JP2017107463A - Pedestrian terminal device, communication system, and pedestrian location acquisition method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow improvement of accuracy of location information on a pedestrian at a low cost.SOLUTION: A pedestrian terminal device comprises: a communication unit 12 that wirelessly communicates with an on-vehicle terminal device 3; and a control unit 14. The communication unit is configured to receive location information to be transmitted from the on-vehicle terminal device, and the control unit is configured to: select at least two on-vehicle terminal devices from among the on-vehicle terminal device having the location information received as a reference point; and acquire location information on a self on-vehicle terminal device by a reference point surveying method on the basis of the location information on the on-vehicle terminal device serving as the reference point. Specifically, the control unit is configured to: acquire a distance between the two devices serving as the reference point on the basis of the location information on the two devices serving as the reference point; acquire a distance between each of the two devices serving as the reference point and the self device from an electric wave arrival time of a radio wave signal to be transmitted to the self device from each of the two devices serving as the reference point; and acquire the location information on the self device by a trilateration surveying method on the basis of the distances.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a pedestrian terminal device that is carried by a pedestrian and performs wireless communication with at least one of an in-vehicle terminal device and a roadside device, and between the pedestrian terminal device and at least one of the in-vehicle terminal device and the roadside device. The present invention relates to a communication system for performing wireless communication and a pedestrian position acquisition method for acquiring pedestrian position information in a pedestrian terminal device possessed by a pedestrian.

  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 radio system, vehicle-to-vehicle communication that communicates between in-vehicle terminal devices mounted on a vehicle, or road-to-vehicle communication that communicates between a roadside device installed on a road and an in-vehicle terminal device, Vehicle position information is communicated to alert the vehicle driver to avoid accidents.

  In recent years, in order to prevent a pedestrian accident, inter-pedal communication has been proposed in which communication is performed between a pedestrian terminal device carried by a pedestrian and an in-vehicle terminal device. In this pedestrian-to-vehicle communication, the pedestrian terminal device and the vehicle-mounted terminal device can communicate with each other directly, so that both pedestrians and vehicle drivers can be alerted at appropriate timing. A great effect is expected to prevent accidents.

  In such inter-pedestrian communication, in the pedestrian terminal device and the in-vehicle terminal device, the position information of the pedestrian and the vehicle is acquired using a satellite positioning system such as GPS, and the position information is obtained from the pedestrian terminal device and the in-vehicle terminal. By exchanging with the device, the risk 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.

  Conventionally, as a technology to compensate for the degradation of position information accuracy by such satellite positioning systems, index objects such as road signs and landmarks have been detected by sensors such as radar and cameras, and the position of the detected index object is detected here. A technique for correcting the position information of a vehicle by calculating the amount of position deviation from the position of the index object in the map information is known (see Patent Document 1).

JP 2012-211843 A

  However, in the conventional technique, the accuracy of the position information is increased with reference to the index object appearing on the map. Therefore, when there is no appropriate index object in the vicinity, the accuracy of the position information is increased. There is a problem that can not be. Such a problem can be solved by creating detailed map information including the position information of a large number of index objects, but this requires enormous costs, and a technique for improving the accuracy of position information at a low cost is required. desired.

  In addition, the size of the satellite positioning antenna is small in order to ensure portability of the pedestrian terminal device, and there are various ways to carry it, such as putting it in a pocket of clothes or storing it in the back. Because pedestrians walk 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. Become. For this reason, it is desired to improve the accuracy of pedestrian location information.

  The present invention has been devised to solve such problems of the prior art, and its main purpose is to improve the accuracy of pedestrian location information at low cost. Another object is to provide a pedestrian terminal device, a communication system, and a pedestrian position acquisition method.

