JPS5899712A - Slant angle measuring device - Google Patents

Abstract

PURPOSE:To enhance the measuring accuracy, by reflecting measuring luminous flux by a free liquid surface by a plurality of times. CONSTITUTION:The luminous flux from an index 34 is made to be the approximately parallel luminous flux by a collimate lens 40 through a reflecting mirror 38 and inputted into a transmitting surface 44 of a liquid surface reflecting member 42. The luminous flux, which is inputted into the transmitting surface 44 of the liquid surface reflecting member 42, passes the free liquid surface of silicon oil 50, reflected by a reflecting surface 46, reflected again by the free liquid surface of the silicon oil 50, and thereafter emitted from the transmitting surface 44. The luminous flux emitted from the transmitting surface 44 is converged by the collimate lens 40, and an index image is formed on a CCD detector 36. Therefore, the slant angle of the device can be obtained from the amount of the movement of said index image.

Description

[Detailed description of the invention] This invention relates to an inclination angle measuring device based on direction.

As an example of a conventional tilt angle measuring device based on the direction of gravity, there is a known device that uses a free pendulum and measures the tilt angle, displacement, etc. of the free pendulum optically or electromagnetically.

However, there are problems with the stability and restorability of this device 1H pendulum, and in order to improve this, the device must become mechanically complex and large. As another example of a conventional tilt angle measuring device based on the direction of gravity, there is a known device that uses the free liquid level of mercury to measure the deviation angle of light reflected by the mercury liquid level.

However, this device has problems with the toxicity of mercury and the high cost of mercury.In addition, mercury has a high surface tension and requires a large surface area to obtain a flat reflective surface. Too sensitive and lacks stability. Therefore, a device for optically measuring the deviation angle of light reflected by the liquid surface using the free liquid surface of a liquid with higher viscosity than mercury as an inclination angle measuring device is disclosed in US Pat. It has been proposed by No. ts. A more detailed configuration of this device is that the light beam from the light emitting element is made incident on the incident surface of a prism attached to the bottom of the liquid container, the incident light beam is totally reflected on the free surface of the liquid, and further, the reflected light beam is is emitted from an exit surface provided on the opposite side to the entrance surface of the prism, and the amount of deviation of the emitted light is measured by a light receiving position detection element.

This device uses total reflection on the free surface of a highly viscous liquid, so it is sensitive to external vibrations, has good recovery properties, and can measure relatively large volumes with an extremely simple structure. Although this has certain advantages, in order to further improve measurement accuracy, it is necessary to increase the distance from the free surfaces of several bodies to the light receiving position detection element, which prevents the entire device from becoming large. I can't do it. In particular, the problem of increasing the size of this device becomes a fatal drawback when the inclination angle measuring device is incorporated into a photoelectric reading type theodolite to measure the inclination angle of the theodolite body.

The present invention aims to provide an inclination angle measuring device that solves the above-mentioned conventional problems, and its structural features include a light emitting section, a light receiving section, and a liquid surface reflection system. , a lens system that makes the light beam from the light emitting section enter the liquid surface reflection system as a substantially parallel light beam, and makes the light beam reflected by the liquid surface reflection system enter the light receiving section; A fixed transmission surface through which incident light and reflected light pass.

It consists of a free liquid surface and a fixed reflective surface that reflects reflected light from the free liquid surface and reflects it back toward the free liquid surface. As described above, the present invention makes it possible to use a common transmitting surface for incident light and reflected light by providing a fixed reflective surface, and to provide a light emitting part and a light receiving part on one side of the liquid surface, etc. By reflecting multiple times on the free liquid surface,
It is possible to obtain an inclination angle measuring device that is small in size, has high measurement accuracy, and can be incorporated into a photoelectric reading type theodolite. Furthermore, in the present invention, since a light beam having a large cross-sectional area is incident on and exits from the transmission surface of the liquid surface reflection system, the transmission surface is less affected by dirt, dust, and dust.

