JP2006038769A - Vehicle circumference monitoring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for optimizing the setting of an incident angle relative to a bumper, etc. even if mounting the device in too tight a space to tilt the whole thereof. <P>SOLUTION: This vehicle circumference monitoring device provided inside the exterior of a vehicle for monitoring objects existing in the circumference of the vehicle, is equipped with a transmission antenna for emitting a transmission wave through the exterior toward the surroundings, a reception antenna for receiving reflected waves from surrounding objects, and a transmission wave reflector provided between the transmission antenna and the exterior. The wave reflector is used to adapt an incident angle of the transmission wave from the transmission antenna relative to the surface of the exterior in order to reduce reflections of the transmission wave on the surface of the exterior. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicle periphery monitoring device using a radar device.

  The conventional vehicle periphery monitoring device has to be attached to the inside of a bumper that cannot be seen from the outside, for example, so as not to impair the appearance of the vehicle. However, the space inside the bumper is very narrow.

  On the other hand, when the vehicle periphery monitoring device is attached to the inside of the bumper, it is necessary to set in consideration of the incident angle of the transmission wave to the bumper in order to reduce reflection of the transmission wave on the bumper surface. In addition, it was necessary to individually adjust the mounting angle of the device depending on the type of vehicle and the state of assembling the bumper cover. Therefore, the incident angle is set and adjusted by inclining the entire apparatus with a mounting screw inside the bumper (see, for example, Patent Document 1).

JP 2002-071788 A

  In the conventional vehicle periphery monitoring device, since the mounting angle is set and adjusted by tilting the entire device, both ends of the device come into contact with the bumper surface and the vehicle body surface in the space inside the bumper, so that the optimum angle is obtained. Optimal adjustment was difficult because some models could not be set, and when the device was tilted in a narrow space inside the bumper, the space for tools and the like was reduced, and installation took time.

  The present invention has been made to solve the above-described problems, and the object of the present invention is to optimize the setting of the incident angle with respect to a bumper or the like even if the entire apparatus is mounted in a space that cannot be tilted. It is to provide an apparatus.

  The vehicle periphery monitoring device according to the present invention monitors an object that is provided inside the exterior of the vehicle and exists around the vehicle. The transmission antenna transmits a transmission wave toward the periphery through the exterior, and the surrounding object. A transmission wave reflecting mirror provided between a receiving antenna for receiving a reflected wave from the transmitting antenna and the outer surface of the transmitting antenna, and an incident angle of the transmitting wave from the transmitting antenna with respect to the outer surface of the outer surface And a transmission wave reflecting mirror that reduces reflection at the surface.

  According to this vehicle periphery monitoring apparatus, since the transmission wave reflecting mirror is provided between the transmission antenna and the exterior, the reflection of the transmission wave transmitted from the transmission antenna on the exterior surface is reduced, and the exterior The vehicle periphery monitoring device can be installed in a narrow space inside the vehicle without being inclined with respect to the exterior surface.

Embodiment 1 FIG.
Hereinafter, a vehicle periphery monitoring apparatus according to Embodiment 1 of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram illustrating a configuration of a vehicle periphery monitoring device, and FIG. 2 is a schematic diagram illustrating a state of the vehicle periphery monitoring device provided inside the bumper.

  In the example shown in FIGS. 1 and 2, the vehicle periphery monitoring device is provided inside the bumper. However, the vehicle periphery monitoring device is not only a bumper but also a fender, a door mirror cover, etc. It can also be provided inside the exterior of the vehicle made of material. 1 and 2, the vehicle periphery monitoring device 100 includes a vehicle periphery monitoring unit 1 and a transmission wave reflecting mirror 14. The vehicle periphery monitoring unit 1 transmits a transmission wave 3 transmitted through the bumper 2 and radiated to the periphery of the vehicle, and a reflected wave reflected by an object existing around the vehicle and returning to the vehicle side. A high-frequency circuit unit 9 having a receiving antenna 6 that receives 5, a transmitting circuit 7 that is connected to the transmitting antenna 4 and transmits a transmission wave 3, and a receiving circuit 8 that is connected to the receiving antenna 6 and receives a reflected wave 5; And a signal processing circuit unit 10 connected to the high-frequency circuit unit 9 for processing the received signal, and a signal processing result is displayed to the driver by a display 11 connected to the signal processing circuit unit 10. Here, the vehicle periphery monitoring device 100 is provided inside the bumper 2 of the vehicle, and the indicator 11 is provided in the passenger compartment.