  The pedestrian terminal device of the present invention is a pedestrian terminal device that a pedestrian possesses and performs wireless communication with at least one of an in-vehicle terminal device and a roadside device, and a communication unit that performs the wireless communication; A control unit, wherein the communication unit receives position information transmitted from at least one of the in-vehicle terminal device and the roadside device, and the control unit receives the position information and the in-vehicle terminal device At least two devices are selected as reference points from the roadside devices, and the position information of the own device is acquired by the reference point surveying method based on the position information of the device serving as the reference point.

  The communication system of the present invention is a communication system that performs wireless communication between a pedestrian terminal device and at least one of an in-vehicle terminal device and a roadside device, wherein the in-vehicle terminal device and the roadside device are the wireless A communication unit that performs communication, the communication unit transmits position information of the device itself to the pedestrian terminal device, and the pedestrian terminal device includes a communication unit that performs the wireless communication; and a control unit. The communication unit receives the position information transmitted from at least one of the in-vehicle terminal device and the roadside device, and the control unit is configured to receive the position information from the in-vehicle terminal device and the roadside device. Therefore, at least two devices are selected as reference points, and the position information of the own device is obtained by the reference point surveying method based on the position information of the device serving as the reference point.

  The pedestrian position acquisition method of the present invention is a pedestrian position acquisition method for acquiring pedestrian position information in a pedestrian terminal device possessed by a pedestrian, and is at least one of an in-vehicle terminal device and a roadside device. And receives at least two devices as reference points from the in-vehicle terminal device and the roadside device that have received the position information, and uses the position information of the device as the reference point. It is set as the structure which acquires the pedestrian's positional information by the reference point survey method based on it.

  According to the present invention, the position information of the in-vehicle terminal device and the roadside device is highly accurate, and the position information of the pedestrian terminal device is acquired based on the position information of the in-vehicle terminal device and the roadside device. The accuracy of the position information can be improved. Moreover, since the vehicle-mounted terminal device of the vehicle stopped and traveling on the road or the roadside device installed on the road may be set as the reference point, the accuracy of the position information of the pedestrian can be improved at low cost. .

1 is an overall configuration diagram of a communication system according to a first embodiment. Explanatory drawing which shows the outline | summary of the process which acquires the positional information on the pedestrian terminal device 1. The block diagram which shows schematic structure of the pedestrian terminal device 1 The block diagram which shows schematic structure of the vehicle-mounted terminal device 3 The flowchart which shows the procedure of the process performed with the pedestrian terminal device 1 and the vehicle-mounted terminal device 3 Explanatory drawing which shows the outline | summary of the communication system which concerns on 2nd Embodiment. The flowchart which shows the procedure of the process performed with the pedestrian terminal device 1 and the vehicle-mounted terminal device 3 Explanatory drawing which shows the outline | summary of the communication system which concerns on 3rd Embodiment. Explanatory drawing which shows the outline | summary of the communication system which concerns on 4th Embodiment.

  A first invention made to solve the above-mentioned problem is a pedestrian terminal device possessed by a pedestrian and performing wireless communication with at least one of an in-vehicle terminal device and a roadside device, wherein the wireless communication A communication unit that performs communication, and a control unit, wherein the communication unit receives position information transmitted from at least one of the in-vehicle terminal device and the roadside device, and the control unit receives the position information. A configuration in which at least two devices are selected as reference points from the in-vehicle terminal device and the roadside device, and the position information of the own device is acquired by the reference point survey method based on the position information of the device serving as the reference point And

  According to this, the position information of the pedestrian terminal device is obtained because the position information of the in-vehicle terminal device and the roadside device is highly accurate, and the position information of the pedestrian terminal device is acquired based on the position information of the in-vehicle terminal device and roadside device. Accuracy can be improved. Moreover, since the vehicle-mounted terminal device of the vehicle stopped and traveling on the road or the roadside device installed on the road may be set as the reference point, the accuracy of the position information of the pedestrian can be improved at low cost. .

  In the second aspect of the invention, the control unit obtains a first distance between two reference point devices based on position information of the two reference point devices, and two The second and third distances between each of the devices serving as the reference points and the own device are acquired, and based on the first, second and third distances, the own device is determined by the trilateration method. The position information is acquired.

