JPH1027299A - Automotive radar equipment - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To detect an obstacle in an area which needs to be monitored with a limited number of beams, in a radar for front or side monitoring. In a direction in which data at a long distance is desired, such as a straight traveling direction on the same lane, a beam 19 having a narrow beam width is emitted, and it is not necessary to reach a distant position such as an oblique front near a side. By radiating beams 20 and 21 having a wide beam width in an azimuth where a wide area is desired to be monitored, an obstacle is detected by efficiently using a limited number of beams.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-vehicle radar device having a multi-beam antenna, and more particularly to an on-vehicle radar device in which a part or all of the beam width is changed for each radiating direction.

[0002]

2. Description of the Related Art A conventional vehicle obstacle detecting device of this type is disclosed in Japanese Patent Application Laid-Open No. 5-205199. As shown in FIG. 4, the conventional vehicle obstacle detection device includes a variable beam width antenna 1 capable of emitting and receiving a beam and capable of changing a beam width, and a variable beam width antenna 1. A signal processing means 2 for performing signal processing such as A / D conversion on the signal received at the step S1; a distance speed detecting means 3 for detecting a distance from the output of the signal processing means 2 to a target, a relative speed, and a moving direction of the target; It is composed of

The operation of the thus configured vehicle obstacle detecting device will be described. The transmission signal is transmitted using the beam width variable antenna 1 with a beam width suitable for the traveling environment of the own vehicle. The beam reflected by the obstacle and returned is received by the variable beam width antenna 1 again, and the received signal is sent to the signal processing means 2. After signal processing such as A / D conversion is performed by the signal processing unit 2, the distance and relative speed from the own vehicle to the obstacle are detected by the distance / speed detection unit 3.

FIG. 3 is a diagram showing a relationship between a beam emitted by the own vehicle and a preceding vehicle, and a specific operation will be described with reference to FIG. For a preceding vehicle or obstacle at a long distance, the obstacle can be detected when the beam is emitted with the beam width of the beam 4, and when it is necessary to monitor a wide area in a short distance area such as a low visibility. However, if the beam width is expanded to the area of the beam 5, an obstacle can be detected, so that an obstacle at a short distance can be easily detected. By operating as described above, it is possible to detect an obstacle regardless of a long distance or a short distance.

As a conventional radar apparatus for a vehicle of this type, one disclosed in Japanese Patent Application Laid-Open No. 5-264730 is known.

As shown in FIG. 6, in the conventional on-vehicle radar device, components having the same configuration and the same function and effect as those shown in FIG. 4 are denoted by the same reference numerals. An antenna switching type multi-beam antenna 9 comprising a front antenna 6, an oblique left front antenna 7 and an oblique right front antenna 8 is provided, and the front antenna 6 can avoid reflection from a reflector located outside the lane. Antennas that radiate a beam with a narrow beam width, the diagonally left front antenna 7 and the diagonally right front antenna 8 can radiate beams with the same beam width as the front direction antenna 6, and are diagonally left and right and diagonally right, respectively. Beams can be emitted forward, and by switching with a switch, beams can be emitted in different directions. The vehicle environment detection sensor 10 includes a vehicle environment detection sensor 10 and a processing determination unit 11. The vehicle environment detection sensor 10 acquires information such as the vehicle position and the traveling direction of the vehicle using GPS, a vehicle speed sensor, map information, and the like. Further, the processing determining unit 11 includes a vehicle environment detection sensor.
From the information on whether the vehicle is traveling straight or curved from the output of 10, it is determined which of the plurality of radiated beams the signal received from the preceding vehicle is the signal obtained from the preceding vehicle.

[0007] The operation of the vehicle-mounted radar device configured as described above will be described. The transmission signal is a multi-beam antenna 9
The antenna is radiated as an electromagnetic wave beam using the front antenna 6, the oblique left front antenna 7, and the oblique right front antenna 8. The beam reflected from the obstacle is received by the front antenna 6, the left front antenna 7, and the right front antenna 8, and a reception signal is sent to the signal processing unit 2 including information on which antenna was received. , And A / D conversion. Further, from the information obtained by the own vehicle environment detection sensor 10, the processing determining unit 11 determines which beam can detect a vehicle or an obstacle in the own lane by using the beam. Distance speed detection means 3
Then, using the information of the signal processing means 2 and the information of the processing determination unit 11, the distance and the relative speed to the preceding vehicle and the obstacle in the own lane are detected.

