JPH01237486A - Multiplexed optical fiber type railroad crossing obstruction detector - Google Patents

Abstract

PURPOSE:To prevent a detection oversight of obstructions by one-sided shielding light by providing a light emitting device and a light receiving device each formed of one lens with an emitting end and an incident end of an duplex optical fiber cable placed at the focal points of the respective lenses. CONSTITUTION:Composite optical fiber cables are formed of duplex optical fiber cables 3, 4 at the emitting side and other optical fiber cables 9, 10 at the light receiving side thereof. The respective emitting sides of the cables 3, 4 are placed at the focal distance of a lens forming a light emitting device 5 and the respective incident ends of the cables 9, 10 are arranged at the focal distance of the lens of a light receiving device. Optical beams from light emitting parts 1, 2 are emitted from the lens 6 through the cables 3, 4, received by light receiving parts 11, 12 through the lens 8 and the cables 9, 10, relays RY1, RY2 are actuated to judge obstructions respectively. Therefore, erroneous detection by one-sided light shielding can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a multiplexed level crossing obstacle detection device using optical fiber cables.

(Prior Art) A general level crossing obstacle detection device that detects whether or not an obstacle such as a moving object exists on a railway level crossing is well known.

In order to improve the detection performance of the level crossing obstacle detection device, a double system optical fiber cable was used as the optical transmission line, and a system with a double system of beams was published in Japanese Patent Publication No. 62-29256.
In addition to the one using a half mirror as disclosed in Japanese Patent Publication No. 62-292595, there is one as shown in FIGS. 3(a) and 3(b).

The light projector 19 and the light receiver 22 are arranged facing each other at predetermined positions across the railroad crossing.

The light beams from the emitters 15.16 are each emitted via a fiber optic cable 17.18 from a lens 20.21 constituting the floodlight 19, and if there are no obstacles on the level crossing, the light beams emit from the lens 20.21 of the floodlight 19. The light emitted from .
3.24, optical fiber cable 25.26
The light is received by the light receiving unit 27.28 via the relay Ry
and rty2 is operated. As a result, the operating contacts Ry 1° and Ry 2° are closed, and the relay Ry '3 is activated and it is determined that there is no obstacle. When no light is received, it is determined that there is an obstacle.

Therefore, in the case of a Bonne-Soto car 29 where there is a low obstacle, one of the light beams may emit light, but the other light beam may not be blocked, as shown in FIG.
On a moving object with a high loading platform, such as a truck, one light beam may shine brightly, but the lower light beam may not shine.In either case, regardless of the presence of an obstacle, the This is extremely dangerous because it will be determined that the item is missing.

(Problems to be Solved by the Invention) In view of the above-mentioned current situation, the present invention solves the above-mentioned one-sided light beam by making it possible to emit and enter a dual system of light beams along almost the same optical axis. This is an attempt to effectively prevent failure to detect obstacles caused by light.

(Failure to solve the problem) The projector and receiver each consist of one lens.

- Place the emitting end and the incoming end of a single optical fiber cable or a multiplex optical fiber cable (hereinafter referred to as "composite optical fiber cable") at the focal position of the corresponding lens.

(Function) According to the present invention, the emitting ends of a plurality of optical fiber cables on the light emitting section side are arranged at the focal position of the lens constituting the light emitter, and the plurality of optical fiber cables on the light receiving section side are arranged at the focal position of the lens constituting the light receiver. However, since the distance between the centers of the optical fiber cables at the emission end and the input end is small, the plurality of light sources at the emission end can be regarded as one point light source, and each of the plurality of optical fiber cables The light beams from the two are projected with almost the same optical axis.

(Example) The present invention will be explained according to the example shown in FIGS. 1(a) to 2.

The present invention emits a light beam from a multiple light emitting unit through a composite optical fiber cable and a floodlight on the light emitting unit side,
1. In this riii proposal, the light emitter 5 and the light receiver 7 are combined into one lens 6. and 8. 3 In this embodiment, the composite optical fiber cables are double optical fiber cables 3.4 (on the light emitting part side) and 9.
, IO (light receiving section l1111). −
The respective emitting ends 31.41 of the stopper optical fiber cables 3' and 4 are placed at the focal position of the lens 6 constituting the projector 5, with a part of the outer periphery of the clat 32.42 as shown in FIG. 1(c). are placed in contact. The input end 91.10 of the optical fiber cable 9.10 on the light receiving section side is similarly arranged at the focal position of the lens 8 constituting the light receiving device 7. In addition, in FIG. 1(c), 33 and 43
is the core.

