JP2000057485A - Communication system between road and vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the extension of power distribution on a road and to surely avoid communication with an on-vehicle radio equipment of a vehicle running on an adjacent lane by composing plural beams different in beam direction and beam width. SOLUTION: Two or more beams different in beam direction in a running direction 3 on a lane set in a communication area and different in beam width in a lane direction 4 orthogonal to the running direction 3 are composed by a road equipment antenna system 7 including plural element antennas and a feeder circuit. Thereby a composite beam radiated from the system 7 constitutes a communication boundary 10 in which power distribution on the road is suppressed in the lane direction 4 independently of the expected angle η 16 of the system 7 and a no-response boundary 11. Namely an on-vehicle radio equipment 6a loaded on a vehicle 5a running on the lane 1a acts as a road- vehicle communication system capable of surely communicating with the system 7 in an area surrounded by the boundary 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a road-to-vehicle communication system that enables communication only in a predetermined area regardless of the expected angle of a roadside antenna device with respect to each position on a road.

[0002]

2. Description of the Related Art FIG. 10 is a perspective view showing a conventional road-vehicle communication system, and FIG. 11 is an arrangement diagram showing an arrangement of beams by a roadside antenna device. FIG. 12 is a cross-sectional view showing a cross-sectional shape of a beam by a roadside antenna apparatus, which is described in T. Watanabe etc., “Cir.
Cully Polarized Microst
rip Antenna Having Sector
Beam for the Automatic V
vehicle IdentificationSystem
em, "ITS YOKOHAMA, pp. 1559-
1564, 1995).

In the figure, 1a and 1b denote lanes, 2a and 2
b is a separation zone, 3 is a traveling direction in the lane 1a, 4 is a lane direction in which the lanes 1a and 1b are arranged, 5a and 5b are vehicles traveling on the lanes 1a and 1b, respectively, and 6a and 6b are vehicles 5a respectively. And 5b mounted on the on-board wireless device, 7 is a roadside antenna device for communicating with the on-board wireless device 6a, 8 is a mount for fixing the roadside antenna device 7, 9
Is a communication area assigned to the roadside antenna apparatus 7, 10 is a communication boundary indicating an area where the roadside antenna apparatus 7 can actually communicate, and 11 is a no-response in which the roadside antenna apparatus 7 cannot communicate. A boundary, 12 is an X axis parallel to the lane direction 4, 13 is a Y axis parallel to the traveling direction 3,
14 is a Z axis perpendicular to the X axis 12 and the Y axis 13;
Is a reference axis on a plane formed by the Y axis 13 and the Z axis 14,
16 and 17 are angles η and ξ measured from the reference axis 15 toward the Y axis 13 and the X axis 12, respectively, and 30e is the lane direction on a plane formed by the X axis 12 and the reference axis 15. 4, the beam width of the above-mentioned roadside antenna device 7;
31c is a beam shape in the traveling direction of the roadside antenna device 7 on a plane formed by the Y axis 13 and the reference axis 15;
2c is a beam shape in the lane direction of the roadside antenna device 7 on a plane formed by the X axis 13 and the reference axis 15;
Is a single beam formed by the roadside antenna device 7.

Next, the operation will be described. Here, it is assumed that the reference axis 15 is set so that the single beam 43 substantially covers the communication area 9. The roadside antenna device 7 has a traveling direction beam shape 31c and a lane direction beam shape 3
A single beam 43 having 2c is irradiated in the direction of the reference axis 15. For this reason, it functions as a road-vehicle communication system capable of communicating with the on-vehicle wireless device 6a mounted on the vehicle 5a traveling on the lane 1a and within the prescribed communication area 9. When this road-to-vehicle communication system is used for an automatic toll collection system or the like, the lane 1 such as an adjacent lane or a general road is used.
It is necessary that communication with the in-vehicle wireless device 6b mounted on the vehicle 5b traveling on the vehicle b cannot be established. However, in practice, the communication boundary 10 where communication is reliably established and the non-response boundary 11 where communication is not established have a large angle η16, which is the estimated angle of the roadside antenna device 7 with respect to an arbitrary position on the road, as shown in FIG. As the shape becomes wider in the lane direction 4, it acts so that communication is established depending on the situation between the on-vehicle wireless device 6 b and the on-road unit antenna device 7.