FIG. 5 is a diagram showing the relationship between the beam emitted by the own vehicle and the preceding vehicle. The operation will be described in detail with reference to FIGS. A beam 12 is emitted from the front antenna 6, a beam 13 is emitted from the left oblique front antenna 7, and a beam 14 is emitted from the right oblique front antenna 8.
The own vehicle environment detection sensor 10 detects the traveling direction and position of the own vehicle, map information, and the like, and based on the information, the processing determination unit 11 determines whether the own vehicle is traveling straight or whether it is traveling on a curved road. To determine if they are.

When it is judged by the processing judging section 11 that the vehicle is traveling straight, it is judged that the area of the beam 12 is in the same lane, and the distance / speed detecting means 3 passes through the signal processing means 2 to the preceding vehicle. The distance and the relative speed with the own vehicle can be detected. When the vehicle is running to the left on a curved road, the processing determining unit 11 determines that the area of the beam 13 is in the same lane as shown in FIG. Means 3 detects the distance and the relative speed between the preceding vehicle and the own vehicle. Further, when the vehicle is running to the right on a curved road, it is determined that the area of the beam 14 is the same lane, and
The determination is made at 11, and the distance and relative speed between the preceding vehicle and the own vehicle are detected by the distance / speed detecting means 3 via the signal processing means 2.

By operating as described above, even when the vehicle is traveling on a curved road, it is possible to detect the preceding vehicle traveling on the own lane without losing sight of the preceding vehicle.

[0011]

However, the vehicle obstacle detecting device having the structure as shown in FIG. 4 cannot detect the direction of the obstacle as viewed from the own vehicle when detecting an obstacle at a short distance. There was a problem. In addition, when detecting a wide range of obstacles at a short distance, there is a problem that the beam gain is reduced because the beam width is increased, and the accuracy of detecting a target is reduced.

Further, the vehicle radar device having the configuration as shown in FIG. 6 has a problem that if an obstacle is present at a short distance, the obstacle cannot be detected because the beam width is narrow.

The present invention solves the above-mentioned conventional problem. By providing a multi-beam antenna that emits a plurality of beams having different beam widths for some or all of the beams, the present invention can provide a wide-range short-range antenna. It is an object of the present invention to provide an on-vehicle radar device capable of detecting the obstacle including the direction.

[0014]

In order to achieve this object, an on-vehicle radar device according to the present invention radiates and receives a plurality of beams having different beam widths, and a multi-beam antenna receiving the beams from the multi-beam antenna. Signal processing means for performing signal processing such as A / D conversion of a signal; and distance / speed detecting means for detecting a distance from a vehicle to an obstacle and a relative speed based on an output of the signal processing means. It is composed.

When radiating a beam by the multi-beam antenna, a beam having a narrow beam width is radiated in the front direction of the vehicle, and a beam having a wide beam width is radiated in a diagonally forward direction of the vehicle. It is configured such that an obstacle can be detected with high accuracy, and an obstacle can be detected even in a wide area in a diagonally forward direction.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 2 shows the configuration of the on-vehicle radar device according to the embodiment of the present invention. Here, the same reference numerals are given to components having the same configuration and the same operation and effect as those described in FIGS. 4 and 6 showing the conventional example. As shown in FIG. 2, the on-vehicle radar device includes an antenna switching type multi-beam antenna 18 including a front antenna 15, an oblique left front antenna 16, and an oblique right front antenna 17. Is an antenna that emits a beam with a narrow beam width, the oblique left front antenna 16 and the oblique right front antenna 17 are antennas that emit a beam with a beam width wide enough to detect an obstacle at a short distance, and a frontal antenna 15. By switching the diagonally left front antenna 16 and diagonally right front antenna 17 with a switch, beams can be emitted in different directions. In this multi-beam antenna 18 of the antenna switching type, the antennas are discretely switched. However, the same function can be realized by changing the beam width for each angle even with the continuously scanning antenna.

