JP2004354178A - Millimeter wave radar loading structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a millimeter wave radar loading structure capable of securing excellent measurement of the distance to an object in front of the car body or the like by the millimeter wave, concerning an on-vehicle battery loading structure. <P>SOLUTION: In this millimeter wave radar loading structure for measuring at least one of the distance to the object in front of the car body, the relative speed and an azimuth angle by the millimetric wave radar 6, the millimeter wave radar 6 is arranged near a hood opening part 2 inside the car body. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a millimeter-wave radar mounting structure for measuring a distance to an object in front of a vehicle body.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a millimeter-wave radar mounting structure in which a millimeter-wave radar for measuring a distance to an object in front of a vehicle body is provided on a rear side of the vehicle body on a front grille is known (for example, see Patent Document 1). In this millimeter wave radar mounting structure, radio waves radiated from the millimeter wave radar pass through the front grill and are reflected by an object in front of the vehicle body. Then, the radio wave reflected by the object in front of the vehicle body passes through the front grill and is received by the millimeter wave radar. According to this structure, it is possible to secure the route of the radio wave between the millimeter-wave radar and the front of the vehicle body, cover the millimeter-wave radar with the front grill, and measure the distance to the object in front of the vehicle body with the millimeter-wave radar.
[0003]
[Patent Document 1]
JP 2000-159039 A
[Problems to be solved by the invention]
However, in the above-described conventional structure, the millimeter-wave radar is disposed on the rear side of the front grill provided at a relatively low position with respect to the center of gravity of the vehicle. When the center of gravity is higher than that of the own vehicle, there is a problem that the radio wave emitted by the millimeter wave radar is not sufficiently reflected by the preceding vehicle and the millimeter wave radar cannot reliably measure the distance to the preceding vehicle.
[0005]
Also, when rain, snow, etc. adhere to the front grill, the intensity of the radio wave received by the millimeter wave radar and reflected by the object in front of the vehicle body is attenuated by the rain, snow, etc. attached to the front grill. Cannot accurately measure the distance to an object in front of the vehicle body.
[0006]
The present invention has been made in view of such a situation, and an object of the present invention is to provide a millimeter-wave radar mounting structure that can ensure good measurement of a distance to an object ahead of a vehicle body by the millimeter-wave radar. And
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the millimeter wave radar mounting structure according to the present invention employs the following means.
[0008]
That is, the invention according to claim 1 is a millimeter-wave radar mounting structure in which the millimeter-wave radar measures at least one of a distance, a relative speed, and an azimuth angle with respect to an object in front of the vehicle body. And is disposed near the hood opening.
[0009]
According to the first aspect of the invention, the millimeter wave radar is disposed inside the vehicle body and near the hood opening, and the path of the radio wave radiated and received by the millimeter wave radar is secured at the hood opening. According to this, since the millimeter wave radar is provided near the hood opening at a position relatively high with respect to the center of gravity of the vehicle, even if the center of gravity of the preceding vehicle is higher than the own vehicle, the millimeter wave radar is The radio waves emitted by the wave radar are sufficiently reflected by the preceding vehicle. In addition, since the millimeter wave radar is provided above the vehicle body of the engine, even if rain or snow adheres to the millimeter wave radar, the heat of the engine evaporates rain, snow, etc., and the millimeter wave radar receives the millimeter wave radar. The intensity of a radio wave reflected by an object ahead of the vehicle body is not attenuated. Therefore, according to the present invention, it is possible to ensure good measurement of the distance to an object ahead of the vehicle body by the millimeter wave radar.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of a millimeter wave radar mounting structure provided in a vehicle according to the present invention will be described with reference to the drawings.
[0011]
FIG. 1 is a perspective view of a vehicle having an opening in a hood. FIG. 2 is a side sectional view of a millimeter wave radar mounting structure according to an embodiment of the present invention.
[0012]
In the present embodiment, the vehicle has a hood opening 2 provided substantially at the center of a hood 1 that covers an upper part of an engine room. The hood opening 2 is formed so as to communicate with the engine room in order to take air for cooling the engine into the engine room. The hood opening 2 is formed at the vehicle body front end of a hood projection 3 which is formed in a substantially central portion of the hood 1 so as to protrude upward from the vehicle body. An engine 4 is provided in the engine room. An engine cover 5 is provided above the engine 4.
[0013]
A millimeter wave radar 6 is provided in the engine room and near the hood opening 2. The millimeter wave radar 6 is fixed on the upper surface of the engine cover 5 on the rear side of the vehicle body inside the hood projection 3. The millimeter-wave radar 6 radiates radio waves (millimeter waves of 30 GHz to 300 GHz) from the hood opening 2 to the front of the vehicle body while scanning in the horizontal direction, and receives from the hood opening 2 radio waves reflected by an object in front of the vehicle body. This has a function of measuring at least one of the distance to the object ahead of the vehicle body, the relative speed, and the azimuth angle. That is, the millimeter wave radar 6 is provided so that a predetermined area in front of the vehicle body can be monitored through the hood opening 2. Note that the millimeter wave radar 6 may be fixed to the lower surface of the hood projection 3.
[0014]