  In FIG. 2, the vehicle periphery monitoring unit 1 is provided inside the bumper 2 between the bumper 2 and the vehicle body 12, and is fixed to the bumper 2 with a bolt 13. Here, the transmission wave reflecting mirror 14 is provided by a support member 21 extending from the bumper 2 on the radio wave propagation path of the transmission wave 3 between the transmission antenna 4 and the bumper 2. The transmission wave reflecting mirror 14 may be a conductive metal plate, but may be a resin substrate formed with a conductive film. In this example, the transmission wave reflecting mirror 14 is attached to the support member 21 extending from the bumper 2, but the support member 21 may be provided on the housing of the vehicle periphery monitoring unit 1 to attach the reflecting mirror. The transmission wave reflecting mirror 14 is provided with an adjusting portion 22 so that the angle can be adjusted with a screw or the like even after installation or during an accident.

  In FIG. 1 or FIG. 2, the transmission wave 3 generated by the transmission circuit 7 in the high-frequency circuit unit 9 is radiated from the transmission antenna 4, changed in direction by the transmission wave reflecting mirror 14, and then incident on the bumper 2. Is transmitted around the vehicle. A reflected wave 5 reflected from an object or the like around the vehicle and returning to the vehicle side from each direction enters from the outside of the bumper 2, passes through the bumper 2, and is received by the receiving antenna 6. The reflected wave 5 is input to the receiving circuit 8 in the high frequency circuit unit 9, and the input reflected wave 5 is converted into a low frequency by the high frequency circuit unit 9 and then input to the signal processing circuit unit 10. In the signal processing circuit unit 10, the distance to the obstacle and the relative speed are calculated, and when it is determined that there is a risk of a collision, a display notifying the danger is displayed on the connected indicator 11 to alert the driver. It has become.

  As described above, by using the transmission wave reflecting mirror 14 provided between the transmission antenna 4 and the bumper 2, the incident angle of the transmission wave 3 transmitted from the transmission antenna 4 with respect to the bumper 2 can be set to the surface of the exterior of the transmission wave 3. It is possible to set so that the reflection at the surface is reduced. Further, it is not necessary to perform complicated beam shaping in the transmission antenna 4 of the vehicle periphery monitoring unit 1, and the vehicle periphery monitoring unit 1 can be attached to a narrow space inside the bumper 2 without being inclined with respect to the exterior surface. .

  FIG. 3 is a graph showing the measurement results of the reflection amount with respect to the horizontal polarization incidence of polypropylene generally used for the bumper 2 for polypropylenes of various thicknesses. The horizontal axis represents the incident angle θ [deg] of the radio wave with respect to the polypropylene, and the vertical axis represents the reflection amount R [dB] from the polypropylene.

  From FIG. 3, the reflection amount R is generally small when the incident angle θ is about 56 degrees, regardless of the thickness d [mm] of the polypropylene. This angle is called the Brewster angle. In a dielectric material such as polypropylene, there is an angle at which electromagnetic waves are almost completely transmitted with respect to horizontal polarization incidence.

  Here, in FIG. 2, the transmission wave reflecting mirror 14 is provided at a position where the incident angle θ of the transmission beam 3 with respect to the bumper 2 of the main beam is near 56 degrees which is the Brewster angle. The angle of the reflecting mirror is set when the reflecting mirror is attached, or is adjusted to be close to the Brewster angle by tightening the screw of the adjusting unit 22 after the reflecting mirror is attached.

  In FIG. 2, the transmission wave 3 transmitted from the transmission antenna 4 is reflected by the transmission wave reflecting mirror 14 and enters the bumper 2. Here, since the incident angle θ is a Brewster angle, the main beam of the transmission wave 3 is hardly reflected on the surface of the bumper 2, and almost all the main beam of the transmission wave 3 is transmitted through the bumper 2 and radiates around the vehicle. Is done.

  Thus, by providing the transmission wave reflecting mirror 14 so that the main beam of the transmission wave 3 is incident on the bumper 2 in the vicinity of the Brewster angle, the amount of transmission wave 3 transmitted through the bumper 2 is maximized, and the incidence efficiency is increased. Can be maximized. Accordingly, since many reflected waves 5 reflected by the object are also received, the periphery of the vehicle can be monitored with higher accuracy.