[0005]

Since the conventional road-to-vehicle communication system is configured as described above, the power distribution on the road becomes more lane-like as the expected angle of the roadside antenna device with respect to an arbitrary position on the road becomes larger. There is a problem that communication between the on-vehicle wireless device of the vehicle traveling on an adjacent lane or a general road and the on-road antenna device may be established. Further, in order to avoid such a problem, it is necessary to form a shaped beam in which the power distribution on the road narrows in the lane direction as the expected angle of the on-road unit antenna device increases, which is extremely large compared to the wavelength. A complicated aperture antenna having a large mirror aperture and an aperture antenna having a plurality of primary radiators must be used, and there is a problem in downsizing and thinning the antenna.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and suppresses the spread of power distribution on the road irrespective of the expected angle of the roadside antenna device at an arbitrary position on the road. It is an object of the present invention to reliably avoid communication between a vehicle-mounted wireless device of a vehicle traveling on an adjacent lane other than a lane in which a communication area is set or a general road and a roadside antenna device.

[0007]

A road-vehicle communication system according to a first aspect of the present invention has different beam directing directions in a traveling direction in a lane in which a communication area is set, and has different beam widths in a lane direction orthogonal to the traveling direction. Two or more beams are combined by a roadside antenna device including a plurality of element antennas and one feeder circuit.

A road-vehicle communication system according to a second aspect of the present invention includes a plurality of element antennas, two or more power supply circuits for forming an excitation distribution corresponding to at least two beams, and each of the above-described power supply circuits. A roadside antenna device is constituted by a plurality of combining circuits for combining outputs corresponding to element antennas.

A road-vehicle communication system according to a third aspect of the present invention has a communication region extending over one or more lanes, and transmits two or more beams having different beam widths from the beam direction in the lane direction. It is characterized in that the signals are synthesized by a local antenna device.

A road-vehicle communication system according to a fourth aspect of the present invention has a communication area extending over one or more lanes, and the beam directing directions are different in both a traveling direction and a lane direction orthogonal to the traveling direction. And three or more beams having different beams in the two directions are combined by a roadside antenna device.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a perspective view of a road-vehicle communication system according to Embodiment 1 of the present invention.
And FIG. 3 are a layout diagram and a cross-sectional view, respectively, showing an arrangement and a cross-sectional shape of a beam to be synthesized by the on-road antenna device according to the first embodiment, and FIG. , 1 to 17 and 30 to 32 are exactly the same as the conventional road-vehicle communication system.

In the figure, reference numerals 18 and 19 denote a first beam and a second beam combined by the on-road unit antenna device 7, respectively.
20 and 21 are angles η _a and η _{b respectively} defining the traveling direction beam shape 31a of the first beam 18;
2 and 23 are an angle η _c and an angle η _d , 24 which define the traveling direction beam shape 31b of the second beam 19, respectively.
And 25 are angles ξ _a and ξ _b respectively defining the lane direction beam shape 32 a of the first beam 18, and 26 and 27 are angles ξ _c and angle respectively defining the lane direction beam shape 32 b of the second beam 19. ξ _d , 28 and 2
9 is an angle η _e and an angle η _f defining the beam widths 30a and 30b of the first beam 18 and the second beam 19 in the lane direction 4 respectively, 33 is an element antenna in the roadside antenna device 7, and 34a is A power supply circuit connected to the element antenna 33, 35 is the power supply circuit 34a
Connected thereto input, the 36 is the excitation distribution E _n is set to the element antenna 33.