  According to this, the position information of the pedestrian terminal device can be obtained with high accuracy by the trilateral survey method.

  According to a third aspect of the present invention, the control unit calculates a radio wave arrival time from a transmission time and a reception time of a radio signal transmitted from each of the two reference point devices to the own device, and the radio wave arrival time. The radio wave arrival distance is calculated by multiplying time by the radio wave velocity, and the radio wave arrival distance is acquired as the second and third distances.

  According to this, it is possible to obtain the second and third distances, that is, the distance between each of the devices serving as the two reference points and the pedestrian terminal device with high accuracy.

  In addition, according to a fourth aspect of the present invention, the communication unit receives measurement result information about at least one of a distance and an angle that defines a relative position of a pedestrian with respect to the vehicle, acquired by a measurement device mounted on the vehicle. The said control part is set as the structure which acquires the positional information on an own apparatus by the said reference point survey method based on the said measurement result information.

  According to this, the position information of the pedestrian terminal device can be obtained with high accuracy by the trilateral survey method or the triangulation method.

  The fifth invention is a pedestrian terminal device possessed by a pedestrian and performing wireless communication with at least one of the in-vehicle terminal device and the roadside device, the communication unit performing the wireless communication, and a control And the communication unit receives position information transmitted from at least one of the in-vehicle terminal device and the roadside device, and uses at least one of the in-vehicle terminal device and the roadside device as a reference point. The position information transmitted from another pedestrian terminal device that has acquired the position information of the own device by the reference point surveying method is received, and the control unit is configured to receive the in-vehicle terminal device, the roadside device, and the another pedestrian terminal. A configuration in which at least two devices are selected as reference points from among the devices, and the position information of the own device is obtained by a reference point survey method based on the position information of the device serving as the reference point; That.

  According to this, the position information of the in-vehicle terminal device and the roadside device is highly accurate, and the position information of another pedestrian terminal device acquired based on the position information of the in-vehicle terminal device and the roadside device is also highly accurate. By acquiring the position information of the pedestrian terminal device based on these highly accurate position information, the accuracy of the position information of the pedestrian terminal device can be improved.

  Moreover, 6th invention represents having acquired the positional information by the reference point survey method in the positional information transmitted from the said another pedestrian terminal device which acquired the positional information of the own apparatus by the reference point survey method. The configuration includes information.

  According to this, it can be easily identified that the position information transmitted from another pedestrian terminal device is acquired by the reference point survey method.

  Moreover, 7th invention is a communication system which performs radio | wireless communication between a pedestrian terminal device and at least any one of a vehicle-mounted terminal device and a roadside device, Comprising: The said vehicle-mounted terminal device and the said roadside device are said radio | wireless communication. The communication unit transmits position information of the device itself to the pedestrian terminal device, and the pedestrian terminal device includes a communication unit that performs the wireless communication, and a control unit. The communication unit receives the position information transmitted from at least one of the in-vehicle terminal device and the roadside device, and the control unit is selected from among the in-vehicle terminal device and the roadside device that have received the position information. At least two devices are selected as reference points, and the position information of the own device is obtained by the reference point surveying method based on the position information of the device serving as the reference point.

  According to this, like the first invention, the accuracy of the position information of the pedestrian can be improved at low cost.

  The eighth invention is a pedestrian position acquisition method for acquiring position information of a pedestrian in a pedestrian terminal device possessed by a pedestrian, and is transmitted from at least one of an in-vehicle terminal device and a roadside device. Reference point surveying based on the positional information of the device that receives position information, selects at least two devices as reference points from the in-vehicle terminal device and the roadside device that have received the position information It is set as the structure which acquires the pedestrian's positional information by a method.

  According to this, like the first invention, the accuracy of the position information of the pedestrian can be improved at low cost.

  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 device 1 and a portable information terminal device 2 possessed by a pedestrian, and an in-vehicle terminal device 3 and a car navigation device 4 mounted on the vehicle.

