JPH11120486A - Road side beacon - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify installing operation and to reduce operating time by providing a communication means communicating between with an on-vehicle equipment by setting power generated by a power generating means generating power by light irradiated from an illuminating lamp to be a power source. SOLUTION: A road side beacon 1 is provided with a photoelectric conversion unit 10 and two plane array antenna 11 and the unit 10 and the antennas 11 of these are provided inside of a housing 12. An internal optical fiber 13 is connected to this unit 10 and is connected to an external optical fiber inserted to an illuminating pole 8 through a connector 14 provided for the housing 12. In addition, on the upper part of the housing 12, a solar battery panel 15 is provided. Then the unit 10 is provided with a power source part provided with power from the panel 15 and the unit 10 and the antennas 11 are operated by power generated at this power source part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roadside beacon installed on a roadside and communicating with a vehicle-mounted device.

[0002]

2. Description of the Related Art Conventionally, a roadside beacon for transmitting road data to an on-vehicle device and receiving vehicle data from the on-vehicle device has been known. The roadside beacon is usually attached to a pole erected on the roadside. A commercial power line is drawn into the pole, and power is supplied to the roadside beacon via the commercial power line.

[0003]

However, in the above-mentioned conventional apparatus, when a roadside beacon is installed, a commercial power line must be drawn into the pole, and the installation work is very complicated, and time is required for installation. There was a problem that it took. Therefore, an object of the present invention is to solve the above-mentioned technical problems and to provide a roadside beacon that can perform installation work easily and in a short time.

[0004]

Means for Solving the Problems and Effects of the Invention The invention according to claim 1 for achieving the above object is provided within an illumination range of an illumination lamp attached to an illumination pole installed on a roadside. Power generation means capable of generating power by at least light emitted from the illumination lamp,
A roadside beacon characterized by including communication means for performing communication with an in-vehicle device mounted on a vehicle using power generated by the power generation means as a power supply.

According to the present invention, the electric power generation means can generate electric power from sunlight or illumination light of an illumination lamp. Then, the generated power is used as a power source of the communication means. Therefore, it is not necessary to draw in the commercial power supply line as in the related art in order to obtain the power supply of the communication unit. Therefore, the installation work can be performed easily and in a short time.

In addition, the power generating means can generate electric power by photoelectrically converting the light emitted from the illuminating lamp. Therefore, when there is no sunlight such as at night, or when the sun is cloudy or rainy, the power is generated. Electric power can be generated even when the light is weak. Therefore, it is not always necessary to use a charging battery or the like for storing power at night or for cloudy or rainy days. Therefore, the configuration of the roadside beacon is simplified. Needless to say, if it is important to provide a stable supply of power, it is preferable to provide a charging battery.

According to a second aspect of the present invention, there is provided the roadside beacon according to the first aspect, wherein the power generating means is a solar cell panel made of amorphous silicon. According to the present invention, power can be efficiently generated by the power generation means. The roadside beacon according to claim 1 or 2, wherein the power generating means is capable of generating power with at least 5 (W) light energy. It is.

According to the present invention, the electric power generation means can generate electric power if there is at least 5 (W) light energy, so that electric power can be surely generated from the illumination light even at night without sunlight. can do. In particular, when a solar cell panel having a panel area of 1200 (cm ² ) made of amorphous silicon is applied as a power generation means, it can generate about 500 (mW) of power, so that it can be used as a power supply for communication means. Is enough.

According to a fourth aspect of the present invention, there is provided the roadside beacon according to any one of the first to third aspects, wherein the illuminating lamp is a low-pressure sodium lamp or a mercury lamp. According to the present invention, in particular, since the illumination light having a wavelength that is considered to have a high collection efficiency is applied to the solar cell panel made of amorphous silicon, the power can be generated more efficiently by the power generation unit.

