JP2626839B2 - In-vehicle radar device - Google Patents

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 used for a vehicle collision prevention device or the like.

[0002]

2. Description of the Related Art Currently, an on-vehicle radar device is under development for the purpose of preventing vehicle collision. This on-vehicle radar device detects a positional relationship with a preceding vehicle, an oncoming vehicle, and the like by radiating waves such as light, ultrasonic waves, and radio waves in front of a vehicle body and receiving reflected waves thereof. As an on-vehicle radar device using radio waves, as disclosed in Japanese Patent Application No. 64-86964, the FM radar system is considered promising due to the necessity of short-range monitoring.

[0003]

In the conventional on-vehicle radar device using the above-mentioned radio wave, the antenna is treated as long as it has a radio wave transmission / reception function. Little consideration has been given as to whether these are optimal for automotive use. When examining antennas that have conventionally been mounted on moving objects such as ships, a parabolic reflector that rotatably supports an antenna that integrates a transmitting / receiving horn and a parabolic reflector above a block-shaped driver is shown. Antenna rotation type "
A "slot array antenna rotary type" which rotatably supports an antenna body integrally formed by attaching a cover to a slot array and upper and lower reflecting surfaces above a block-shaped driver is mainly used.

[0004] Antennas for on-vehicle radars require a narrower beam width and scan width than the above-mentioned antennas for marine vessels, but are small in size and do not impair the appearance of vehicles. There are circumstances. For this reason, it is inappropriate to follow the conventional form for ships as it is,
It is necessary to devise the best one for in-vehicle use. The optimal form of the antenna also depends on the frequency of the radio wave used. Also,
The higher the frequency of the radio wave, the smaller the antenna can be, but the higher the frequency, the greater the loss of the feeder connecting the antenna and the transceiver, so it is necessary to determine the frequency band of the radio wave to be used from the viewpoint of the radar device as a whole. is there. In determining the frequency band of the radio wave to be used, it is necessary to consider that interference with existing radio equipment is minimized.

[0005]

SUMMARY OF THE INVENTION An on-vehicle radar device according to the present invention is housed in a housing and is installed inside or behind a bumper at a front end portion of a vehicle to transmit and receive high-frequency radio waves such as a millimeter wave band. A transceiver, a plurality of radiators that are electrically coupled to the transceiver and project outward from the inside of the housing in which the transceiver is housed, and are fixed to the housing of the transceiver. A reflector that is arranged above the bumper and that constitutes an offset multi-beam antenna that emits a plurality of radio wave beams in front of the vehicle together with the plurality of radiators;

[0006]

1 is a side view (A) and a front view (B) showing the configuration of an on-vehicle radar device according to an embodiment of the present invention, wherein 1 is a transceiver, 2 feed horn (radiator), 3 Is a parabolic reflector, and 4 is a reflector mounting member.

[0007] The transceiver 1 is installed at the front end of the vehicle while being housed in the housing 1a. The front view (B) is a view as seen from the front side of the vehicle. Therefore, in the side view (A), the right side is the front side of the vehicle. Four feed horns 2 electrically connected to the transceiver 1 are provided on the upper surface of the housing 1a.
a, 2b, 2c, 2d are planted in a state of being arranged in the lateral direction, and each emits a millimeter wave band radio wave behind and diagonally above the vehicle. Since the feed horns 2a to 2d are implanted in the housing 1a of the transmitter / receiver 1, the power supply path formed by the waveguide between the feed horn and the transmitter / receiver is greatly shortened, and the loss and the manufacturing cost are reduced. Has been achieved.

The parabolic reflector 3 is held diagonally above the four feed horns 2a to 2d by the mounting member 4 implanted in the housing 1a so as to focus on the midpoint between the feed horns 2b and 2c. Have been. As indicated by the dotted line in the side view (A), the millimeter wave radio wave radiated obliquely rearward and upward from the feed horn 2a is reflected by the parabolic reflector 3 and radiated forward as a substantially horizontal beam. As described above, the parabolic antenna in which the feed horns 2a to 2d are arranged outside the path of the transmission / reception beam has an offset
It is called a parabolic antenna. This offset parabolic antenna is suitable for use in a vehicle because the feed horn does not block the beam, so that the aperture efficiency is improved and the directivity is sharpened, and the parabolic reflector can be reduced in size. In particular, in a configuration having a plurality of radiators, the offset type is suitable because it does not block the beam.

