JP4155045B2 - Road-to-vehicle communication system and base station - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a road-to-vehicle communication system that controls a directivity of an antenna to provide a service by communication with a plurality of vehicle-mounted terminals, a base station thereof, and a vehicle-mounted terminal.
[0002]
[Prior art]
Conventionally, a roadside-to-vehicle communication system in which a base station for narrow area wireless communication (DSRC) installed in a parking space in a general facility such as a convenience store, a gas station, or a parking lot communicates with a plurality of surrounding vehicles. It has been proposed (see, for example, Patent Document 1).
[0003]
In such a road-to-vehicle communication system, it is proposed that service information such as menu information and billing information is transmitted from the base station to the vehicle, or the vehicle downloads a file via the base station. ing. (For example, see Patent Documents 2 and 3.)
[0004]
[Patent Document 1]
JP 2002-152841 A
[0005]
[Patent Document 2]
Japanese Patent No. 3070853
[0006]
[Patent Document 3]
JP 2001-218275 A
[0007]
[Problems to be solved by the invention]
In such a system, one base station may constitute a communication area (cell) including a plurality of surrounding vehicles. However, in that case, since the cell must have a size including a plurality of vehicles, the antenna of the base station must be a small gain antenna compared to the case of configuring a cell including only one vehicle, and the transmission power If the same, the line margin will decrease, so there is a problem that the communication speed must be set low.
[0008]
In view of the above points, the present invention provides a communication service with high communication speed by suppressing a decrease in line margin when a cell including a plurality of vehicles is configured in a road-to-vehicle communication system that communicates with a plurality of surrounding vehicles. The purpose is to do.
[0009]
[Means for Solving the Problems]
  In order to achieve the above object, an invention according to claim 1 is a road-to-vehicle communication system comprising a base station installed on a roadside and a plurality of in-vehicle terminals, and providing a service from the base station to the in-vehicle terminals by communication. The base station includes a narrow directivity antenna having a narrow directivity, a vehicle position specifying means for specifying the position of the vehicle, a service request receiving means for receiving a request for the service, and the vehicle position specifying means Based on the position of the vehicle, directivity control means for controlling the directivity of the narrow directional antenna so as to be able to communicate with the vehicle-mounted terminal mounted on the vehicle, and communication with the vehicle-mounted terminal via the narrow directional antenna A communication processing unit for service that performs the service, and the in-vehicle terminal includes a communication processing unit for service that receives a service from the base stationThe narrow directional antenna and the in-vehicle antenna included in the in-vehicle terminal are linearly polarized antennas, and the narrow directional antenna is installed to be inclined downward from a horizontal plane, and the narrow directional antenna is offset. The angle formed between the wave and the polarization of the in-vehicle antenna becomes closer to a right angle as the distance between the base station and the in-vehicle antenna is smaller, and becomes closer to a parallel as the distance between the base station and the in-vehicle antenna is larger. The narrow directional antenna and the in-vehicle antenna are installed so that the angle formed by the respective polarizations is a right angle in the arrangement in which the base station exists in front of the vehicle,The on-vehicle terminal is a road-to-vehicle communication system characterized by receiving the service at a position that can be specified by the vehicle position specifying means.
[0010]
  Accordingly, since the antenna of the base station has a narrow directivity, it is possible to provide a communication service having a higher communication speed even when transmission is performed with the same power as that of the antenna that does not. In addition, since the directivity of the narrow directional antenna can be controlled so that it can communicate with an in-vehicle terminal mounted on the vehicle, it is possible to communicate with a plurality of surrounding vehicles individually or simultaneously. Therefore, in a road-to-vehicle communication system that provides services by communication with a plurality of surrounding vehicle-mounted terminals, it is possible to suppress a decrease in communication speed due to the expansion of the communication area.
  This also makes it possible to configure a narrow directional antenna with an antenna having a simple structure..
  In addition, this makes it possible to alleviate the difference in received power among a plurality of in-vehicle terminals having different distances from the base station, so that the dynamic range (receivable power range) required for the base station and the in-vehicle terminal is reduced. Can do.
  In addition, as a result, in the range where the base station does not exist in front of the vehicle, the angle formed by the polarization of the narrow directional antenna and the polarization of the in-vehicle antenna becomes perpendicular as the distance between the base station and the vehicle decreases. As the distance between the base station and the vehicle increases, the distance between the base station and the vehicle can be closer to each other.
[0011]
Further, the invention according to claim 2 is the road-to-vehicle communication system according to claim 1, wherein the directivity control means can communicate with only the in-vehicle terminal of one vehicle at a time. It is characterized by controlling the directivity of the antenna.
[0012]
As a result, the base station controls the directivity of the narrow directional antenna so that it can communicate with only one in-vehicle terminal at a time, so the directivity can be narrowed to the minimum necessary range, and transmission with the same power is possible. Even so, a communication service with a high communication speed can be provided. Moreover, since it is one-to-one communication, communication control can be simplified. Further, an in-vehicle terminal mounted on a vehicle other than the vehicle that provides the service can communicate with the base station.
[0013]
The invention according to claim 3 is the road-to-vehicle communication system according to claim 1 or 2, wherein the directivity control means is within the range where the antenna of the in-vehicle terminal of the vehicle may be installed. The received power that is higher than the reception sensitivity of the in-vehicle terminal is obtained in the in-vehicle terminal, and the received power that is higher than the reception sensitivity of the in-vehicle terminal is not obtained in a range where the in-vehicle antenna of the vehicle other than the vehicle may be installed The narrow directional antenna is controlled.
[0014]
As a result, the communicable area between the base station and the in-vehicle terminal can be reduced to the minimum necessary size.
[0025]
  Claims4In the road-to-vehicle communication system according to any one of claims 1 to 3, at least one of the narrow directional antenna and the in-vehicle antenna included in the in-vehicle terminal is circularly polarized. It is characterized by that.
[0026]
Thereby, stable received power can be obtained regardless of the angular relationship between the narrow directional antenna and the polarization of the in-vehicle antenna.
[0027]
  Claims5The invention described in claim 1 to claim 14In the road-vehicle communication system according to any one of the above, the narrow directional antenna is an antenna that controls directivity by changing a direction of a fixed directivity antenna by the directivity control means. Features.
[0028]
Thereby, the directivity of a narrow directivity antenna can be controlled simply. Moreover, since the opening surface of the narrow directional antenna is directed toward the vehicle, the opening area of the antenna can be utilized to the maximum regardless of the positional relationship between the base station and the vehicle. Furthermore, since the direction of the antenna is changed, the angle of polarization of the antenna can be changed according to the direction.
[0029]
  Claims6The invention described in claim 1 to claim 14In the road-to-vehicle communication system according to any one of the above, the narrow directional antenna is a variable directivity antenna in which a plurality of antenna elements are arranged and the directivity is changed by their interaction. .
[0030]
As a result, the directivity of the narrow directional antenna can be controlled without a movable part, so that it is excellent in durability and can be controlled in a very short time to electrically control the directivity.
[0031]
  Claims7The invention described in claim6In the road-to-vehicle communication system according to claim 1, the narrow directional antenna is the antenna with variable directivity in the depression direction, and the directivity control means changes a horizontal direction of the narrow directional antenna, It is characterized in that the directivity in the depression direction of the narrow directivity antenna is changed.
[0032]
As a result, a variable directivity antenna having a relatively simple structure can be used, and the directivity of a narrow directivity antenna can be controlled by a posture control device having a relatively simple structure to change only the horizontal direction. Can be controlled. Further, since the horizontal direction is changed, the angle of polarization of the antenna can be changed according to the horizontal direction.
[0033]
  Claims8The invention described in claim 1 to claim 17In the road-to-vehicle communication system according to any one of the above, the position that can be specified by the vehicle position specifying means is a parking mass.
[0034]
Thereby, the position of the vehicle can be specified accurately.
[0035]
  Claims9The invention described in claim8In the road-to-vehicle communication system according to claim 1, a plurality of the parking masses exist adjacent to each other, and the base station is installed near the center of a plurality of parking masses that provide a service among the plurality of parking masses.CollectionAnd
[0036]
Thereby, it is possible to provide services to the largest number of vehicles with the same transmission power.
[0037]
  Claim 10The invention described in claim8In the road-to-vehicle communication system according to claim 1, there are a plurality of parking spaces in the parking lot adjacent to the vicinity of the building, and the base station includes a plurality of parking spaces that provide services among the plurality of parking spaces. It is installed in a building near the center.
[0038]
Thereby, the installation cost of a base station can be significantly reduced rather than constructing a new building for installing a base station.
