JP2019041354A - Terminal device, roadside device, communication system, and position acquisition method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To move oneself without being confused with the position information of another moving body in the terminal device when transmitting the position information of the moving body acquired by using a radar to a terminal device held by the moving body. Allows the body position information to be acquired from the roadside device. SOLUTION: A roadside machine 5 detects a moving body on a road by a radar 51, acquires the position information of the moving body, and detects a message including the position information of the moving body by a radar from a communication antenna 55. When a terminal device receives a plurality of messages transmitted from the communication antennas of two roadside units by transmitting with a transmission beam whose transmission direction is limited in the direction in which the moving object exists, the position information included in the messages is transmitted by the own device. It is acquired as the position information of. [Selection diagram] Fig. 2

Description

  The present invention relates to a terminal device held by a mobile body, a roadside device installed on a road, a communication system including the terminal device and the roadside device, and a position for acquiring position information of the mobile body holding the terminal device from the roadside device. It relates to the acquisition method.

  In recent years, studies for practical application and spread of a safe driving assistance wireless system using ITS (Intelligent Transport System) have been underway. In this safe driving support wireless system, vehicle-to-vehicle communication that communicates between in-vehicle terminals mounted on a vehicle, or road-to-vehicle communication that communicates between a roadside unit installed on a road and the in-vehicle terminal, Messages including location information are exchanged to alert the vehicle driver to avoid accidents.

  In recent years, in order to prevent pedestrian accidents, inter-pedal communication has been proposed in which communication is performed between a pedestrian terminal carried by a pedestrian and an in-vehicle terminal. In this inter-vehicle communication, the pedestrian terminal and the in-vehicle terminal directly exchange messages including position information, etc. to notify the in-vehicle terminal of the presence of the pedestrian and notify the pedestrian terminal of the presence of the vehicle. Since it is possible to alert both the pedestrian and the driver of the vehicle at an appropriate timing, a great effect is expected in preventing a pedestrian accident.

  In such inter-pedestrian communication, the pedestrian terminal and the in-vehicle terminal acquire the position information of the pedestrian and the vehicle using a satellite positioning system such as GPS, and the position information is transmitted between the pedestrian terminal and the in-vehicle terminal. The risk determination (collision determination) for determining the necessity of alerting is performed based on the position information. However, the position information obtained by the satellite positioning system may have a large error, and this position information error may cause an erroneous determination in the risk determination. Therefore, a technology that compensates for the decrease in accuracy of position information by the satellite positioning system is desired.

  In addition, the size of the satellite positioning antenna is small in the pedestrian terminal to ensure portability, and there are various ways to carry it, such as putting it in the pocket of clothes or storing it in the back, Since the pedestrian walks in the vicinity of the building at the end of the road, satellite positioning is greatly affected by the building, and the degree of freedom of movement is high, so that the positional information error is larger than that of the in-vehicle terminal. For this reason, it is desired to improve the accuracy of pedestrian location information.

  As a technology to compensate for the degradation of position information accuracy by such a satellite positioning system, conventionally, based on the position information of other terminals that perform short-range wireless communication with its own device, and the communication area range of short-range wireless communication, A technique for estimating the position of its own device is known (see Patent Document 1).

JP 2005-223436 A

  Now, as in the prior art, by acquiring information useful for specifying the position of the own apparatus from another apparatus, it is possible to acquire highly accurate position information. For example, in a so-called infrastructure radar equipped with a radar that detects pedestrians and vehicles existing on the road in the roadside machine, it is possible to acquire highly accurate position information about pedestrians and vehicles existing in the vicinity. It is conceivable to provide position information by radar to a pedestrian terminal.

  However, since there is no information for associating the pedestrian detected by the radar with the pedestrian terminal possessed by the pedestrian, if there are other pedestrian terminals around the pedestrian terminal, There is a problem that it cannot be determined whether or not the position information received from the roadside device is related to the own device.

  Therefore, the present invention obtains position information of a moving body on a road using a radar, and transmits the position information to a terminal apparatus held by the moving body. It is a main object to provide a terminal device, a roadside device, a communication system, and a position acquisition method that can acquire the position information of its own mobile body without being confused with the position information.

  The terminal device of the present invention is a terminal device held by a mobile body, installed on a road, from a roadside device that detects a mobile body on the road by object detection and acquires position information of the mobile body, Transmitted by a transmission beam limited to the direction in which the moving object exists from a communication unit that receives a message including position information of the moving object and a plurality of communication antennas provided apart from each other in one or more of the roadside devices. When the communication unit receives a plurality of messages to be received, the control unit acquires position information included in the message as position information of the own device.

  The roadside device of the present invention is a roadside device installed on a road, and includes an object detection unit that detects a moving body on the road, a communication unit that communicates with a terminal device held by the moving body, There is a moving object obtained by acquiring position information of the moving object based on the measurement result of the object detecting unit and detecting a message including the position information of the moving object from the communication antenna of the communication unit by the object detecting unit. And a control unit that transmits by a transmission beam limited to a direction.