Embodiment 2. FIG.
FIG. 4 is a schematic diagram showing a state of the vehicle periphery monitoring device 100 provided inside the bumper 2 and monitoring a specific direction in Embodiment 2 of the present invention. In FIG. 4, the reflected wave 5 incident on the bumper 2 from the outside of the bumper 2 is reflected at the same angle as the transmission wave reflector 14 for the transmitted wave 3 on the radio wave propagation path between the receiving antenna 6 and the bumper 2. A reflecting mirror 15 is provided. Other configurations are the same as those of the first embodiment.

  In FIG. 4, the main beam of the transmitted wave 3 incident on the bumper 2 at the Brewster angle is reflected by an object around the vehicle and the same direction as the main beam of the reflected wave 5, that is, with respect to the outer surface of the bumper 2. It returns to the vehicle side at the star angle and efficiently enters the bumper 2. The main beam of the reflected wave 5 incident on the bumper 2 is transmitted through the bumper 2, and then the reflected wave reflector 15 provided at an angle at which the reflected wave 5 incident on the bumper at a Brewster angle is vertically incident on the receiving antenna 6. The direction is changed by the above and the light enters the receiving antenna 6 perpendicularly.

  Thus, by providing the reflected wave reflector 15 between the receiving antenna 6 and the bumper 2 with respect to the main beam of the reflected wave 5, for example, by receiving a reflected wave having a good angle of transmission to the bumper 2. The reflected wave 5 in a specific direction can be intensively incident on the receiving antenna 6, and the specific direction can be monitored intensively.

  When the inner surface and the outer surface of the bumper 2 are not parallel due to the shape of the bumper 2, the main beam of the reflected wave 5 does not enter the bumper 2 at the Brewster angle, so that the reflection occurs on the outer surface of the bumper 2. Since the reflected wave reflected by the outer surface of the vehicle is not received by the receiving antenna 6, the vehicle periphery monitoring apparatus 100 is not adversely affected.

Embodiment 3 FIG.
FIG. 5 is a diagram showing the state of the vehicle periphery monitoring unit 1, the transmission wave reflecting mirror 14, and the bumper 2 provided inside the bumper 2 according to Embodiment 3 of the present invention. In FIG. 5, the transmission wave reflecting mirror 14 is made of a conductive film plated on an integrally molded surface 16 provided on the bumper 2, and is integrated with the bumper 2. Other configurations are the same as those of the second embodiment. Although the transmission wave reflecting mirror 14 is integrally formed with the bumper 2 in FIG. 5, the transmission wave reflecting mirror 14 may be integrally formed with the vehicle periphery monitoring unit 1.

  Thus, by integrating the transmission wave reflecting mirror 14 with the bumper 2 or the vehicle periphery monitoring unit 1, the number of parts can be reduced, the apparatus can be downsized, and the cost can be reduced. Further, the transmission wave reflecting mirror 14 can be easily and accurately set.

  Further, by integrally forming the transmission wave reflecting mirror 14 on the bumper 2, the angle of the transmission wave reflecting mirror 14 is set so that the main beam of the transmission wave 3 is incident on the bumper 2 at a Brewster angle at every mounting position of each vehicle type. It only has to be designed on the bumper 2 side. Therefore, since it is not necessary to customize the direction of the transmission / reception antenna depending on the mounting position of the vehicle periphery monitoring unit 1, a large number of vehicle periphery monitoring units 1 having the same function can be produced, and versatility can be improved.

  The conductive film fixed to the bumper 2 or the vehicle periphery monitoring unit 1 is not limited to plating, but may be fixed using other methods such as vapor deposition.

Embodiment 4 FIG.
Hereinafter, a vehicle periphery monitoring apparatus according to Embodiment 4 of the present invention will be described with reference to the drawings.
FIG. 6 is a diagram showing the measurement results of the reflection amount of the polypropylene used for the bumper 2 with respect to the incidence of vertical polarization. It is the figure which showed [dB].

