JPS60262219A - Optical guide device of traveling object - Google Patents

Abstract

PURPOSE:To increase the allowance range for vertical movements of a traveling object by irradiating beams into a space having a slender section shape simultaneously or with parallel sweeping. CONSTITUTION:The slender and flat parallel light beams are radiated to a receiver 20 set on an unmanned truck 1 from an optical system 40 or 41. The truck 1 is guided by these beams and also projects some of flat beams in the lateral direction rectangular to a main drive route through a branch mirror 52. The approximate position of a target station can be known previously by the distance travelled of the truck 1. Thus the truck 1 is driven at a low speed at the positions near the target station and at the same time gives attention to the optical signal given from a photoelectric element 53. When the light sent from the mirror 52 hits a small reflector 51, the reflected light is irradiated to the element 53. Thus the electric signals can be obtained from the element 53, and the truck 1 can be stopped accurately at a desired position.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an optical guidance device for automatically guiding, positioning and stopping a traveling moving object such as an automatic guided vehicle or a mobile robot using a light beam.

[Prior art]

Traditionally, for example, the ``5th Vehicle Automation Symposium'' was held at the Japan Automatic Control Association on January 26th and 27th, 1982, and January 2nd, 1982.
As announced at the 6th Vehicle Automation Symposium held on the 5th and 26th, it is generally known that automated guided vehicles can be automatically guided using light beams such as laser beams. ing.

16 (tab) and (b) U respectively show conventional devices of this kind, and FIG. 17 is a detailed view of the device shown in FIG. 16 (b) K, and FIG. 18 is a detailed view of the light receiving device. In the figure, (1) is an automatic guided vehicle, (2) is a light receiving device in which a large number of photoelectric sensors (2a) such as solar cells are arranged laterally in an array, as shown in FIG. (8) is He
- A laser light source such as an Nθ firing tube, (4) is a swinging mirror driven by a beam scanner (5) Ic, and (6) is a narrow straight line that irradiates the light receiving device (2) from the laser light source (8). Beam s (6a).

(6b) is the maximum amplitude of the light beam swept in a fan shape at an angle α by the swinging mirror (4), and (γ) is the travel course of the automatic guided vehicle (1). Further, (8) is the central axis of the light receiving device (2), and (9) is the central axis of the vehicle body.

Next, the operation will be explained. In the conventional device 2 shown in FIG. 16(a), a light beam emitted from a laser light source (8) is applied to a light receiving device (2) Ic as a narrow straight beam (6). Furthermore, in the conventional device shown in FIG. 16 (bJ), the light beam emitted from the laser light source (8) is transmitted to the automatic guided vehicle (1) by the swinging mirror (4) of the beam scanner (6).
Scheduled travel course (γ) VC is sector-shaped with a constant cycle
Sweep, 11. The light is then received by the light receiving device (2). For example, as shown in FIG. 18, the position of the photoelectric sensor (2a) that received the light beam [, J: , the planned travel course of the light receiving device (2) (7)]
It is possible to detect the amount W of lateral deviation n. Therefore,
The automatic guided vehicle (1) travels along the planned travel course (γ) by steering according to the sideways fl amount W so that the projected beam can be received by the photoelectric sensor (2a) in the center. I can do it.

By the way, since the conventional device shown in FIG. 16 (aJ) uses a narrow straight beam, the light intensity is high and the S/N of the optical signal is low.
The ratio is good and signal processing is easy, but the height dimension of the light-receiving surface must be large enough to cope with unevenness of the driving path of the unmanned vehicle, vibration of the vehicle body, sinking of the vehicle body due to load, etc. and optical systems become expensive. Furthermore, since the light intensity is strong, there is a serious problem of danger to human eyes, and there is also a problem that there are restrictions on the installation location.

In contrast to this AfC, the conventional device shown in FIG. 16(b) K sweeps the light beam fan-shaped in a vertical plane, so there is no limit to the height of the light receiving surface, but as the distance from the light projector increases, There is a drawback that the ratio of the light reception time to the sweep period decreases, and the S/N ratio of the optical signal decreases significantly. For this reason, a light-receiving sensor Vc that responds to high speed is required.