[0010]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a conceptual diagram showing a configuration of a roadside beacon system according to an embodiment of the present invention. This roadside beacon system is for communicating between a roadside beacon 1 installed on the roadside of a road (including an expressway and a general road) and an in-vehicle device 3 mounted on a vehicle 2.

A plurality of roadside beacons 1 are installed at predetermined intervals along the longitudinal direction of the road. Each roadside beacon 1 is connected to one base concentrating station 5 via an optical fiber 4, and road data is given to each roadside beacon 1 from this base concentrating station 5 or received by each roadside beacon 1. The obtained vehicle data is provided to the base central station 5. The base central station 5 is connected to a central center (not shown) via a communication network 6 such as a public telephone line network, and the central system controls the entire system including other base central stations. I have.

The roadside beacon 1 is mounted on a roadside, and is attached to an illumination pole 8 having an illumination lamp 7 near the tip for irradiating illumination light for illuminating a road. More specifically, as shown in FIG. 2, the roadside beacon 1 is mounted at a position where the illumination light emitted from the illumination lamp 7 is always emitted, that is, within the illumination range of the illumination lamp 7. in this case,
The distance r between the roadside beacon 1 and the illumination lamp 7 is relatively short, for example, 2 (m). As the illumination lamp 7, a low-pressure sodium lamp, a mercury lamp, or the like can be applied.
The output of the illumination lamp 7 is, for example, 1 (kW).

The roadside beacon 1 has a communication area extending over a predetermined length (for example, 100 (m)) along the longitudinal direction of the road centering on the installation position of the roadside beacon 1. The roadside beacon 1 modulates, for example, radio waves in the 6 (GHz) band with the road data given from the base central station 5 and radiates it to the communication area, and provides the road data to the vehicle 2 entering the communication area. I do. Also, vehicle data is received from the vehicle 2 entering the communication area, and the base station 5
Give to.

FIG. 3 is a schematic perspective view showing the configuration of the roadside beacon 1. The roadside beacon 1 is a photoelectric conversion unit 1
0 and two planar array antennas 11,
The photoelectric conversion unit 10 and each planar array antenna 11 are provided inside a housing 12. The size of the roadside beacon 1 is such that the protruding length from the lighting pole 8 is about 20 (cm), the width is about 10 (cm), and the height is about 20 (cm). Approximately 3 (kg). Each of the planar array antennas 11 sandwiches the photoelectric conversion unit 10 and faces the opposite direction with respect to the longitudinal direction of the road.
2 is provided inside the roadside beacon 1
, A communication area extending along the longitudinal direction of the road is formed.

An internal optical fiber 13 is connected to the photoelectric conversion unit 10.
Illumination column 8 via connector 14 provided in housing 8
It is connected to an external optical fiber inserted inside.
This external optical fiber is connected to the roadside beacon 1 and the base station 5.
And an optical fiber 4 connecting the A solar cell panel 15 is provided on an upper part of the housing 12. Solar panel 1
Numeral 5 is made of, for example, amorphous silicon, which receives sunlight and illumination light, converts the received light into electricity, and generates electric power. In this case, the solar cell panel 15
Panel area is not only sunlight, but also illumination light,
Photoelectric conversion unit 10 and each planar array antenna 11
Is set to a size (for example, 1200 (cm ² )) that generates a necessary and sufficient electric power to operate the.

Next, the setting of the panel area of the solar cell panel 15 will be described. First, power consumption in the roadside beacon 1 will be considered. For example, assuming that the length of the communication area in the longitudinal direction of the road is 100 (m) and the frequency band of the radio wave to be used is 6 (GHz) band, a plane necessary for realizing communication with the vehicle-mounted device 3 is set. The transmission output Sout of the array antenna 11 is -85 (dB) which is the minimum reception sensitivity of the on-vehicle device 3.
When the margin is 10 (dB) and the gain of the planar array antenna 11 is 0 (dB), the free space propagation loss at 100 (m) is 88
(dB), the value is expressed by the following equation (1).