[0039]
  Claim 11The invention described in claim810In the road-to-vehicle communication system according to any one of the above, in a parking lot where the parking mass exists, a parking direction notification that prompts the user to park the parking mass in a direction in which the front of the vehicle approaches the base station Means are provided.
[0040]
Thereby, since the user parks the vehicle in a predetermined direction, the range in which the antenna of the in-vehicle terminal may be installed can be limited. In addition, shadowing due to the roof of the vehicle can be prevented.
[0041]
  Claim 12The invention described in claim 11The road-to-vehicle communication system described in 1. The parking direction notifying means is any one or any combination of road display and sound and radio to a radio mounted on the vehicle.
[0042]
As a result, the user can park the vehicle in the parking space in a predetermined direction.
[0043]
  Claim 13The invention described in claims 1 to 12In the road-to-vehicle communication system according to any one of the above, a range in which the base station provides services does not overlap with a range in which other base stations perform services.
[0044]
Thereby, a service can be provided in the maximum range with respect to the number of base stations to be installed.
[0045]
  Claims14The invention described in claims 1 to 13In the road-to-vehicle communication system according to any one of the above, the range in which the base station provides service overlaps with the range in which the other base station provides service.
[0046]
Thereby, since a plurality of base stations can provide services in the maximum range with respect to the number of overlapping base stations, it is possible to respond to service requests from a plurality of in-vehicle terminals in less time.
[0047]
  Claims15The invention described in claims 1 to 14In the road-to-vehicle communication system according to any one of the above, the base station includes provision order management means for managing a provision order of services to the plurality of in-vehicle terminals.
[0048]
Thereby, a service can be provided in response to a request for a service from a plurality of in-vehicle terminals at the same time.
[0049]
  Claims16The invention described in claims 1 to 14Provided in the road-to-vehicle communication system according to any one of claims 1 to 5, wherein communication with a plurality of the base stations is possible, and management of a service provision order for the plurality of in-vehicle terminals in the plurality of base stations is collectively performed It has an order batch management means.
[0050]
Thereby, a service can be provided in response to a request for a simultaneous service from a plurality of in-vehicle terminals. In addition, since the order of service provision at a plurality of base stations is collectively managed, the operating status of each base station can be easily grasped.
[0051]
  Claims17The invention described in claim15Or16In the road-to-vehicle communication system described in the above, the provision order collective management means, in response to a service request from the in-vehicle terminal that the other base station is performing the service first, or that is scheduled to perform the service, The service provision order is set so that the service is not performed at the same time.
[0052]
Thereby, since service provision from a plurality of base stations is not performed simultaneously for one in-vehicle terminal, it is possible to prevent a plurality of base stations from being interfered by each other's radio and deteriorating communication quality.
[0053]
  Claims18The invention described in claim17In the road-to-vehicle communication system according to claim 1, the provision order collective management unit cooperates with the provision order management unit included in the other base station by communication.
[0054]
As a result, a base station is added to a system installed so that there is no overlapping range where the base stations provide services, so that the ranges where the base stations provide services overlap each other. Therefore, the system can be flexibly configured according to the service frequency.
[0055]
  Claims19The invention described in claim 1 to claim 118In the road-to-vehicle communication system according to any one of the above, the service communication processing unit uses the same frequency in the plurality of base stations.
[0056]
As a result, services by a plurality of base stations can be provided with fewer frequencies.
[0057]
  Claim 20The invention described in claim 1 to claim 118In the road-to-vehicle communication system according to any one of the above, the service communication processing unit uses different frequencies in the plurality of base stations.
[0058]
Thereby, it is possible to avoid degradation of communication quality due to interference of radio signals from a plurality of base stations.
[0059]
  Claim 21According to the invention described in claim 1,0In the road-to-vehicle communication system according to claim 1, the base station includes a plurality of the narrow directional antennas and the service communication processing unit, and simultaneously provides services to the plurality of in-vehicle terminals.
[0060]
Thereby, since a service can be provided to a plurality of in-vehicle terminals at the same time, it is possible to respond to a request for service from a plurality of in-vehicle terminals in less time.
[0061]
  Claim 22The invention described in claim 21In the road-to-vehicle communication system according to claim 1, the plurality of service communication processing units use the same frequency.
[0062]
As a result, services by a plurality of base stations can be provided with fewer frequencies.
[0063]
  Claim 23The invention described in claim 21In the road-to-vehicle communication system according to claim 1, the plurality of service communication processing units use different frequencies.
[0064]
Thereby, it is possible to avoid deterioration of communication quality due to radio interference from a plurality of service communication processing units.
[0065]
  Claim 24According to the invention described in claim 1,3In the road-to-vehicle communication system according to any one of the above, the service communication processing unit performs bidirectional communication.
[0066]
Accordingly, communication by the service communication processing unit can be performed using a general-purpose communication control method.
[0067]
  Claims25According to the invention described in claim 1,4In the road-to-vehicle communication system according to any one of the above, the service request accepting unit performs wireless communication between a service accepting communication processing unit provided in the base station and a service accepting communication processing unit provided in the in-vehicle terminal. It is characterized by using.
[0068]
Thereby, since a service request can be made wirelessly from the in-vehicle terminal, the user can make a service request without leaving the vehicle.
[0069]
  Claims26The invention described in claim25In the road-to-vehicle communication system according to claim 1, the service communication processing unit provides a downlink from the base station to the in-vehicle terminal, and the service reception communication processing unit is provided from the in-vehicle terminal to the base station. Asymmetric communication that provides uplinkCollectionAnd
[0070]
Thereby, since the transmission part of the communication processing part for services can be omitted from the in-vehicle terminal, the cost for the in-vehicle terminal can be reduced.
[0071]
  Claims27In the road-to-vehicle communication system according to claim 30 or 31, the communication processing unit for service performs data transmission from the base station to the in-vehicle terminal using Meta-Content technology, The communication processing unit is used for confirming completion of data transmission.
[0072]
Thereby, since the transmission part of the communication processing part for services can be omitted from the in-vehicle terminal, the cost for the in-vehicle terminal can be reduced. In addition, even if the communication speed of the service reception communication processing unit is very low compared to the communication speed of the service communication processing unit, it is possible to provide a service at the communication speed of the service communication processing unit.
[0073]
  Claims28According to the invention described in claim 1,4In the road-to-vehicle communication system according to any one of the above, the service request receiving means is a service request receiving terminal capable of communicating with the base station.
[0074]
As a result, it is not necessary to provide the service reception communication processing unit in the base station and the in-vehicle terminal, and the cost for the base station and the in-vehicle terminal can be reduced.
[0075]
  Claims29According to the invention described in claim 1,4In the road-to-vehicle communication system according to any one of the above, the service request receiving terminal has a function of notifying a user of the content of the service and receiving a service request by a user operation.
[0076]
This makes it possible to use a monitor that is larger and more detailed than the in-vehicle terminal, so that it is possible to improve the visibility when checking the content of the service or when requesting the service.
[0077]
  Claim 30In the road-to-vehicle communication system according to claim 33 or 34, the service request reception terminal has a function of reading recording medium data including a user identification symbol.
[0078]
Thereby, the convenience for the user is high, and higher security than that of the wireless communication can be ensured.
[0079]
  Claim 31The invention described in claims 1 to 30In the road-to-vehicle communication system according to any one of the above, the service request receiving terminal is installed directly below the base station.
[0080]
As a result, the space installed by the service request receiving terminal and the base station can be shared, and the service can be operated in the minimum installation space. Also, a service that allows a user to complete a service request in a short time on the spot, such as when there are few options, is particularly convenient for the user.
[0081]
  Claim 32The invention described in claims 1 to 30In the road-to-vehicle communication system according to any one of the above, the service request reception terminal is installed in a store having the parking lot or a store in the vicinity of the parking lot.
[0082]
Thereby, the content of the service can be confirmed at a place away from the vehicle, and the service can be requested. Moreover, the convenience of the user is particularly high in the case of a service where it is desirable to examine the contents because the user is in the store or a service with many options.
[0083]
  Claim 33The invention described in claims 1 to 32In the road-to-vehicle communication system according to any one of the above, the service request accepting unit accepts a range in which a plurality of base stations provide a service.
[0084]
As a result, the total number of service request receiving terminals can be reduced.
[0085]
  Claim 34The invention described in claims 1 to 33In the road-to-vehicle communication system according to any one of the above, the high-frequency radio unit of the service communication processing unit is integrated with the narrow directional antenna.
[0086]
Thereby, since there is no movable part between a high frequency circuit part and an antenna, the lifetime of the cable etc. which connect a high frequency circuit part and an antenna part can be lengthened.
