JP2003182488A - Stop lamp recognition device - Google Patents

Abstract

(57) [Problem] To provide an inexpensive device for recognizing that a stop lamp of a vehicle traveling ahead on a road is turned on. Provided is a device having a simple mounting structure and a short time for determination. A first optical sensor for detecting the amount of light transmitted through a red filter and a second optical sensor for detecting the amount of light transmitted through a complementary color filter for red (visible in blue green) are provided as a pair structure. The blinking state of the stop lamp is selected from the relative values of the detection outputs of the two optical sensors.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for automatically detecting that a vehicle preceding a vehicle running on a road has braked. The present invention relates to an improvement of a device that detects that a stop lamp of a preceding vehicle is turned on as an electric signal. INDUSTRIAL APPLICABILITY The present invention is used for preventing a rear-end collision of an automobile and other purposes.

[0002]

2. Description of the Related Art A vehicle running on a road is required by law to interlock when a brake is applied so that a red stop lamp equipped as a tail light is turned on. The driver recognizes that the preceding vehicle will decelerate when the stop lamp of the preceding vehicle lights up on the road,
Driving operations such as loosening the accelerator pedal or switching from the accelerator pedal to the brake pedal are performed.

There is known a device which detects that a stop lamp of a preceding vehicle is turned on as an electric signal and assists the driving operation in a safe direction by the detected output (Japanese Patent Application Laid-Open No. 8-221700). Applicant Suzuki).

[0004]

All of such conventionally known apparatuses use a camera to capture an image of a preceding vehicle and use the output image to perform a specific image processing to stop the vehicle. It is to determine whether the lamp is turned on. In recent digital technology, image recognition by image processing can be performed with reasonable accuracy on any screen in principle. However, the determination of whether or not the stop lamp is lit by image processing is (1) a hardware device is expensive, (2) software for image processing is complicated and expensive, and (3) determination accuracy is improved. Requires a calculation processing time, and the time is limited in time for the interlocking brake control. (4) The device becomes large and a space for mounting it on the vehicle is required. (5)
There are inevitable drawbacks such as complicated equipment and adjustment work. Therefore, there are various problems that still have to be resolved in order to be standardly implemented in a large number of vehicles or designed to be offered as a user option at a reasonable price.

The present invention has been made against such a background, and an object thereof is to provide a stop lamp recognition device having a simple structure and inexpensive. It is an object of the present invention to provide a stop lamp recognition device that is extremely simple and inexpensive both in hardware and software. It is an object of the present invention to provide a stop lamp recognition device that can obtain recognition accuracy that is practically satisfactory and that outputs a recognition output in an extremely short time. The present invention is
It is an object of the present invention to provide a stop lamp recognition device that is easy to mount for mounting and requires almost no adjustment work.

[0006]

The device of the present invention detects light transmitted through a red filter and light transmitted through a complementary color (apparently blue-green) filter of the red filter by separate optical sensors, The greatest feature is to determine whether or not the stop lamp of the preceding vehicle is lit by using the relative values of the outputs of the two optical sensors. With this configuration, a pair of photosensors can be used, and no camera is needed to capture images.
Hardware devices are extremely simple and inexpensive. Further, the software is extremely simple because it is not necessary to perform simple determination and image processing based on the relative output value of the optical sensor. Furthermore, since the processing time for determination is shortened, the time from when the stop lamp of the preceding vehicle is turned on to when the brake control is started can be extremely shortened.

That is, the present invention provides a red filter (3).
A first optical sensor (1) for detecting the transmitted light of the red filter, a complementary color filter (4) for the red filter, and a second optical sensor (2) for detecting the transmitted light of the complementary color filter. Is arranged in front of the vehicle, and determines whether or not the stop lamp of the preceding vehicle is lit by the relative value of the detection output level of the first optical sensor (1) and the detection output level of the second optical sensor (2). (5) is provided.

The operating principle of the simplest case will be described. During the daytime, when the two photosensors receive sunlight, the two photosensors having a pair structure have outputs. At night, when the two sensors have almost no light input, the two light sensors have no output. When the two sensors are receiving the red light of the stop lamp that is turned on, the first optical sensor has a detection output and the second optical sensor has no detection output. With such a relative state, it is possible to detect the lighting state of the stop lamp of the preceding vehicle with a simple logic.

The red filter (3), the first photosensor (1), the complementary color filter (4), and the second photosensor (2) are sensitive to light incident from substantially the same direction. It is desirable to have a structure in which one package (6) is mounted, and a plurality of these packages are attached to the front bumper of the vehicle or in the vicinity thereof.

The numbers in the above parentheses are the reference numbers in the drawings of the embodiment apparatus described later. This is provided for easy understanding of the configuration of the present invention, and is not intended to limit the understanding of the configuration of the present invention to the examples.

The determining means is a logic circuit, and preferably a processor (that is, a program control circuit) is used. Further, it is preferable that the configuration includes means for changing the determination logic depending on whether it is day or night. A flashing signal of the headlamp of the vehicle is taken into the determining means, and means for distinguishing the day and night from the presence or absence of the flashing signal of the headlamp may be included. With this configuration, it is possible to finely change the determination logic between daytime when the amount of noise light is large and night when the amount of noise light is small, and to reduce erroneous determination.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The apparatus of the embodiment of the present invention will be described in more detail with reference to the drawings. FIG. 1 is a sectional structural view of a photosensor package having a pair structure. FIG. 2 is a perspective view for explaining a mounting state of this device on a vehicle. FIG. 3 is a circuit configuration diagram of the device of the present invention. FIG. 4 is a flowchart of the operation of the main part of the determination circuit.

The device of the present invention is characterized in that the blinking state of the stop lamp of the preceding vehicle is identified by comparing the light intensity passing through the red color filter and the light intensity passing through the complementary color filter. The embodiments of the present invention will be described from the structure of the filter and the optical sensor for this purpose. As shown in FIG. 1, the first optical sensor 1 receives the incident light through the red filter 3. The red filter 3 is an optical filter that selectively transmits the light wavelength emitted by a standard stop lamp. The second optical sensor 2 receives the incident light through the complementary color filter 4 for this red color. The complementary color filter 4 is a filter configured to selectively block the light wavelength emitted by a standard stop lamp. The complementary color of red is apparently almost bluish green or dark green. The two photosensors 1 and 2 are housed in separate partitions so as to receive only the light transmitted through the respective filters 3 or 4 without being interfered with each other. A transparent protective plate 7 is provided on the front surface of the filters 3 and 4.
Are placed. The transparent protective plate 7 is for protecting the filter from being damaged by pebbles or the like that are pushed up from the road surface. It is composed of a transparent plastic plate.

In this way, the pair of filters and the pair of optical sensors are formed in one package 6, and as shown in FIG. 2, the incident light from the front is received from the hole formed in the bumper of the vehicle. Implement as much as you can.
The example shown in FIG. 2 has a structure in which two packages 6 of this pair structure are further arranged, one each on the left and right of the bumper.

Explaining the connection of the electric circuit hardware with reference to FIG. 3, the output of this optical sensor is the sensor (RR) of the red transmitted light of the package mounted on the right side, and the transmitted light of the complementary color of the package mounted on the right side. Sensor (RC), sensor of red transmitted light (L
G), and a complementary color transmitted light sensor (L
G), which are input / output circuits (I /
It is input to the judgment circuit 5 for judging the presence or absence of lighting via O). In addition to this, a signal (HL) representing the lighting state of the headlamp for identifying whether it is day or night is input to the determination circuit 5. The judgment output of the judgment circuit 5 is supplied to the brake control circuit (B) through the input circuit (I / O) and the alarm chime (C) inside the cab.

The determination circuit 5 is a processor formed on a small semiconductor chip. Software is implemented in this processor. FIG. 4 is a flowchart showing the main part of software for operating this processor as a determination circuit. This operation will be described. When the determination circuit 5 is activated, first, the night mode or the daytime mode is set depending on whether or not the headlamp is turned on. In this embodiment, the night mode and the daytime mode are distinguished from each other by setting the value of the parameter α. Then, the output of each optical sensor is taken in, and the output of the first optical sensor 1 with respect to the light transmitted through the left red filter is set to the output of the second optical sensor 2 with respect to the light transmitted through the right complementary color filter with the parameter α. It is determined whether it is larger than the added value. The determination is similarly performed for the two sensors on the left side. That is, if either of the transmitted light amount of the left red filter> the transmitted light amount of the left complementary color filter + α or the transmitted light amount of the right red filter> the transmitted light amount of the right red filter + α is satisfied, the stop lamp of the preceding vehicle is turned on. Judge as something.