  The communication system of the present invention is a communication system including a terminal device held by a moving body and a roadside device installed on a road, wherein the roadside device detects an object on a road. Based on the measurement result of the detection unit, the communication unit that communicates with the terminal device, and the object detection unit, the position information of the moving body is acquired, and a message including the position information of the moving body is sent to the communication unit A control unit that transmits from a communication antenna using a transmission beam limited to a direction in which the moving object detected by the object detection unit exists, and the terminal device transmits a message including position information of the moving object to the roadside device. When the communication unit receives a plurality of messages transmitted from a plurality of communication antennas provided separately from each other in one or a plurality of the roadside devices, The position information contained in the message as a constituent and a control unit for acquiring as a position information of the own device.

  Further, the position acquisition method of the present invention is a position acquisition method in which a terminal device held by a moving body acquires position information of its own moving body from a roadside device installed on a road. Detecting a moving body on the road by object detection to acquire the position information of the moving body, and transmitting a message including the position information of the moving body from the communication antenna to the direction in which the detected moving body exists When the terminal apparatus receives a plurality of the messages transmitted from the plurality of communication antennas provided apart from each other in one or a plurality of the roadside apparatuses, the message is transmitted to the message. It is assumed that the included position information is acquired as the position information of the own device.

  According to the present invention, since a plurality of transmission beams that transmit a message including position information of a mobile body intersect at the position of the mobile body, when the terminal device can receive a plurality of messages, The plurality of messages can be determined as including the positional information of the mobile object that holds the message. Thereby, in a terminal device, the position information of the mobile body holding itself can be acquired without being confused with the position information of other mobile bodies.

1 is an overall configuration diagram of a communication system according to a first embodiment. Explanatory drawing which shows the condition of the transmission beam at the time of transmitting the message containing the positional information on a pedestrian from the roadside machine 5 which concerns on 1st Embodiment. The block diagram which shows schematic structure of the roadside machine 5 which concerns on 1st Embodiment. The block diagram which shows schematic structure of the pedestrian terminal 1 which concerns on 1st Embodiment. The flowchart which shows the operation | movement procedure of the roadside machine 5 and pedestrian terminal 1 which concern on 1st Embodiment. Explanatory drawing which shows the division area which concerns on 2nd Embodiment. Explanatory drawing which shows the condition of the transmission beam at the time of transmitting the message containing the positional information on a pedestrian from the roadside machine 5 which concerns on 3rd Embodiment. Explanatory drawing which shows the condition of the transmission beam at the time of transmitting the message containing the positional information on a pedestrian from the roadside machine 5 which concerns on 4th Embodiment. Explanatory drawing which shows the condition of the transmission beam at the time of transmitting the message containing the positional information on a pedestrian from the roadside machine 5 which concerns on 5th Embodiment.

  A first invention made to solve the above-described problem is a terminal device held by a moving body, which is installed on a road, detects the moving body on the road by object detection, and the position of the moving body There is a moving body from a communication unit that receives a message including position information of a moving body from a roadside apparatus that acquires information and a plurality of communication antennas that are provided apart from each other in one or more of the roadside apparatuses. When the communication unit receives a plurality of messages transmitted by a transmission beam limited to a direction, the control unit acquires position information included in the message as position information of the own device.

  According to this, since a plurality of transmission beams that transmit a message including the position information of the mobile body intersect at the position of the mobile body, when the terminal device can receive a plurality of messages, It can be determined that the message includes the position information of the mobile unit. Thereby, in the terminal device, the position information of its own mobile body can be acquired without being confused with the position information of other mobile bodies.

  In addition, according to a second aspect of the present invention, when the position information of the moving body included in the plurality of messages matches, the control unit selects the position information included in the message as the position information of the own device. .

  According to this, it is possible to accurately determine whether or not the position information received from the roadside device relates to the own device.

  In addition, according to a third aspect of the present invention, when the position information of the moving body included in the plurality of messages matches and the position information is acquired during the same period, The included position information is selected as the position information of the own device.

  According to this, it is possible to accurately determine whether or not the position information received from the roadside device relates to the own device.

  A fourth invention is a roadside device installed on a road, the object detecting unit detecting a moving body on the road, the communication unit communicating with a terminal device held by the moving body, and the object The direction in which the moving body exists by acquiring the position information of the moving body based on the measurement result of the detecting section and detecting the message including the moving body position information from the communication antenna of the communication section by the object detecting section. And a control unit for transmitting by a transmission beam limited to the above.

  According to this, similarly to the first invention, the terminal device can acquire the position information of its own mobile body without being confused with the position information of other mobile bodies.

  Moreover, 5th invention sets it as the structure which the said control part transmits the message containing the positional information on the said mobile body synchronizing with the other roadside apparatus which can detect the same mobile body.

  According to this, the terminal device can quickly acquire highly accurate position information measured by the roadside device.

  Moreover, 6th invention sets it as the structure which controls the direction of the transmission beam at the time of the said control part at the time of transmitting the message containing the positional information on the said mobile body up and down.

  According to this, even when there is a gradient on the road, a transmission beam for transmitting a message including the position information of the moving body can surely reach the terminal device.

  Moreover, 7th invention sets it as the structure by which the said some communication antenna was provided in the state spaced apart in the horizontal direction.

  According to this, it is possible to cross a plurality of transmission beams that transmit messages including the position information of the moving object at the position of the moving object that is the target of the position information.