[0087]
  Claims35The invention described in claims 1 to 33In the road-to-vehicle communication system according to any one of the above, the service communication processing unit is integrated with the narrow directional antenna.
[0088]
Thereby, the lifetime of the cable etc. which connects the high frequency circuit part of a communication processing part for services, and the other part can be shortened.
[0089]
  Claims36The invention described in claim 1 to claim 135In the road-to-vehicle communication system according to any one of the above, the base station includes vehicle type specifying means for specifying the vehicle type of the vehicle, and the directivity control means includes the vehicle position specifying means and the vehicle type specifying means. The directivity of the narrow directional antenna is controlled so as to be able to communicate with an in-vehicle terminal mounted on the vehicle based on the specified position and vehicle type of the vehicle.
[0090]
Thereby, the range which may install the vehicle-mounted antenna of a vehicle-mounted terminal regardless of a vehicle model can be pinpointed correctly.
[0091]
  Claims37The invention described in claim36In the road-to-vehicle communication system according to claim 1, the vehicle position specifying means has a function of detecting the presence or absence of a vehicle at the position that can be specified, and transmitting a position symbol indicating the position that can be specified. The vehicle position specifying means receives the position symbol and generates a user identification symbol using the position symbol.
[0092]
Thereby, since the position symbol can be notified only to the in-vehicle terminal existing at the identifiable position, the in-vehicle terminal can increase the security of communication by using the identification symbol reflecting the position symbol. .
[0093]
  Claims38The invention described in claim 1 to claim 137The road-to-vehicle communication system according to any one of the above, has a file server capable of communicating with the base station.
[0094]
Thereby, it is not necessary to store all the files in a plurality of base stations, and the contents of the service can be easily updated.
[0095]
  Claims39The invention described inNarrow fingerHave tropismNarrow directivityThe vehicle, the vehicle position specifying means for specifying the position of the vehicle, and the vehicle position specified by the vehicle position specifying means so as to be able to communicate with the communication terminal of the vehicle.Narrow directivityDirectivity control means for controlling the directivity of the antennaThe narrow directional antenna is a linearly polarized antenna, and the narrow directional antenna is installed inclined downward from a horizontal plane, and the polarized wave of the narrow directional antenna and the in-vehicle antenna of the in-vehicle terminal The angle formed by the linearly polarized wave is controlled to be closer to a right angle as the distance between the base station and the vehicle-mounted antenna is smaller, and to be closer to parallel as the distance between the base station and the vehicle-mounted antenna is larger, The narrow directional antenna is installed such that an angle formed by polarization with respect to the vehicle-mounted antenna is a right angle in an arrangement in which the base station is present in front of the vehicle.It is a base station.
[0096]
  Accordingly, since the antenna of the base station has directivity, it is possible to provide a communication service with a higher communication speed even when transmission is performed with the same power as that of the antenna that is not. In addition, since the directivity of the antenna can be controlled so that it can communicate with the communication terminal of the vehicle, it is possible to communicate with a plurality of surrounding vehicles individually or simultaneously. Therefore, in a base station that communicates with a plurality of surrounding vehicles, it is possible to suppress a decrease in communication speed due to the expansion of the communication area..
  In addition, this makes it possible to alleviate the difference in received power among a plurality of in-vehicle terminals having different distances from the base station, so that the dynamic range (receivable power range) required for the base station and the in-vehicle terminal is reduced. Can do.
  In addition, as a result, in the range where the base station does not exist in front of the vehicle, the angle formed by the polarization of the narrow directional antenna and the polarization of the in-vehicle antenna becomes perpendicular as the distance between the base station and the vehicle decreases. As the distance between the base station and the vehicle increases, the distance between the base station and the vehicle can be closer to each other.
[0097]
“Control of antenna directivity” refers to controlling the direction of directivity of an antenna having directivity, and is a concept including control of physically changing the direction of the antenna, for example.
[0098]
  Claim 40The invention described in claim39In the base station described above, the directivity control means controls the directivity of the antenna so that it can communicate with only one communication terminal of the vehicle at a time.
[0099]
As a result, the base station controls the directivity of the antenna so as to communicate with only one vehicle at a time, so that the directivity can be narrowed, and the communication speed becomes higher even with the same transmission power.
[0100]
  Claims40"Only" in the above means that the communication using the antenna described above is performed only with the vehicle described above, and the base station has other wireless communication means and antennas, so that other than the vehicle. It is not excluded to communicate with.
[0101]
  Claim 41The invention described in claim39Or 40The base station according to claim 1, further comprising vehicle type specifying means for specifying a vehicle type of the vehicle, wherein the directivity control means is based on the vehicle position and vehicle type specified by the vehicle position specifying means and the vehicle type specifying means. The directivity of the antenna is controlled so that it can communicate with the communication terminal of the vehicle.
[0102]
This makes it possible to control the antenna directivity with higher accuracy based on the vehicle type.
[0104]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
FIG. 1 shows a schematic diagram of a road-vehicle communication system according to a first embodiment of the present invention. In this road-to-vehicle communication system, a base station 2 is installed in the center of a parking lot 1 having a plurality of adjacent parking spaces that can park a total of 2 rows and 16 vehicles, and the vehicle A parked in the parking lot 1 B and C are provided with a download service by narrow area communication or the like.
[0105]
At that time, when the vehicle A, B, or C downloads the file, the base station 2 acquires the file from the file server 6 connected to the base station 2 by wire and transmits the file to the vehicle A, B, or C. To do. In the present embodiment, this download is performed by allocating a communication line exclusively to one vehicle at a time. For example, even if a download request is received from the vehicles A, B, and C at one time, the download is performed in order by dividing the time one by one. The download order is set by the base station 2. The order setting method may be a first-come-first-served basis for download requests, or may be another method.
[0106]
In addition, the base station 2 controls the DSRC antenna unit 4 having an antenna for downloading for the one-to-one communication so that the directivity of this antenna is matched to the vehicle to be downloaded. Yes.
[0107]
In the present embodiment, for the right-handed Cartesian coordinates and the right-handed Cartesian coordinates with the z-axis as the vertical direction, the xy plane as the horizontal plane, and the y-axis as the arrangement direction of the parking masses, Description will be made using spherical coordinates such that = r · sin (θ) · cos (φ), y = r · sin (θ) · cos (φ), and z = r · cos (θ). The origin of the Cartesian coordinates is an intersection of a rotation axis 45 (described later) and the direction of the DSRC antenna 42.
[0108]
FIG. 2 shows configurations of the base station 2 and the DSRC antenna unit 4. The base station 2 includes a DSRC communication processing unit 23, a request reception communication processing unit 24, an information processing unit 27, an external communication control unit 28, and a vehicle sensor 29.
[0109]
The DSRC communication processing unit 23 (service communication processing unit that communicates with a vehicle-mounted terminal via a narrow directivity antenna) performs D / A conversion on digital download data for wireless transmission input from the information processing unit 27 Then, modulation, amplification, etc. are performed, and the resulting signal is output to the high frequency radio unit 41 of the DSRC antenna unit 4 as a DSRC intermediate frequency signal.
[0110]
The request reception communication processing unit 24 (service reception communication processing unit) performs amplification, frequency conversion, demodulation, A / D conversion, and the like on the radio signal in the microwave band received from the request reception antenna 5. The resulting signal is output to the information processing unit 27 as digital data. Further, the request receiving communication processing unit 24 performs D / A conversion, modulation, frequency conversion, amplification, etc. on the digital data for wireless transmission input from the information processing unit 27, and the resulting signal is a wireless signal. To the request receiving antenna 5.
[0111]
The information processing unit 27 is configured by a microcomputer having a CPU, a RAM, and a ROM. This CPU executes the processing described in the program recorded in the ROM, writes / reads information to / from the RAM as necessary, and if necessary, the DSRC communication processing unit 23, request acceptance communication Signals are exchanged with the processing unit 24, the external communication control unit 28, the vehicle sensor 29, the θ angle control motor 43, and the φ angle control motor 44. Processing executed by the information processing unit 27 will be described later.
[0112]
The external communication control unit 28 receives the command data from the information processing unit 27, shapes the command data so as to conform to the communication standard between the base station 2 and the file server 6, and transmits the command data to the file server 6. The external communication control unit 28 shapes the data received from the file server 6 into a data format that can be handled by the information processing unit 27 and outputs the data to the information processing unit 27.
[0113]
The vehicle sensor 29 has a plurality of infrared sensors whose optical axes are aligned with the respective parking masses of the parking lot 1, detects that the vehicle has entered the parking lot 1 by the infrared sensor, and informs that the detection has been made as a signal. The data is output to the processing unit 27. Further, the vehicle sensor 29 can transmit a position symbol (for example, a parking cell number) unique to the corresponding parking cell.