Sout = −85 + 10 + 88 = 13 (dBm) (1) Therefore, in order to secure the transmission output of 13 (dBm),
For example, when a GaAs FET having a transmission output of about 20 (dBm) (for example, product name FLK012XP manufactured by Fujitsu Ltd.) is used for the photoelectric conversion unit 10, the required transmission power Pout is as follows.
(2) For example, "FUJITSU SEMICONDUCTOR DEVICE DATABOOK 1996 GaAs FET small signal, high power GaAsFE
T chip page 60 ”, refer to the column of product name FLK012XP).

Pout = 10 (V) × 36 (mA) = 360 (mW) (2) Since most of the power consumption of the roadside beacon 1 is occupied by the photoelectric conversion unit 10, the power consumption in other circuits In consideration of the above, 500 (mW) is sufficient as the power consumption of the roadside beacon 1. Next, the efficiency of the solar cell panel 15 will be considered. A solar cell panel made of amorphous silicon has a panel area of 1200 (c
When m ² ) is adopted, it is known that a photoelectric conversion efficiency of about 10 (%) can be obtained. On the other hand, a light source usually used as an illumination lamp is a low-pressure sodium lamp or a mercury lamp, and its emission wavelength is 500 to 500, which is considered to be high in collection efficiency in a solar cell panel made of amorphous silicon.
600 (nm). Therefore, regardless of whether sunlight or illumination light is photoelectrically converted, the panel area is 1200
(cm ² ), the photoelectric conversion efficiency is about 10 (%). Therefore, the light energy required to generate 500 (mW) power in the solar panel is about 5 (W).

On the other hand, solar energy on the surface of the earth is about 1 (k
W / m ² ), the solar energy applied to a solar cell panel having a panel area of 1200 (cm ² ) is about 120 (W), which sufficiently satisfies the above condition of 5 (W). If the output of the lighting 7 is 1 (kW) and the distance r between the lighting 7 and the roadside beacon 1 is 2 (m), the light energy given to the roadside beacon 1 is 1 (kW) / 4. πr ² ≒ 20 (W). Therefore, even in this case, the condition of 5 (W) is satisfied. Therefore, if the panel area is set to 1200 (cm ² ), sufficient power can be generated in the solar cell panel 15 regardless of whether sunlight or illumination light is incident light.

FIG. 4 is a block diagram showing an electrical configuration of the roadside beacon system. The base central station 5 includes an interface unit 20 and a photoelectric conversion unit 21.
The interface unit 20 functions as an interface with the communication network 6 (see FIG. 1), and processes road data given via the communication network 6 and vehicle data to be transmitted to the communication network 6. The photoelectric conversion unit 21
A plurality of optical transmission units 30 provided for each of the plurality of roadside beacons 11 to be controlled, and a reference signal generation unit 31 including a crystal oscillator or the like for providing a reference signal to the optical transmission unit 30 are provided. And is connected to the optical fiber 4 via the connector 32.

The optical transmission section 30 includes a modulation / demodulation section 40 which modulates road data supplied from the interface section 20 to generate an electric road signal and supplies the generated road signal to the optical transmission section 41. The optical transmitter 41 converts the given road signal and the reference signal given from the reference signal generator 31 into an optical signal, and sends this optical signal to the optical fiber 4. The optical transmission unit 30 includes an optical reception unit 42 that converts an optical signal received from the roadside beacon 1 via the optical fiber 4 into an electric vehicle signal. The vehicle signal is
It is provided to the modem 40. The modulation / demodulation unit 40 demodulates the given vehicle signal to restore vehicle data, and supplies the restored vehicle data to the interface unit 20.

The photoelectric conversion unit 10 provided in the roadside beacon 1 has a power supply unit 50 to which electric power is supplied from the solar cell panel 15. The planar array antenna 11 is operated. As the power supply unit 50, a battery, a super capacitor, and the like can be applied.