  The pedestrian terminal device 1 includes a positioning function for acquiring position information of the own device and a communication function for performing inter-pedestrian communication with the in-vehicle terminal device 3, and the pedestrian acquired by these functions and Based on the position of the vehicle, the traveling direction, the moving speed, and the like, a risk determination is performed to determine whether or not the vehicle is likely to collide with a pedestrian carrying the device.

  The portable information terminal device 2 is a smartphone, a mobile phone, a tablet terminal, a wearable terminal, or the like. The pedestrian terminal device 1 and the portable information terminal device 2 are connected to each other. When the pedestrian terminal device 1 determines that the possibility of a collision is high, a warning is given to the pedestrian for avoiding an accident. The portable information terminal device 2 is caused to perform an output operation (for example, voice output or vibration). Note that the pedestrian terminal device 1 itself may perform a warning output operation.

  The in-vehicle terminal device 3 includes a positioning function for acquiring position information of the own device and a communication function for performing inter-pedestrian communication with the pedestrian terminal device 1, and the pedestrian acquired by these functions and Based on the position of the vehicle, the traveling direction, the moving speed, and the like, risk determination is performed to determine whether or not the vehicle on which the device is mounted is likely to collide with a pedestrian.

  The car navigation device 4 provides route guidance to the driver. The in-vehicle terminal device 3 and the car navigation device 4 are connected to each other, and when the in-vehicle terminal device 3 determines that the possibility of a collision is high, an output operation for alerting the driver to avoid an accident ( For example, the car navigation device 4 is made to perform voice output or screen display. The in-vehicle terminal device 3 itself may perform a warning output operation.

  Note that the in-vehicle terminal device 3 may be connected to the portable information terminal device 2 possessed by the driver and cause the portable information terminal device 2 to perform an output operation such as alerting the driver.

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

  In this communication system, information such as the position, traveling direction, and moving speed of pedestrians and vehicles necessary for risk determination is exchanged between the pedestrian terminal device 1 and the in-vehicle terminal device 3, Information exchange is performed by inter-pedal communication using a frequency band (for example, 700 MHz band or 5.8 GHz band) adopted in a safe driving support radio system using ITS (Intelligent Transport System).

  In this inter-walk communication, messages are transmitted and received between the pedestrian terminal device 1 and the in-vehicle terminal device 3. The message transmitted from the pedestrian terminal device 1 includes identification information (terminal ID, MAC address, etc.) of the pedestrian terminal device 1 in addition to the location information of the pedestrian. The message transmitted from the in-vehicle terminal device 3 includes identification information (terminal ID, MAC address, etc.) of the in-vehicle terminal device 3 in addition to the vehicle position information. In addition, the message transmitted from the pedestrian terminal device 1 includes information on the traveling direction and the moving speed of the pedestrian acquired by a sensor (not shown) provided in the pedestrian terminal device 1 or the portable information terminal device 2. included. The message transmitted from the in-vehicle terminal device 3 includes information on the traveling direction and the moving speed of the vehicle acquired by a sensor (not shown) provided in the in-vehicle terminal device 3 or the car navigation device 4.

  Next, an outline of processing for acquiring position information of the pedestrian terminal device 1 will be described. FIG. 2 is an explanatory diagram showing an outline of processing for acquiring position information of the pedestrian terminal device 1.

  The pedestrian terminal device 1 and the in-vehicle terminal device 3 acquire position information of the own device by a satellite positioning system such as GPS (Global Positioning System), QZSS (Quasi-Zenith Satellite System), or GLONASS (Global Navigation Satellite System).

  Here, in the pedestrian terminal device 1, the size of the satellite positioning antenna is small in order to ensure portability, and there are various ways to carry it, such as putting it in a pocket of clothes or storing it in the back. In addition, 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 since the degree of freedom of movement is high, the horizontal error of the position information is large, for example, It is about 5m.

