a plane. 2. Description of the Related Art There has been known an inclination angle detection device that uses an element two-dimensional array, compares signals from the four photoelectric conversion elements, and detects an inclination angle by comparing light amounts. In the case of this type, the variation or aging of the photoelectric conversion characteristics among the four photoelectric conversion elements causes an error. That is, even if the light quantity is the same, a difference occurs between the converted signals, and the difference between the signals causes an error in the detection of the tilt angle, and the importance of the calibration of the photoelectric conversion characteristics of the photoelectric conversion element increases. Some photoelectric conversion elements are provided with a calibration light source for each photoelectric conversion element to facilitate the calibration of the photoelectric conversion characteristics. However, since the light sources themselves also vary, the problem cannot be completely solved. In the present invention, the two-dimensional array of photoelectric conversion elements is used to detect a boundary position between substances in the light-projected portion, and the inclination angle is detected based on the inclination of the boundary position between the substances. Therefore, a slight variation in the conversion characteristics of the photoelectric conversion element and aging do not cause an error. Since the substance contained in the container is a combination of a transparent or translucent gas and a transparent or translucent liquid, or a combination of a plurality of types of transparent or translucent liquids, a two-dimensional array of photoelectric conversion elements Thus, it is possible to obtain a light amount distribution near the boundary surface between the different substances on the inner wall of the container, and to detect the boundary position between the different substances from the light amount distribution with subpixel accuracy of the photoelectric conversion element array. Yes, highly accurate tilt angle detection is possible.
[0014]
(7) The boundary between the two substances contained in the container forms a plane perpendicular to the direction of gravity or includes a plane perpendicular to the direction of gravity, the light receiving unit includes a two-dimensional photoelectric conversion element array, The part detects the whole or a part of the boundary position between the plane and the inner surface of the container. Then, linear approximation is performed on the detected boundary position. (4) The optical inclination angle detection device according to (4), wherein the inclination angle is detected based on the inclination of a straight line obtained by linear approximation with respect to the detected boundary position. (Claim 3)
Since the substance contained in the container is a combination of a transparent or translucent gas and a transparent or translucent liquid, or a combination of a plurality of types of transparent or translucent liquids, a two-dimensional array of photoelectric conversion elements Thereby, a light amount distribution near the boundary between the different substances on the inner wall of the container can be obtained. With this light quantity distribution, it is possible to obtain a boundary position between different kinds of substances. A straight line approximation is performed for the detected boundary position between different substances on the inner surface of the container, and the inclination angle is calculated from the inclination of the straight line. In order to measure the inclination itself of the boundary between different kinds of substances, a change in the height of the boundary between different kinds of substances due to a change in volume ratio due to expansion and contraction of the substance due to a change in temperature, etc., may cause a tilt angle measurement error. There is no. The principle description of this is the same as the content described in the section (4).
[0015]
(8) In the light receiving section, the whole or part of the three-dimensional shape of the container constituting the light-projected part and the whole or part of the three-dimensional position between the different kinds of substances are detected, and the inclination angle of both is detected. The optical tilt angle detecting device according to any one of (2), (3), (4), (5), (6), and (7), which performs the calculation. (Claim 4)
The relative positional relationship between the container constituting the light-receiving portion and the boundary surface at the time of measurement is detected, and the relative positional relationship between the light-emitting portion, the light-receiving portion, and the light receiving portion is moved by vibration, impact, or the like. Even if it occurs, it can be measured with high accuracy. Therefore, it is possible to measure the tilt angle robustly against vibration, impact, and the like.
An example will be described with reference to FIG. The tilt angle of the configuration including the electroluminescent device 5 constituting the light projecting unit, the triangular prism transparent container 23 containing a transparent or translucent solution and air inside the projecting unit, and the camera 19 constituting the light receiving unit The detection device will be described. It is assumed that the relative positions of the light projecting unit, the light projecting unit, and the light receiving unit are fixed. The camera 19 includes a two-dimensional image sensor, and can capture a two-dimensional image of the light-projected portion. The shape of the container constituting the light-projected portion is a right-angled triangular prism, and two sides of the same shape among three sides have a side d. ₃ And the shape is known at the time of measurement. Here, a case is considered as an example where a change is added to the relative positional relationship between the light receiving unit and the light projecting unit, and the relative positional relationship between the light projecting unit and the light projecting unit does not change.