Furthermore, even if the conventional device Vcfo- has no upper eaves, it detects the amount of lateral deviation n with respect to the center axis of the photoelectric sensor that receives light, so for example, the attitude angle ψ shown in FIG. It can only be calculated after driving straight,
Rapid course correction maneuvers were not possible, and other means such as magnetic, optical, or mechanical were required to position the automated guided vehicle to the target location.

[Summary of the invention]

This invention was made with the aim of eliminating all such drawbacks, by improving the shape of the original beam or the sweeping method, as well as improving the structure of the light receiving device.
A target position detecting device is installed on the traveling vehicle, which detects the amount 2 and the attitude angle at the same time to enable quick trajectory correction and steering, and uses the above-mentioned light beam to determine the stopping position of the traveling vehicle. The present invention proposes a light guiding device for a traveling moving object that can achieve good positioning and stopping.

[Embodiments of the invention]

The present invention will be explained in detail below with reference to FIGS. 1 to 15.

FIG. 1 is an overall configuration diagram of a light guiding device according to the present invention, in which (1) is an automatic guided vehicle, (8) is a laser light source, and (6) is an automatic guided vehicle.
c) and (6a) are the upper and lower ends of the vertically long and horizontally narrow beam, and the latter is a light receiving device that is installed on the automatic guided vehicle (1) and simultaneously detects the amount of lateral displacement and attitude angle of the traveling moving object with respect to the n light beam. The detection device is equipped with a target position detection device for detecting the stop position of a traveling moving body, and is an optical system that forms a vertically long, horizontally narrow, oblate and parallel light beam.

However, by using a vertically elongated beam, there is no restriction in the height direction of the destination light surface, and since the light reception time can be the same even at a point far from the laser light source (8), the S/N of the optical signal
The decrease in ratio is extremely small. Furthermore, since the light beam is expanded vertically, the intensity of light entering the human eye is reduced, making it safe. In addition, since the flattened light beam has a horizontally narrow cross-sectional shape, there is an advantage that accuracy does not deteriorate when detecting the amount of lateral deviation and attitude angle of the automatic guided vehicle (1).

FIG. 2 shows a complete embodiment of a light projection device' according to the invention.

1 is a beam expander, 8) is a cylindrical concave lens, 2) is a cylindrical convex lens,
The decoy represents the cross-sectional shape of the flattened light beam. The lens decoy expands the parallel beam with a thin circular cross-section from the lens decoy into a fan shape only on the vertical plane, and the lens) converts this fan-shaped light into a parallel beam only on the vertical plane. maintains a width equal to the incident beam diameter. The enclosed beam expander 1 converts the beam from the laser beam (8) into a circular parallel beam of the required diameter.

The above-mentioned optical system has a system that provides a uniform light intensity over the entire area of the flat cross section.As another method, even if the entire flat cross section is swept up and down with a circular parallel beam, the light intensity is uniform. You can get the same effect.

Figures 6(a) to 6(d) show schematic configuration examples of the
8) ノ is a polygonal rotating mirror, concave) is a collimator lens,
(49a) and (49b) are parallel mirrors or parallel prisms that swing at the same angle as a pair; Prior to explaining the device, the principle of detecting the amount of lateral deviation and attitude angle will be explained.

Is Figure 4 (a) and (b) the linear position sensor principle? 1A bias voltage VB? is applied to a flat photoconductive element. By adding the entire amplifier circuit as shown in Fig. 4(a), the voltage level proportional to the position where the light beam is irradiated becomes as shown in Fig. 4('b).
obtained as shown in .

FIG. 5(a) is a plan view of the basic part of the light receiving device related to this light emitting device, and FIG. 5(b) is a front view thereof. s in the figure
(s□)′J? and (S2) are linear position sensors, which are installed in parallel with each other at a known interval e. Also, these are installed at different quotients, as shown in Figure 5 (1) l. ! 11% vertically long and horizontally narrow light beams can be received simultaneously without interference.

In Fig. 5(a), when the light beam is irradiated at a certain angle ψ with respect to the central axis of the linear position sensor (S□) p ("2) installed in parallel t', each of the seven From the output of the operational amplifier added to the height (S) y (8g), the light beam can be detected at a distance of 1ifd, a2.Here, the distance e between each sensor (S), (612) is Since it is known and exists, the difference between the sensor center 0 and the optical beam axis fL
ny and the angle ψ between the sensor center axis and the light beam axis is v
= (a, -a2)/2 ...(1) is easily 1
It is possible to issue c'X.

