JPH0840138A - Detection device of travelling vehicle in night-time - Google Patents

Abstract

PURPOSE:To judge night and daytime and detect light of a headlamp of an approaching vehicle by one optical sensor. CONSTITUTION:This detection device is provided with a computing element 5 to output a signal by providing directivity by way of installing a cover 2 with a pin hole 3 on an optical sensor 1, judging it as night-time in the case when a value to be outputted from the optical sensor 1 is lower than a specific value and judging that there is an approaching vehicle in the case when light of a headlamp is detected by the optical sensor 1 while this judgement is being carried out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for detecting a vehicle traveling by turning on a headlight at night.

[0002]

2. Description of the Related Art Generally, as a means for detecting a vehicle running at night, two sensors, a day / night detection sensor and a headlight light detection sensor, are used. The day / night detection sensor determines whether it is day or night. The headlight light detection sensor detects the light of the vehicle's headlight, determines that the vehicle is approaching when signals are being output from both sides, and only the day / night detection sensor detects the brightness below a certain level. When the signal shown is output, it is determined that no vehicle approaches.

[0003]

However, in the case of the above configuration, since two photosensors are required, the cost of parts is increased, the circuit is complicated, and the chance of failure of the photosensor by simple calculation is increased. Doubles. Therefore, for example, when the conventional vehicle detection device is used as a rear-end collision prevention device for a vehicle parked or stopped at night, the product becomes expensive and the reliability is low.

The present invention is proposed in view of the above point, and it is an object of the present invention to make it possible to detect daylight and nightlight and to detect headlight light of an approaching vehicle with a single optical sensor. .

[0005]

The constitution of the present invention is as follows.

1. An optical sensor that detects the ambient brightness and the light of an approaching vehicle headlight, and a signal indicating the ambient brightness detected by the optical sensor are monitored. When the value is smaller than the set value, and at this time, the optical sensor outputs a signal indicating a certain brightness or more, it is determined that there is a vehicle approaching and the control signal is output. An arithmetic unit,
A device for detecting a traveling vehicle at night.

2. An optical sensor having a light entrance control cover with a small hole attached to the front, and an A / D converter for converting an analog signal output from the optical sensor into a digital signal,
If the magnitude of the signal output from the A / D converter is less than a certain value, it is determined as night, and if a signal having a magnitude greater than a certain value is input during this night, A device for detecting a traveling vehicle at night, which comprises a computing unit that outputs a control signal by judging that the light is from a vehicle headlight.

3. 1. An average value of a plurality of signals output from an optical sensor within a fixed time is taken, and the magnitude of this average value is used to judge the distinction between nighttime and daytime.
Alternatively, the detecting device for a traveling vehicle at night as described in 2 above.

4. 4. The apparatus for detecting a traveling vehicle at night according to the above 1 or 2 or 3, which is configured to determine whether or not a vehicle is approaching by the rise of a signal output from an optical sensor.

5. When the magnitude of the signal output from the optical sensor is in the increasing direction, it is determined that there is an approaching vehicle, and when it is in the decreasing direction, it is determined that the vehicle is going away. Or the detection device of the traveling vehicle at night according to 4.

6. The detection device for a traveling vehicle at night as described in 1 or 2 or 3 or 4 or 5, wherein two optical sensors are provided and the presence or absence of an approaching vehicle is judged based on a signal output from each optical sensor. .

[0012]

The optical sensor outputs a voltage signal proportional to the brightness when the surrounding brightness exceeds the sensitivity. This signal is converted into a digital signal by an A / D converter and input to a computing unit (microcomputer). When the magnitude of the input signal is equal to or greater than a certain value, the computing unit determines that it is daytime, and when it is less than a certain value, for example, 2 lux or less, it is determined to be nighttime. Then, while the light sensor detects light exceeding 2 lux (light of headlight) while this night is judged, and this signal is input to the calculator, it is judged that there is an approaching vehicle, Output a control signal. This control signal drives, for example, the blinking lamp of the rear-end collision prevention circuit.