When calculating the tilt angle only from the position of the boundary between different substances obtained from the image obtained by the camera 19, the calculated value of the tilt angle naturally includes an error. On the other hand, by obtaining the position and shape of both the outer shape of the container and the boundary between different kinds of substances by the camera 19, it is possible to reduce the error included in the value of the calculated inclination angle. For example, FIG. 5 is an image of the light-projected portion obtained by the camera 19 in the tilt angle detection device of FIG. According to the image shown in FIG. 5, the distances 94 from each vertex 62, 63, 64, 65, 66, 67 to the boundary between different substances are s, 95 are t, 96 is u, 97 is p, 98 is q, 99 Is r. At this time, it is assumed that the mixed liquid 7 is on the lower side and the air 9 is on the upper side. According to FIG. 5, the ratios of s and p, t and q, u and r can be obtained, and one side is d. ₃ In addition, s, t, u, p, q, and r are calculated. Then, the coordinates θ and φ shown in 2 of FIG.
θ = tan ^-1 ((-R + q) / d ₃ ),
φ = tan ^-1 ((-P + q) / d ₃ ). That is, even after the relative positional relationship fluctuates, the boundary 11 between different materials and the outer shape 21 of the container can be obtained from the image, and the vertices 62, 63, 64, 65, 66, 67 obtained from the image and the vertices of the actual container If the correspondence is clear, it is possible to measure at least the inclination angle with respect to the projection target portion. This can also be applied to calibration of the relative positional relationship between the light emitting unit, the light receiving unit, and the light receiving unit.
[0016]
(9) In the processing unit, disturbance such as a wave is removed from the information on the boundary position between the different substances accompanied by the time information, and the inclination angle is calculated from the inclination of the boundary between the different substances. (3), (4), (5), (6), (7), the optical tilt angle detecting device according to any one of (8). (Claim 5)
At the time of measuring the tilt angle, even when a wave is left at the interface between the different materials in the container, the tilt angle can be calculated. It is effective for tilt angle measurement at
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to the drawings.
[0018]
(Embodiment 1) As shown in FIG. 1, a mixed liquid 7 of alcohol and water and air 9 are sealed in a transparent sealed container 1 having a rectangular parallelepiped shape. At this time, the inside of the rectangular parallelepiped transparent container 1 is sealed so that the boundary surface between the mixed liquid 7 and the air 9 forms a plane in the container. This plane is perpendicular to the direction of gravity. A light beam is radiated vertically on the one side surface of the rectangular parallelepiped closed container 1 by the electroluminescent device 5 from the outside. A one-dimensional array 3 of charge-coupled devices is arranged outside a surface facing the surface irradiated with the light beam. The position of the boundary line 11 is detected by each of the two-dimensional arrays 3 of the two charge-coupled devices, and the slope of the line connecting the detected positions is calculated, whereby the position in the φ direction in the coordinates indicated by 2 in FIG. The inclination angle is calculated. In this case, the boundary line becomes two lines due to the surface tension between the liquid and the closed container, or becomes a thick line when the focus is blurred, but the center of the two lines is used, or the center of the thick line is used. . Of course, it is possible to use a line above or below the two boundary lines, or when the focus becomes blurred and a thick line, the upper end or the lower end of the line can be used. In the following embodiments, similar processing can be performed if necessary. When measuring the tilt angle, take into account geometric conditions such as the shape of the container constituting the light receiving part and the amount of the substance contained in the container, or the light transmittance and light refraction of the substance inside the container. Taking into account the optical properties such as the rate, it is possible to distinguish between a certain tilt angle value and a tilt angle having a difference of 180 degrees with respect to the tilt angle value. This is the same for the following embodiments.
[0019]
(Embodiment 2) In FIG. 2, a mixed liquid 7 and air 9 of alcohol and water are sealed in a transparent sealed container 1 having a rectangular parallelepiped shape, and a boundary surface between the mixed liquid 7 and air 9 is formed inside the container 1 inside the container. Make a plane. This plane is perpendicular to the direction of gravity. Light is emitted perpendicularly from the outside to one side surface of the transparent container by the electroluminescent device 5, and the two-dimensional array 17 of charge-coupled devices is arranged outside on the side surface facing the surface. The electroluminescent device 5 and the two-dimensional array 17 of charge-coupled devices are opposed to each other.
Here, a part of the position 11 of the boundary surface between the alcoholic liquid 7 and the air 9 on the inner wall of the side surface on which the two-dimensional array 17 of the charge-coupled elements is disposed among the side surfaces of the transparent container is replaced with the two-dimensional array 17 Is detected by The light quantity distribution near the boundary position 11 between the alcoholic liquid 7 and the air 9 in the transparent or translucent rectangular parallelepiped closed container 1 is detected, and the boundary position 11 between the alcoholic liquid 7 and the air 9 is calculated with subpixel accuracy. I do. The calculated boundary position is approximated by a straight line, and the inclination angle in the φ direction of the coordinates indicated by 2 in FIG. 2 is calculated from the inclination of the straight line.
[0020]
(Embodiment 3) As shown in FIG. 3, a mixed liquid 7 and air 9 of alcohol and water are sealed in a transparent or translucent rectangular parallelepiped closed container 1, and a boundary surface 11 of the alcohol liquid 7 and air 9 inside the container. Has a plane inside the container. One side surface of the rectangular parallelepiped container is vertically irradiated with parallel light rays by the electroluminescent device 5 from the outside. A camera 19 is provided at a position facing the electroluminescent device 5 with the rectangular parallelepiped transparent container 1 interposed therebetween. The camera 19 includes a two-dimensional image sensor array, and is capable of capturing a two-dimensional image.
The camera 19 detects the boundary position 11 on the inner wall of the container and the vicinity thereof, among the shape of the side surface of the rectangular parallelepiped transparent container 1 and the boundary surface between the mixed liquid 7 and the air 9 sealed in the rectangular parallelepiped. At this time, by changing the focus position, it is possible to obtain a boundary position 32 on a plane near the camera 19 and a boundary position 33 on a plane far from the camera 19. With respect to the side surface of the transparent container focused by the camera, the light amount distribution near the boundary surface position 32 or 33 between the alcohol-water mixed liquid 7 and the air 9 on the inner wall of the side surface is detected by the camera 19. The boundary position 32 or 33 is calculated from the detected light amount distribution. Then, a straight line approximation is performed on the calculated boundary position 32 or 33, and the inclination angle in the φ direction of the coordinates indicated by 2 in FIG. 3 is calculated from the inclination of the straight line. Further, by using the difference between the height of the straight line on the near surface and the height of the straight line on the far surface, it is possible to calculate the inclination angle in the θ direction of the coordinates indicated by 2 in FIG. The shape of the container can be obtained by using the camera 19. Therefore, at the time of measuring the inclination angle, it is possible to calibrate the relative positional relationship between the transparent or translucent rectangular parallelepiped closed container 1 and the camera 19.
[0021]
(Embodiment 4) As shown in FIG. 4, a mixed liquid 7 and air 9 of alcohol and water are sealed in a transparent or translucent right-angled triangular prism-shaped closed container 23, and the boundary surface between the mixed liquid and air is a container inside the container. It is a structure that forms a plane inside. The camera 19 is disposed at a position where two sides forming the right angle of the transparent or translucent right-angled triangular prism-shaped closed container 23 can be seen. The electroluminescent device 5 is disposed at a position opposed to the camera 19 with a right-angled triangular prism-shaped transparent container 23 interposed therebetween. The camera 19 has a two-dimensional image sensor array in the electroluminescent device, and can capture a two-dimensional image. At this time, that is, the camera 19 is at a position where two planes forming a right angle among the side surfaces of the right-angled triangular prism-shaped container 23 can be imaged.