Next, the case where the light receiving device i using this principle is mounted on an automatic guided vehicle will be described.

In FIG. 6, (llffl is a light receiving device mounted on an automatic guided vehicle (1), and ■) is a light projecting device that generates all flat beams as described in MiJ. Also, A knee A2 is the optical beam axis, B
Knee B2 and C□-C2 are the center axis of the vehicle body of the automatic guided vehicle (1).

2 in Fig. 6, the light receiving device (10) is mounted in alignment with the center axis of the vehicle body, so the attitude angle ψ of the vehicle body and the amount of elliptical deviation y are calculated from equations (1) and (2) above. It can be done immediately. However, when s 1/ rψ is large, r 1/C
The light receiving device α0) and the linear position sensor (S
It is also necessary to increase the dimensions of (Y) and (E12).

FIG. 7 shows an example of a light receiving device improved in this respect, and the same reference numerals indicate the same components.

In this case, the light receiving device (ICi)
The light receiving device itself is also mounted so as to be able to rotate. The movement 2 and rotation mechanism described above is such that the light beam axis A knee A2 is connected to the light receiving device
Follow-up control is performed to match the central axis of the axis.

According to such a method, an increase in ψ, 1 can be dealt with using a small light receiving device and a linear position sensor.

FIG. 8 is an explanatory diagram for calculating the attitude angle ψ and the horizontal angle ψ by the light receiving device fLfc mounted on the automatic guided vehicle. In order to simplify the explanation, FIG. 8 shows a case where the rotatable axis of the light receiving device and the optical beam axis coincide with the center of the linear position sensor (S). In the figure, 0 is the center of the vehicle body, θ is the turning angle of the light receiving device, W is the amount of lateral movement of the light receiving device, d is the detected deviation amount of the linear position sensor (S2) I/l:, 1:, and θ
- It is assumed that W.d can be detected by a measurement decoration device. At this time, 'II = w cos ψ1111
@ (It can be calculated as 41.It goes without saying that even if the rotatable axis of the light receiving device and the optical beam axis do not coincide with the center of the linear position sensor (S work), calculations can be made using roughly the same method. do not have.

The ninth thing is the structure outline of the main part of the light receiving device.''''C
A V, the same figure tar is a plan view, the same figure (b) is a front view, the same figure tel is a side view. In the figure, 01J is a dark box, (121
041 is a rotating filter (threshold is a hood that protects from disturbance light, and 041 is a filter that transmits the wavelength of the projected beam).

Figure 10 is for explaining the outline of the structure in which the light receiving device is rotated and moved on the transport vehicle, and (to) is the sensor #
Shifting the light receiving device along the moving axis C1': A horizontal drive mechanism that can also detect the amount of deviation W from the reference axis as well as zero.
(16i is a light receiving device turning mechanism which can be moved in the horizontal direction by a horizontal drive mechanism C15 and can also detect the turning angle θ with respect to the vehicle body reference direction.

Next, a target position detection device for positioning the automatic guided vehicle (1) at a target position using the flat light beam according to the present invention will be described. Figure 11 is an explanatory diagram of its principle. The branch mirror t581 is built into the target position detection device, and t581 is a photoelectric element such as a linear position sensor.

As shown in Figure Vc, while the automatic guided vehicle (1) is traveling guided by the flat light beam on the main road, part of the flat light beam is deflected in the lateral direction perpendicular to the main road by the branching mirror +5. It is projecting. Since the approximate location of the destination station can be known in advance by the distance traveled, etc., while driving at low speed near the destination station, pay attention to the light signal from the light beam. When the projected light from the branching mirror hits the station's small reflector φllIC, the photoelectric element receives the reflected light, so it can accurately detect the target position.
Can be positioned and stopped.

FIG. 12 schematically shows the structure of the target position detection device, in which the above-mentioned branching mirrors Mj, -J and photoelectric elements (53a) such as linear position sensors are housed in an example of the device housing. . The main flattened light beam enters through the intake window 9) and is split into a branch beam window tn by a branch mirror.
i is projected toward the small reflecting mirror (51a) at the target position. The reflected light from (51a) is received by a photoelectric element (S3a) provided in the branched beam window).The position of the automatic guided vehicle (1) relative to the target position is determined by the light receiving position on the photoelectric element (53a). can be known accurately.

