JPS5946324B2 - Attitude detection device using hologram - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device that detects an attitude angle using a hologram.

There is a conventional "attitude detection device" as a device for detecting the attitude angle of a small-diameter pipe burying machine, a tunnel excavator, etc.

As shown in FIG. 1, the laser beam L irradiated from the laser transit 1 installed at a predetermined position is focused by the lens 3 of the detection device 2 and formed into an image on the position sensor 4. The azimuth angle and pitch angle of the detection device 2 are detected based on an output signal corresponding to a change in the position of the light spot P from the center position 4a of the position sensor 4 due to a change in the attitude angle with respect to the laser beam L. However, in the conventional detection device described above, there are severe limitations on the aberration of the condensing lens, and a large diameter lens is required to cover the parallel movement of the device.

Such a large-diameter lens is technically difficult to manufacture and is also quite heavy. Moreover, it is extremely expensive. Further, the position sensor also has poor output linearity, and since it is an analog element, there are problems such as drift. The present invention has been newly developed in view of the above-mentioned points, and the detection principle is completely different from that of the conventional detection device described above. A hologram is used instead of a lens, and coherent waves emitted from a laser transit or the like are detected. The present invention provides an attitude detection device using a hologram that detects an attitude angle with respect to the laser beam. The present invention will be described in detail below based on one embodiment of the accompanying drawings.

First, the principle of the present invention will be briefly explained.

As shown in FIG. 2, a pinhole PH is provided at a predetermined position in front of the three-dimensional hologram 5, and when this pinhole PH is irradiated with a plane wave laser beam Lpo, the laser beam Lpo that passes through this pinhole PH becomes a spherical wave Ls. The three-dimensional hologram system 5 is irradiated with light. Indeed, this three-dimensional hologram 5 is an extremely sensitive photographic film. On the other hand, a predetermined attitude angle (azimuth angle θ, pitch angle φ
) is irradiated with a plane wave laser beam Lp, the spherical wave Ls and this plane wave Lp are exposed and printed at the same time, and then development processing is performed. In this way, a hologram is created. Next, when the three-dimensional hologram 5 created as described above is irradiated with a plane wave laser beam Lp from the same attitude angle (azimuth angle θ, pitch angle φ) as before as shown in FIG. The light is focused on the hologram 5 at a position y that is plane symmetrical to the pinhole PH. That is, the three-dimensional hologram 5 functions similarly to a lens. In this way, the hologram can be reproduced. In this way, one light spot (real image) corresponds to a laser beam incident at a certain angle.

Therefore, by disposing a sensor at this light spot position, the angle of incidence can be detected. Therefore, by repeating the above-mentioned hologram creation operation (multiple exposure), it is possible to make many light points correspond to arbitrary positions at many angles. By arranging light receiving elements such as small photocells, it is possible to detect changes in the angle of incidence of the incident laser beam.

The present invention is based on the above-mentioned principle. First, as shown in FIG. 4, the attitude angle detection range of the apparatus of the present invention is defined as azimuth angle θ, ˜θ, 01 and pitch angle φ, ˜φ, o.

Now, FIG. 5 is a diagram showing the creation of a hologram. The three-dimensional hologram 5 is, for example, a high-sensitivity photographic film, and at a predetermined position in front of this three-dimensional hologram 5 there are pinholes PHθ for the azimuth angle θ and the pitch angle ψ. , PHψ are arranged at predetermined intervals.

When creating a hologram with two-dimensional angles such as azimuth angle θ and pitch angle ψ, it is necessary to use either the azimuth angle θ or the pitch angle φ as a parameter, and in this example, the pitch angle is The angle ψ is treated as a parameter. The three-dimensional hologram 5 is irradiated with a plane wave laser beam Lp from the front side of the three-dimensional hologram 5 at an azimuth angle θ and a pitch angle φ.

The beam diameter of this laser beam Lp is set to be larger than that of the three-dimensional hologram 5. On the other hand, pinhole P
Hθ and PHφ are arranged at predetermined positions P, , Q, respectively, and a plane wave laser beam Lp is applied to both pinholes PHθ and PHψ.
The three-dimensional hologram 5 is irradiated with O as a spherical wave laser beam L8 through the pinholes PHθ and PHφ.
Then, exposure is performed simultaneously with the laser beam Lp (5Ls).Next, only the azimuth angle of the laser beam Lp is changed to the direction of θ2 while keeping the pitch angle of the laser beam Lp as φ.

Further, the pinhole PHθ is moved downward (in the direction of arrow A) by a predetermined distance d to move to position P2. The pinhole PHφ is fixed at a position Q. Then, in this positional relationship, the three-dimensional hologram 5 is exposed to the laser beams Lp and Ls at the same time.
In this way, only the azimuth angle is sequentially changed from θ3 to θ,o without changing the pitch angle φ, of the laser beam Lp, and only the pinhole PHθ is fixed while the pinhole PHφ is fixed at the position Q. It is moved by a predetermined distance in the direction of arrow A from positions P3 to P, O in accordance with the change in the azimuth angle. As mentioned above, the incident direction θ3, φ, ~
θ, 0, φ, and pinhole PHθ position P3 to P, O
The three-dimensional hologram 5 is exposed every time. Next, pinhole P
Lower Hφ by a predetermined distance d in the direction of arrow B to position Q2.
and fix it.