As shown in FIG. 5, the camera 19 uses a camera to determine the shape of the closer one of the side surfaces of the right-angled triangular prism closed container and the boundary position 11 on the inner wall of the container among the boundary surface between the alcoholic liquid 7 and the air 9 sealed in the right-angled triangular prism container. Is detected. As a result, the distances 97, 98, and 99 from the bottom surface to the boundary position for each of the three sides that intersect with the boundary position 11 between the alcohol liquid 7 and the air 9 on the inner wall of the container of the right triangular prism shape container in FIG. The ratio of the lengths of the distances 94, 95, 96 from the upper surface to the boundary position can be detected. FIG. 5 shows a case where air exists on the upper side and liquid exists on the lower side. Since the shape of the container is known, the inclination angle of the boundary line 11 can be calculated from the detected boundary surface 11 and the shape of the container side surface for each detected surface.
[0022]
Embodiment 5 As shown in FIG. 6, a mixed liquid 7 and air 9 of alcohol and water are sealed in a transparent closed container 29 having a triangular pyramid shape, and a boundary surface 11 between the mixed liquid 7 and air 9 is set inside the container. However, it shall be a structure which forms a plane in a container. Light is emitted from the electroluminescent device 5 to the bottom surface of the triangular pyramid-shaped container 29 vertically from the outside. One-dimensional arrays 3 of the charge-coupled devices are arranged one on each of the three side surfaces except the bottom surface. When the boundary position 11 between the mixed liquid 7 and the air 9 is at the position where the boundary position 11 between the mixed liquid 7 and the air 9 is detected in all the one-dimensional arrays 3 of the charge-coupled devices, three points on the boundary between the mixed solution 7 and the air 9 which are not on the same straight line are It is detected with pixel accuracy, and it is possible to calculate the inclination angles in the φ and θ directions of the coordinates indicated by 2 in FIG.
[0023]
Embodiment 6 A mixed liquid 7 of alcohol and water and air 9 are sealed in a transparent or translucent triangular pyramid closed container 29 shown in FIG. Inside the triangular pyramid closed container 29, a boundary surface between the mixed liquid 7 and the air 9 forms a plane in the container. This plane is perpendicular to the direction of gravity. Light is emitted from the outside of the bottom surface of the triangular pyramid sealed container 29 by the electroluminescent device 5. A camera 19 is provided at a position facing the electroluminescent device 5 with a triangular pyramid-shaped container 29 interposed therebetween. The camera 19 includes a two-dimensional image sensor array, and is capable of capturing a two-dimensional image. At this time, the camera 19 is at a position overlooking the three side surfaces of the triangular pyramid-shaped transparent container 29. The relative positional relationship between the camera 19, the electroluminescent device 5, and the triangular pyramid-shaped transparent container 29 is fixed. When measuring the tilt angle, the relative positional relationship between the camera 19, the electroluminescent device, and the container, and the shape of the triangular pyramid-shaped transparent container 29 are known. The position 11 of the boundary surface between the mixed liquid and air generated on the inner wall of the container is detected by the camera 19 with sub-pixel accuracy, and the detected position is approximated by a straight line. Since the shape of the triangular pyramid-shaped container 29 is known, the three-dimensional position of the straight line is calculated from the relative positional relationship with the outer contour 70 of the triangular pyramid-shaped container in FIG. Accordingly, it is possible to calculate the inclination angles of the coordinates indicated by 2 in FIG. 7 in the φ and θ directions.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a first embodiment.
FIG. 2 is a configuration diagram showing a second embodiment.
FIG. 3 is a configuration diagram showing a third embodiment.
FIG. 4 is a configuration diagram showing a fourth embodiment.
FIG. 5 is an image captured by a camera in a fourth embodiment.
FIG. 6 is a configuration diagram showing a fifth embodiment.
FIG. 7 is a configuration diagram showing a sixth embodiment.
FIG. 8 is an image captured by a camera in a sixth embodiment.
FIG. 9 is a view for explaining a device configuration capable of measuring tilt angles in two directions.
FIG. 10 is a diagram showing a relationship between a plane and an inclination angle at a certain coordinate.
FIG. 11 shows an example of an optical tilt angle detection device using an opaque liquid.
FIG. 12 shows an example of tilt angle measurement of the optical tilt angle detection device shown in FIG.
FIG. 13 shows an example of tilt angle measurement by the optical tilt angle detection device shown in FIG. 11;
14 is an output example of the one-dimensional image sensor in FIGS. 12 and 13. FIG.