In such a configuration, the light beams emitted from the light emitting units l and 2 are connected to optical fiber cables 3.4, respectively.
via the emission end 31.41 at the focal point of the lens 6.
If there are no obstacles on the level crossing, the light beam is emitted from the light receiver 7 via the lens 8, and the light beam is emitted from the optical fiber on the light receiver side, which is placed at the focal point of the lens 8. Input end 91.10 of cable 9.10
1, the light is received by the light receiving section 11.12 via the optical fiber cables 9 and 10, and the relays Ry I and Ry2 are activated. Thereby, its operating contact Ry
1', Ry 2' close, relay Ry3 is activated, and it is determined that there is no obstacle. 1. When an obstacle exists, the light beam from the emitter 5 is blocked by the obstacle, and the receiver 7 does not receive light and relays Ry l and Ry
2 falls, relay Ry3 falls, and it is determined that there is an "obstacle".

(Effect of the invention) According to the invention, the dual optical fiber cable 3.4
The relationship between the emission end 31.41 of the optical fiber cable 9.10 and the lens 6 and the input end 91.101 of the optical fiber cable 9.10 and the lens 8
Since the relationship between 7 side fiber optic cable 9.
1o is incident on the incident end 91.101 in a symmetrical manner as shown in FIG. The emitting end 31.4 of the duplex optical fiber cable 3.4 is arranged as shown in FIG. at the focal position of l-)
There are two light sources that are regarded as point light sources, and beams with almost the same optical axis are emitted from the projector.

According to the results of experiments conducted by the inventor, the center-to-center spacing of the optical fiber cable 3.4 at the launching end 31; 41 is 250 mm.
In the case of μm, beam 13 at a point 10m away from there
．． The center-to-center spacing between 13 and 14.14 was approximately 5 cm.

A two-light beam generally has a spread of 0.5 to 2 degrees, and the beam diameter at a point 10 meters away is 8 to 2 degrees.
Since the length is 30 cm, by adopting the configuration of the present invention, the light beams from the dual optical fiber cable are emitted as beams having substantially the same optical axis.

Therefore, unlike the conventional method described above, false detection due to light on one side does not occur.

In the above embodiment, an example was mainly described in which the optical fiber cables 3.4 and 9.10 were made into a duplex system. If a multiplex optical fiber cable is installed, and light is emitted and received between a projector consisting of a single lens and a receiver consisting of a single lens,
Furthermore, detection failure due to light can be effectively prevented if one side is used.

[Brief explanation of the drawing]

FIG. 1(a) is a circuit diagram showing an embodiment of the present invention;
b) is a circuit diagram showing the determination device in the embodiment shown in FIG. 1(a), FIG. 1(c) is a sectional view showing the arrangement at the emitting end of the optical fiber cable in FIG. 1(a), and FIG. is a front view showing the emission state of the light beam from the floodlight shown in FIG. 1(a), FIG. 3(a) is a circuit diagram showing a conventional level crossing obstacle detection device using an optical fiber cable, and FIG. b) is a circuit diagram showing the determination device in the level crossing obstacle detection device shown in FIG. 3(a); FIG. 4 is a circuit diagram showing the determination device in the level crossing obstacle detection device shown in FIG. 3(a); FIG. 1.2. ,,Double light emitting unit, 3.40. . Duplex optical fiber cable on the light emitting unit side, 511. Floodlight, 601. Lens, 701. Light receiver, 818. Lens, 9.10. ,,duplex optical fiber cable on the light receiving section side, 11.12,,,duplex light receiving section, 31.4],.

Claims (1)

[Claims] 1) Light beams from the dual-system light emitting units are emitted from the projector through the dual-system optical fiber cables, are received by the light receivers, and are transmitted through the dual-system optical fiber cables. In the device in which the light is received by a dual-system light-receiving section, the projector and receiver are each composed of a single lens, and the emitting end and the incoming end of the optical fiber cable are placed at the focal position of each lens. 2) A multi-system optical fiber level crossing obstacle detection device consisting of a light emitting part, a light receiving part, and an optical fiber cable, and the emitting end and the input end of each optical fiber cable are connected to the light emitting part and the light receiving part. 2. The multiplexed optical fiber type level crossing obstacle detection device according to claim 1, wherein the multiple optical fiber type level crossing obstacle detection device is arranged at the focal position of the constituent lenses.