  From FIG. 6, there is no incident angle at which electromagnetic waves are completely transmitted with respect to vertically polarized waves with respect to polypropylene of any thickness d [mm], and there is a Brewster angle as shown in the first embodiment. Thus, it can be seen that the transmission efficiency of vertically polarized waves is not good. Considering this and the existence of the Brewster angle with respect to the horizontal polarization shown in FIG. 3, if the vertical polarization component of the electromagnetic wave is converted into the horizontal polarization component, the electromagnetic wave can be efficiently transmitted through the polypropylene. I understand that I can do it.

  FIGS. 7 and 8 are diagrams showing a reflector unit 18 including a polarization conversion unit 17 that converts the polarization of the transmission wave 3. The reflecting mirror unit 18 in FIG. 7 includes a plate-like dielectric 23, a plate-like conductor 24 provided on one surface of the dielectric 23, and a plurality of parallels provided on the other surface of the dielectric 23. And a strip-shaped conductor 25 spaced apart from each other. The plate-like conductor 24 is an electromagnetic wave reflecting mirror, and the polarization conversion unit 17 in which the dielectric 23 provided on the conductor 24 that is the reflecting mirror and the strip-like conductor 25 performs horizontal polarization conversion of the electromagnetic wave. It is composed. The reflecting mirror unit 18 in FIG. 8 includes a plate-like dielectric 23 having one flat surface and a corrugated groove 26 on the other surface, and a plate-like conductor 24 provided on the flat surface of the dielectric 23. I have. The plate-like conductor 24 is an electromagnetic wave reflecting mirror, and a dielectric 23 having a corrugated groove 26 provided on the reflecting mirror constitutes a polarization conversion unit 17 that horizontally converts the electromagnetic wave. These reflecting mirror units 18 can be used in place of the transmission wave reflecting mirror 14 or the reflecting wave reflecting mirror 15 of the embodiment described so far. For example, in the embodiment of FIG. 2, the transmission wave reflecting mirror 14 can be replaced with the reflecting mirror unit 18 shown in FIG. 7 or FIG. Even if the polarization converter 17 of FIG. 7 or FIG. 8 is attached to the transmission wave reflecting mirror 14 or the reflecting wave reflecting mirror 15, the configuration is the same as that of the reflecting mirror unit 18. For example, in the case of the embodiment of FIG. 5, the polarization conversion unit 17 of FIG. 7 or 8 can be attached to the conductive film deposited on the integral molding surface 16. When such a reflector unit 18 is used, the polarization conversion unit 17 is provided in the reflector between the transmission antenna 4 and the bumper 2, and the transmission wave radiated from the transmission antenna is horizontally polarized. Then, the light enters the bumper 2.

  FIG. 9 is a diagram illustrating the vehicle periphery monitoring apparatus 100 in which the reflector unit 18 including the polarization conversion unit 17 is attached to the bumper 2. A reflector unit 18 having a polarization conversion unit 17 shown in FIG. 7 or 8 is attached to the bumper 2 instead of the transmission wave reflector 14 for the transmission wave 3 shown in FIG. Here, the transmitting antenna 4 is designed to transmit horizontally polarized waves, and the reflecting mirror unit 18 is attached such that the strip-shaped conductor 25 and the corrugated groove 26 face the vertical direction. Other configurations are the same as those of the first embodiment.

In FIG. 9, the transmission antenna 4 is designed to transmit horizontal polarization, but the transmission wave 3 includes some vertical polarization component depending on how the vehicle periphery monitoring unit 1 is attached.
The transmission wave 3 is reflected by the reflecting mirror unit 18 including the polarization converter 17 and enters the bumper 2. At this time, in FIG. 7, there is a path difference between the transmission wave 3 reflected by the strip-like conductor 25 of the polarization converter 17 and the transmission wave 3 reflected by the plate-like conductor 24, and thus a phase difference. Here, the transmission wave 3 can be converted into horizontal polarization by adjusting the inclination of the reflecting mirror unit 18 according to the vertical polarization component of the transmission wave 3. In FIG. 8, the transmission wave 3 that is transmitted through the concave portion of the corrugated groove 26 of the dielectric 23 of the polarization conversion unit 17 and reflected by the plate-like conductor 24 and the convex portion are transmitted through the plate-like conductor 24. There is a path difference between the reflected transmission wave 3 and a phase difference. Here, similarly, the transmission wave 3 can be converted into horizontal polarization by adjusting the inclination of the reflecting mirror unit 18 according to the vertical polarization component of the transmission wave 3. Therefore, the polarization of the transmission wave 3 is converted into a horizontal polarization and enters the bumper 2.

