JP2007163334A - On-vehicle radar device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an on-vehicle radar device for a vehicle that is not affected by electromagnetic noise (disturbances noise) from the other on-vehicle apparatus. <P>SOLUTION: This radar device for the vehicle comprises a parabolic reflector 1, a radiator 10 for radiating electromagnetic wave toward the parabolic reflector 1, a driving means 7 for rotating and rocking the parabolic reflector 1 and changing the angle of reflection of the electromagnetic wave in the parabolic reflector 1, a light radiating means 14 for radiating light toward a rear face conductor 4 of the parabolic reflector 1, a light receiving means 15 for receiving the reflected light reflected by the rear face conductor 4, and a signal processing means 21 for detecting the rotating/rocking angle of the parabolic reflector 1 based on the output signal from the light receiving means 15 output according to the variation of the received light amount received by the light receiving means 15. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicular radar apparatus that irradiates an electromagnetic wave around a vehicle and detects a distance, a relative speed, a direction, and the like from the reflected wave to an obstacle around the vehicle.

As a conventional vehicle radar device, a parabolic reflector, a radiator that radiates electromagnetic waves toward the parabolic reflector, and the parabolic reflector that rotates and swings the parabolic reflector A device having a driving means for changing the reflection angle of electromagnetic waves is known.
In this case, as a method of detecting the rotation angle of the parabolic reflector, a Hall IC is arranged between a pair of angle detecting magnets attached to the central portion of the parabolic reflector, and the angle detecting mirror is used. The rotation angle of the parabolic reflector is detected from the value of the output voltage from the Hall IC that is output according to the change in the magnetic flux density from the magnet.

JP 2003-318627 A

  In conventional vehicle radar, the rotation angle of the parabolic reflector is detected using a Hall IC. However, the Hall IC is affected by electromagnetic noise (disturbance noise) from other on-vehicle equipment. There was a problem that a shielding structure against noise had to be provided.

  An object of the present invention is to provide a vehicular radar apparatus that is not affected by electromagnetic noise (disturbance noise) from other on-vehicle equipment. Objective.

  A vehicle radar apparatus according to the present invention includes a parabolic reflector, a radiator that radiates electromagnetic waves toward the parabolic reflector, and a parabolic reflector that rotates and swings the parabolic reflector. Driving means for changing the reflection angle of the electromagnetic wave, light irradiating means for irradiating light toward the reflecting part of the parabolic reflector, light receiving means for receiving the reflected light reflected by the reflecting part, and Signal processing means for detecting the rotational swing angle of the parabolic reflecting mirror based on an output signal from the light receiving means that is output in accordance with a change in the amount of light received by the light receiving means or a change in the light receiving position. Yes.

  According to the vehicle radar device of the present invention, there is no need to provide a shielding structure against disturbance noise because it is not affected by electromagnetic noise (disturbance noise) from other on-vehicle equipment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or equivalent members and parts will be described with the same reference numerals.
Embodiment 1 FIG.
FIG. 1 is a schematic diagram showing a configuration of a vehicle radar apparatus according to Embodiment 1 of the present invention.
The radar device for a vehicle includes a parabolic reflector 1, a radiator 10 that radiates electromagnetic waves toward the parabolic reflector 1, and a parabolic reflector that rotates and swings the parabolic reflector 1. Drive means 7 for changing the reflection angle of the electromagnetic wave 1, light irradiation means 14 for irradiating light toward the parabolic reflector 1, and light reception for detecting a change in the amount of received light reflected by the parabolic reflector 1. And means 15.
The vehicular radar apparatus is provided opposite to the parabolic reflector 1, reflects the magnetic wave toward the paraboloid reflector 1, and reflects the electromagnetic waves reflected by the paraboloid reflector 1. Signal processing for detecting the rotational swing angle of the paraboloidal reflecting mirror 1 based on the output signal from the planar reflecting mirror 11 that transmits the light and the light receiving means 15 that is output according to the change in the amount of light received by the light receiving means 15. Means 21.