FIG. 13 shows a branch mirror M'k (b) that can be rotated, and a photoelectric element (53b) such as another linear position sensor.
By installing the optical tome element (53a) and the tiltVC at the target position, it is possible to also detect the small reflector (51b) at the target position on the opposite side of the main road. Furthermore, by rotating the branching mirror f51180°N or using a double-sided mirror, it is shown that it is possible to cope with the case where the traveling direction of the automatic guided vehicle is reversed and the direction of the flat light beam is reversed.

Figure 14 shows a specific example of the target position detection device, where (a) is a plan view (partial view), and (b) is a top view.
03 is a side view, the same figure (03 is an elevational view. In the figure, (b) is a hood, a (rotation) is a filter, and rj is a rotational drive mechanism of a branching mirror.

Fig. 15 shows an example of an unmanned transport system using a light guidance method to which a light projecting device, a light receiving device, and a target position detecting device are applied according to the present invention. 06 is a light receiving device rotating mechanism, -) is a light receiving device for detecting the position and orientation of a single unit similar to that explained in Fig. 10, and (b) is a target similar to that explained in Fig. 14. The position detecting device %'61) is a target position detecting device installed at a station or the like, and the decoy represents the cross-sectional shape of the flat light beam on the main path.

In the above embodiment, in order to clarify the configuration, the light receiving device (1) and the target position detecting device 1591 are independent devices, and -'
Although the structure is shown as a combination of Hn et al., the light receiving device (58
) target position detection device! - By adding a branching mirror 171k similar to that built in, the Isono function of the above two devices can be improved. Needless to say, it is possible to realize all the devices that have the same features. Also,
The mounting position 2 and mounting direction of the various devices according to the present invention on the automatic guided vehicle (1) can be not only perpendicular to the upper part of the vehicle body and the main beam, but also various methods.

Also, the arrangement of the two photoelectric sensors in the light receiving device is as follows.

Fig. 5 shows a device installed with a step, but it is also possible to split the light using a semi-transparent mirror or a prism so that the sensors can simultaneously receive the flat light beams without interfering with each other. A similar effect can be obtained with Ding.

The photoelectric sensor can be used not only as a linear position sensor C', but also as long as it can read the light receiving position, such as an integrated photodiode array or a line image sensor.

〔Effect of the invention〕

As explained above, the present invention is capable of transmitting light beams simultaneously or using a parallel body in a space having a vertically long and horizontally thin cross-sectional shape. Since it is designed to irradiate light, it has a large tolerance for vertical movement of the traveling moving object, the vertical field of view of the light receiving device and light receiving sensor may be small, and furthermore, it has a high S/N ratio without decreasing the light receiving time at the apogee. Optical signals can be obtained.

'1' In addition, a plurality of sensors arranged at predetermined intervals in the irradiation direction of the light beam and receiving the light beam simultaneously without mutual interference are used to simultaneously detect the amount of lateral deviation and the attitude angle of the traveling moving body with respect to the light beam. Therefore, the steering of the traveling vehicle can be quickly corrected and the traveling accuracy can be improved.

Additionally, a target position thf detection device is installed on the traveling vehicle, which receives the light beam, reflects at least part of it to the side of the traveling vehicle, and receives the reflected light reflected at the target position to detect the stop position of the traveling vehicle. Is there another light source for positioning? The target position information can be quickly obtained without the need for accurate information including the attitude of the moving vehicle.

The target position in the enclosure only needs to have the function of reflecting the light beam from the target position detection device, and no special positioning means is required. ! can be made.

Furthermore, if all seven optical position detection sensors based on the same principle are used in common as the light receiving device and the target position detection device, it is possible to configure the device to have the functions of both devices, and an inexpensive detection means can be obtained.

Further, by making both of these devices movable and rotatable so that the light beam can be tracked at all times, the field of view of both devices and the dimensions of the photoelectric sensors can be reduced.

In that case, what is the amount of movement and turning angle of both devices? The method can be applied not only to trajectory correction on main roads, but also to moving vehicles that require complex steering control such as moving the vehicle closer to its width or driving diagonally.