[0013]

1 is an embodiment of a vehicle detection device according to the present invention, in which 1 is an optical sensor, 2 is a cover covering the front of the optical sensor 1, and the front center of the cover 2 is The small hole 3 is provided, and the small hole 3 has a directivity that reacts only to light within the range of the angle θ, and the cover 2 blocks ambient light.

Reference numeral 4 is an A / D converter for converting an analog signal (voltage) proportional to the amount of light output from the optical sensor 1 into a digital signal.

Reference numeral 5 denotes an arithmetic unit. The arithmetic unit 5 calculates an average value of the magnitudes of the signals output from the optical sensor 1, judges day and night from this value, and judges night. The light sensor 1 detects the light of the headlight of the approaching vehicle while the vehicle is approaching, and when an output of a certain value or more is detected, it is determined that there is an approaching vehicle and a control signal is output to the rear-end collision prevention device 6, for example.

The magnitude of the signal output from the optical sensor 1 need not be averaged if the conditions are good.

[0017]

The effects of the present invention are as follows.

A. Since it is possible to determine the nighttime and the daytime with one optical sensor, it is not necessary to separately provide a daytime detection sensor and a vehicle detection sensor for detecting the light of the vehicle headlight as in the conventional case.

B. Since there is only one optical sensor, the number of parts and the circuit configuration are reduced, the product price can be reduced, and the failure rate is halved.

[Brief description of drawings]

FIG. 1 is an explanatory view of a traveling vehicle detection device at night according to the present invention.

[Explanation of symbols]

 1 Optical Sensor 2 Cover 3 Small Hole 4 A / D Converter 5 Computing Unit (Microcomputer) 6 Rear-end Collision Prevention Device

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B60R 21/00 Z 8817-3D G01V 8/12 (72) Inventor Kazuhiro Sugaya Tajiri-cho, Hitachi-shi, Ibaraki 2197-98 (72) Inventor Kenji Nihei 2-34-9 Kujimachi, Hitachi City, Ibaraki Prefecture

Claims (6)

[Claims] 1. An optical sensor for detecting the brightness of the surroundings and the light of a headlight of an approaching vehicle, and a signal indicating the brightness of the surroundings detected by the optical sensor is monitored and When the brightness is smaller than the preset value, and when the optical sensor outputs a signal indicating brightness above a certain value, it is determined that there is a vehicle approaching. A device for detecting a traveling vehicle at night, which includes a computing unit that outputs a control signal. 2. An optical sensor comprising a light entrance control cover with a small hole attached to the front, an A / D converter for converting an analog signal output from the optical sensor into a digital signal, and the A / D conversion. If the magnitude of the signal output from the vessel is below a certain value, it is judged as night, and if a signal of a certain value or more is input during this night, the headlight of the vehicle A traveling vehicle detection device at night, which includes a computing unit that determines that the light is present and outputs a control signal. 3. A configuration in which an average value of a plurality of signals output from an optical sensor within a fixed time period is calculated, and the discrimination between nighttime and daytime is determined based on the magnitude of the average value.
Alternatively, the detecting device for a traveling vehicle at night as described in 2 above. 4. The apparatus for detecting a traveling vehicle at night according to claim 1, 2 or 3, wherein it is configured to judge whether or not the vehicle is approaching by the rise of a signal output from the optical sensor. . 5. A structure configured to judge that an approaching vehicle is present when the magnitude of the signal output from the optical sensor is in the increasing direction, and to determine that the vehicle is going away when the signal is in the decreasing direction. Item 1. A device for detecting a traveling vehicle at night according to 1 or 2 or 3 or 4. 6. The nighttime according to claim 1, 2 or 3 or 4 or 5, wherein two photosensors are provided and the presence / absence of a day / night or approaching vehicle is judged based on a signal output from each photosensor. Vehicle detection device in.