JPS62285089A - Sensing of vehicle - Google Patents

Abstract

PURPOSE:To enable the sensing of a vehicle regardless of the type thereof, by reflecting light emitted from a light emitter on a road surface to receive the reflected light with a receiver. CONSTITUTION:Light 4 emitted from a light emitter 1 is reflected on a road 3 to be incident into a light receiver 2. When a vehicle runs on the road 3, the light 4 is intercepted by the vehicle and hence, the presence of the vehicle is sensed. Here, as the light 4 is projected slantly, the light beam is surely intercepted regardless of the height of the vehicle when the vehicle passes. Thus, a vehicle can be sensed regardless of the type thereof.

Description

[Detailed description of the invention] 3. Detailed description of the invention [Industrial application field] This invention senses vehicles passing on the road.

Among sensors that measure traffic volume, speed, occupancy rate, etc., this relates to a vehicle sensing method that detects a vehicle by blocking light beams from the vehicle.

[Conventional technology]

Conventionally, a photoelectric vehicle sensing device has been proposed that detects a vehicle by providing a light emitter and a light receiver on both sides of a lane in which a vehicle passes. One is a method in which the emitter and receiver face each other directly, emitting a horizontal beam of light, and is used at the entrances and exits of parking lots.

[Problem that the invention seeks to solve]

However, with such conventional devices, if the light beam is placed at a convenient height for a passenger car, the light beam will be below the cargo bed in a large trunk, so there will be places where the light beam can pass through. On the other hand, if the height of the light beam is set at a position convenient for large trucks, there is a problem that the light beam can pass through the window of a passenger car and cannot be detected by a low-height sports car. .

This kind of problem can be solved by splitting the light beams at different heights and making sure that one of the light beams is blocked whenever a vehicle passes by, but such a device would be large and complex. In addition, installation and adjustment are not easy. Furthermore, transmission of light from a light emitter and light receiver close to the road surface is likely to be obstructed by mud scattered by a traveling vehicle.

[Means for solving problems]

In order to solve these problems, the present invention reflects the light emitted from the light emitter on the road surface.

[Effect]

The light beam is blocked when a vehicle passes regardless of the vehicle height.

〔Example〕

FIG. 1 is a diagram showing an embodiment of the present invention, and 1.2 is a light emitter and a light receiver installed at an appropriate height.95 Light 4 emitted from the light emitter 1 is reflected by the road 3. , are made incident on the photoreceiver 2.

With this configuration, when the vehicle runs on the road 3,
The light 4 is blocked by the vehicle and the presence of the vehicle is sensed. Here, unlike the conventional method, the light 4 is spread diagonally rather than horizontally, so the light beam is blocked when the vehicle passes, regardless of the height of the vehicle.

Figure 2 shows an example when the road width is wide, and in this case, the height of the light emitter 1 or the light receiver 2 is increased.

The incident angle of the light ray 4 with respect to the road 3 is ensured.

Figure 3 shows an example when the heights of the emitter and receiver are limited.
By sending out the light and receiving it by the light receivers 2a and ib, it is possible to prevent a decrease in detection accuracy.

The above method is an example when no one is walking on the road, but if the method is left as is when a person is walking, the light rays will be blocked by the person's walking, which may cause malfunctions. In such a case, two light beams may be set in the direction in which the vehicle is traveling, and if these two light beams are blocked at the same time, it may be determined that the vehicle is present.

In the above embodiments, FIGS. 1 to 3 are shown as diagrams in which the angle of incidence and angle of reflection of the light rays are equal, but it is also possible to use diffuse reflection on the road, and in this case, the light emission There are fewer restrictions on where the receiver and light receiver can be installed.

〔Effect of the invention〕

As explained above, this invention has the effect of being able to detect a vehicle regardless of the type of vehicle, since the light emitted from the light emitter is reflected on the road surface and this reflected light is sensed.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing one embodiment of the present invention, and FIGS. 2 and 3 are explanatory diagrams showing other embodiments. 1, 1a, ib・see light emitter, 2, 2m, 2b
-...Receiver, 3...Road, 4, 4 &, 4
b... light.

Claims (1)

[Claims] In a vehicle sensing method that detects the presence of a vehicle by receiving light emitted from a light emitter with a light receiver and blocking that light, the light emitted from the light emitter is reflected on the road surface and the reflected light is received by a light receiver. A vehicle sensing method characterized by: