JPS61139899A - Front monitor for automobile - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a forward monitoring device for an automobile that monitors the area in front of the automobile and issues a warning to prevent a rear-end collision with the vehicle in front.

[Conventional technology]

Radar brake systems (Japanese Patent Publication No. 55-15337, AdaptiveSpe
ed Control for Automobile
e, Bendix Teah, J.

There are many reports such as Autumn, 1969, P. 46).

This system measures the distance to the vehicle in front by emitting radio waves or light and measuring the time it takes to travel back and forth. This is a system that issues a warning and applies the brakes.

[Problem that the invention seeks to solve]

However, in the above-mentioned conventional technology, the system for distance measurement is extremely complicated and expensive, making it difficult to put it into practical use.

The present invention was made in order to eliminate the above-mentioned problems, and an object of the present invention is to obtain a forward monitoring device for an automobile that is simple in structure and inexpensive.

[Means for solving problems]

A forward monitoring device for an automobile according to the present invention is provided with an infrared sensor that detects infrared rays from the front.

[Effect]

When the vehicle in front decelerates, the stop lamp turns on or the distance between the vehicles decreases, and the amount of reflection from your own military lights increases. This is detected by an infrared sensor and an alarm is issued.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 is an optical system that connects images in front, 2 is an infrared sensor provided on the rear side of optical system 1,
3 is a signal processing device that processes the detected infrared signal, and 4 is a display device that displays an alarm. The optical system 1 mainly consists of a lens, and the image of the vehicle in front is the infrared sensor 2.
projected on.

Normally, a tail lamp, a stop lamp, and a turn hazard lamp are installed at the rear of a car, and the stop lamp lights up when the brake pedal is pressed. Also, the turning lamp flashes when the turn is displayed. The taillights are turned on at night, but when you press the brake pedal, there are some models where the stoplight lights up alongside the taillights, and others where the brightness of the taillights increases. Furthermore, a corner cube is installed, and when the light is irradiated, the direction of the irradiation -
It is designed to reflect. Therefore, if you shine your car's headlights on the rear of the vehicle in front of you, the reflected light will return to the surrounding area, centering on your own headlights. By the way, since these light sources are incandescent light bulbs, they emit a large amount of infrared light in addition to visible light. Of course, there is also infrared rays from sunlight, but since this is almost uniform, it can be considered as a pack ground.

Assuming that the vehicle is traveling at a certain distance from the preceding vehicle, the signal entering the infrared center t2 is constant. At this time, when the preceding vehicle steps on the brake, the stop lamp lights up and the signal from the outside line sensor 2 suddenly increases. The signal processing bag [13] detects this, and in response to this detection force, the display device 4 starts flashing the lamp or flashes an alarm to warn that the vehicle ahead has stepped on the brake. ing. As the infrared sensor 2, a silicon or rumanium photodiode with a filter applied thereto may be used, a photodiode sensor may be used, or an image sensor such as a COD may be used.

The signal processing device 3 may be an analog signal comparison circuit, but it is more convenient to use a microcomputer because it can handle various situations.

The optical system 1 and the infrared sensor 2 are each provided as a pair on the left and right, and are installed near the head rung. Since the tail lamps, turn signal lamps, and stop lamps of automobiles are usually cast on both sides of the vehicle, it is best to position the optical system 1 and the infrared sensor 2 so that the field of view includes both sides of the vehicle. . The signal processing device 3 monitors the outputs of both infrared sensors 2. When the vehicle ahead steps on the brake, the stop lamp lights up, and when the infrared sensor 2 detects this, the output level increases rapidly as shown in FIG. Subsequently, as the distance between vehicles decreases, the size of the stop lamp that forms an image on the infrared sensor 2 increases, and the infrared sensor 2
The output increases in inverse proportion to the square of the distance. At this time, the signal processing bag Vt3 sends a signal to the display device 4 to issue an alarm. However, the infrared sensors 2 on both the left and right sides do not necessarily detect the stop lamps of the vehicle ahead on both sides, and it is possible that only one of the stop lamps of the vehicle ahead is disconnected, so the pair of infrared sensors 2 If the output of either of them changes as described above, it is assumed that the distance between vehicles is decreasing and a warning is issued.

The turn signal flashes when the vehicle ahead turns right, left, or changes lanes. At this time, as shown in Figure 3, the output of the infrared sensor 2 repeats increases and decreases at regular intervals, but when turning right or left, the brake is also pressed to decelerate, so the stop lamp lights up, and the output of the infrared sensor 2 The signal level rises rapidly and an increase/decrease signal due to the turn signal also appears. Therefore, the signal processing device 3 instructs the display device 4 to issue an alarm at this time as well.

Further, when the vehicle ahead lights up its tail lamp at night, the output of the infrared sensor 2 is at a constant level. Here, when the vehicle in front steps on the brakes, naturally the infrared sensor 2
As shown in FIG. 4, the signal level increases rapidly, and as the distance between vehicles decreases, it increases in inverse proportion to the square of the distance. An alarm is also issued in such cases.

In addition, some vehicles drive without their tail lights on at dusk, making them difficult to see.Of course, if the vehicle in front steps on the brakes, the infrared sensor 2 will detect this, but the distance between the vehicles will gradually shorten. In some cases, it is very difficult to dissolve. At this time, if K leaves his headlamp on, the light from the headlamp will be reflected by the corner reflector of the vehicle ahead and enter the infrared sensor 2, so that K can detect the approach to the vehicle ahead. In this case, as shown in FIG. 5, the signal from the infrared sensor 2 increases in inverse proportion to the fourth power of the head distance, and since the signal is detected at a fairly close distance, an alarm is issued.

In the above embodiment, one pair of infrared rays 2 is provided, but it goes without saying that more detailed control can be achieved by further increasing the number of infrared rays 2.

[Effect of the invention] As described above, in the present invention, infrared art
The system detects the approach of the vehicle in front based on changes in the speed of the vehicle, and there is a risk of a rear-end collision if the vehicle is slightly distracted or distracted, such as when the vehicle is starting or stopping repeatedly in traffic jams, or when slowing down at a toll booth. In such cases, it is possible to detect whether the vehicle in front has stepped on the brakes or the distance between the vehicles has shortened based on changes in the amount of infrared rays, and by issuing a warning to the driver, it is possible to prevent rear-end collisions. Moreover, since the distance to the vehicle in front is not measured as in the conventional method, the device can be constructed easily and inexpensively.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the apparatus of the present invention, and FIGS. 2 to 5 are output characteristic diagrams of the infrared sensor according to the present invention in various cases. DESCRIPTION OF SYMBOLS 1... Optical system, 2... Infrared sensor, 3... Signal processing device, 4... Display device. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] (1) Equipped with an infrared sensor that detects infrared rays from the front, a signal processing device that processes the output of the infrared sensor, and a display device that issues an alarm in response to the output of the signal processing device,
1. A warning monitoring device for an automobile, characterized in that a display device issues an alarm when the output of an infrared sensor increases rapidly or increases over time.