Next, the operation of the road-vehicle communication system will be described. The beam pointing direction of the first beam 18 (angle η _e 28) is the beam pointing direction of the second beam 19 (angle η _e 28).
_f 29), and the beam width 30a of the first beam 18 in the direction of the angle # 17 is equal to the beam width 30 of the second beam 19.
different from b. In the power supply circuit 34a, these first beams 1
8 and an excitation distribution E _n 36 obtained by combining two types of excitation distributions forming the second beam 19 (where the subscript n means the excitation distribution corresponding to the # n-th element antenna 33)
Is set to the element antenna 33. Therefore, the combined beam radiated from the roadside antenna device 7 has a power distribution on the road suppressed to the lane direction 4 regardless of the expected angle of the roadside antenna device 7 with respect to an arbitrary position on the lane 1a. A boundary 10 and a non-response boundary 11 are formed. That is, it functions as a road-to-vehicle communication system that can surely communicate the on-vehicle wireless device 6a mounted on the vehicle 5a traveling on the lane 1a with the on-road device antenna device 7 in an area surrounded by the communication boundary 10. Further, in order to form an electric power distribution on the road without overlapping the lane 1b which is the adjacent lane, the area surrounded by the non-response boundary 11 is connected to the on-vehicle wireless device 6b mounted on the vehicle 5b traveling on the lane 1b. It functions as a road-to-vehicle communication system in which communication cannot be established with the machine antenna device 7.

In the case of the conventional road-vehicle communication system as shown in FIG. 10, the roadside antenna device 7 communicates with the on-vehicle wireless device 6b mounted on the vehicle 5b running on the adjacent lane 1b. There is. In order to avoid this problem, it is necessary to form a shaped beam in which the power distribution on the road narrows in the lane direction 4.
For example, a complex aperture antenna having a mirror-like shape having an aperture diameter much larger than the wavelength or an aperture antenna in which a plurality of primary radiators are arranged may be used. An antenna or the like for limiting the area must be provided. On the other hand, in the road-vehicle communication system according to the present embodiment, the lane la in which the communication area 9 is set by the small and thin on-road device antenna device 7 without using an aperture antenna or a communication area limiting antenna is used. On-board wireless device 6b and on-road unit antenna device 7 of vehicle 5b running on an adjacent lane or a general road other than
Communication with the server can be reliably avoided.

Here, in the road-vehicle communication system according to the first embodiment, the case where two beams (the first beam 18 and the second beam 19) are combined in the traveling direction 3 has been described. The present invention is not limited to this, and two or more beams may be combined in the traveling direction 3.

Embodiment 2 FIG. 5 is a configuration diagram of the on-road unit antenna device 7 in the road-to-vehicle communication system according to Embodiment 2 of the present invention. In the second embodiment, the input terminal 3
5 are connected to the first beam 18
Power supply circuit 34b for the second beam 19 and the power supply circuit 34 for the second beam 19
c, respectively, to form the first beam forming excitation distribution B ¹ _n 39 by the power supply circuit 34b, and to form the second beam forming excitation distribution B ² _n 40 by the power supply circuit 34c. Synthesis circuit 38 corresponding to antenna 33
The excitation distribution E _n 36 THAT synthesized and obtained constitutes a road unit antenna device 7 to set to the element antenna 33. The perspective view for explaining the operation of the road-vehicle communication system according to the second embodiment is the same as FIG. 1, and the beam configuration diagram and the beam cross-sectional view are shown in FIG. 2 and FIG.
Is the same as

As described above, according to the road-vehicle communication system according to the second embodiment, the power distribution on the road is realized without the area surrounded by the non-response boundary 11 overlapping with the adjacent lane 1b. synthetic beam can be obtained by excitation distribution E _n 36 shown in the following equation which is formed by the synthesis circuit 38 connected to the respective feeding circuit 34b and 34c.

[0018]

(Equation 1)

[0019] Here, k is the beam number indicating the k th beam, n is the element number indicating the n-th antenna element 33, the excitation distribution B ^k _n forming the k th beam is represented by the following formula .