[Brief explanation of the drawing]

FIG. 1 is an overall schematic diagram showing a light guiding device according to the present invention; FIG. 2 is a perspective view showing an example of a light projecting device according to the present invention; Figure 4(b) is a schematic diagram showing the principle of a linear position sensor; Figure 5(a) is a power waveform diagram thereof; A plan view showing the principle of such a light receiving device, Figure 6) is a front view of the same, and Fig. 6 is an example of mounting the light receiving device on a moving vehicle. 7 is a plan view showing another example of mounting the light receiving device on a moving vehicle, and FIG. 8 is a plan view showing the amount of lateral deviation and attitude angle of the moving vehicle using the light receiving device shown in FIG. An explanatory diagram showing the calculation method, Fig. 9 faJ is a plan view showing the configuration of the main part of the light receiving device, the same figure (bl is the front view, the same figure (C) is the same side view, and Fig. 10 is the plan view of the light receiving device. FIG. 11 is a plan view showing the principle of the target position detection device according to the present invention; FIG. 12 is a perspective view showing an example of the target position detection device; FIG. 15 is a perspective view showing the target position detection device. FIG. 14(a) is a perspective view showing another example of the device; FIG. 14(a) is a plan view showing a specific example of the target position detecting device; FIG. Light projecting device and light receiving device.Target position detection device?A perspective view showing an example of a commonly used optical guidance type unmanned transportation system, Fig. 16 (aJ T (1)
) is a first portrait showing a conventional light guiding device, and FIG. 17 is a detailed view of the conventional device shown in FIG. 16(b). The 18th quotient is a detailed diagram of the light receiving device shown in FIG. 17. (1): Automatic guided vehicle (S): Laser light source (1,0)
p night): Light receiving device 0: Horizontal drive mechanism (1O): Light receiving device rotating mechanism: Optical system decoy: Cross-sectional shape of flat light beam 150, dual purpose station t511, (51a), (51b): Small reflecting mirror i5: Branching mirror 1581, (53a), (53b): Photoelectric element -
) Two target position detection devices (S), (S2): Linear position/sensor In the two valley diagrams, the same reference numerals indicate the same or parallel parts. Agent Masuo Oiwa 11'' Figure 1 Figure 16 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 8 Figure 27- Figure 9 1 Figure 10 Figure 11 Figure 1 Continued @ Inventor: Hiroyuki Sasai, Roo Ichizuka, tjBTs Technology Research Institute, No. 1, No. 1 Mitsubishi Electric Corporation Production Engineering Procedures Amendment (self-initiated) l Indication of the case Patent Application No. 59-118022 No. 2, Name of Invention Traveling Vehicle Light guiding device 3, representative of the person making the correction Hitoshi Katayama Department 6, Contents of the correction (1) The description “lateral deviation amount” on page 6, line 7 of the specification is corrected to “lateral deviation amount” do. (2) The description "light light surface" on page 6, lines 11 and 12 of the specification is corrected to "light receiving surface." (3) The description "lens (42) J" on page 7, line 4 of the specification is corrected to "beam expander (42)." (4) The description ry=(dt-d2)/2 J on page 9, line 5 of the specification is changed to [Y=
Correct it as (dt +62)/2 J. (5) On page 11, line 10 of the specification, the statement ``The figure (b) is a top view,'' has been changed to ``The figure (b) is a front view (partially sectional view).
1.1. (6) The statement "target position" on page 13, line 14 of the specification is supplemented with "slightly symmetrical position." (7) Correct the drawing medium temperature 4 (b) as shown in the attached sheet. 7. Inventory drawing of attached documents 1 copy or more L No. 41 (b) →L

Claims (2)

[Claims] (1) A light projector installed at a fixed point on the ground side that irradiates a light beam simultaneously or in a parallel sweep into a space with a vertically long and narrow cross-sectional shape; A light receiving device that simultaneously measures the amount of lateral deviation and attitude angle of a traveling moving body with respect to the light beam using a plurality of light receiving sensors that receive the light beam simultaneously without interference with each other at a predetermined interval in the irradiation direction; A target position for stopping the traveling movable body installed at a fixed point and located to the side of the traveling movable body, and a target position for stopping the traveling movable body installed at a fixed point and located on the side of the traveling movable body, The stopping position of the traveling moving object is determined by receiving the reflected light reflected at the above target position? 1. A light guiding device for a traveling moving body, comprising: a target position detecting device for detecting a target position. (2) The light guide device for a traveling moving object according to claim 1, characterized in that at least one of the light receiving device and the target position detecting device is capable of horizontal movement and rotation on a horizontal plane.