A millimeter-wave radar cover 7 that protects the antenna of the millimeter-wave radar 6 and protects the millimeter-wave radar 6 from being exposed from the outside is provided in the engine room and in front of the vehicle body of the millimeter-wave radar 6. . The millimeter-wave radar cover 7 is formed in a plate shape and extends in the vehicle width direction. The millimeter-wave radar cover 7 is provided so as to be inclined with respect to the upper surface of the engine cover 5 (in this example, the front surface is inclined so as to face downward), and the lower edge portion of the engine cover 5 is provided. It is fixed to the upper surface. The millimeter wave radar cover 7 is formed of a resin (for example, polycarbonate) that transmits radio waves and has a small dielectric loss. The millimeter wave radar cover 7 may be fixed to the lower surface of the hood projection 3 at the upper edge. Further, the millimeter wave radar cover 7 may be formed integrally with the millimeter wave radar 6, or may be formed integrally with the engine cover 5.
[0015]
In the present embodiment, the distance to an object in front of the vehicle body is measured by a millimeter wave radar 6 provided in the engine room and near the hood opening 2. The radiating and receiving paths of the radio wave between the millimeter wave radar 6 and the front of the vehicle body are secured by the hood opening 2. In such a structure, since the millimeter wave radar 6 is provided at a position relatively high with respect to the center of gravity of the vehicle body, the preceding vehicle may be used for a radio wave emitted from the millimeter wave radar 6 in a truck or a motorcycle having a high center of gravity of the vehicle body. Even if there is, it is sufficiently reflected by the preceding vehicle. Therefore, according to the millimeter-wave radar mounting structure of the present embodiment, even if the preceding vehicle is a vehicle having a high center of gravity of the vehicle body such as a truck or a motorcycle, the distance to the preceding vehicle can be reliably measured.
[0016]
In this embodiment, the millimeter wave radar cover 7 is provided in the engine room and near the hood opening 2. Since the vicinity of the hood opening 2 in the engine room is above the engine 4, the millimeter wave radar cover 7 receives the heat of the engine. FIG. 3 is a diagram showing the relationship between the time from the start of the engine and the temperature inside the vehicle body when the outside air temperature is −20 ° C. The solid line in FIG. 3 indicates a change in temperature in the vicinity of the hood opening 2 in the engine room. The dashed line in FIG. 3 indicates a change in temperature change on the rear side of the vehicle body of the front grill. The temperature near the hood opening 2 inside the vehicle body becomes 0 ° C. in about 10 minutes after the engine is started. Therefore, if the millimeter-wave radar cover 7 has snow or freeze, the snow and freeze melt in a short time. On the other hand, the temperature of the front grill on the rear side of the vehicle body is lower than 0 ° C. even after a long time (for example, 30 minutes) has elapsed since the engine was started. For this reason, if the millimeter wave radar cover is provided on the rear side of the vehicle body of the front grill, and the millimeter wave radar cover has snow or freeze, the snow and freeze do not melt even after a long time. If the millimeter-wave radar cover 7 has snow or freezes, the radio wave intensity received by the millimeter-wave radar 6 and reflected by the object in front of the vehicle body is attenuated, and the millimeter-wave radar 6 determines the distance to the object in front of the vehicle body. It will not be possible to measure accurately. In this regard, according to the millimeter-wave radar mounting structure of the present embodiment, even if snow or freezing occurs on the millimeter-wave radar cover 7, the snow and freezing melt in a short time due to the heat of the engine 4 to become water. The radio wave intensity reflected by an object in front of the vehicle body received by the millimeter-wave radar 6 is not attenuated by snowfall or freezing of the millimeter-wave radar cover 7, so that the millimeter-wave radar 6 can prevent the radio wave intensity from being reduced by the millimeter wave radar 6. Distance and the like can be accurately measured.
[0017]
In this embodiment, since the millimeter wave radar 6 is provided in the engine room and near the hood opening 2 at a position relatively high with respect to the center of gravity of the vehicle body, the millimeter wave radar 6 is provided at the center of gravity of the vehicle body. In comparison with the case where the front grill is provided on the rear side of the front grill at a relatively low position, damage to the millimeter wave radar cover 7 due to stones or the like that the preceding vehicle bounces off can be reduced.
[0018]
Also, when the millimeter-wave radar is installed at a relatively low position with respect to the center of gravity of the vehicle body, the radio wave radiated from the millimeter-wave radar is reflected by the metal object provided at the seam of the road and should be measured originally Otherwise, the distance to the metal object or the like may be measured. In this regard, according to the millimeter-wave radar mounting structure of the present embodiment, since the millimeter-wave radar 6 is provided near the hood opening 2 at a relatively high position with respect to the center of gravity of the vehicle body, it should not be measured originally. Measurement of the distance to the metal object or the like can be prevented.
[0019]
Further, when the millimeter wave radar is provided on the rear side of the vehicle body of the front grill, the decorative member such as the emblem provided on the front grill cannot be formed of a metal material that reflects radio waves, so that the degree of freedom of design in the front grill is low. Become. In this regard, according to the millimeter-wave radar mounting structure of the present embodiment, the millimeter-wave radar 6 is provided in the engine room and near the hood opening 2, so that the degree of freedom in designing the front grill is reduced. Can be prevented.
[0020]
【The invention's effect】
As described above, according to the first aspect of the present invention, it is possible to ensure a good measurement of the distance to the object ahead of the vehicle body by the millimeter wave radar.
[Brief description of the drawings]
FIG. 1 is a perspective view of a vehicle having an opening in a hood.
FIG. 2 is a side sectional view of a millimeter wave radar mounting structure according to an embodiment of the present invention.
FIG. 3 is a diagram showing a relationship between a time from an engine start and a temperature inside a vehicle body.
[Explanation of symbols]
1 Hood 2 Hood opening 4 Engine 6 Millimeter wave radar 7 Millimeter wave radar cover

Claims (1)

A millimeter-wave radar mounting structure in which the millimeter-wave radar measures at least one of a distance to an object in front of the vehicle body, a relative speed, and an azimuth angle,
A millimeter-wave radar mounting structure, wherein the millimeter-wave radar is disposed inside a vehicle body and near a hood opening.

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