[0020]

(Equation 2)

[0021] However, A ^k _n and phi ^k _n is the excitation amplitude and excitation phase for forming each k th beam. Equation 1 above
C ^k is the complex coefficient so that the desired combined beam from the first beam forming for excitation distribution B ¹ _n 39 by the second beam forming array weight B ² _n 40 are obtained accurately synthesizing circuit 38 in Given by Therefore, the first beam 18
When the amplitude and phase one of the feeder circuit of the excitation distribution E _n 36 by the beam shape of the second beam 19 to form a combined beam (e.g., the power supply road equipment antenna device 7 in the first embodiment shown in FIG. 4 The distribution may be unrealistic to be realized by the circuit 34a), and even in such a case, a desired combined beam, that is, a desired non-response boundary 11 can be easily realized. Further, if as is not shown in FIG be optionally adjusted the amplitude and phase of the complex coefficient C ^k in the synthesis circuit within 38, the feeder circuit 34b and 34
The amplitude and phase errors in the distribution characteristic of c can also be corrected.

Here, in the road-vehicle communication system according to the second embodiment, two power supply circuits 34b and 34c
Although the case where each of the plurality of beams (the first beam 18 and the second beam 19) is formed has been described, the present invention is not limited to this, and a plurality of beams may be formed and synthesized by a plurality of feed circuits.

Embodiment 3 FIG. FIG. 6 is a perspective view of a road-vehicle communication system according to Embodiment 3 of the present invention. Also,
FIG. 7 is an arrangement diagram showing an arrangement of beams to be combined by the on-road unit antenna apparatus according to Embodiment 3 of the present invention. In the third embodiment, the lanes 1a and 1c in which the communication area 9 is set are set.
The two beams (the first beam 18 and the second beam 19) having different beam directing directions in the lane direction 4 (corresponding to the angle # 17 direction) and different beam widths in the lane direction 4 are transmitted to the roadside antenna device 7. Is synthesized. The configuration diagram of the on-road unit antenna device 7 according to the third embodiment is the same as FIG. 4 or FIG.

As described above, according to the road-vehicle communication system according to the third embodiment, the first beam 18 and the second beam 19 having different beam directing directions and beam widths 30a and 30b in the lane direction 4 are transmitted on the road. The non-response boundary 11 can be formed just before the lane 1b in the lane direction 4 because the signals are synthesized by the vehicle antenna device 7. For this reason,
The communication area 9 has a plurality of lanes 1a and 1c in the lane direction 4.
The communication boundary 10 and the no-response boundary 11 unnecessarily spread in the lane direction 4 even if the expected angle in the direction of the angle # 17 of the roadside antenna device 7 with respect to an arbitrary position on the road is large. Thus, the desired communication area 9 can be covered to a minimum without the need. Therefore, the communication area 9
Crosses over a plurality of lanes 1a and 1c in lane direction 4,
In addition, even when a lane 1b (an adjacent lane or a general road, etc.) for which communication with the on-road unit antenna device 7 should not be established ahead of the lane 1c is adjacent, the on-vehicle radio mounted on the vehicle 5b running on the lane 1b. Communication between the aircraft 6b and the roadside antenna device 7 can be reliably avoided.

In the road-vehicle communication system according to the third embodiment, the case where two beams are combined in the lane direction 4 has been described. However, the present invention is not limited to this. 4 may be combined.

Embodiment 4 FIG. 8 is a perspective view of a road-vehicle communication system according to Embodiment 4 of the present invention. Also,
FIG. 9 is an arrangement view showing an arrangement of beams to be combined by the on-road unit antenna apparatus according to Embodiment 4 of the present invention. In the fourth embodiment, the lanes 1a and 1c in which the communication area 9 is set are set.
In the traveling direction 3 (corresponding to the angle η16 direction), the beam directing directions are different in both directions of the lane direction 4 (corresponding to the angle ξ17 direction) orthogonal to the traveling direction 3 and the four beams (the beam widths are different in the two directions) The first beam 18, the second beam 19, the third beam 41, and the fourth beam 42) are combined by the on-road unit antenna device 7. The configuration diagram of the on-road unit antenna device 7 in the fourth embodiment is the same as FIG. 4 or FIG.