Then, as mentioned above, the incident angle of the laser beam Lp is set to θ, .
While sequentially changing from φ2 to θ, 0, ψ2, and sequentially shifting the position of the pinhole PHθ from P, to P, O according to the change in the azimuth of the laser beam Lp, each position P1 to P,
The laser beams Lp and Ls are exposed simultaneously for each O. In this way, the pinholes PHφ are placed at positions Q3 to Q. The laser beams Lp and L8 are simultaneously exposed at each position as described above while sequentially moving up to the point. Therefore, in the case of this embodiment, multiple exposure is performed 100 times. After completing all the steps, the three-dimensional hologram 5 is developed to create a hologram. The code of the three-dimensional hologram after development is 5'. Now, suppose that the three-dimensional hologram 5' is irradiated with laser light Lp at an incident angle of, for example, an azimuth angle θ4 and a pitch angle θ6, as shown in FIG.

As mentioned above, this laser beam Lp is applied to the three-dimensional hologram 5.
The position P4 of the pinholes PHθ, PHφ with respect to /
The light is focused on positions Pl and P6, which are plane symmetrical to Q, respectively. That is, the beam Lp incident within the range of azimuth angle θ1~θ,01 and pitch angle ψ,~ψ,o is the position name ~PlO,ql~ of pinhole PHθ, PHφ corresponding to the incident angle (θ, φ).
The light is focused on either position P or q of Q or O. Therefore, the azimuth angle θ1~θ,o and the pitch angle φ,~φ,o are 10×
10 = 100 types of information are published at the focal point P. , Q, ~Q
, O can be represented by 10+10=20 points. That is, the information of (MXn) can be represented by (m+n) points. In this way, the hologram can be recreated. As shown in FIG. 7, the detection unit 6 is disposed behind the three-dimensional hologram 5' at a planar position including each of the condensing positions P/~P, O, α~CX, O of the three-dimensional hologram 5'. , each focal point P, ~P].

, Q1-Q, O are light-receiving elements such as photocells P8, -
PS2O is fixedly installed. The photocells PSl to P8lO arranged at the focal points P, ~Y, O change the azimuth θ to the photocells PSll to PS arranged at the focal points Q'1 to Q'10.
2O produces the pitch angle ψ. These photocell PS
1 to PS2O output electrical signals e1 to E2O upon receiving light. These signals E, ~E2O are then sent to the display circuit (
(not shown) or another control circuit (not shown). In this way, the detection device 7 of the present invention is configured. Now, suppose that the laser beam Lp is irradiated onto the three-dimensional hologram y at an incident angle of azimuth θ4 and pitch angle θ6, as shown in FIG.

As described above, this laser beam Lp is directed to two points P4 and G by the three-dimensional hologram y. The light is focused on the photocell PS4
, PS,6. Therefore, this photocell PS4
, PS,6 outputs a signal E4,e,6. Therefore, the incident angle of the laser beam Lp can be detected based on the signals E4 and e6. Therefore, on the contrary, it is possible to detect the attitude angle of the detection device 7 with respect to the laser beam Lp irradiated in the reference direction. Yes, in this example, the focal points P1 to P,
.

,q,,~Cl. , O in two vertical rows has been described, but the hologram is not limited to this; for example, it may be created in two horizontal rows or in a cross shape. be. Further, the sensor is not limited to the illustrated photocell, but a commercially available linear type sensor or matrix type sensor may be used, and essentially the same is true.

As explained above, according to the present invention, there is no aberration like a lens, so there is no parallax caused by the irradiation location, it is resistant to dirt, and it is completely independent of the beam diameter of the laser beam, and the hologram It can be detected even if a part of it is lost due to damage etc.

Furthermore, MXn pieces of information can be detected by m+n sensors, and since the measurement is digital, there is no worry about drift or the like. Further, even when an analog type sensor is used, the interval between the light spots can be set arbitrarily, so that the resolution of the sensor can be made to a level that does not pose a problem in practice. Furthermore, there are excellent effects such as a simple configuration, a lightweight and large-diameter device that can be provided at low cost.

[Brief explanation of the drawing]

Figure 1 is a diagram showing an outline of a conventional attitude detection device, Figures 2-3
The figure shows the principle of the present invention, Figures 4 and 5 show the creation of a three-dimensional hologram used in the device of the present invention, and Figure 6 shows the 5-dimensional hologram.
FIG. 7 is a schematic diagram showing an embodiment of an attitude detection device using a hologram according to the present invention. 5... Three-dimensional hologram, 6... Light receiving section, Ps, ~PS2O... Photo cell, PHθ,
PHφ...pinhole, Lp...plane wave laser light, Ls...spherical wave laser light.

Claims (1)

[Claims] 1 Azimuth angle θ_1 to θm, pitch angle ψ_ for each predetermined angle
Plane wave laser beams incident from directions θi, ψj within the m×n range of 1 to ψ_1_1 to the corresponding P_1 to Pm, Q
A three-dimensional hologram that has been printed with multiple exposures in advance to focus light on two points Pi and Qj out of m+n of _1 to Qn, and a three-dimensional hologram that is arranged at the rear focal point position of the three-dimensional hologram and focuses on two points Pi and Qj.
and a light receiving element that outputs signals ei and ej according to the
An attitude detection device using a hologram, which detects an angle of incidence of incident light based on the signals ei and ej.