2 is a front view of the parabolic reflector 1 shown in FIG. 1 when viewed in the direction of arrow B, and FIG. 3 is a side sectional view of the parabolic reflector 1 shown in FIG.
The parabolic reflecting mirror 1 is rotatably supported by a rotating shaft 5. A parabolic reflector 1 having a radiation hole 6 formed in the central portion is provided with a plurality of dielectrics 2 and parallel surfaces spaced apart from each other on the surface of the dielectric 2 on the plane reflecting mirror 11 side to reflect electromagnetic waves. The linear conductor 3 and the back conductor 4 which is a reflection part which reflects the electromagnetic wave which passed through the linear conductor 3 and permeate | transmitted the dielectric material 2 are provided in the whole surface by the side of the radiator 10 of the dielectric material 2.

4 is a front view of the planar reflecting mirror 11 of FIG. 1 as viewed along the direction of arrow A, and FIG. 5 is a side sectional view of the planar reflecting mirror 11 of FIG.
The planar reflecting mirror 11 is a reflecting mirror for realizing selective reflection according to the deflection direction of the electromagnetic wave, and is disposed in the vicinity of a position half the distance to the focal point of the parabolic reflecting mirror 1.
The plane reflecting mirror 11 is provided in parallel to the dielectric 12 and the surface of the dielectric 12 on the paraboloidal reflecting mirror 1 side so as to be parallel to each other and to reflect the electromagnetic wave toward the parabolic reflecting mirror 1. And a conductor 13.
The dielectrics 2 and 12 are made of resin. The straight conductors 3 and 13 are formed by a process combining plating and etching. The back conductor 4 which is a reflection part is formed by nickel plating etc., for example, and has the characteristic with favorable light reflectivity.

Driving means 7 for changing the direction of the beam radiated from the vehicular radar apparatus are provided on both sides of the parabolic reflecting mirror 1, respectively. The drive means 7 is composed of a pair of opposed magnets 8 and coils 9.
The magnetic repulsive drive means 7 is connected in series so that reverse currents flow through the two coils 9, and the paraboloidal reflector 1 rotates around the rotation axis 5 depending on the direction of the current, or It rotates counterclockwise and the rotation angle is controlled by the magnitude of the current.

  The light irradiation means 14 is configured by an LED (light emitting diode), an LD (laser diode), or the like. The light receiving means 15 is composed of a PD (photodiode), a CCD (charge imaging device), or the like. The output voltage output from the light receiving means changes corresponding to the change in the amount of light received by the light receiving means 15.

Next, the operation of the vehicular radar apparatus having the above configuration will be described.
When the polarization direction of the electromagnetic wave radiated from the vehicle radar apparatus is inclined 45 degrees to the right as shown in FIG. 4, it is radiated from the radiator 10 through the radiation hole 6 with the polarization of 45 degrees to the left. The electromagnetic wave is totally reflected by the linear conductor 13 of the plane reflecting mirror 11.
The electromagnetic wave totally reflected by the linear conductor 13 toward the parabolic reflecting mirror 1 is the linear conductor 3 of the parabolic reflecting mirror 1 arranged at 45 degrees with respect to the linear conductor 13 of the planar reflecting mirror 11, that is, The direction of polarization is changed by 90 degrees by the deflecting torsional reflection means, and the reflected light is reflected by the paraboloidal reflecting mirror 1 after being tilted to 45 degrees to the right, and then radiated through the plane reflecting mirror 11 into the air. .
The direction of the beam of the vehicle radar device is determined by the direction and magnitude of the current flowing in the coil 9 of the driving means 7.

Next, the detection operation of the rotation angle of the parabolic reflecting mirror 1 will be described.
As shown in FIG. 6, the light irradiated from the light irradiating means 14 toward the parabolic reflecting mirror 1 is reflected by the back conductor 4 of the parabolic reflecting mirror 1 in a normal line symmetry and enters the light receiving means 15. Shine.
In FIG. 6, the light irradiating means 14 and the light receiving means are applied to the parabolic reflecting mirror 1 so that the output voltage from the light receiving means 15 is maximized when the rotational swing angle θ of the parabolic reflecting mirror 1 is 0 deg. 15 is arranged.
In this vehicular radar apparatus, as shown in FIG. 7, when the parabolic reflector 1 rotates clockwise by an angle θ (deg), the light incident position to the light receiving means 15 shifts to the left, and accordingly. The output voltage from the light receiving means 15 decreases.
Note that the relationship between the rotational swing angle θ of the parabolic reflector 1 and the output voltage of the light receiving means 15 is as shown in FIG. 8, and this data is stored in the signal processing means 21 in advance.
This output signal from the light receiving means 15 is sent to the signal processing means 21, and the signal processing means 21 detects the rotational swing angle of the parabolic reflecting mirror 1 based on the output signal.