[0114]
The vehicle sensor 29 does not need to detect the entry by the infrared sensor, and any method can be used as long as the entry of the vehicle to the parking lot 1 can be detected. For example, you may detect using an ultrasonic sensor.
[0115]
The DSRC antenna unit 4 includes a high-frequency radio unit 41, a DSRC antenna 42, a θ angle control motor 43, and a φ angle control motor 44.
[0116]
The high frequency radio unit 41 frequency-converts the intermediate frequency signal input from the DSRC communication processing unit 23 into a high frequency signal and outputs it to the DSRC antenna 42. In the present embodiment, this high frequency signal is a millimeter wave band signal.
[0117]
The DSRC antenna 42 is a narrow area communication horn antenna having a narrow directivity in the front. The DSRC antenna 42 as the narrow directivity antenna may be a variable directivity antenna in which a plurality of antenna elements such as an array antenna are arranged and the directivity is changed by their interaction. In the case of an antenna that physically changes the direction of the antenna with fixed directivity, since the opening surface of the antenna is directed toward the vehicle, the opening area of the antenna can be used effectively. Further, in the case of an array antenna or the like, since there is no moving part, the durability is excellent, and the switching time is very short in order to electrically switch the directivity.
[0118]
The θ angle control motor 43 and the φ angle control motor 44 are operated by receiving control from the information processing unit 27, and the direction of the DSRC antenna 42 is changed by the operation. FIG. 3 shows an outline of the structure and operation of the θ angle control motor 43 and the φ angle control motor 44.
[0119]
The DSRC antenna unit 4 is connected to the base station 2 via a flexible cable 48. The high-frequency radio unit 41 is provided with a rotation shaft 45 horizontally, which is in contact with the θ angle control motor 43 through the rotation shaft 45, thereby being supported by the θ angle control motor 43. The DSRC antenna 42 is fixed to the high frequency radio unit 41 so that the direction thereof is orthogonal to the rotation axis 45.
[0120]
The θ angle control motor 43 can change the rotation angle around the rotation axis 45 of the DSRC antenna 42 fixed to the high frequency radio unit 41 based on the control from the information processing unit 27. . The θ angle control motor 43 is provided with a rotation shaft 46 that faces in the vertical direction (z-axis direction in the figure). The rotation shaft 46 contacts the φ angle control motor 44 and is thereby supported by the φ angle control motor 44. ing.
[0121]
The φ angle control motor 44 is fixed at the installation location, and the rotation angle around the rotation axis 46 of the θ angle control motor 43 can be changed based on the control from the information processing unit 27. Yes.
[0122]
By configuring the DSRC antenna unit 4 in such an arrangement, the θ angle control motor 43 can change the direction of the DSRC antenna 42 and the φ angle control motor 44 can change the φ angle in polar coordinates. FIG. 4 shows a visual representation of the correspondence between Cartesian coordinate display (x, y, z) and polar coordinate display (r, θ, φ) used here. The origin of the Cartesian coordinates and polar coordinates is the intersection of the θ angle control motor 43 and a straight line (corresponding to the dotted line in FIG. 3) in the direction of the DSRC antenna 42 that passes through the center of the DSRC antenna 42.
[0123]
FIG. 5 shows a configuration of the in-vehicle terminal 3 provided in the vehicles A, B, and C and used for downloading from the base station 2. The in-vehicle terminal 3 includes a parking lot sensor 30, a DSRC antenna 31, a request antenna 32, a DSRC communication processing unit 33, a request communication processing unit 34, a buffer 35, a download processing unit 36, an information processing device 37, an input / output unit 38, A display unit 39 and a mass storage device 40 are provided.
[0124]
The DSRC communication processing unit 33 performs amplification, frequency conversion, demodulation, A / D conversion, and the like on the DSRC radio signal received by the DSRC antenna 31 and outputs the resulting signal to the download processing unit 36 as digital data. .
[0125]
The request communication processing unit 34 (service reception communication processing unit) performs amplification, frequency conversion, demodulation, A / D conversion, etc. on the radio signal received from the request antenna 32, and converts the resulting signal into digital data. To the information processing device 37. The request communication processing unit 34 performs D / A conversion, modulation, frequency conversion, amplification, etc. on the digital data for wireless transmission input from the information processing device 37, and uses the resulting signal as a wireless signal. Output to the request antenna 32.
[0126]
The buffer 35 has a memory that is faster than the data writing speed to the large-capacity storage device 40, accumulates data when the data is input from the download processing unit 36, and requests data from the download processing unit 36. If there is, it is output to the download processing unit 36. Note that this buffer has a capacity of about several tens GB in this embodiment.
[0127]
The download processing unit 36 outputs the download data received from the DSRC communication processing unit 33 to the buffer 35, and extracts the data from the buffer 35 and outputs it to the information processing device 37 when the download is not being performed. However, when the buffer 35 is a dual port RAM, data may be extracted from the buffer 35 and output to the information processing device 37 even during downloading. The download processing unit 36 is realized by using an FPGA (Field Programmable Gate Array) which is an IC capable of programming a hardware configuration.
[0128]
The information processing device 37 is configured by a microcomputer having a CPU, a RAM, and a ROM. This CPU performs the processing described in the program recorded in the ROM, writes / reads information to / from the RAM as necessary, and, if necessary, the parking lot sensor 30, the request communication processing unit 34. , Exchanges information with the download processing unit 36, the input / output unit 38, the display unit 39, and the mass storage device 40.
[0129]
The input unit 38 is composed of an input device such as a button, and outputs a signal to the information processing device 37 in response to the operation of the user of the vehicle operating the input device.
[0130]
The display unit 39 outputs sound, characters, images, and the like based on input of signals from the information processing device 37.
[0131]
The large-capacity storage device 40 includes a memory having a storage capacity of several TB (terabytes), and receives data read / write control from the information processing device 37.
[0132]
The configuration of the road-vehicle communication system of this embodiment is as described above. Hereinafter, the operation of this road-vehicle communication system will be described.
[0133]
First, the processing contents of the CPU of the information processing unit 27 will be described. The CPU of the information processing unit 27 determines whether the base station 2 (1) detects entry of a vehicle, (2) receives a download menu request from the vehicle that has entered, and (3) receives a download request. Start the corresponding process. The download menu is a list of files to be downloaded that can be provided by the base station 2.
[0134]
FIG. 6 shows that a vehicle equipped with the in-vehicle terminal 3 enters and enters the parking lot 1 within the communicable range (service range) of the base station 2 and the vehicle sensor 29 detects the entry of the vehicle. The warehousing process of the CPU of the information processing unit 27 starting from the above will be described. The service range means that the base station 2 can communicate with the in-vehicle terminal 3 by controlling the direction of the DSRC antenna 42. The parking lot 1 may be displayed on the road as a parking direction notification means for urging to enter each parking slot forward to the parking stop position of the parking slot, or it may be notified wirelessly to that effect. May be. Further, the parking direction notification means may be any one or any combination of road display, voice display, and radio to a radio mounted on the vehicle.
[0135]
First, this processing is started when the CPU of the information processing unit 27 receives a detection signal from the vehicle sensor 29 (step 710).
[0136]
Next, in step 720, the on-board terminal 3 is notified of the parking lot symbol. Specifically, it outputs a control signal for causing the vehicle sensor 29 to transmit a parking lot symbol. Thereby, the vehicle sensor 29 transmits the parking lot symbol to the in-vehicle terminal 3 and its surroundings by infrared rays. A parking lot symbol is an identifier for identifying a parking lot, such as a serial number.
[0137]
In step 730, data notifying that the in-vehicle terminal 3 is within the service range is output to the request receiving communication processing unit 24. As a result, the notification is wirelessly transmitted to the in-vehicle terminal 3 through the request receiving communication processing unit 24 and the request receiving antenna 5. This is the end of the warehousing process. This warehousing process may be performed simultaneously on a plurality of vehicles in the parking lot 1.
[0138]
FIG. 7 shows the menu transmission process of the CPU of the information processing unit 27 that starts by receiving a download menu request from the in-vehicle terminal 3 that has received the goods, received the parking lot symbol, and received the notification that it is within the service range. It is.
[0139]
First, the CPU of the information processing section 27 receives the input of the download menu request from the request receiving communication processing section 24 and starts processing (step 740).
[0140]
In step 750, a list of download target files that can be provided, that is, a download menu is output to the request reception communication processing unit 24 as a notification to the in-vehicle terminal 3. As a result, the download menu is transmitted from the base station 2 to the in-vehicle terminal 3. Then, the process ends.