  Moreover, 8th invention is set as the structure by which the said some communication antenna was provided in the state spaced apart in the perpendicular direction.

  According to this, it is possible to cross a plurality of transmission beams that transmit messages including the position information of the moving object at the position of the moving object that is the target of the position information.

  The ninth invention is a communication system comprising a terminal device held by a moving body and a roadside device installed on a road, wherein the roadside device detects an object on a road. A communication unit that communicates with the terminal device, and a position information of the mobile body based on a measurement result of the object detection unit, and a message including the position information of the mobile body is transmitted to the communication unit A control unit configured to transmit from an antenna using a transmission beam limited to a direction in which the moving object detected by the object detection unit exists, and the terminal device sends a message including the position information of the moving object from the roadside device. When the communication unit receives the plurality of messages transmitted from the plurality of communication antennas provided apart from each other in the communication unit to receive and the one or more roadside devices, the message is received. The position information contained in a configuration and a control unit for acquiring as a position information of the own device.

  According to this, similarly to the first invention, the terminal device can acquire the position information of its own mobile body without being confused with the position information of other mobile bodies.

  The tenth invention is a position acquisition method in which a terminal device held by a moving body acquires position information of its own moving body from a roadside device installed on a road, wherein the roadside device is an object. The mobile body on the road is detected to detect the position information of the mobile body, and the transmission direction of the message including the position information of the mobile body is limited from the communication antenna to the direction in which the detected mobile body exists. When the terminal device receives a plurality of the messages transmitted from the plurality of communication antennas provided apart from each other in one or a plurality of the roadside devices, the position included in the message is transmitted by a transmission beam The information is acquired as the position information of the own device.

  According to this, similarly to the first invention, the terminal device can acquire the position information of its own mobile body without being confused with the position information of other mobile bodies.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is an overall configuration diagram of a communication system according to the first embodiment.

  This communication system includes a pedestrian terminal 1 (terminal device) and a portable information terminal 2 carried by a pedestrian (moving body), an in-vehicle terminal 3 (terminal device) and a car navigation device 4 mounted on a vehicle (moving body). And the roadside machine 5 (roadside apparatus) is provided, and communication between walks is performed between the pedestrian terminal 1 and the vehicle-mounted terminal 3. FIG.

  In inter-walk communication, a message including required information such as position information is transmitted and received between the pedestrian terminal 1 and the in-vehicle terminal 3. This inter-vehicle communication uses ITS wireless communication, that is, a frequency band (for example, 700 MHz band or 5.8 GHz band) adopted in a safe driving support wireless system using ITS (Intelligent Transport System). Send and receive messages via wireless communication.

  In this embodiment, in addition to inter-vehicle communication, road-to-step communication for transmitting and receiving messages between the roadside device 5 and the pedestrian terminal 1, and messages between the roadside device 5 and the in-vehicle terminal 3 are transmitted and received. Road-to-vehicle communication is performed, and this road-to-vehicle communication and road-to-vehicle communication is ITS wireless communication similar to inter-vehicle communication, and messages transmitted and received in inter-vehicle communication, road-to-vehicle communication, and road-to-vehicle communication are , Based on common specifications (data structure).

  The pedestrian terminal 1 is connected to the portable information terminal 2. The portable information terminal 2 is a smartphone, a mobile phone, a tablet terminal, a wearable terminal, or the like. In the pedestrian terminal 1, when it is determined that an alert is required by transmitting / receiving a message to / from the in-vehicle terminal 3, an instruction to alert is output to the portable information terminal 2. In the portable information terminal 2, the pedestrian terminal In response to an instruction from 1, an output operation for alerting a pedestrian (for example, voice output or vibration) is performed.

  The in-vehicle terminal 3 is connected to the car navigation device 4. This car navigation device 4 provides route guidance to the driver. When the in-vehicle terminal 3 transmits / receives a message to / from the pedestrian terminal 1 and determines that attention is required, the in-vehicle terminal 3 outputs an instruction to call attention to the car navigation device 4. In response to an instruction from, an output operation for alerting the driver (for example, voice output or screen display) is performed.

  The pedestrian terminal 1 may be built in the portable information terminal 2, and the in-vehicle terminal 3 may be built in the car navigation device 4.

  Alternatively, the pedestrian terminal 1 itself may perform a warning output operation. Further, the in-vehicle terminal 3 itself may perform a warning output operation. Further, the in-vehicle terminal 3 may communicate with the portable information terminal 2 possessed by the driver so that the portable information terminal 2 performs an output operation for alerting the driver.

  Next, the outline | summary of operation | movement of the roadside machine 5 which concerns on 1st Embodiment, and the pedestrian terminal 1 is demonstrated. FIG. 2 is an explanatory diagram illustrating a state of a transmission beam when a message including position information of a pedestrian is transmitted from the roadside device 5.

  Two roadside machines 5 are installed at diagonal positions of the intersection.

  The roadside machine 5 includes a radar 51. The radar 51 detects a pedestrian on the road and measures the direction in which the pedestrian exists and the distance to the pedestrian. The roadside machine 5 converts the relative position information (azimuth and distance) of the pedestrian acquired by the radar 51 into absolute position information (latitude and longitude) of the pedestrian based on the position information of the own device. .

  Further, the roadside machine 5 includes a communication antenna 55. A message including the absolute position information of the pedestrian is transmitted from the communication antenna 55. In particular, the communication antenna 55 has directivity that restricts the transmission direction by narrowing down the transmission beam so that the transmission beam is formed in the direction in which the pedestrian is present based on the measurement result of the radar 51. The direction of the transmit beam is controlled.

  Thereby, the transmission beams of the communication antennas 55 of the two roadside devices 5 intersect at the position where the pedestrian that is the target of the position information included in the message exists, and the pedestrian terminal 1 possessed by the pedestrian has 2 Messages transmitted from the two roadside devices 5 can be received.

  When the pedestrian terminal 1 receives a message from the two roadside devices 5, the position information included in the message is selected as the position information of the own device.

  Here, if another pedestrian that is different from the pedestrian that is the target of the position information included in the message accidentally exists in the transmission beam range when the message is transmitted, the pedestrian possessed by the other pedestrian The terminal 1 receives a message including position information of another pedestrian. Moreover, in this pedestrian terminal 1 of another pedestrian, the message containing the positional information used as the object is also received. For this reason, it is not possible to determine whether or not the position information included in the message is related to the own device only by receiving the message from the two roadside devices 5.

  Therefore, in this embodiment, it is determined whether or not the position information included in the two messages from the two roadside devices 5 matches, and the position information included in the two messages is included in the message. The position information is selected as the position information of the own device.

  Next, a schematic configuration of the roadside machine 5 according to the first embodiment will be described. FIG. 3 is a block diagram showing a schematic configuration of the roadside machine 5.

  The roadside machine 5 includes a radar (object detection unit) 51, an ITS communication unit 52, a control unit 53, and a storage unit 54.

  The radar 51 detects a pedestrian existing on the road by radiating a radio wave and detecting the reflected wave, and measures the direction in which the pedestrian exists and the distance to the pedestrian.

  In addition to searching for omnidirectional pedestrians by rotating the radar beam 360 degrees in the radar 51, there are pedestrians based on the position information of the pedestrians included in the message received from the pedestrian terminal 1. You may make it search for a pedestrian limited to a range.

  The ITS communication unit 52 transmits / receives a message to / from the pedestrian terminal 1 by ITS communication (road-to-walk communication), and transmits / receives a message to / from the in-vehicle terminal 3 by ITS communication (road-to-vehicle communication).

  The ITS communication unit 52 includes a communication antenna 55. The communication antenna 55 is an adaptive array or a sector antenna, and has directivity that limits the transmission direction by narrowing the transmission beam. Thereby, a message can be transmitted only to the pedestrian terminal 1 located in a specific direction.

  The storage unit 54 stores a program executed by the processor that constitutes the control unit 53.

  The control unit 53 includes a position information conversion unit 61, a transmission direction control unit 62, and a message control unit 63. The control unit 53 is configured by a processor, and each unit of the control unit 53 is realized by executing a program stored in the storage unit 54 by the processor.

  The position information conversion unit 61 uses the relative position information (azimuth and distance) of the pedestrian acquired by the radar 51 based on the position information of the own device stored in the storage unit 54 as the absolute position of the pedestrian. Convert to information (latitude and longitude).

  Based on the position information (azimuth) of the pedestrian acquired by the radar 51, the transmission direction control unit 62 forms a transmission beam when transmitting a message in the direction in which the pedestrian detected by the radar 51 exists. Thus, the direction of the transmission beam is controlled.

  The message control unit 63 transmits a message including the absolute position information of the pedestrian acquired by the position information conversion unit 61 from the ITS communication unit 52 to the pedestrian terminal 1.

  In addition to the pedestrian location information, the message includes the roadside machine ID of the device itself, time information (detection time, etc.), etc., and the pedestrian terminal 1 is based on the roadside machine ID included in the message. Thus, it is possible to determine the roadside device 5 that is the transmission source of the message, and it is possible to determine the period during which the position information included in the message is acquired based on the time information.

  Next, a schematic configuration of the pedestrian terminal 1 according to the first embodiment will be described. FIG. 4 is a block diagram illustrating a schematic configuration of the pedestrian terminal 1.

  The pedestrian terminal 1 includes a positioning unit 11, an ITS communication unit 12, an input / output unit 13, a control unit 14, and a storage unit 15.

  The positioning unit 11 measures the position of the own apparatus using a satellite positioning system such as GPS (Global Positioning System), QZSS (Quasi-Zenith Satellite System), and acquires position information of the own apparatus. In addition, you may make it acquire the positional information on an own apparatus using the positioning function which the portable information terminal 2 has.

  The ITS communication unit 12 transmits / receives a message to / from the roadside machine 5 by ITS communication (road-to-step communication), and transmits / receives a message to / from the in-vehicle terminal 3 by ITS communication (step-to-step communication).

  The input / output unit 13 performs input / output of information with the portable information terminal 2. Based on the information output from the input / output unit 13, the mobile information terminal 2 performs a warning operation for a pedestrian.

  The storage unit 15 stores map information, a program executed by a processor constituting the control unit 14, and the like. The map information may be acquired from the portable information terminal 2.