FIG. 15 shows an example of tilt angle measurement of the optical tilt angle detection device shown in FIG.
FIG. 16 shows an output example of the one-dimensional image sensor in FIG.
FIG. 17 shows an example of the configuration of the present invention.
18 shows an example of tilt angle measurement of the optical tilt angle detection device shown in FIG.
19 is an example of tilt angle measurement of the optical tilt angle detection device shown in FIG.
20 shows an example of tilt angle measurement of the optical tilt angle detection device shown in FIG.
FIG. 21 shows an example of the configuration of the present invention.
FIG. 22 shows an example of the configuration of the present invention.
FIG. 23 shows an example of the configuration of the present invention.
FIG. 24 shows an example of an optical tilt angle detection device using an opaque liquid.
FIG. 25 shows an example of an optical tilt angle detection device using an opaque liquid.
26 shows an example of tilt angle measurement by the optical tilt angle detection device shown in FIG.
27 is an output example of the one-dimensional photoelectric conversion element array in FIG. 26;
[Brief description of reference numerals]
1 Transparent closed container of rectangular parallelepiped shape
2 Coordinate axes set for explanation
3 One-dimensional array of charge-coupled devices
5 Electroluminescent device
6 Transparent or translucent solution
7 Liquid mixture of alcohol and water
9 air
11 The boundary line between the liquid mixture and the air formed on the inner wall of the closed vessel
13. One of the positions of the boundary between the liquid mixture and the air detected by the one-dimensional array of the charge-coupled device
14. One of the positions of the boundary between the liquid mixture and air detected by a one-dimensional array of charge-coupled devices
15. One of the positions of the boundary between the mixed liquid and air detected by the one-dimensional array of the charge-coupled device
16 Mounting angle of charge-coupled device
17 Two-dimensional array of charge-coupled devices
19. Camera with two-dimensional array of charge-coupled devices
21 Outline of Transparent Sealed Container
23 Transparent sealed container with right triangle shape
29 Triangular pyramid-shaped transparent sealed container
32 Boundary position on a plane close to the camera
33 Boundary position on a plane far from the camera
34 A surface represented by ax + by + cz = d
35 One of the point positions for explanation
36 One of the point positions for explanation
37 One of the point positions for explanation
38 One of the point positions for explanation
39 A virtual rectangular parallelepiped provided for description, with each side being parallel to the coordinate axis of the coordinates shown in FIG.
40 x-axis intercept a '
41 y-axis intercept b '
42 z-axis intercept c '
43 origin
44 faces
45 One-dimensional image sensor
46 One-dimensional image sensor
48 communicating pipe
49 opaque liquid
50 surface light source
Light rays emitted from 51 surface light sources
Light rays emitted from 52 surface light sources
Light rays emitted from 53 surface light sources
Light rays emitted from 54 surface light sources
Light rays emitted from 55 surface light sources
Light rays emitted from 56 surface light sources
Light rays emitted from 57 surface light sources
Light rays emitted from 58 surface light sources
Light rays emitted from 59 surface light sources
Light rays emitted from 60 surface light sources
61 Distance between centers of one-dimensional image sensor
62 One of the tops of a triangular prism shaped transparent container
63 One of the tops of a triangular prism shaped transparent container
64 One of the tops of a triangular prism shaped transparent container
65 One of the tops of a triangular prism shaped transparent container
66 One of the tops of a triangular prism shaped transparent container
67 One of the vertices of a triangular prism shaped transparent container
68 Boundary position detected by one-dimensional image sensor
69 Boundary position detected by one-dimensional image sensor
70 Image of outline of transparent container
71 Image of the boundary line between the liquid mixture and the air formed on the inner wall of the container
73 Detection boundary position by one-dimensional photoelectric conversion element array
75 One-dimensional photoelectric conversion element array
76 One-dimensional photoelectric conversion element array
77 Boundary position detected by one-dimensional photoelectric conversion element array 75
78 Boundary position detected by one-dimensional photoelectric conversion element array 76
79 Inclination angle θy
80 Tilt angle θx
81 Center-to-center distance of one-dimensional photoelectric conversion element array
Light rays emitted from 82 surface light sources
Light rays emitted from 83 surface light sources
Light rays emitted from 84 surface light sources
85 Camera
86 lenses
87 One-dimensional photoelectric conversion element array
88 Boundary position on the surface near the one-dimensional photoelectric conversion element array