[0141]
FIG. 8 shows an update process of the schedule table of the CPU of the information processing unit 27, which starts by receiving a download request transmitted from the in-vehicle terminal 3 that has received the download menu. The schedule table is a list in which entries including information regarding individual downloads are recorded in the order of download, and is stored in the RAM of the information processing unit 27. Each entry includes information such as the ID of the vehicle or user to be downloaded, the name of the file to be downloaded, the vehicle type (sedan, wagon, or truck) of the vehicle.
[0142]
First, the CPU of the information processing unit 27 receives a download request from the request receiving communication processing unit 24 and starts processing (step 760). The download request includes a file name to be downloaded, a vehicle to be downloaded or a user ID (user identification symbol), a vehicle type of the vehicle, and a position symbol. Note that the user ID may be generated using a position symbol.
[0143]
In step 770, a new entry based on the received download request is added to the schedule table. If the download is first-come-first-served basis, a new entry is added at the end of the schedule table. Then, the process ends.
[0144]
FIG. 9 shows the processing of the information processing unit 27 that actually transmits a download target file to the in-vehicle terminal 3 based on the schedule table updated as described above. This process is periodically executed in parallel with other processes.
[0145]
First, in step 810, the schedule table in the RAM of the information processing unit 27 is referred to.
[0146]
In step 820, it is determined whether there is an entry in the schedule table. If there is no entry, the process ends.
[0147]
If there is an entry, the process proceeds to step 830 to refer to the entry at the top of the schedule table, that is, the download request with the highest priority.
[0148]
In step 840, vehicle type information and position symbols are read from the entry, and the direction of the DSRC antenna 42 is determined based on these information. Specifically, a correspondence table as shown in FIG. 10 is stored in the ROM in advance at the time of factory shipment or the like, and the θ angle and φ angle corresponding to the above-described vehicle type information and position symbol (parking slot number) are set as DSRC. The direction of the antenna 42 is assumed.
[0149]
In the table of FIG. 10, parking lot symbols 1, 2, and 3 are parking lot symbols corresponding to the parking spaces where vehicles A, B, and C are parked in FIG. It is a parking lot symbol corresponding to an empty parking space next to the parking space of the vehicle C. Although this table is actually a table for 16 parking lot symbols, only a part of them is shown in FIG.
[0150]
In FIG. 10, even in the same parking slot, the angle of the direction of the DSRC antenna 42 is changed for each vehicle type such as a sedan, a wagon, and a truck. This is because it is assumed that the installation position of the DSRC antenna 31 of the in-vehicle terminal 3 differs depending on these vehicle types. In general, the in-vehicle terminal 3 is attached to the dashboard of the vehicle or in the vicinity thereof. When the vehicle is stopped at the correct position in the parking slot, for example by bringing the front wheel into contact with the wheel stopper installed in the parking slot, the dashboard position depends on the height of the vehicle, such as the wagon, sedan, and truck. The horizontal distance from the base station 2 is different. FIG. 11 schematically shows the difference in the direction of the DSRC antenna 42 when a sedan or a truck is stopped at the parking lot 1. By changing the angle of the DSRC antenna 42 in response to such a difference, the DSRC antenna 42 can be directed more accurately in the direction of the DSRC antenna 31 of the in-vehicle terminal 3 with simple division, and thus more stable communication. It can be performed.
[0151]
In step 850, the θ angle control motor 43 and the φ angle control motor 44 are controlled so that the determined θ angle and φ angle are realized. That is, a control signal is output to the θ angle control motor 43 so as to realize the determined θ angle, and a control signal is output to the φ angle control motor 44 so as to realize the determined φ angle.
[0152]
Thus, in a range where there is a possibility of installing the DSRC antenna 31 of the in-vehicle terminal 3, the in-vehicle terminal 3 can obtain reception power that is higher than the reception sensitivity of the in-vehicle terminal 3, and the DSRC antenna 31 of vehicles other than the vehicle can be installed The DSRC antenna 42 is controlled so that reception power equal to or higher than the reception sensitivity of the in-vehicle terminal 3 cannot be obtained within a certain range.
[0153]
When the control is completed, in order to transmit the file to be downloaded to the vehicle-mounted terminal 3 in step 860, a request for the file is made to the file server 6 via the external communication control unit 28, and thereby via the external communication control unit 28. The file is received from the file server 6 and output to the DSRC communication processing unit 23. Note that the base station 2 has a large-capacity memory such as a buffer, and the file is previously acquired from the file server 6 and stored in the large-capacity memory. The file may be read out and output to the DSRC communication processing unit 23.
[0154]
When the transmission is completed, the download entry is deleted from the schedule table in step 880. Then, the process ends.
[0155]
Next, the operation of the information processing device 37 of the in-vehicle terminal 3 will be described. FIG. 12 shows information that starts when a vehicle equipped with the in-vehicle terminal 3 enters and enters the parking lot 1 within the communicable range of the base station 2 and the parking lot sensor 30 detects the incoming vehicle. This is a process of the CPU of the processing device 37.
[0156]
First, in step 305, the CPU receives a parking lot symbol and a location symbol from the parking lot sensor 30, and sends data indicating that the vehicle is within the service range from the base station 2 via the request communication processing unit 34. Receive.
[0157]
Next, in step 310, display data for prompting the user of the vehicle to determine whether to receive the download service is output to the display unit 39. In step 315, an input from the user is waited, and if there is an input, it is determined whether the input is for receiving a service. If no service is received, the process ends.
[0158]
When receiving the service, the process proceeds to step 320, and the request for the download menu based on the user input, the vehicle identifier (vehicle ID), the parking lot symbol, and the location symbol are sent to the base station via the request communication processing unit 34. 2 to send.
[0159]
Next, in step 325, the download menu transmitted from the base station 2 is received and the menu is displayed on the display unit 39.
[0160]
In step 345, it is determined whether or not the content of download has been determined by the input from the input unit 38 of the user of the in-vehicle terminal 3. If the download content is determined, the process proceeds to step 365 to transmit a download request to the base station 2. If not determined, the determination in step 345 is repeated.
[0161]
After the process of step 365, download is performed in step 395, and the process ends when the download ends.
[0162]
With the configuration and operation as described above, the antenna of the base station has directivity, so that the gain in the direction of directivity is improved even when transmission is performed with the same power as compared with other antennas. Even if it exists, a communication service with a high communication speed can be provided. Moreover, since the direction of the antenna can be controlled so as to be able to communicate with the communication terminal of the vehicle according to the vehicle type, it is possible to communicate with each of the vehicles at a plurality of surrounding positions in order. Therefore, in a road-to-vehicle communication system that communicates with a plurality of surrounding vehicles, it is possible to provide a communication service with a high communication speed by suppressing a reduction in line margin when a cell including a plurality of vehicles is configured.
[0163]
In addition, the base station is an antenna with a narrow directivity so that it can communicate with only one vehicle at a time, and the directivity of the antenna is controlled so as to communicate with only one vehicle at a time, so the communication speed is Get higher. Moreover, since it is one-to-one communication, communication control can be simplified.
[0164]
The DSRC antenna 42 may be linearly polarized or circularly polarized. In addition, the DSRC antenna 42 and the DSRC antenna 31 may use the same combination of polarizations (straight-straight line, circle-circle), or may use a combination of different polarizations (straight-circle). When different combinations of polarized waves are used, the signal power is deteriorated as compared with the case where the same polarized waves are used, but stable signal power can be obtained regardless of the angular relationship of the transmitting and receiving antennas.
[0165]
In FIG. 13, when linearly polarized waves are used for the DSRC antenna 42 and the DSRC antenna 31 and the DSRC antenna 31 is fixed to the vehicle, the angle of the DSRC antenna 42 is controlled in the control order as in this embodiment. The relationship of the polarization between the DSRC antenna 42 and the DSRC antenna 31 is shown.
[0166]
The polarization direction of the DSRC antenna 31 is designed to be parallel to the x axis, and the polarization direction of the DSRC antenna 42 is the z axis when the DSRC antenna 42 is oriented in a direction parallel to the x axis. Suppose they are designed to be parallel. That is,
The DSRC antenna 42 and the DSRC antenna 31 are installed so that the angles formed by the respective polarizations are parallel to each other in the arrangement in which the base station exists in front of the vehicle.
[0167]
In FIG. 13, each line segment in the parking mass having arrows at both ends is obtained by projecting the polarization direction of the radio wave from the DSRC antenna 42 onto the xy plane when the DSRC antenna 42 is directed to the parking mass. Indicates the direction. The reason why the polarization xy plane component is present in the parking mass in front of the base station 2 is that the DSRC antenna 42 is inclined downward. The farther the parking mass is from the base station 2, the closer the transmission / reception polarization approaches, and the closer the parking mass from the base station 2, the more parallel the transmission / reception polarization direction.