  The control unit 14 includes a message control unit 21, a position information selection unit 22, a collision determination unit 23, and an alerting control unit 24. This control part 14 is comprised with a processor, and each part of the control part 14 is implement | achieved by running the program memorize | stored in the memory | storage part 15 with a processor.

  The message control unit 21 controls transmission of a message including pedestrian information such as terminal ID and position information. That is, when transmitting pedestrian information, the message containing pedestrian information is produced | generated and the message is transmitted to the vehicle-mounted terminal 3 from the ITS communication part 12. FIG.

  When the position information selection part 22 receives the message containing the pedestrian's position information from the two roadside devices 5, whether the position information contained in the two messages respectively received from the two roadside devices 5 is the same. Determine whether. Further, based on the time information included in the two messages, it is determined whether or not the position information included in the two messages is acquired during the same period. When the position information included in the two messages is the same and the position information included in the two messages is acquired during the same period, the same position information included in the two messages is obtained. Select as the location information of the pedestrian.

  The position information included in the two messages only needs to match within the measurement error range.

  On the other hand, when the message containing the location information of the pedestrian is not received from the two roadside devices 5, the location information contained in the two messages is not the same, or the location information contained in the two messages is acquired in the same period If not, the position information acquired by the positioning unit 11 is selected as the position information of the pedestrian.

  The collision determination unit 23 determines whether or not there is a risk of the vehicle colliding with the own pedestrian based on the selected position information of the own pedestrian and the position information of the vehicle included in the message received from the in-vehicle terminal 3. Determine.

  The alerting control unit 24 alerts the pedestrian according to the determination result of the collision determination unit 23. In the present embodiment, an instruction for alerting is output to the portable information terminal 2 via the input / output unit 13, and an output operation for alerting a pedestrian in the portable information terminal 2 in accordance with this instruction (for example, voice output) And vibration).

  In addition, when selecting the position information included in the message received from the roadside machine 5 as the position information of the own pedestrian, the past position information is obtained for the time required for processing and communication in the roadside machine 5, and therefore the own pedestrian If the moving speed of is high, the error becomes large. Therefore, the position information of the pedestrian may be corrected according to the moving speed of the pedestrian.

  Next, the operation procedure of the roadside machine 5 and the pedestrian terminal 1 according to the first embodiment will be described. FIG. 5 is a flowchart showing the operation procedure of the roadside machine 5 and the pedestrian terminal 1.

  As shown in FIG. 5A, in the roadside machine 5, first, the radar 51 acquires relative position information (azimuth and distance) of pedestrians present on the road (ST101). Then, in the position information conversion unit 61, based on the position information of the own device stored in the storage unit 54, the pedestrian's absolute position is obtained from the relative position information (azimuth and distance) acquired by the radar 51. The position information (latitude and longitude) is acquired (ST102).

  Next, in the transmission direction control unit 62, based on the relative position information (azimuth) of the pedestrian acquired by the radar 51, the transmission beam of the communication antenna 55 is formed in the direction in which the pedestrian exists. The direction of the transmission beam of communication antenna 55 is controlled (ST103). Then, the message control unit 63 transmits a message including the position information of the pedestrian from the ITS communication unit 52 to the pedestrian terminal 1 (ST104).

  In addition, the operation | movement procedure shown to FIG. 5 (A) is the same with the two roadside machines 5. FIG.

  As shown in FIG. 5 (B), in the pedestrian terminal 1, first, when the ITS communication unit 12 receives a message including the position information of the pedestrian from the two roadside devices 5 (Yes in ST201), the position information selection unit 22, it is determined whether or not the positional information included in the two messages received from the two roadside devices 5 is the same (ST202).

  Here, when the location information included in the two messages is the same (Yes in ST202), the location information included in the two messages is the same based on the time information included in the two messages. It is determined whether or not it is acquired during the period (ST203).

  Here, when the position information included in the two messages is acquired during the same period (Yes in ST203), the same position information included in the two messages is selected as the position information of the own pedestrian. (ST204).

  Then, when the ITS communication unit 12 receives a message transmitted from the in-vehicle terminal 3 (Yes in ST206), the collision determination unit 23 then includes the vehicle position information included in the message from the in-vehicle terminal 3 and the self-walking. Based on the position information of the person, a collision determination is made as to whether or not there is a risk of the vehicle colliding with the pedestrian (ST207). And it is determined in the alerting control part 24 whether alerting with respect to a pedestrian is required based on the determination result of the collision determination part 23 (ST208).

  Here, when it is necessary to alert the pedestrian (Yes in ST208), alerting the pedestrian is performed (ST209).

  On the other hand, when the message containing the location information of the pedestrian is not received from the two roadside devices 5 (No in ST201), or the location information included in the two messages is not the same (No in ST202), the two messages When the included position information is not acquired during the same period (No in ST203), the position information acquired by the positioning unit 11 is selected as the position information of the own pedestrian (ST205). And it progresses to the process after ST206.

  Moreover, when the message transmitted from the vehicle-mounted terminal 3 is not received (No in ST206), or when alerting a pedestrian is not necessary (No in ST208), the process ends without performing any particular processing.

  In the present embodiment, the description has been given of the point where the radar 51 detects the pedestrian and provides the pedestrian terminal 1 with the position information of the pedestrian. However, the radar 51 detects the vehicle on the road and detects the position of the vehicle. May be provided to the pedestrian terminal 1 together with the position information of the pedestrian. Thereby, in the pedestrian terminal 1, a highly accurate collision determination can be performed.