The millimeter wave band radio waves radiated from the four radiators arranged near the focal point of the parabolic reflector 3 are radiated forward as four beams having different radiation directions. In this manner, a form in which a plurality of radiators are arranged at a position shifted from the focal position of the parabolic reflector to emit a plurality of beams having different radiation directions is called a defocused multi-beam antenna. This defocused multi-beam antenna has an optimum form as an in-vehicle antenna that requires a small size while having a smaller beam width and a smaller scan width than a marine antenna.

As described above, since radio waves in the millimeter wave band with high frequency and large attenuation are used, the radiation beam does not propagate to a distance of several hundred meters or more which is not necessary for a vehicle, and the existing beam does not propagate. Since many wireless communication facilities use radio waves of lower frequency than the microwave band, interference with these facilities can be minimized.

FIGS. 2, 3 and 4 are side views showing the configuration of an on-vehicle radar apparatus according to another embodiment of the present invention, together with a state of being mounted on a vehicle body. Is a parabolic reflector, 4 is a mounting member, 4a is an adjusting mechanism, 5 is a mounting frame, and 6 is a radome.

In any of the configurations shown in FIGS. 2 to 4, the transceiver 1 and the four feed horns represented by 2a are accommodated in a bumper shown by a dotted line at the tip of the vehicle to thereby control the vehicle. The effect on the appearance of the parabolic reflector 3 is minimized, and the parabolic reflector 3 is installed above the bumper. Recently, vehicle bumpers are often made of radio wave permeable materials such as resin,
In consideration of the influence of the reinforcing member and the metallic coating, it is not preferable in terms of characteristics to transmit and receive radio waves through such a bumper. Therefore, the parabolic reflector 3 is arranged above the bumper to transmit and receive radio waves without passing through the bumper. Further, a thin radome 6 made of cloth, resin, or the like is provided to prevent rain and dew on the radar device and to minimize the influence on the appearance of the vehicle.

The mounting member 4 includes a position and angle adjusting mechanism 4a for mounting the parabolic reflector 3.

The configuration using a parabolic reflector is exemplified above, but various parabolic reflectors including some deformed shapes can be used.

[0015]

Since the on-vehicle radar device of the present invention has the above-described configuration, it is possible to achieve a reduction in size and cost. Further, according to the embodiment using the radio wave of the millimeter wave band, the interference with the existing wireless communication equipment can be minimized.

[Brief description of the drawings]

FIG. 1 is a side view (A) and a front view (B) of an on-vehicle radar device according to an embodiment of the present invention.

FIG. 2 is a side view showing a configuration of an on-vehicle radar device according to another embodiment of the present invention together with a state of being mounted on a vehicle body.

FIG. 3 is a side view showing a configuration of an on-vehicle radar device according to still another embodiment of the present invention, together with a state of being mounted on a vehicle body.

FIG. 4 is a side view showing a configuration of an on-vehicle radar device according to still another embodiment of the present invention, together with a state of being mounted on a vehicle body.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transceiver 1a Housing which accommodates transceiver 1 2a-2d Feed horn (radiator) 3 Parabolic reflector 4 Mounting member 4a Adjusting mechanism 5 Mounting frame 6 Radome

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location H01Q 19/17 H01Q 19/17

Claims (2)

(57) [Claims] 1. A front end of a vehicle housed in a housing.
Is Installation within or behind the bumper parts high-frequency radio waves
A transceiver for transmitting and receiving a signal, and a transceiver electrically coupled to the transceiver and the transceiver
A plurality of which protrude outside from the inside of the housing in which
Radiator, and fixed to the housing of the transceiver, above the bumper
A plurality of radiators are arranged in front of the vehicle together with the plurality of radiators.
Offset Mar Chibimu-A to emit a radio wave beam
An on-vehicle radar device comprising: a reflector that forms an antenna. 2. The on-vehicle radar device according to claim 1, wherein the high frequency radio wave is a millimeter wave band radio wave .