[0168]
In the case of FIG. 13, the polarization direction of the DSRC antenna 31 may be changed to be set to a direction in the xy plane orthogonal to the traveling direction of the vehicle, or the polarization direction of the DSRC antenna 42 is The DSRC antenna 42 may be designed to be parallel to the y-axis when facing the direction parallel to the x-axis. That is, the DSRC antenna 42 and the DSRC antenna 31 may be installed so that the angles formed by the respective polarizations are perpendicular to each other in the arrangement where the base station is present in front of the vehicle. In these cases, since the polarization of the transmitting and receiving antennas becomes more parallel as the parking slot is further away from the base station 2, the change in signal power received by the in-vehicle terminal 3 is reduced with respect to the increase in propagation attenuation due to the propagation distance. Can do. As a result, the dynamic range (allowable received power range) required for the in-vehicle terminal 3 can be reduced.
[0169]
In the present embodiment, control of the angle of the DSRC antenna 42 is performed in the order of the spherical coordinates θ → φ with the vertical axis as the z axis. However, the angle may be controlled in the order of θ → φ in spherical coordinates (denoted as spherical coordinates 2) with respect to the Cartesian coordinates where the x-axis of the Cartesian coordinates is the z-axis and the −z axis is the x-axis. However, the values of θ and φ are not the values shown in FIG. 10, but the values converted to θ and φ in the spherical coordinate 2 are used.
[0170]
FIG. 14 shows the DSRC antenna 42 when the angle is controlled in the order of θ → φ in the spherical coordinate 2 when linearly polarized waves are used for the DSRC antenna 42 and the DSRC antenna 31 and the DSRC antenna 31 is fixed to the vehicle. And the polarization relationship between the DSRC antenna 31 and FIG. In this case, even when the distance between the base station and the parking mass is large, the polarization of transmission and reception is substantially parallel.
[0171]
Further, the configuration of the DSRC antenna unit 4 may be changed to that shown in FIG. 15 instead of the DSRC antenna unit 4 ′ shown in FIG. 3. The DSRC antenna unit 4 ′ in FIG. 15 includes a high-frequency radio unit 41 equivalent to the DSRC antenna unit 4, a DSRC antenna 42, a θ angle control motor 43, and a φ angle control motor 44. However, the φ angle control motor 44 is fixed to a ψ angle control motor 47 in the φ angle rotation axis direction.
[0172]
The ψ angle control motor 47 is fixed at the installation location, and the rotation angle around the horizontal y-axis is changed by the control of the information processing unit 27. As the ψ angle control motor 47 rotates, the high-frequency radio unit 41, the DSRC antenna 42, the θ angle control motor 43, and the φ angle control motor 44 rotate around the ψ angle rotation axis in the drawing. The antenna control shown in FIG. 14 is realized by rotating the ψ angle by 90 ° from the state of FIG. 3 and fixing the angle.
[0173]
The DSRC antenna 42 is an antenna with variable directivity in the depression direction, and the horizontal direction may be physically changed, and the directivity may be changed in the depression direction.
[0174]
(Second Embodiment)
In FIG. 16, the schematic diagram of the road-vehicle communication system which concerns on 2nd Embodiment of this invention is shown. This embodiment is different from the first embodiment in that the base station 2 does not have the request reception antenna 5, but instead a request reception terminal 7 (service request reception means) that can be directly operated by the user. It is installed near the base station 2. In the following, parts of the present embodiment that are different from the first embodiment will be described.
[0175]
FIG. 17 shows the configuration of the base station 2 ′ of this embodiment. The base station 2 ′ is different from the base station 2 of the first embodiment in that the base station 2 does not have the request reception communication processing unit 24 and the external communication control unit 28 has a request reception request. The information from the terminal 7 is received, and the received information is transmitted to the information processing unit 27. In this figure, the same components as those of the base station 2 of the first embodiment are denoted by the same reference numerals.
[0176]
FIG. 18 shows the configuration of the request receiving terminal 7. The request reception terminal 7 includes a display unit 71 that receives and displays image data from the information processing unit 73, an input unit 72 such as an operation button that outputs a signal based on an input by the user to the information processing unit 73, and an information processing unit 73 and an external communication control unit 74.
[0177]
The external communication control unit 74 receives the data from the information processing unit 73, shapes the data to match the communication standard between the base station 2 ′ and the request receiving terminal 7, and transmits the data to the external communication control unit 28. . The external communication control unit 74 shapes the data received from the external communication control unit 28 into a data format that can be handled by the information processing unit 73 and outputs the data to the information processing unit 73.
[0178]
The information processing unit 73 converts the data received from the external communication control unit 74 into video data and outputs it to the display unit 71. The signal input from the input unit 72 is output to the external communication control unit 74 as input data.
[0179]
The operation of the information processing unit 27 in the present embodiment performs processing equivalent to the processing of FIGS. 6 to 9 of the information processing unit 27 shown in the first embodiment. However, the reception of the download menu request and the transmission of the download menu in FIG. 7 are performed by transmission / reception with the request reception terminal 7 via the external communication control unit 28. In addition, the download request in FIG. 8 is received by reception from the request reception terminal 7 via the external communication control unit 28.
[0180]
Even with such a configuration, the same effect as in the first embodiment can be obtained. Moreover, since it becomes unnecessary to provide the request | requirement antenna 32 and the request communication process part 34 in the vehicle-mounted terminal 3 by such a structure, it leads to the cost reduction of the vehicle-mounted terminal 3. FIG. Further, as authentication for receiving the download service, a user-specific password is input to the request receiving terminal 7 or the request receiving terminal 7 has an ID card reading function, thereby reading the user's ID card. And higher security than wireless can be secured. In addition, since the request receiving terminal 7 includes the display unit 71, the display unit 71 can be realized with a monitor that is more detailed than the display unit 39 in a vehicle with a limited space. Visibility is improved.
[0181]
One request receiving terminal 7 may receive a region where one base station 2 ′ provides a download service, or may accept a region where a plurality of base stations provide a service. . FIG. 19 shows an overhead view of a parking lot having two base stations 2 ′. Each base station 2 'uses a different parking slot as a service range (see the arrow in the figure), but the request receiving terminal 7 shares it. In this way, the total number of request receiving terminals 7 can be reduced in a system having a plurality of base stations.
[0182]
Further, when the request receiving terminal 7 and the base station 2 ′ are in one-to-one correspondence as in the present embodiment, the base station 2 ′ and the request receiving terminal 7 may be directly connected. However, for example, when the request reception terminal and the base station are in a one-to-many, many-to-one, or many-to-many relationship and the request reception needs to be integrated, In addition, a request reception server for integration processing may be provided, and the request reception terminal and the external communication control unit of the base station may exchange information via the request reception server.
[0183]
Further, the request receiving terminal 7 may be installed directly under the base station 2 ′, or may be installed at a remote place, for example, a store having the parking lot or a store near the parking lot.
[0184]
FIG. 20 shows a conceptual diagram when the request receiving terminal 7 is installed immediately below the base station 2 ′. In such a case, the service can be operated at the minimum installation location. Further, this method is more convenient for the user for a service that allows the user to complete the request in a short time on the spot (such as when there are a small number of options). In FIG. 20, the file server 6 is installed in a nearby building.
[0185]
FIG. 21 is a conceptual diagram in the case where the request receiving terminal 7 is installed at a location away from the base station 2 ′. In this figure, the base station 2 'and the request receiving terminal 7 are connected via the request receiving server described above. In such a case, the download menu can be confirmed at a location away from the parking lot and a request can be made. In the case of a service where it is desirable for the user to examine the contents in a store or a service with many options, this method is more convenient for the user.
[0186]
In each embodiment of the present invention, the process for detecting warehousing shown in FIG. 6 constitutes a vehicle position specifying means for specifying the position of the vehicle.
[0187]
Further, the processing in steps 840 and 850 in FIG. 9 constitutes directivity control means.
[0188]
Further, the process of step 760 in FIG. 8 constitutes a download request accepting unit.
[0189]
Further, the processing in step 770 in FIG. 8 constitutes a provision order management unit.
[0190]
In each embodiment, the communication between the base station and the vehicle does not have to be for download, and may be any communication.