As described above, according to the road-vehicle communication system according to the fourth embodiment, the beam directing directions are different in both the traveling direction 3 and the lane direction 4, and the beam widths 30a to 30d and 30e-30
h, the first beam 18, the second beam 19, the third beam 41, and the fourth beam 42
Therefore, the non-response boundary 11 can be formed before the lanes 1b and 1d on both sides of the communication area 9 in the lane direction 4. Therefore, even when the communication area 9 is long in the traveling direction 3 and extends in the lane direction 4 in a plurality of lanes 1a and 1c, the angle η16 and the angle ξ17 of the roadside antenna device 7 with respect to an arbitrary position on the road. , The communication boundary 10 and the non-response boundary 1
The desired communication area 9 can be covered to a minimum without the number 1 spreading unnecessarily in both the traveling direction 3 and the lane direction 4. Therefore, the communication area 9 extends to the lanes 1a and 1c in the lane direction 4 and the lanes 1a and 1c
Vehicle 5b traveling in the lane 1b even if the lanes 1b and 1d (such as an adjacent lane or a general road) adjacent to each other should not establish communication with the on-road unit antenna device 7
The communication between the on-board wireless device 6b mounted on the vehicle and the on-board wireless device 6d mounted on the vehicle 5d traveling in the lane 1d and the on-road unit antenna device 7 can be reliably avoided.

Here, in the road-to-vehicle communication system according to the fourth embodiment, a case has been described where two beams are combined in both the traveling direction 3 and the lane direction 4, but the present invention is not limited to this. 3 depending on the size and shape of 9
More than one beam may be combined in the traveling direction 3 and the lane direction 4.

In the road-vehicle communication system according to the above-described first to fourth embodiments, the plurality of beams combined by the on-road unit antenna device 7 are converted into a cosecant beam or a beam for compensating for a span loss due to a propagation distance difference. Any beam, such as a sector beam, that maintains a generally constant power level within the width may be used.

[0030]

According to the first aspect of the present invention, two or more beams having different beam directing directions in the traveling direction in the lane in which the communication area is set and having different beam widths in the lane direction orthogonal to the traveling direction are formed. Multiple element antennas and one
The power distribution that does not broaden in the lane direction regardless of the expected angle in the running direction of the roadside antenna device is small and thin on the road because it is combined and irradiated by the roadside antenna device including The effect that can be realized by the antenna device of the aircraft is obtained, and the communication between the on-board radio device and the antenna device on the road device of the vehicle traveling on an adjacent lane other than the lane where the communication area is set or on a general road is reliably avoided. Is obtained.

According to the second aspect of the present invention, after each excitation distribution corresponding to two or more beams is formed by two or more feeding circuits in the on-road unit antenna apparatus, the antenna is connected to each element antenna. Since the synthesis is performed by each of the synthesis circuits, an effect that can be easily realized even with an unrealistic excitation distribution to be realized by one feeder circuit is obtained depending on the shape of the target synthesis beam. Further, an effect is obtained that an error in amplitude and phase in the distribution characteristic of each feed circuit for forming each beam to be combined can be corrected by a combining circuit connected for each element antenna.

According to the third aspect of the present invention, there is provided a roadside antenna device having a communication region extending over one or more lanes and having two or more beams having different beam widths from the beam direction in the lane direction. Therefore, even if the communication area spans a plurality of lanes in the lane direction, and an adjacent lane or general road where communication with the on-road unit antenna device should not be established is adjacent to the lane direction of the communication area. In addition, the communication between the on-vehicle wireless device existing on the adjacent lane or the general road and the antenna device on the road device can be reliably avoided.

According to the fourth aspect of the present invention, there is provided a communication area extending over one or more lanes, and the beam directing directions are different in both the traveling direction and the lane direction orthogonal to the traveling direction. Since three or more beams having different beams in both directions are combined by the roadside antenna device, a communication area that is very long in the traveling direction extends to a plurality of lanes in the lane direction, and communication with the roadside antenna device is established. Even when adjacent lanes or general roads that should not be adjacent to each other in the lane direction of the communication area, the effect of reliably avoiding communication between the on-board radio and the roadside antenna device existing on the adjacent lane or general road, etc. Is obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a road-vehicle communication system according to a first embodiment of the present invention;

FIG. 2 is an arrangement diagram showing an arrangement of beams to be combined by the on-road unit antenna device.