  In this case, as in the case of a pedestrian, the azimuth in which the vehicle exists and the distance to the vehicle are measured by the radar 51, and the relative position information (azimuth and distance) of the vehicle is obtained from the roadside machine 5. The absolute position information (latitude and longitude) is used to convert the vehicle into absolute position information (latitude and longitude), and a message including the absolute position information of the vehicle is transmitted to the pedestrian terminal 1. .

  Further, the vehicle position information measured using the radar 51 in the roadside device 5 may be provided to the in-vehicle terminal 3. In this case, the in-vehicle terminal 3 may have the same configuration as the pedestrian terminal 1 shown in FIG. 4, and the operation procedure of the in-vehicle terminal 3 is also shown in FIG. 5 by replacing the pedestrian with a vehicle. This is the same as the case of the pedestrian terminal 1.

  Alternatively, the radar 51 may detect a pedestrian and provide the pedestrian's position information to the in-vehicle terminal 3 together with the position information of the vehicle. Thereby, the vehicle-mounted terminal 3 can perform highly accurate collision determination.

(Second Embodiment)
Next, a second embodiment will be described. Note that points not particularly mentioned here are the same as in the above embodiment.

  In the first embodiment, the two roadside devices 5 independently transmit a message including the position information of the pedestrian acquired from the measurement result of the radar 51. However, in the present embodiment, the two roadside devices 5 Cooperate to transmit a message including the location information of the pedestrian. That is, the control information regarding the transmission timing is exchanged between the two roadside devices 5, and the two roadside devices 5 synchronize and transmit a message including the position information of the pedestrian.

  When the pedestrian terminal 1 receives two messages transmitted from the two roadside devices 5 within a predetermined time, when the position information included in the two messages is the same, the position information included in the message is automatically acquired. Determined to be related to the device.

  As a result, the timing at which the message including the pedestrian's position information is transmitted from the two roadside devices 5 largely deviates, and it takes a long time to determine whether the position information included in the message is related to the own device. Thus, the pedestrian terminal 1 can quickly acquire position information with high accuracy measured by the roadside device 5.

  In addition, in the pedestrian terminal 1, when two messages are received within the predetermined time, the two messages are likely to include the same position information regarding the pedestrian. For this reason, it may be determined that the message includes the position information of the own pedestrian only by receiving the two messages within a predetermined time. In this case, the position information of the pedestrian included in the two messages is The determination of whether or not they match can be omitted.

  In addition, the exchange of control information related to transmission timing may be performed by ITS communication (roadside communication) between the roadside devices 5. That is, a message including control information is transmitted from the ITS communication unit 52 provided in the roadside device 5 to another roadside device 5.

  Further, the roadside device 5 may be provided with a network communication unit to exchange control information via a network such as the Internet. Also, a management server that manages the transmission timings of the two roadside devices 5 may be provided, and the management server may instruct the transmission timings to the two roadside devices 5 via the network.

  Next, the divided areas according to the second embodiment will be described. FIG. 6 is an explanatory diagram showing divided areas.

  In the present embodiment, when the two roadside devices 5 transmit a message including pedestrian position information in synchronization, the direction of the transmission beam is controlled in units of divided areas obtained by dividing the target area into a plurality of areas. That is, based on the position information of the pedestrian, a divided area where the target pedestrian is located is acquired, and the direction of the transmission beam is controlled so that the transmission beam reaches the divided area. Thereby, the transmission beams of the two roadside devices 5 intersect in the range of the divided area where the target pedestrian is located, and the message transmitted from the two roadside devices 5 can be received by the pedestrian terminal 1. .

  Moreover, in this embodiment, when a plurality of pedestrians are detected simultaneously by the radar 51 of the roadside machine 5, messages including pedestrian position information based on the measurement results of the radar 51 are sequentially transmitted. Send the message according to the specified priority.

  Here, when the owner of the pedestrian terminal 1 rides a bicycle or a motorcycle and the movement speed of the pedestrian is fast, the danger level is high and it is desirable to promptly notify the pedestrian's position information. It is. Therefore, in the present embodiment, when a plurality of pedestrians are detected at the same time by the radar 51, the message including the position information of the pedestrian having a high moving speed is given priority over the message including the position information of the pedestrian having a low moving speed. Send first.

  Further, when notifying the pedestrian terminal 1 of the position information of the pedestrian and notifying the in-vehicle terminal 3 of the position information of the vehicle, the vehicle is faster than the pedestrian and has a higher risk. It is desirable to notify information quickly. Therefore, when the radar 51 detects the pedestrian and the vehicle at the same time, the message including the position information of the vehicle is transmitted prior to the message including the position information of the pedestrian.

  Moreover, in the pedestrian terminal 1, the precision of the positional information by a satellite positioning system becomes low compared with the vehicle-mounted terminal 3. Therefore, a message including pedestrian position information may be transmitted prior to a message including vehicle position information.

(Third embodiment)
Next, a third embodiment will be described. Note that points not particularly mentioned here are the same as in the above embodiment. FIG. 7 is an explanatory diagram illustrating a state of a transmission beam when a message including position information of a pedestrian is transmitted from the roadside device 5 according to the third embodiment.