[0191]
Further, when two or more base stations provide a download service in one parking lot, each base station may have a service range independent from each other as shown in FIG. It may be present (see arrow in FIG. 22). However, the device configuration and processing differ between the two. When the service areas are independent from each other, the service can be provided in more areas. If there are overlapping areas, it is possible to respond to many requests in less time. In this case, in order not to perform wireless communication with the same vehicle at the same time, mutual base stations cooperate with each other, or another control station (providing order batch management means) performs the operation of a plurality of base stations. Control all at once. This provision order collective management means cooperates with the provision order management function of the base station through communication. As a control method, for example, in response to a request for service from an in-vehicle terminal that has already been serviced by another base station or scheduled to be serviced, the service is not performed at the same time. The provision order may be set. In addition, it is possible to add a base station to a system installed so as to be independent from each other by making it operate even if there are overlapping areas, so the system can be flexibly configured according to the service frequency can do.
[0192]
In either case, the plurality of base stations may use the same frequency, or may use different frequencies. When the same frequency is used in a plurality of base stations, a plurality of services can be provided simultaneously in a smaller frequency band. Further, when communication quality deteriorates due to radio signal interference of a plurality of base stations, this can be avoided by using different frequencies in the plurality of base stations.
[0193]
In addition, one base station may have one antenna and a communication device, and may provide a download service to one area (spot cell) at a time, or may have a plurality of antennas and communication devices at the same time. Services may be provided to the area. In the latter case, since one base station has a plurality of communication devices, it is possible to respond to many requests in a shorter time. In this case, the plurality of communication devices included in the base station may use the same frequency or different frequencies. When the same frequency is used, communication with a plurality of spot cells can be performed in one frequency band, so that services can be provided in a smaller frequency band. Further, when radio signals of a plurality of communication devices constituting adjacent spot cells interfere with each other and communication quality deteriorates, this interference can be prevented by using different frequencies in the plurality of communication devices.
[0194]
Further, the position where the DSRC antenna of the base station is installed may be the center of all spot cell groups provided by the base station as in the first and second embodiments, or may be a position that is not the center depending on the installation environment. You may install in. If the base station antenna is installed in the center of the spot cell group, the service can be provided to the largest number of vehicles with the same transmission power. Further, when the base station is close to an existing building, the installation cost can be greatly reduced by installing the base station antenna in the building (see FIGS. 23 and 24). However, even in that case, it can be installed in a building near the center of the plurality of parking spaces that provide the service among the plurality of parking spaces.
[0195]
As for the wireless communication system, bidirectional communication may be performed by DSRC, or asymmetric communication using request reception radio using DSRC for the downlink may be used. In the case of asymmetric communication, downloading may be performed using a Meta-Content (registered trademark) technology capable of data transmission only by one-way communication by DSRC, and the uplink may be used only for confirmation of completion of reception of all data.
[0196]
Further, control of the antenna directivity of the DSRC antenna may be performed using a parking lot symbol as in the first and second embodiments, or the direction of the in-vehicle antenna is estimated by estimating the arrival direction of a radio signal emitted from the in-vehicle terminal. May be set each time so as to face the direction.
[0197]
In the first and second embodiments, in the base station 2 and the DSRC antenna unit 4, the high frequency radio unit 41, which is a high frequency part of the radio communication function, changes its direction integrally with the DSRC antenna 42. In this case, a signal in the intermediate frequency band flows through the flexible cable 48 (see FIG. 25). In this case, since there is no bending variation of the high-frequency cable between the high-frequency radio unit 41 and the DSRC antenna 42, the life of the high-frequency cable can be extended. However, such a configuration is not necessarily required. For example, the high-frequency radio unit 41 may be incorporated in the base station 2 and the movable unit may be only the DSRC antenna 42 (see FIG. 26). The processing unit 23 and the high-frequency radio unit 41 may be integrated with the DSRC antenna 42 (see FIG. 27). In the former case, since the weight of the movable part can be minimized, the life of the attitude control device can be extended. In the latter case, neither the cable that transmits the signal at the intermediate frequency of the wireless communication device nor the high-frequency cable is bent, so that the life of the cable can be extended.
[Brief description of the drawings]
FIG. 1 is a diagram showing an outline of a road-vehicle communication system according to a first embodiment of the present invention.
FIG. 2 is a diagram illustrating configurations of a base station 2 and a DSRC antenna unit 4;
FIG. 3 is a diagram showing an outline of the structure and operation of a θ angle control motor 43 and a φ angle control motor 44;
FIG. 4 is a diagram illustrating a relationship between Cartesian coordinates and spherical coordinates.
FIG. 5 is a diagram showing a configuration of an in-vehicle terminal 3;
FIG. 6 is a flowchart of warehousing processing of the information processing unit 27;
7 is a flowchart of menu transmission processing of the information processing section 27. FIG.
FIG. 8 is a flowchart of schedule table update processing of the information processing unit 27;
FIG. 9 is a flowchart of processing for transmitting a file in the information processing section 27;
FIG. 10 is a chart showing a relationship between a vehicle type, a position symbol, and a control angle of the DSRC antenna 42;
FIG. 11 is a diagram schematically showing a difference in the direction of the DSRC antenna 42 when a sedan or a truck is stopped at the parking lot 1;
12 is a flowchart of processing of the information processing apparatus 37. FIG.
13 is a diagram showing a polarization relationship between a DSRC antenna 42 and a DSRC antenna 31. FIG.
14 is a diagram showing a polarization relationship between a DSRC antenna 42 and a DSRC antenna 31. FIG.
FIG. 15 is a diagram showing an outline of the structure and operation of a DSRC antenna unit 4 '.
FIG. 16 is a schematic diagram of a road-vehicle communication system according to a second embodiment of the present invention.
FIG. 17 is a diagram illustrating a configuration of a base station 2 '.
18 is a diagram showing a configuration of a request receiving terminal 7. FIG.
FIG. 19 is an overhead view of a parking lot having two base stations 2 '.
FIG. 20 is a conceptual diagram when a request receiving terminal 7 is installed directly under a base station 2 '.
FIG. 21 is a conceptual diagram in the case where the request receiving terminal 7 is installed at a location away from the base station 2 '.
FIG. 22 is an overhead view of a parking lot when there are overlapping areas in each base station.
FIG. 23 is an overhead view of a parking lot when a base station antenna is installed in an existing building.
FIG. 24 is an overhead view of a parking lot when a base station antenna is installed in an existing building.
25 is a schematic diagram of the base station 2 and the DSRC antenna unit 4 when the high-frequency part of the wireless function is integrated with the DSRC antenna 42. FIG.
FIG. 26 is a schematic diagram of the base station 2 and the DSRC antenna unit 4 when the high-frequency part of the wireless function is in the base station 2;
FIG. 27 is a schematic diagram of the base station 2 and the DSRC antenna unit 4 when the intermediate frequency part and the high frequency part of the wireless function are integrated with the DSRC antenna 42;
[Explanation of symbols]
1 ... Parking, 2, 2 '... Base station, 3 ... In-vehicle terminal,
4, 4 '... DSRC antenna unit, 5 ... request receiving antenna,
6 ... file server, 7 ... request receiving terminal,
23 ... DSRC communication processing unit, 24 ... Request receiving communication processing unit,
27 ... Information processing unit, 28 ... External communication control unit, 29 ... Vehicle sensor,
30 ... Parking sensor, 31 ... DSRC antenna,
32 ... Request antenna, 33 ... DSRC communication processing unit,
34 ... communication processing unit for request, 35 ... buffer,
36 ... Download processing unit, 37 ... Information processing device, 38 ... Input unit,
39 ... Display unit, 40 ... Mass storage device, 41 ... High frequency radio unit,
42 ... DSRC antenna, 43 ... θ angle control motor, 44 ... φ angle control motor,
45, 46 ... rotating shaft, 47 ... ψ angle control motor, 48 ... flexible cable,
71 ... display unit, 72 ... input unit, 73 ... information processing unit, 74 ... external communication control unit.