  As described above, in the vehicular radar apparatus having the above-described configuration, the rotation of the paraboloidal reflector 1 at that time is determined from the value of the output voltage output from the light receiving means 15 without being affected by electromagnetic noise from the on-vehicle equipment. The swing angle can be easily detected.

In this vehicular radar apparatus, the paraboloidal reflecting mirror 1 is repeatedly expanded and contracted due to a temperature change, so that the shape of the reflecting surface is changed. Also, the dielectric 2 made of resin, the linear conductor 3 made of metal, the back conductor 4, cracks or peeling occurs on the surfaces of the dielectric 2, the straight conductor 3, and the back conductor 4 due to a difference in linear expansion coefficient. Further, the metal linear conductor 3 and the back conductor 4 are corroded.
These phenomena lead to a decrease in radar performance. In these cases, the light reception level output from the light receiving means 15 is extremely reduced, so that the paraboloid can be detected by always detecting the light reception level. Abnormality of the reflecting mirror 1 can be detected quickly.

In addition, since the irradiation position of the light for detecting the rotation angle is curved surface reflection on the convex surface of the parabolic reflector 1, the reflection direction of the light changes greatly even if the rotation angle (displacement) is very small, and the detection resolution is high. There is also an effect.

Embodiment 2. FIG.
FIG. 9 is a schematic diagram showing a main part of a vehicle radar apparatus according to Embodiment 2 of the present invention.
In this embodiment, the light receiving means 16 detects a change in the light receiving position for receiving the reflected light reflected by the back conductor 4 of the parabolic reflecting mirror 1. The light receiving means 16 is constituted by a PD, a CCD, or the like in which an element capable of detecting a light receiving position is divided.
Other configurations are the same as those of the first embodiment.

In this embodiment, as shown in FIG. 10, when the parabolic reflector 1 is rotated clockwise by an angle θ (deg), the light incident position to the light receiving means 16 is shifted to the left side, and the light receiving means 16 Then, the output voltage decreases corresponding to the shift position.
The relationship between the rotational swing angle θ of the paraboloidal reflecting mirror 1 and the output voltage of the light receiving means 16 is as shown in FIG. 11, and the curve a indicates the output characteristics of the elements 1 and 2 of the light receiving means 16. Curve B shows the output characteristics of the elements 3 and 4.
This output signal from the light receiving means 16 is sent to the signal processing means 21 in which the output characteristics of the light receiving means 16 are stored in advance, and the signal processing means 21 rotates the parabolic reflector 1 based on the output signal. The moving angle is detected.

Embodiment 3 FIG.
FIG. 12 is a schematic diagram showing a main part of a vehicle radar device according to Embodiment 3 of the present invention.
In this embodiment, two light irradiation means 14a, 14b and two light receiving means 15a, 15b are arranged.
Other configurations are the same as those of the first embodiment.

In this embodiment, the light irradiated from the first light irradiation means 14a toward the parabolic reflector 1 is reflected by the back conductor 4 and enters the first light receiving means 15a. The light irradiated from the second light irradiation means 14b toward the parabolic reflector 1 is reflected by the back conductor 4 and enters the second light receiving means 15b.
As indicated by the dotted line from the solid line in FIG. 12, when the parabolic reflector 1 is deformed so that the radius of curvature is reduced by the deformation angle θ (deg), the first light entering the first light receiving means 15a. The light incident position of the light from the irradiating means 14a is shifted to the right side, and the output voltage of the first light receiving means 15a decreases corresponding to the shifted position.
The light from the first light irradiating means 14b that has entered the second light receiving means 15b shifts the light incident position to the left, and the second light receiving means 15b outputs an output voltage corresponding to the shift position. Decreases.

The relationship between the deformation angle θ of the parabolic reflecting mirror 1 and the output voltages of the first light receiving means 15a and the second light receiving means 15b is the relationship shown in FIG. 13, and the curve A is the first light receiving means. The output characteristic of 15a is shown, and the curve b shows the output characteristic of the second light receiving means 15b.
The output signals from the first light receiving means 15a and the second light receiving means 15b are sent to the signal processing means 21 in which the output characteristics of the light receiving means 115a and 15b are stored in advance, and the signal processing means 21 outputs the output signal. The deformation angle of the parabolic reflecting mirror 1 is detected based on the above.

