JPH02259415A - Vehicle-loaded radar apparatus - Google Patents

Abstract

PURPOSE:To enable stable and accurate detection of an inter-vehicle distance and a direction to the preceding vehicle for a long time even when there is a stain of a light-emitting unit or a light-sensing unit, an environmental change such as a change in temperature, or a change with time, by detecting an object- point area wherein light beams from the light-emitting unit are located and by detecting therefrom the inter-vehicle distance and the direction. CONSTITUTION:A light-emitting unit 2 fitted to the rear part of the preceding vehicle 1 and emitting nonvisible light beams backward and a plurality of light- sensing units Li disposed at prescribed intervals in the front part of the following vehicle 4 and having narrow directivity toward respectively, are provided. The light-sensing units Li are disposed so that the sensible areas thereof overlap each other and thereby a plurality of divided object-point areas are formed in front of the following vehicle 4. By detecting the object-point area wherein the light beams from the light-emitting unit 2 are located, the inter-vehicle distance and the direction to the preceding vehicle 1 are detected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an on-vehicle radar device for detecting the distance and direction to a preceding vehicle.

[Conventional technology]

In recent years, the frequency of road congestion has increased due to the increase in the number of automobiles, and congestion on general roads and expressways, particularly in and around urban areas, has become chronic. On these congested roads, the burden on drivers increases significantly, and the frequency of rear-end collisions and the like is also increasing due to reduced judgment ability due to fatigue. For this reason, it has become necessary for vehicles to be equipped with safety devices such as distance keeping devices, distance warning devices, or automatic control B devices to mechanically and electrically avoid rear-end collisions. The development of an automatic tracking device has significantly reduced the burden on drivers. In order to make these devices function effectively, an on-vehicle radar device is required to know the distance and direction between the preceding vehicle and the own vehicle (pursuing vehicle).

[Problems to be Solved by the Invention] Therefore, as this type of in-vehicle radar device, for example, there is a system disclosed in Japanese Patent Laid-Open No. 49-43328. A light source is installed at the rear of the preceding vehicle, and the light emitted from this light source is irradiated to multiple light receivers installed on the own vehicle.The difference in the amount of light received between the receivers is used to determine the distance between vehicles and the direction to the preceding vehicle. It was designed to seek. However, with this method, the amount of received light varies depending on the individual receiver, due to changes in the amount of light received due to dirt on the light source or receiver, changes in the amount of light emitted from the light source due to temperature changes or changes over time, and changes in the sensitivity of each receiver. However, there was a problem in that stable detection over a long period of time could not be expected.

This invention was made to solve the above-mentioned problems, and the following distance can be maintained stably over a long period of time without being affected by environmental changes such as dirt on the light emitting device or receiver, temperature changes, or changes in optical elements over time. An object of the present invention is to obtain an on-vehicle radar device that detects direction and direction.

[Means to solve the problem]

The in-vehicle radar device according to the present invention includes a light emitter that is attached to the rear of a preceding vehicle and emits invisible light toward the rear;
A plurality of light receivers are provided at the front of the own vehicle (tracking vehicle) and are arranged at predetermined intervals with narrow directivity forward, and the light receiving areas of the respective light receivers are arranged so as to intersect with each other. A device that detects the inter-vehicle distance and direction to the preceding vehicle by forming a plurality of divided object point areas in front of the vehicle and detecting which object point area the light beam from the light emitter is located in. It is.

[For production]