The principle and embodiments of the present invention will be explained below with reference to the drawings. As shown in FIG. 1, the principle of construction of the present invention is that the light beam 8 from the light emitting part z1, the light receiving element 4, the liquid surface reflection system 6, and the light emitting part 2 is made into a substantially parallel light beam and is incident on the liquid surface reflection system 6. Lens system 1 that makes the reflected light beam 10 from the reflection system 6 enter the light receiving element 4
Consists of 2. The liquid surface reflection system 6 includes a prism section 14 and a liquid section 18 whose volume is partially filled with a liquid 16. liquid 1
6 is placed directly on the prism part 14, and the side surface of the prism part 14 has a fixed transmitting surface 20 through which the light flux 8. A fixed reflective surface 2z is provided. In the above configuration, even if the device is tilted, the free surface of the liquid 16 remains horizontal, so as a result, when the device is tilted, the position of incidence of the reflected light beam 10 on the light receiving element 4 changes, and the amount of change By detecting , the tilt angle of the device can be calculated. A first embodiment of the present invention is shown in FIGS. 2 and 3. The light emitting section 24Fi is composed of a light emitting element 801, a condenser lens 8B, and an index 84. Light from the light emitting element 80 is condensed by a condenser lens 82 and illuminates an index 84. The light beam from the index 84 passes through the reflecting mirror 38 , is made into a substantially parallel light beam by the collimating lens 40 , and is incident on the transmission surface 44 of the liquid surface reflecting member 42 . Reflection member 42Fi, transmission surface 4
4 and a reflective surface 46, a prism part 48 made of glass with a refractive index of i, s:l, and a liquid part 5 in which silicone oil 50 with a reflectance of /, ll is sealed in the upper part of the prism 48.
Formed by 2. Transmissive surface 44 of liquid surface reflection member 4z
The incident light flux passes through the free liquid surface of the silicone oil 50, is reflected by the reflective surface 46, and returns to the silicone oil 50.
After being reflected at the free liquid level of 0, the light is emitted from the transmission surface 44. The light flux emitted from the transmission surface 44 is condensed by the collimating lens 40 described above, and an index image is formed on a COD detector (accumulation effect sensor) 86. The index 84 and the CCO detector 86 are arranged at the focal position of the collimating lens 40, and an IJ rack system is established.

The use of a telesend link optical system has the advantage that defocus errors do not affect measurement accuracy.

In the above configuration, the tilt angle θ of the device, the CCO detector 8
If the amount of movement of the index image on 6 is P, the focal length of the collimating lens group is ft/, and the tilt coefficient is k, then θ= k - ta
There is a relationship n"'-'(!-).-〇=/", e
= i, 2μm, when f=SOB' = '/48
8, and the inclination angle θ can be determined from the detected movement amount e. In this case, k(It is the angle of incidence on the free liquid surface and the refractive index of 50 mizorism is /, 52,
- This is a value when the refractive index of silicone oil is /, t.

Various methods can be considered for selecting the index 84 and the detection divided by 86, which will be described based on FIGS. 4 to 6. 12
The image formed on the 1Fi detector 86 is the next index image. The second figure shows a case where the index is composed of a slit and the detector is composed of a line sensor of 86f/dimension. The y”F plane is a plane containing the incident and reflected optical axes in FIG. 2, and the X plane is a plane perpendicular to the X plane.The index image 12 is
1 moves in the y direction. Detector 8 which is a line sensor
6 is detected and converted into an inclination angle to obtain a measurement result. In this case, the index image is tilted in the X plane.
It does not affect the inclination angle measurement result in the X plane simply by moving in the direction.

FIG. S shows a configuration that allows the position of the target image to be detected with even higher precision. In this case, the index consists of a reference slit or turn and a grid/mother turn.

122.128 is the former two/? It is a turn image. Detector 86 is a seven-dimensional line sensor. The l pitch of the lattice nodatan image has a slight difference from the l pitch of the line sensor, and they are in a vernier relationship with each other. With this configuration, the first measurement result is obtained for the imaging position e2 of the reference slit/'P turn with an accuracy of l pitch of the line sensor,
Furthermore, the vernier relationship between the lattice pattern 64; 2B and the line sensor is used to further interpolate within 1 pitch and combine it with the first measurement result to obtain the final result. index@
424 is an image of the mother turn (X direction inclination angle limit),
When the angle of inclination in the direction becomes large, the pattern moves in the X direction on the line sensor during a turn, and by detecting the deviation of the pattern from the line sensor, a lamp or sound can be used to indicate the need for adjustment. It is possible.