FIG. 3 is a cross-sectional view showing a cross-sectional shape of a beam synthesized by the on-road unit antenna device.

FIG. 4 is a configuration diagram of a road unit antenna device.

FIG. 5 is a configuration diagram of an on-road unit antenna apparatus showing a second embodiment of the road-to-vehicle communication system according to the present invention;

FIG. 6 is a perspective view of a road-vehicle communication system according to a third embodiment of the present invention.

FIG. 7 is an arrangement diagram showing an arrangement of beams to be combined by the on-road unit antenna device.

FIG. 8 is a perspective view showing a road-vehicle communication system according to a fourth embodiment of the present invention.

FIG. 9 is an arrangement diagram showing an arrangement of beams to be combined by the on-road unit antenna device.

FIG. 10 is a perspective view showing a conventional road-vehicle communication system.

FIG. 11 is an arrangement diagram showing an arrangement of beams by the on-road unit antenna device.

FIG. 12 is a cross-sectional view showing a cross-sectional shape of a beam by the on-road unit antenna device.

[Explanation of symbols]

1 lane, 2 dividers, 3 driving directions, 4 lane directions,
5 vehicle, 6 in-vehicle radio, 7 roadside antenna device,
8 gantry, 9 communication area, 10 communication boundary, 11 no response boundary, 12 X axis, 13 Y axis, 14 Z axis, 15
Reference axis, 16 angle η, 17 angle ξ, 18 first beam, 19 second beam, 20 angle η _a , 21 angle η _b
, 22 angle η _c , 23 angle η _d , 24 angle ξ
_a , 25 angle ξ _b , 26 angle ξ _c , 27 angle ξ _d ,
28 angle η _e , 29 angle η _f , 30 beam width, 3
1 running direction beam shape, 32 lane direction beam shape,
33 element antenna, 34 feeding circuit, 35 input terminal,
36 excitation distribution E _n, 37 a distribution circuit, 38 combining circuit,
39 first beam forming excitation distribution B ¹ _n , 40 second beam forming excitation distribution B ² _n , 41 third beam, 42 fourth
Beam, 43 single beam.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Kenichi Kakizaki 2-3-2 Marunouchi, Chiyoda-ku, Tokyo F-term (reference) 5H180 AA01 BB04 CC12 FF13 5J021 AA05 AA07 AA09 AB06 CA03 DB02 FA32 GA02 GA04 HA05 HA10 5K067 AA03 BB21 EE02 EE12 KK02 KK03

Claims (4)

[Claims] 1. In a road-vehicle communication system including an on-vehicle wireless device and an on-road unit antenna device, a beam direction differs in a traveling direction of a vehicle equipped with the on-vehicle wireless device, and in a lane direction orthogonal to the traveling direction. A road-vehicle communication system comprising: means for synthesizing two or more beams having different beam widths, wherein the on-road unit antenna device is constituted by a plurality of element antennas and one feed circuit. 2. A road-vehicle communication system including an on-vehicle wireless device and an on-road device antenna device, wherein a beam direction differs in a traveling direction of a vehicle equipped with the on-vehicle wireless device, and in a lane direction orthogonal to the traveling direction. Means for combining two or more beams having different beam widths, a plurality of element antennas, two or more feed circuits for forming an excitation distribution corresponding to each of the beams, and each of the elements of each of the feed circuits A road-to-vehicle communication system, wherein the roadside antenna device comprises a plurality of combining circuits for combining outputs corresponding to the antennas. 3. The road-to-vehicle communication system according to claim 1 or 2, wherein a means for combining two or more beams having different beam directions and beam widths in a lane direction of a vehicle equipped with the on-vehicle wireless device is provided as a roadside antenna. A road-vehicle communication system provided in a device. 4. The road-to-vehicle communication system according to claim 1, wherein a beam direction is different in both a traveling direction of a vehicle equipped with the on-vehicle wireless device and a lane direction orthogonal to the traveling direction. A road-to-vehicle communication system, comprising: a roadside antenna device that includes means for combining three or more beams having different beam widths.