  In this way, by converting the polarized wave into the horizontally polarized wave and making it incident on the bumper 2, the main beam of the transmission wave 3 can be made incident on the bumper 2 at the Brewster angle, and the reflected wave is small, so transmission is performed. The amount of the wave 3 transmitted through the bumper 2 is the largest, and the incident efficiency can be maximized.

It is a figure which shows the structure of the vehicle periphery monitoring apparatus which is Embodiment 1 of this invention. It is a figure which shows the state of the vehicle periphery monitoring apparatus provided in the bumper which is Embodiment 1 of this invention. It is a figure which shows the measurement result of the reflection amount with respect to the horizontal polarization input of the polypropylene used for the bumper which is Embodiment 1 of this invention. It is the schematic which shows the state of the vehicle periphery monitoring apparatus at the time of being provided in the bumper which is Embodiment 2 of this invention, and monitoring a specific direction. It is a figure which shows the form of the vehicle periphery monitoring apparatus which is Embodiment 3 of this invention, a reflective mirror, and a bumper. It is a figure which shows the measurement result of the reflection amount with respect to the vertical polarization input of the polypropylene used for the bumper which is Embodiment 4 of this invention. It is a figure which shows the polarization conversion part which converts the polarization of the transmission wave which is Embodiment 4 of this invention. It is a figure which shows another polarization conversion part which converts the polarization of the transmission wave which is Embodiment 4 of this invention. It is a figure which shows the state of the vehicle periphery monitoring apparatus provided in the bumper which is Embodiment 4 of this invention, and provided with the polarization converter.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Vehicle periphery monitoring part, 2 Bumper, 3 Transmitted wave, 4 Transmitting antenna, 5 Reflected wave, 6 Receiving antenna, 14 Transmitted wave reflecting mirror, 15 Reflected wave reflecting mirror, 17 Polarization converter, 100 Vehicle periphery monitoring apparatus.

Claims (9)

In the vehicle periphery monitoring device that is provided inside the exterior of the vehicle and monitors objects existing around the vehicle,
A transmission antenna that transmits the transmission wave toward the periphery through the exterior; and
A receiving antenna that receives reflected waves from surrounding objects;
A transmission wave reflecting mirror provided between the transmission antenna and the exterior, wherein an incident angle of the transmission wave from the transmission antenna with respect to the exterior surface is reflected on the surface of the exterior of the transmission wave. A vehicle periphery monitoring device comprising: a transmission wave reflecting mirror that reduces the number of transmission wave reflection mirrors.   2. The vehicle periphery monitoring device according to claim 1, wherein the transmission wave reflecting mirror is disposed at an angle at which an incident angle of the transmission wave with respect to the surface of the exterior is in the vicinity of a Brewster angle.   The vehicle periphery monitoring device according to claim 1, wherein the transmission wave reflecting mirror is provided so as to be adjustable in angle.   The said reflected wave reflective mirror is comprised with the electroconductive film, and it is provided in either the said vehicle periphery monitoring apparatus or the said exterior, The any one of Claims 1-3 characterized by the above-mentioned. Vehicle periphery monitoring device.   2. A reflected wave reflecting mirror provided between the receiving antenna and the exterior, comprising a reflected wave reflecting mirror for specifying a direction of the reflected wave received by the receiving antenna. The vehicle periphery monitoring device according to claim 1.   6. The vehicle periphery monitoring device according to claim 5, wherein the reflected wave reflecting mirror is disposed at an angle near a Brewster angle with respect to the surface of the exterior.   The vehicle periphery monitoring device according to claim 5 or 6, wherein the reflected wave reflecting mirror is provided so as to be adjustable in angle.   The said reflected wave reflective mirror is comprised with the electroconductive film, It is provided in either the said vehicle periphery monitoring apparatus or the said exterior, The any one of Claims 5-7 characterized by the above-mentioned. Vehicle periphery monitoring device.   Polarization conversion means provided between the transmission antenna and the exterior, and provided in the reflecting mirror that horizontally polarizes the transmission wave radiated from the transmission antenna and enters the exterior. The vehicle periphery monitoring device according to any one of claims 1 to 8, wherein

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