Explaining the parameter α, the state is simplified and easy to understand if α = 0 is considered.
Outputs of the first optical sensor 1 and the second optical sensor 2 when there is no incident light, when the incident light is “red light”, and when the incident light is another color such as “white light” Considering, it becomes like the following table.

[0018]

【table 1】 That is, when the output of the first optical sensor is “present” and the output of the second optical sensor is “not present”, it is determined that the stop lamp of the preceding vehicle is lit, and the outputs of the two optical sensors are both output. When there is no output, or when the two optical sensors have outputs, it is not determined that the stop lamp is lit. If there is incident light of blue-green which is the complementary color of red, there is no output light from the first photosensor and there is output light from the second photosensor, but this is not the lighting of the stop lamp either.

By setting the parameter α to a certain finite value, it is possible to judge not by "present" or "absent" but by the fact that the level difference of the detected output reaches a corresponding relative value. it can. This parameter α depends on whether it is day or night, and when it is night, the ambient brightness
Alternatively, different values can be set according to the sensitivity characteristics of the optical sensor or the characteristics of the filter.

With the device according to the present invention, when the lighting of the stop lamp is recognized in the running vehicle, the recognition output can be used to generate a chime sound in the driver's seat to warn the driver. Not only warning but also control such as starting the brake control circuit by this recognition output to supply the first stage air pressure, or reducing the fuel supply amount of the engine to the engine / brake state You can

In the above description, the package having the pair structure is used, but this can be realized without necessarily using the pair structure. In the above description, the optical sensor is mounted behind the opening provided in the front bumper of the vehicle, but the present invention can be implemented by mounting the optical sensor in another position in front of the vehicle. In the above-mentioned embodiment, the sensor output is described as being added or subtracted by the parameter α, but the present invention can be carried out even if the parameter is multiplied, that is, the parameter is added to or subtracted from the logarithmic value of the sensor output. .

[0022]

The apparatus of the present invention is extremely simple in both hardware and software and can be provided at a low cost. The decision logic of the present invention is simple,
Practically satisfactory recognition accuracy is obtained, and the time required for the determination is extremely short. The apparatus of the present invention does not require mounting of a digital camera, the mounting work for mounting is simple, and the adjustment work is almost unnecessary.

[Brief description of drawings]

FIG. 1 is a sectional structural view for explaining an optical sensor package of an embodiment pair structure of the present invention.

FIG. 2 is a perspective view illustrating a mounting structure of the device according to the embodiment of the present invention.

FIG. 3 is a block diagram of an electric circuit of a device according to an embodiment of the present invention.

FIG. 4 is a main part flowchart of a device determination circuit according to an embodiment of the present invention.

[Explanation of symbols]

1 First optical sensor 2 Second optical sensor 3 red filter 4 Complementary color filter 5 Judgment circuit 6 packages 7 Transparent protective plate

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masakatsu Kagawa             3-1, Hinodai, Hino City, Tokyo 1 Hino             Inside the automobile corporation F-term (reference) 5H180 AA01 CC01 CC05 LL04 LL07                       LL09

Claims (4)

[Claims] 1. A vehicle comprising a red filter, a first optical sensor for detecting transmitted light of the red filter, a complementary color filter for the red filter, and a second optical sensor for detecting transmitted light of the complementary color filter. It is arranged in front, and is provided with means for determining whether or not the stop lamp of the preceding vehicle is lit based on the relative value of the detection output level of the first optical sensor and the detection output level of the second optical sensor. Stop lamp recognition device. 2. The red filter, the first optical sensor,
The complementary color filter and the second optical sensor are mounted in one package so as to be sensitive to light incident from substantially the same direction, and a plurality of the packages are respectively mounted on the front bumper of the vehicle or in the vicinity thereof. 1
Stop lamp recognition device described. 3. The stop lamp recognition device according to claim 1, wherein the determining means is a processor, and includes means for changing the discrimination level depending on whether it is day or night. 4. The stop lamp recognizing device according to claim 3, further comprising means for fetching a blinking signal of a headlamp of the vehicle into the determining means, and distinguishing the day and night from the presence or absence of the blinking signal.