89 Boundary position on plane far from one-dimensional photoelectric conversion element array
91 Distance from bottom surface to boundary on surface near one-dimensional photoelectric conversion element array
92 Distance from bottom surface to boundary on surface far from one-dimensional photoelectric conversion element array
94 Length s occupied by air on one side
95 Length t occupied by air on one side
96 Length u occupied by air on one side
97 Length p occupied by mixed liquid on a side
98 Length q of liquid mixture on one side
99 Length r occupied by mixed liquid on one side
100 Angle φ
101 Angle θ
102 Angle θx
103 Angle θy
105 Vertical line -θx
106 Angle-θy
107 Line at the boundary between transparent or translucent liquid and air formed on the inner wall of the container
108 Transparent or translucent liquid-air boundary line formed on inner wall of container after moving
109 Boundary moving distance
110 Boundary movement distance
111 Transparent or translucent container
112 Emitter
114 Distance between the boundary position detected by the one-dimensional image sensor 68 and the boundary position detected by the one-dimensional image sensor 69 in the z direction
115 Distance in the z direction between the boundary position detected by the one-dimensional photoelectric conversion element array 75 and the boundary position detected by the one-dimensional photoelectric conversion element array 76
116 Length of one side of the container

Claims (5)

A light projecting part including a container containing two or more types of substances, a light projecting part that projects light to the light projecting part, and a light projecting part from the light projecting part to the light projecting part, and an optical effect at the light projecting part. A light receiving unit that receives light including the received light, converts the light into an electronic signal and outputs the signal, and a processing unit that receives an electronic signal from the light receiving unit and calculates a tilt angle with respect to the direction of gravity based on the electronic signal. In the tilt angle detection device having a configuration including, the two or more types of substances contained in the container constituting the light-projected portion are at least transparent or translucent liquid and transparent or semi-transparent liquid in the container when measuring the tilt angle. Includes a portion that forms a boundary of a planar shape perpendicular to gravity with a combination of transparent gases, or a portion that forms a boundary of a planar shape that is perpendicular to gravity with a combination of two types of transparent or translucent liquids. Calculation of tilt angle with respect to gravity direction from surface tilt And performs optical inclination angle detecting device. 2. The optical tilt angle detecting device according to claim 1, wherein the light receiving section includes a one-dimensional array of photoelectric conversion elements, and the two-dimensional array of the photoelectric conversion elements determines two positions of the planar boundary surface between the different kinds of materials. An optical tilt angle detection device that detects the above and calculates the tilt angle with respect to the direction of gravity from the tilt of the line segment connecting the points by the processing unit. 2. The optical tilt angle detecting device according to claim 1, wherein the light receiving unit includes a two-dimensional array of photoelectric conversion elements, and the whole or a part of a boundary position formed between the different kinds of substances by the two-dimensional array of the photoelectric conversion elements. An optical tilt angle detection device that detects a boundary angle, performs linear approximation on the whole or a part of the detected boundary position, and calculates a tilt angle with respect to the direction of gravity from the gradient of the straight line. 2. The optical tilt angle detecting device according to claim 1, wherein the light receiving unit includes a one-dimensional array or a two-dimensional array of photoelectric conversion elements, and the light is projected by the one-dimensional array or the two-dimensional array of the photoelectric conversion elements. The whole or part of the three-dimensional shape of the container constituting the part and the whole or part of the three-dimensional position of the boundary generated between the different substances contained in the container are detected, and the inclination angle is determined from the relative positional relationship between the two. Optical tilt angle detector for calculating the angle of inclination. 5. The optical tilt angle detecting device according to claim 1, 2, 3, 4, wherein time information is considered in the boundary image between different substances obtained by the light receiving unit, and disturbance of the boundary between different substances such as a wave is considered. An optical tilt angle detection device that detects the tilt angle by removing it.

Images