In this invention, a plurality of object point areas are formed at the front of the host vehicle by arranging the light receiving areas of each light receiver so that they intersect with each other, and the light beam from the light receiver is directed to one of the object point areas. By detecting whether a vehicle is present, the distance and direction to the preceding vehicle can be determined.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. 1st
The figure is a schematic diagram of an in-vehicle radar device according to the present invention,
1 is a leading vehicle, 2 is a light emitting device installed at the center of the rear of the leading vehicle 1 and emits invisible light toward the rear, and 3 is a light emitting device 2.
A modulator that modulates light from, for example, a light emitter 2
is a near-infrared light source, and the modulator 3 includes an oscillator and an amplifier for pulse-modulating the near-infrared light emitted from the light emitter 2. Reference numeral 4 denotes the own vehicle (tracking vehicle), on the front of which a plurality of light receivers L1 having narrow forward directivity are provided at predetermined intervals. As shown in FIG. 2, the light receiver LA is arranged so that the respective light-receiving areas intersect with each other, forming a plurality of divided object point areas aj in front of the own vehicle 4, and emitting light in the winter black area. The inter-vehicle distance and direction to the preceding vehicle 1 are detected by determining which light receiver receives the presence of the vehicle 2. Each combination of two light receivers t and i corresponds to each object point area. Hi is the receiver,
For example, in FIG.
0 is located at the center of the own vehicle, the distance tel and nl between each light receiver, and the angle of incidence of light is θ, then each light receiver L
+ forms an isosceles triangle to detect the presence of emitter 2, so when the receiver and L receive the light, the direction to the preceding vehicle is α-m-'C"2"-〇)m+n (m+n)! And the following distance is x= 2 − (□ − 〇)
Therefore, depending on the distance (n-m) 1 between the light receivers 51 (m+n) and the incident angle θ of the light, the preceding vehicle 1
The inter-vehicle distance and direction between the host vehicle 4 and the host vehicle 4 are calculated.

In addition, as shown in Fig. 2, the incident angle of the light receiver L1 is input to the I10 board 5 of the computer, the combination of numbers of the light receivers L1 is detected, and the combination of the light receivers L1 is mapped in the memory in advance to the CPU 6. Then, the inter-vehicle distance and direction determined by the combination of light receivers Lλ can be quickly calculated by reading the memory of the CPU 6 without calculation. As mentioned above, this invention does not detect the distance and direction between vehicles based on the amount of light received as in conventional devices, but uses a light receiver to detect the position by receiving light, so detection is possible even if the lens surface is dirty. It will not cause any trouble.

Figure 4 shows the configuration of the light receiving section. According to this, light receivers L+ are arranged in two rows, and in front of them, light is blocked so that the light enters only a specific light receiver LL depending on the direction of the light source. A slit portion 7 is arranged, and a condenser lens H is provided as shown in FIG.
There is no need to provide two light receivers Li for one light receiver Li, and by doing so, the device can be made inexpensive.

In addition, as shown in Figure 6, by arranging the condenser lens H and the light receiver on a curved surface, the field of view can be expanded over a wide angle, making it possible to downsize the device, and the object point area that can receive light can also be reduced to a fan. Because it spreads across the shape, the closer the distance, the better the distance resolution becomes.

〔Effect of the invention〕

As explained above, according to the present invention, the rear part of the preceding vehicle is provided with a light emitter that emits invisible light toward the rear, and the front part of the own vehicle is provided with a plurality of light receivers, and the light receiving area of the light receivers is provided. are arranged so that they intersect with each other to form a plurality of divided object point areas in front of the host vehicle, and by detecting which object point area the light beam from the light emitter is located, it is possible to detect the distance to the preceding vehicle. Since the system detects the distance and direction between vehicles, it is possible to detect the distance and direction between vehicles stably and accurately over a long period of time, even if there is environmental change such as dirt on the emitter or receiver, temperature changes, or changes over time. .

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of an in-vehicle radar device according to an embodiment of the present invention, Fig. 2 is a detailed configuration diagram of the light receiving section, Fig. 3 is an explanatory diagram for calculating the inter-vehicle distance and direction, and Fig. 4 is the light receiving section. FIG. 5 is a block diagram showing another example of the light receiving section. l... Leading vehicle, 2... Light emitter, 4... Own vehicle,
Li...light receiver, aj...object point area. Note that the same reference numerals in the figures indicate the same or equivalent parts. Agent Masuo Oiwa Figure 2 Figure 1: Leading vehicle 2: Emitter 4: Own vehicle Li: Receiver oj: Object point area Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] A light emitter that is attached to the rear of the leading vehicle and emits invisible light toward the rear, and a plurality of light receivers that are installed at the front of the own vehicle (pursuing vehicle) and arranged at predetermined intervals with narrow directivity forward. The light-receiving areas of the respective light receivers are arranged so as to intersect with each other to form a plurality of divided object point areas in front of the host vehicle, and the light beam from the light emitter is arranged so that the light receiving areas of the light receivers intersect with each other to form a plurality of divided object point areas, An in-vehicle radar device is characterized in that it detects an inter-vehicle distance and direction to a preceding vehicle by detecting whether the preceding vehicle is present.