  When there is a gradient on the road, the positional relationship between the pedestrian and the roadside machine 5 changes according to the gradient of the road. Therefore, the roadside machine 5 simply controls the direction of the transmission beam of the communication antenna 55 two-dimensionally. The transmitted beam may not reach the pedestrian terminal 1 in some cases.

  Therefore, in this embodiment, the direction of the transmission beam is controlled three-dimensionally. That is, in addition to controlling the direction of the transmission beam around the vertical axis, the direction of the transmission beam is controlled around the horizontal axis (up and down). Thereby, even when there is a slope on the road, the transmission beam of the roadside machine 5 can surely reach the pedestrian terminal 1.

  For example, an intersection with an uphill as shown in FIG. 7B and an intersection with a downhill as shown in FIG. 7C are compared with a flat intersection as shown in FIG. 7A. Then, in one roadside machine 5, the direction of the transmission beam is changed to the upper side, and in the other roadside machine 5, the direction of the transmission beam is changed to the lower side.

  7 shows the state of the transmission beam of the communication antenna 55, the same applies to the radar beam of the radar 51. FIG. That is, when there is a slope on the road, the radar beam may not reach the pedestrian and the radar 51 may not be able to detect the pedestrian on the road only by controlling the direction of the radar beam two-dimensionally.

  Therefore, in this embodiment, the direction of the radar beam is controlled three-dimensionally. That is, in addition to controlling the direction of the transmission beam around the vertical axis, the direction of the radar beam is controlled around the horizontal axis (up and down). Thereby, even when there is a slope on the road, the radar beam can surely reach the pedestrian terminal 1 and the detection failure of the radar 51 can be prevented.

(Fourth embodiment)
Next, a fourth embodiment will be described. Note that points not particularly mentioned here are the same as in the above embodiment. FIG. 8 is an explanatory diagram illustrating a state of a transmission beam when a message including position information of a pedestrian is transmitted from the roadside device 5 according to the fourth embodiment.

  In the first embodiment (see FIG. 2), two roadside machines 5 are installed at diagonal positions of the intersection. However, in this embodiment, one roadside machine 5 is installed, and the one roadside machine 5 is installed. Two communication antennas 55 are provided. The two communication antennas 55 are arranged in a state of being separated in the horizontal direction, and two transmission beams having different transmission directions are formed by the two communication antennas 55.

  Even in such a configuration, only the pedestrian terminal 1 located in an area where two transmission beams intersect can receive a message transmitted from the two communication antennas 55.

  In the present embodiment, the two communication antennas 55 are arranged apart from each other in the horizontal direction, but a configuration in which one communication antenna 55 moves in the horizontal direction may be adopted. In this case, the direction of the transmission beam of the communication antenna 55 may be controlled at two positions separated in the horizontal direction so that the two transmission beams intersect at the position of the pedestrian.

(Fifth embodiment)
Next, a fifth embodiment will be described. Note that points not particularly mentioned here are the same as in the above embodiment. FIG. 9 is an explanatory diagram illustrating a state of a transmission beam when a message including position information of a pedestrian is transmitted from the roadside device 5 according to the fifth embodiment.

  In the fourth embodiment (see FIG. 8), the two communication antennas 55 are spaced apart in the horizontal direction, but in the present embodiment, the two communication antennas 55 are spaced apart in the vertical direction. The roadside machine 5 controls the directions of the transmission beams of the two communication antennas 55 so that the transmission beams of the two communication antennas 55 intersect at the position of the pedestrian.

  For example, in the case of an intersection with a downhill, a message from one roadside machine 5 may not reach the pedestrian terminal 1 because the transmission beam of one roadside machine 5 is blocked by the road surface of the road. In this case, two transmission beams can be crossed at the position of the pedestrian by arranging the two communication antennas 55 apart from each other in the vertical direction as in this embodiment.

  In the present embodiment, the two communication antennas 55 are arranged apart from each other in the vertical direction, but one communication antenna 55 may be moved in the vertical direction. In this case, the direction of the transmission beam of the communication antenna 55 may be controlled at two positions separated in the vertical direction so that the two transmission beams intersect at the position of the pedestrian.

  By the way, in the above-mentioned embodiment, since only one roadside machine 5 cannot detect all the surrounding pedestrians at the intersection of the crossroads, the two roadside machines 5 are installed in the diagonal direction. In some cases, all the surrounding pedestrians can be detected by only one roadside machine 5 like the intersection of. In this case, a message including pedestrian location information is transmitted to the pedestrian terminal 1 by only one roadside device 5.

  For example, when there is only one pedestrian in the range of the transmission beam of the communication antenna 55, the pedestrian terminal 1 is not confused with the position information of other pedestrians. A message including the position information of the pedestrian is transmitted to the pedestrian terminal 1.