Claims (41)

A road-to-vehicle communication system comprising a base station installed on the roadside and a plurality of in-vehicle terminals, providing a service from the base station to the in-vehicle terminal by communication,
The base station has a narrow directivity antenna having narrow directivity,
Vehicle position specifying means for specifying the position of the vehicle;
Service request accepting means for accepting a request for the service;
Directivity control means for controlling the directivity of the narrow directional antenna so as to be able to communicate with an in-vehicle terminal mounted on the vehicle based on the position of the vehicle specified by the vehicle position specifying means;
A communication processing unit for services that communicates with the in-vehicle terminal via the narrow directional antenna,
The in-vehicle terminal includes a communication processing unit for service that receives a service from the base station,
The narrow directional antenna and the in-vehicle antenna provided in the in-vehicle terminal are linearly polarized antennas,
The narrow directional antenna is installed inclined downward from a horizontal plane,
The angle formed between the polarization of the narrow directional antenna and the polarization of the in-vehicle antenna becomes closer to a right angle as the distance between the base station and the in-vehicle antenna is smaller, and the distance between the base station and the in-vehicle antenna. is controlled so that is close enough to flat row large,
The narrow directional antenna and the in-vehicle antenna are installed so that the angle between the respective polarized waves is a right angle in the arrangement in which the base station is present in front of the vehicle,
The on-vehicle terminal receives the service at a position that can be specified by the vehicle position specifying means.   The road-to-vehicle communication system according to claim 1, wherein the directivity control means controls the directivity of the narrow directional antenna so that it can communicate with only the in-vehicle terminal of one vehicle at a time. The directivity control means, in a range where there is a possibility of installing an antenna of the in-vehicle terminal of the vehicle, received power that is higher than the reception sensitivity of the in-vehicle terminal is obtained in the in-vehicle terminal,
2. The narrow directional antenna is controlled so that reception power exceeding the reception sensitivity of the in-vehicle terminal cannot be obtained in a range in which the in-vehicle antenna of a vehicle other than the vehicle is likely to be installed. Or the road-vehicle communication system according to 2;   The road-to-vehicle communication system according to any one of claims 1 to 3, wherein at least one of the narrow directional antenna and the in-vehicle antenna included in the in-vehicle terminal is circularly polarized. The narrow directional antenna, by the directivity control unit, one or fourth shift claims 1, characterized in that an antenna that controls directivity by changing the orientation of the directional fixing of the antenna The road-to-vehicle communication system described. The road according to any one of claims 1 to 4 , wherein the narrow directional antenna is a variable directivity antenna in which a plurality of antenna elements are arranged and the directivity is changed by their interaction. Inter-vehicle communication system. The narrow directional antenna is an antenna with variable directivity in the depression direction, and the directivity control means changes the horizontal direction of the narrow directional antenna and directs the narrow direction antenna in the depression direction. The road-to-vehicle communication system according to claim 6 , wherein the characteristics are changed. The road-to-vehicle communication system according to any one of claims 1 to 7 , wherein the position that can be specified by the vehicle position specifying means is a parking mass. The parking stall is adjacent to plurality of the base station according to installation near the center of a plurality of parking stalls for providing a service of said plurality of parking stalls to claim 8, FEATURES Road-to-vehicle communication system. There are a plurality of parking spaces in the parking lot adjacent to the vicinity of the building, and the base station is installed in a building near the center of the plurality of parking spaces that provide the service among the plurality of parking spaces. The road-to-vehicle communication system according to claim 8 . Wherein the parking parking stall exists, claims, characterized in that the front of the vehicle to the parking trout parking direction notifying means for prompting the user to park in a direction approaching the base station are provided 8 The road-to-vehicle communication system according to any one of 1 to 10 . The parking direction notification means, road-vehicle communication system of claim 1 1, characterized in that any or any combination of radio to radio to be mounted on the street view and the voice and the vehicle. Range where the base station performs a service, road-vehicle communication system according to any one of claims 1 to 1 2, characterized in that the other of said base stations do not overlap the range for the service. Range where the base station performs a service, road-vehicle communication system according to any one of claims 1 to 1 2, characterized in that the overlap is in the range of another one of the base station performs the service. The base station, the road-vehicle communication system according to any one of claims 1 to 1 4, characterized in that it has provided order management means for managing the providing sequence of the service to a plurality of the in-vehicle terminal. 2. A provision order collective management unit capable of communicating with a plurality of base stations and collectively managing a provision order of services to a plurality of the in-vehicle terminals in the plurality of base stations. to 1 4 road-vehicle communication system according to any one of. The provision order batch management means does not perform the service at the same time in response to a request for service from the in-vehicle terminal that the other base station has already performed the service or is scheduled to perform the service. The road-to-vehicle communication system according to claim 15 or 16 , wherein a service provision order is set. The road-to-vehicle communication system according to claim 17 , wherein the provision order collective management means cooperates with the provision order management means of the other base station by communication. The road-to-vehicle communication system according to any one of claims 1 to 18 , wherein the service communication processing unit uses the same frequency in a plurality of the base stations. The road-to-vehicle communication system according to any one of claims 1 to 18 , wherein the service communication processing unit uses different frequencies in the plurality of base stations. The base station has a plurality of the narrow directional antenna reserve the service communication processing unit, the road-vehicle according to claim 1 or 2 0 and providing a service at the same time to a plurality of the onboard terminal Communications system. Road-vehicle communication system according to claim 2 1 a plurality of said service communication processing unit, which comprises using the same frequency. The plurality of service for communication processing section, road-vehicle communication system according to claim 2 1, which comprises using different frequencies. The service communication processing unit, according to claim 1 or 2 3 road-vehicle communication system according to any one of and performs bidirectional communication. The service request receiving means, and service reception communication processing section provided in the base station, claims 1, characterized by using a wireless communication with the service acceptance communication processing unit provided in the vehicle-mounted terminal either 2 4 The road-vehicle communication system as described in any one. The service communication processing unit provides a downlink from the base station to the in-vehicle terminal, and the service reception communication processing unit performs asymmetric communication to provide an uplink from the in-vehicle terminal to the base station. road-vehicle communication system according to claim 25, it features that. The communication processing unit for service performs data transmission from the base station to the in-vehicle terminal using a Meta-Content technology, and the communication processing unit for service reception in the previous period is used for confirmation of completion of data transmission. The road-to-vehicle communication system according to 25 or 26 . The service request receiving means, road-vehicle communication system according to any one of Claims 1 to 2 4, wherein the a service request receiving terminal capable of communicating with the base station. The service request receiving terminal notifies the contents of the service to the user, road according to any one of claims 1 to 2 4, characterized in that it has a function of receiving a request for service by a user's operation Inter-vehicle communication system. 30. The road-vehicle communication system according to claim 28 or 29 , wherein the service request receiving terminal has a function of reading recording medium data including a user identification symbol. The service request receiving terminal, the road-vehicle communication system according to 3 any one of 0 to claim 1, characterized in that it is placed directly below the base station. The service request receiving terminal may store or road-vehicle communication system according to 3 any one of 0 claims 1, characterized in that it is installed in a nearby shop of the parking lot with the parking. The service request receiving means, road-vehicle communication system according to one any of the 3 2 claims 1 a plurality of the base stations and performing the scope acceptance of providing a service. RF radio portion of the service for the communication processing unit, the road-vehicle communication system according to any one of claims 1 to 3 3, wherein the a narrow directional antenna and integrated. The service communication processing unit, the road-vehicle communication system according to any one of claims 1 to 3 3, wherein the a narrow directional antenna and integrated. The base station includes vehicle type specifying means for specifying the vehicle type of the vehicle, and the directivity control means for the vehicle based on the vehicle position and vehicle type specified by the vehicle position specifying means and the vehicle type specifying means. 36. The road-to-vehicle communication system according to any one of claims 1 to 35 , wherein directivity of the narrow directional antenna is controlled so as to be able to communicate with a vehicle-mounted terminal mounted. The vehicle position specifying means has a function of detecting the presence or absence of a vehicle at the identifiable position and transmitting a position symbol indicating the identifiable position;
The road-to-vehicle communication system according to claim 36 , wherein the in-vehicle terminal has a function of receiving the position symbol transmitted by the vehicle position specifying means and generating a user identification symbol using the position symbol. . The road-vehicle communication system according to any one of claims 1 to 37 , further comprising a file server capable of communicating with the base station. And the narrow directional antenna with a narrow directivity,
Vehicle position specifying means for specifying the position of the vehicle;
The vehicle position specifying means based on the position of the vehicle has identified, and a directional control means for controlling the directivity of the narrow directivity antenna to communicate with the vehicle terminal of the vehicle,
The narrow directional antenna is a linearly polarized antenna,
The narrow directional antenna is installed inclined downward from a horizontal plane,
The angle formed between the polarization of the narrow directional antenna and the linear polarization of the in-vehicle antenna of the in-vehicle terminal becomes closer to a right angle as the distance between the base station and the in-vehicle antenna is smaller. is controlled to be close to flat row as the distance between the antenna is large,
The base station, wherein the narrow directional antenna is installed so that an angle formed by a polarization with respect to the vehicle-mounted antenna is a right angle in an arrangement in which the base station exists in front of the vehicle. The base station according to claim 39 , wherein the directivity control means controls the directivity of the antenna so that it can communicate with only one communication terminal of the vehicle at a time. A vehicle type specifying means for specifying the vehicle type of the vehicle;
The directivity control means controls the directivity of the antenna so as to communicate with the communication terminal of the vehicle based on the position and vehicle type of the vehicle specified by the vehicle position specifying means and the vehicle type specifying means. the base station according to claim 39 or 4 0 to.

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