The photoelectric conversion unit 10 includes an optical receiving unit 51 that converts an optical signal provided from the optical transmitting unit 41 of the base station 5 via the optical fiber 4 into a signal including a road signal and a reference signal. This signal is provided to the first modulator 52 via a band-pass filter (not shown). When the signal passes through the band-pass filter, a road signal is extracted. Therefore, only the road signal is given to the first modulation section 52. Further, the signal is supplied to the PLL oscillation unit 54 via the low-pass filter 53. When the signal passes through the low-pass filter 53, a low-frequency reference signal is extracted. Therefore, the PLL oscillation unit 54
Is provided with only the reference signal.

The PLL oscillating section 54 generates a 5.8 (GHz) carrier signal based on the reference signal. The created carrier signal is supplied to a first modulation unit 52, and the first modulation unit 52 modulates the signal based on the road signal supplied from the optical reception unit 51. As a result, a road signal for wireless transmission is created. The generated road signal is subjected to high-frequency amplification in the first high-frequency unit 55, and then applied to the planar array antenna 11 via the circulator 56, and radiated from the planar array antenna 11 as a radio wave.

The vehicle signal from the vehicle-mounted device 3 received by the planar array antenna 11 is given to a second high-frequency section 57 via a circulator 56, and after being amplified by the second high-frequency section 57, the PLL oscillation section The signal is supplied to the second modulator 58 to which the carrier signal is supplied from. The second modulator 58 modulates the carrier signal with the vehicle signal to create a vehicle signal for wired transmission. The generated vehicle signal is provided to the optical transmission unit 59, converted into an optical signal in the optical transmission unit 59, and transmitted to the optical fiber 4.

As described above, according to this embodiment, the power generated by the solar cell panel 15 is used as the power source of the roadside beacon 1, and therefore, compared to the conventional device which needs to take in the commercial power line. The installation work of the roadside beacon 1 can be performed easily and in a short time. In addition, since the roadside beacon 1 is provided within the illumination range of the lighting lamp 7, even when there is no sunlight such as at night or when the sunlight energy such as cloudy or rainy is low, the lighting beacon 1 is not used. Sufficient power can be generated by light. Therefore, the configuration of the roadside beacon 1 is simplified because it is not always necessary to provide a charging battery. Therefore, the size and cost of the roadside beacon 1 can be reduced. Needless to say, if it is important to provide a stable supply of power, it is preferable to provide a charging battery.

One embodiment of the present invention is as described above, but the present invention is not limited to the above-described embodiment. For example, in the above embodiment, the roadside beacon 1
Is directly attached to the lighting column 8, for example,
It may be attached to a dedicated pole provided that the solar cell panel 15 is located within the illumination range of the illumination lamp 7.

In addition, various design changes can be made within the scope described in the claims.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a configuration of a roadside beacon system according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a state in which a roadside beacon is attached to a lighting column.

FIG. 3 is a perspective view showing an internal configuration of a roadside beacon.

FIG. 4 is a block diagram showing an electrical configuration of a roadside beacon system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Roadside beacon 3 In-vehicle device 7 Illumination lamp 8 Illumination pole 10 Photoelectric conversion unit (communication means) 11 Planar array antenna (communication means) 15 Solar cell panel (power generation means)

Claims (4)

[Claims] An electric power generation means provided within an irradiation range of an illumination lamp attached to an illumination pole installed on a roadside, and capable of generating electric power by at least light emitted from the illumination lamp, A roadside beacon, comprising: communication means for communicating with an in-vehicle device mounted on a vehicle using the power generated by the power generation means as a power supply. 2. The power generation means according to claim 1, wherein said power generation means is a solar cell panel made of amorphous silicon.
Roadside beacon as described. 3. The roadside beacon according to claim 1, wherein the power generation means is capable of generating power with at least 5 (W) light energy. 4. The lamp according to claim 1, wherein said illuminating lamp is a low-pressure sodium lamp or a mercury lamp.
The roadside beacon according to any one of the above.