  In this embodiment, two light irradiating means 14a and 14b and two light receiving means 15a and 15b are described. However, the number may be three or more.

  In this embodiment, even when a shape change occurs such that the curvature of the parabolic reflector 1 changes due to a temperature change or a secular change, the first light receiving means 15a and the second light receiving means 15b The degree of curvature change can be estimated from the output change.

Embodiment 4 FIG.
FIG. 14 is a schematic diagram showing a main part of a vehicle radar apparatus according to Embodiment 4 of the present invention.
In this embodiment, the light receiving means 16a and 16b are constituted by PDs or CCDs or the like in which elements capable of detecting the light receiving position are divided.
Other configurations are the same as those of the third embodiment.

In this embodiment, the light irradiated from the first light irradiation means 14a toward the parabolic reflector 1 is reflected by the back conductor 4 and enters the first light receiving means 16a. The light irradiated from the second light irradiation means 14b toward the parabolic reflecting mirror 1 is reflected by the back conductor 4 and enters the second light receiving means 16b.
As indicated by the dotted line from the solid line in FIG. 14, when the parabolic reflecting mirror 1 is deformed so that the radius of curvature is reduced by the deformation angle θ (deg), the first light entering the first light receiving means 16a. The light incident position of the light from the irradiating means 14a is shifted to the right side, and the output voltage of the first light receiving means 16a decreases corresponding to the shifted position.
The light from the second light irradiating means 14b that has entered the second light receiving means 16b shifts the light incident position to the left, and the second light receiving means 15b outputs an output voltage corresponding to the shifted position. Decreases.

  In this embodiment, the relationship between the deformation angle θ of the parabolic reflector 1 and the output voltages of the first light receiving means 16a and the second light receiving means 16b is the relationship shown in FIG. Indicates the output characteristics of the elements 3 and 4 of the first light receiving means 16a, curve B indicates the output characteristics of the elements 1 and 2 of the first light receiving means 16a, and curve C indicates the element 3 of the second light receiving means 16b. , 4, and curve D shows the output characteristics of the elements 1 and 2 of the second light receiving means 16 b.

  The output signals from the first light receiving means 16a and the second light receiving means 16b are sent to the signal processing means 21 in which the output characteristics of the first light receiving means 16a and the second light receiving means 16b are stored. The means 21 detects the deformation angle of the parabolic reflector 1 based on the output signal.

In this embodiment, even when a shape change occurs such that the curvature of the parabolic reflector 1 changes due to a temperature change or a secular change, the first light receiving means 16a and the second light receiving means 16b The degree of curvature change can be estimated from the output change.
It is also possible to detect not only the curvature change of the parabolic reflector 1 but also the shape change three-dimensionally. Further, the present invention can be applied not only to the shape change but also to the detection of the displacement of the parabolic reflecting mirror 1.

Embodiment 5 FIG.
FIG. 16 is a block diagram showing a vehicular radar apparatus according to the fifth embodiment.
In this embodiment, the signal processing unit 21 changes the transmission beam width transmitted to the outside based on the output voltage input from the light receiving units 15, 16, 15 a, 15 b, 16 a, 16 b, in the beam scanning direction. The change is estimated, feedback control for controlling the rotation angle of the parabolic reflecting mirror 1 is performed using the driving means 7, and the transmission beam abnormality is detected.
Further, the signal processing means 21 is also configured to determine abnormal rotation angles, abnormal shapes, etc. of the parabolic reflecting mirror 1.

Embodiment 6 FIG.
In each of the above first to fifth embodiments, the reflecting portion that reflects the light from the light irradiation means 14, 14 a, 14 b is the back conductor 4 of the parabolic reflector 1.
In this embodiment, the reflector is attached to the outside of the parabolic reflector 1 to which the magnet 8 is attached. The reflection portion may be made of a material such as a metal having excellent light reflection characteristics, or may be constituted by plating or vapor deposition on the dielectric 2.
In this embodiment, the parabolic reflector 1 is changed based on the change in the amount of light received by the light receiving means 15, 16, 15 a, 15 b, 16 a, 16 b that receives the light reflected by the reflecting portion or the change in the light receiving position. A rotation angle and shape change can be detected.
In addition, in order to detect the reference position and rotation angle in detail, as a reflection part, materials with different reflectivity such as a barcode pattern are alternately attached, or notches are provided, and the reflected light amount according to the rotation angle, The reflection position may be changed in detail.