  In addition to the measured position information of the pedestrian, a message including the position information of the roadside machine 5 and information on the distance from the roadside machine 5 to the pedestrian is transmitted from the roadside machine 5 to the pedestrian terminal 1. In the pedestrian terminal 1, the distance from the roadside machine 5 to the own pedestrian is calculated from the position information of the own apparatus and the position information of the roadside machine 5, and the distance measured by the roadside machine 5 and the pedestrian terminal 1 are calculated. By comparing with the distance calculated in step S5, it is determined whether or not the position information of the pedestrian acquired from the roadside machine 5 is the position information of the own pedestrian. In this case, when the difference between the distance measured by the roadside device 5 and the distance calculated by the pedestrian terminal 1 falls within a predetermined error range, the position information of the pedestrian acquired from the roadside device 5 is Select as the location information of the pedestrian.

  In addition, when there is no other pedestrian in front of the pedestrian whose position information is targeted, the range of the transmission beam is controlled by transmission power so that the transmission beam reaches the measured pedestrian position. Thus, only the pedestrian terminal 1 possessed by the pedestrian that is the target of the position information can receive a message including the position information of the pedestrian.

  As described above, the embodiments have been described as examples of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can be applied to embodiments in which changes, replacements, additions, omissions, and the like have been performed. Moreover, it is also possible to combine each component demonstrated by said embodiment into a new embodiment.

  For example, in the above-described embodiment, the mobile body (pedestrian or vehicle) on the road is detected by the radar and the relative position information (direction and distance) of the mobile body is acquired. The object detection means for detecting the moving body is not limited to the radar, and may be a stereo camera, for example, and can detect the moving body on the road from an image taken by the stereo camera.

  A terminal device, a roadside device, a communication system, and a position acquisition method according to the present invention acquire position information of a moving object on a road using a radar, and store the position information in a terminal apparatus held by the moving object. When transmitting, the terminal device has the effect of being able to acquire the position information of its own mobile body without being confused with the position information of another mobile body, and is held by the mobile body, road It is useful as a roadside device installed in a terminal, a communication system including a terminal device and a roadside device, and a position acquisition method in which the terminal device acquires position information of its own mobile unit from the roadside device.

1 Pedestrian terminal (terminal equipment)
3 In-vehicle terminal (terminal equipment)
5 Roadside machines (roadside equipment)
11 Positioning unit 12 ITS communication unit 14 Control unit 51 Radar (object detection unit)
52 ITS Communication Unit 53 Control Unit 55 Communication Antenna

Claims (10)

A terminal device held by a mobile body,
A communication unit that is installed on a road and receives a message including the position information of the moving body from a roadside device that detects the moving body on the road by object detection and acquires the position information of the moving body;
When the communication unit receives a plurality of messages transmitted by a transmission beam limited to a direction in which a moving object exists from a plurality of communication antennas provided apart from each other in one or a plurality of the roadside devices, A control unit for acquiring the position information included in the message as the position information of the own device;
A terminal device comprising:   The said control part selects the positional information contained in the message as positional information of an own apparatus, when the positional information on the mobile body contained in the said several message corresponds. Terminal device.   When the position information of the mobile body included in the plurality of messages matches and the position information is acquired during the same period, the control unit obtains the position information included in the message of the own device. The terminal device according to claim 2, wherein the terminal device is selected as position information. A roadside device installed on a road,
An object detection unit for detecting moving objects on the road;
A communication unit that communicates with a terminal device held by a mobile body;
Based on the measurement result of the object detection unit, there is a moving object obtained by acquiring the position information of the moving object and detecting a message including the position information of the moving object from the communication antenna of the communication unit by the object detection unit. A control unit that transmits by a transmission beam limited to a direction to perform,
A roadside device comprising:   5. The roadside device according to claim 4, wherein the control unit transmits a message including position information of the moving body in synchronization with another roadside device capable of detecting the same moving body.   The roadside device according to claim 4, wherein the control unit controls the direction of a transmission beam when transmitting a message including position information of the moving body up and down.   The roadside device according to claim 4, wherein the plurality of communication antennas are provided in a state of being separated in the horizontal direction.   The roadside device according to claim 4, wherein the plurality of communication antennas are provided in a state of being separated in the vertical direction. A communication system comprising a terminal device held by a mobile body and a roadside device installed on a road,
The roadside device is
An object detection unit for detecting moving objects on the road;
A communication unit for communicating with the terminal device;
Based on the measurement result of the object detection unit, there is a moving object obtained by acquiring the position information of the moving object and detecting a message including the position information of the moving object from the communication antenna of the communication unit by the object detection unit. A control unit that transmits by a transmission beam limited to a direction to perform,
With
The terminal device
A communication unit that receives a message including the position information of the mobile body from the roadside device;
When the communication unit receives a plurality of the messages transmitted from the plurality of communication antennas provided apart from each other in one or a plurality of the roadside devices, the position information included in the messages is converted into the position information of the own device. A control unit to obtain as
A communication system comprising: A terminal device held by a mobile body is a position acquisition method for acquiring position information of its mobile body from a roadside device installed on a road,
The roadside device is
Detecting moving objects on the road by object detection to acquire the position information of moving objects,
A message including the position information of the moving body is transmitted from the communication antenna by a transmission beam whose transmission direction is limited to the direction in which the detected moving body exists,
The terminal device is
When receiving a plurality of the messages transmitted from a plurality of the communication antennas spaced apart from each other in one or a plurality of the roadside devices, the location information included in the messages is acquired as the location information of the own device. A position acquisition method characterized by.

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