The operation of the on-vehicle radar device configured as described above will be described. The transmission signal is radiated as an electromagnetic wave beam using the front antenna 15, the oblique left front antenna 16, and the oblique right front antenna 17 of the antenna switching type multi-beam antenna 18. The beam reflected from the obstacle is received by the front antenna 15, the oblique left front antenna 16, and the oblique right front antenna 17, and a received signal is sent to the signal processing means 2 including information on which antenna was received. , A
Signal processing such as / D conversion is performed. Then, by processing the output by the distance speed detecting means 3, the distance to the obstacle and the relative speed can be detected.

Hereinafter, the specific operation will be described with reference to the schematic diagram of FIG. FIG. 1 is a plan view of an own vehicle having the on-vehicle radar device having the configuration of FIG. 2 as viewed from above. 1 and 2
The operation will be specifically described with reference to FIG. A beam 19 is radiated from the front antenna 15 and the left oblique front antenna 16
, And a beam 21 is emitted from the obliquely right front antenna 17.

By radiating beams 19, 20, and 21 from the multi-beam antenna 18 in three directions,
A preceding vehicle at a long distance can be detected using a beam 19 having a narrow beam width, and a vehicle traveling in a lane adjacent to the own vehicle at a short distance can be detected using beams 20 and 21 having a wide beam width.

In this manner, a beam 19 having a narrow beam width is emitted with respect to a long-distance obstacle on the own lane, so that the distance between the own vehicle and the obstacle and the own vehicle and the obstacle can be accurately determined. Can be detected. In addition, for a target at a short distance, by using the beam 20 and the beam 21, an obstacle can be detected even in a wide left front area and a right front area. Also, it becomes possible to radiate a beam with a higher gain than trying to detect an obstacle widely with one beam, and the received signal power increases,
Obstacles can be detected with higher accuracy.

[0021]

As described above, according to the present invention, a multi-beam antenna that emits beams having different beam widths for some or all of the beams is used, and the beam width is narrow for an obstacle at a long distance. Emits a beam,
For a short-range target, the position of obstacles can be detected by emitting a wide beam further diagonally forward of the vehicle, and both long-range and short-range obstacles can be detected with high accuracy. This has the effect that the position and the relative speed from the car can be detected.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a relationship between an own vehicle having an on-vehicle radar device of the present invention, a beam emitted by the own vehicle, and an obstacle;

FIG. 2 is a configuration diagram showing an on-vehicle radar device according to an embodiment of the present invention;

FIG. 3 is a schematic diagram showing a relationship between a vehicle equipped with a conventional vehicle obstacle detection device, a beam emitted by the vehicle, and obstacles;

FIG. 4 is a configuration diagram showing a conventional vehicle obstacle detection device;

FIG. 5 is a schematic diagram showing a relationship between an own vehicle equipped with a conventional on-vehicle radar device, a beam emitted by the own vehicle, and an obstacle;

FIG. 6 is a configuration diagram showing a conventional on-vehicle radar device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Beam width variable antenna 2 Signal processing means 3 Distance speed detection means 6, 15 Front direction antenna 7, 16 Diagonal left front antenna 8, 18 Diagonal right front antenna 9, 18 Antenna switching type multi-beam antenna 10 Own vehicle environment detection sensor , 11 processing judgment unit 4, 5, 12, 13, 14, 19, 20, 21 beams

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location H01Q 25/04 G01S 17/88 A

Claims (2)

[Claims] 1. A multi-beam antenna that emits and receives a plurality of beams, a signal processing unit that processes a signal received by the multi-beam antenna, and a distance to an obstacle from information obtained by the signal processing unit. An on-vehicle radar device comprising a distance speed detecting means for detecting a relative speed, wherein a part or all of a plurality of beams radiated from the multi-beam antenna have different beam widths in each radiating direction. . 2. The on-vehicle radar device according to claim 1, wherein in the multi-beam antenna, a beam having a narrow beam width is radiated in a front direction of the vehicle, and a beam having a wide beam width is radiated in a diagonally forward direction of the vehicle. .