In each of the above embodiments, the vehicle radar apparatus provided with the planar reflecting mirror 11 has been described. However, the present invention can be applied to a vehicle radar apparatus without the planar reflecting mirror 11.
In this case, the radiator is formed on the concave surface of the parabolic reflector.

It is a schematic diagram which shows the structure of the radar apparatus for vehicles of Embodiment 1 of this invention. FIG. 2 is a front view of the parabolic reflector of FIG. 1 when viewed along the direction of arrow B. FIG. 3 is a side sectional view of the parabolic reflector of FIG. 2. FIG. 2 is a front view when the planar reflecting mirror of FIG. 1 is viewed along the direction of arrow A. It is a sectional side view of the plane reflective mirror of FIG. It is operation | movement explanatory drawing of the radar apparatus for vehicles of FIG. FIG. 6 is another operation explanatory diagram of the vehicle radar device of FIG. 1. It is an output characteristic figure of the light-receiving means of FIG. It is a schematic diagram which shows the structure of the principal part of the radar apparatus for vehicles of Embodiment 2 of this invention. FIG. 10 is an operation explanatory diagram of the vehicle radar device of FIG. 9. FIG. 10 is an output characteristic diagram of the light receiving means of FIG. 9. It is a schematic diagram which shows the structure of the principal part of the radar apparatus for vehicles of Embodiment 3 of this invention. It is an output characteristic figure of the light-receiving means of FIG. It is a schematic diagram which shows the structure of the principal part of the radar apparatus for vehicles of Embodiment 4 of this invention. It is an output characteristic figure of the light-receiving means of FIG. It is a block diagram which shows the radar apparatus for vehicles of Embodiment 5 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Parabolic reflector, 2,12 Dielectric, 3,13 Linear conductor, 4 Back conductor (reflective part), 5 Rotating shaft, 7 Driving means, 10 Radiator, 11 Planar reflecting mirror, 14 Light irradiation means, 14a First light irradiation means, 14b Second light irradiation means, 15, 16 Light receiving means, 16a First light receiving means, 16b Second light receiving means, signal processing means.

Claims (6)

A parabolic reflector,
A radiator that emits electromagnetic waves toward the parabolic reflector,
Driving means for rotating and swinging the parabolic reflector to change the reflection angle of the electromagnetic wave in the parabolic reflector;
Light irradiating means for irradiating light toward the reflecting portion of the parabolic reflector;
A light receiving means for receiving the reflected light reflected by the reflecting portion;
Signal processing means for detecting the rotational swing angle of the parabolic reflecting mirror based on an output signal from the light receiving means that is output in accordance with a change in the amount of light received by the light receiving means or a change in the light receiving position. A radar device for a vehicle.   There are a plurality of the light irradiating means and the light receiving means, respectively, and the signal processing means changes the rotational swing angle and shape of the parabolic reflector based on the output signals from the light receiving means. The vehicular radar apparatus according to claim 1, wherein:   The signal processing means estimates a change in a transmission beam width transmitted to the outside and a change in a beam scanning direction based on the output signal, and controls the rotation angle of the parabolic reflector using the driving means. The vehicle radar apparatus according to claim 1, wherein feedback control is performed or a transmission beam abnormality is detected.   4. The vehicular radar apparatus according to claim 1, wherein the signal processing unit detects an abnormality of the reflection unit based on the output signal. 5.   A flat reflecting mirror is provided opposite to the parabolic reflecting mirror, reflects the electromagnetic wave toward the parabolic reflecting mirror, and transmits the electromagnetic wave reflected by the parabolic reflecting mirror. The vehicular radar device according to claim 1, wherein the vehicular radar device is a vehicular radar device. The parabolic reflector includes a resin dielectric having a parabolic surface, a plurality of linear conductors arranged in parallel at equal intervals on the parabolic surface on the plane reflecting mirror side and reflecting the electromagnetic wave, And having a back conductor that is the reflecting portion that reflects the electromagnetic wave that has passed through the inside of the dielectric through the linear conductor,
The planar reflector includes a dielectric having a plane and a plurality of linear conductors arranged in parallel at equal intervals on a surface on the parabolic reflector side to reflect the electromagnetic wave toward the parabolic reflector. The vehicular radar apparatus according to claim 5, further comprising:

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