In the above embodiments, the inclination angle in the X plane is measured, but it is possible to measure the two-dimensional inclination angle by selecting the index and detector. The following description will be made according to Fig. 6. The indicator 42 is composed of two slits that are perpendicular to each other. 425.424 are the statues of the former two. 86 is/
It is a light receiver that is a dimensional line sensor. Due to the tilt in the X plane, the index moves in the X direction, e4 changes, and
e3 changes depending on the inclination in the plane. This e,,e
4 and converting it into an inclination angle, it is possible to independently detect inclination angles in two directions. Furthermore, it goes without saying that by forming each slit in a grid-like or lean shape as described in FIG. 5, it is possible to obtain even more accurate measurement.

Also, in this case, the sensitivity of each tilt angle can be selected arbitrarily by changing the slope of the line sensor's tilt angle. Wear.

The above embodiment is of the QFF-AXIS type in which the light emitting element 80 and the CCO detector 86 are arranged symmetrically with respect to the optical axis of the collimating lens group 40. 0N-AX I to separate
It may be S type. In particular, in the QFF-AXIS type, the incident light beam and the reflected light beam share the optical axis, and the light emitting surface and the light receiving surface are in the same plane.
By adjusting the focus using the camera body, the imaging magnification /X can be easily obtained, and the assembly and adjustment of the device is easy.

In the second embodiment of the present invention, as shown in FIG. 7, a liquid surface reflection system 5σ is constructed by enclosing a liquid 56 in a liquid container having a transmission surface 5z and a reflection surface 54.

A third embodiment of the present invention, as shown in FIG. 3, has a liquid surface reflection system 60. It is composed of a prism section 70 consisting of a transmitting surface 62, a prism upper surface 66 including a part of a private illumination surface 64, and a reflecting side surface 68, and a liquid section 7z. 4 is reflected twice at the free liquid surface and has a high measured nv.

The first embodiment of the present invention is an embodiment in which two-dimensional detection of an inclination angle is performed. As described in Figure S, it is difficult to select finger m and perform two-dimensional detection, but with respect to the inclination angle in the plane containing the incident and reflected optical axes in Figure 2, the plane perpendicular to it The sensitivity of detecting the angle of inclination decreases in proportion to the angle of incidence.

Therefore, in order to measure two-dimensional inclination angles, it is recommended to install two light emitting and receiving systems in two directions for one liquid surface reflecting member, and to measure each inclination angle with each light receiving and emitting system. There are cases where it is true. In other words, the ninth
As shown in the figure, two sets of a transmitting surface 8z and a reflecting surface 84 are provided, and an inclination angle measuring device is configured for each set.

As explained above, the present invention measures the inclination angle using the light beam reflected multiple times on the free liquid surface, so the measurement accuracy is high, and since the emitted light beam and the received light beam are output through the common optical path 4, the present invention is compact and simple. It has a certain feature of configuration.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the principle of the present invention, FIG. 2 is an optical diagram of the first embodiment, and FIG. 3 is a diagram showing the mechanics along line 1 in FIG. , somewhat figure 1 ALs [IiK Yuoe, Eiyoi. An explanatory diagram of the index and the detector; FIG. 7 is a cross-sectional diagram of the U embodiment;
FIG. g is a sectional view of the third embodiment, and FIG. 9 is an explanatory diagram of the third embodiment. 2... Light source, 4... Light receiving element, 6... Liquid surface reflection system, 14... Prism part, 16... Liquid, 18...
Liquid part, 20... Fixed transmission surface, 22... Fixed reflection surface, 80... Light emitting element, 82... Condenser lens, 34°... Index, 86... CCD detector. Figure 4], Figure 6

Claims (1)

[Claims] (1) A light emitting section, a light receiving section, a liquid surface reflection system, a light beam from the light emitting section is incident on the liquid surface reflection system as a substantially parallel light beam, and a light beam reflected by the liquid surface reflection system is transmitted to the light receiving section. The liquid surface reflection system is composed of a fixed transmission surface through which the incident light and reflected light are transmitted, a free liquid surface, and a free liquid surface that reflects the reflected light from the free liquid surface and returns to the free surface. An inclination angle measuring device comprising a fixed reflective surface that reflects toward a liquid surface.