  On the other hand, in the in-vehicle terminal device 3, the size of the satellite positioning antenna is large, it is possible to perform highly accurate and stable positioning, and since the vehicle travels on the roadway away from the building, the satellite positioning is In addition, since the vehicle travels along the road lane, the accuracy of the position information can be increased by correction by map matching. Therefore, the horizontal error of the position information is small, for example, 1 m. It will be about.

  Therefore, in the present embodiment, the position information of the pedestrian terminal device 1 is acquired with reference to the in-vehicle terminal device 3 with high position information accuracy. That is, the relative positional relationship between the in-vehicle terminal device 3 and the pedestrian terminal device 1 is acquired, and the pedestrian terminal device is based on the positional relationship and the positional information acquired by satellite positioning in the in-vehicle terminal device 3. 1 position information is acquired. Thereby, the position information of the pedestrian terminal device 1 can be acquired with the same accuracy as the in-vehicle terminal device 3.

  In particular, in this embodiment, as shown in FIGS. 2A and 2B, the position of the pedestrian terminal device 1 is the measurement point MP, and the positions of the in-vehicle terminal devices 3 of the two vehicles V1 and V2 are the reference points RP1. , RP2, the position of the pedestrian terminal device 1 that is the measurement point MP is obtained by the triangulation method. That is, the lengths L1, L2, L3 of the three sides of the triangle constituted by the measurement point MP and the two reference points RP1, RP2 are obtained, and the lengths L1, L2, L3 of the three sides and the two reference points are obtained. The position of the measurement point MP is obtained from the positions of RP1 and RP2.

  Here, among the lengths L1, L2, and L3 of the three sides of the triangle, the length (first distance) L1 of one side connecting the two reference points RP1 and RP2, that is, between the two in-vehicle terminal devices 3 Is obtained from position information acquired by satellite positioning with the in-vehicle terminal device 3. Also, the lengths (second and third distances) L2 and L3 of two sides connecting each of the two reference points RP1 and RP2 and the measurement point MP, that is, each of the two in-vehicle terminal devices 3 and the pedestrian. The distance to the terminal device 1 is obtained from the radio wave arrival time of the message signal transmitted from each of the in-vehicle terminal devices 3 to the pedestrian terminal device 1 by inter-walk communication.

  At this time, the in-vehicle terminal device 3 transmits the message with transmission time information (time stamp), and the pedestrian terminal device 1 acquires the reception time at the timing when the message is received. Then, the radio wave arrival time is calculated from the transmission time and the reception time of the message, and the radio wave arrival time is calculated by multiplying the radio wave arrival time, that is, each of the two in-vehicle terminal devices 3 and the pedestrian terminal device 1. The distance between is calculated.

  In this way, when the position of the pedestrian terminal device 1 is obtained by the trilateral surveying method, two candidate points CP are obtained at positions that are symmetric with respect to a straight line connecting the two reference points RP1, RP2, and this Of the two candidate points CP, the one closer to the position obtained by satellite positioning with the pedestrian terminal device 1 may be selected.

  Here, when selecting the two in-vehicle terminal devices 3 serving as the reference points RP1 and RP2, the in-vehicle terminal device 3 of the parked vehicle is preferentially selected, and there are no two parked vehicles. May select the in-vehicle terminal device 3 of the running vehicle. Note that when the vehicle is traveling, the error in radio wave arrival time becomes large. However, the error in position information due to this is small compared to the error in position information due to satellite positioning, and there is no practical problem.

  Next, a schematic configuration of the pedestrian terminal device 1 will be described. FIG. 3 is a block diagram illustrating a schematic configuration of the pedestrian terminal device 1.

  The pedestrian terminal device 1 includes a satellite positioning unit (position information acquisition unit) 11, a communication unit 12, an input / output unit 13, a control unit 14, an information storage unit 15, and a clock 16.

  The satellite positioning unit 11 acquires position information of its own device by a satellite positioning system such as GPS, QZSS, or GLONASS. In addition, you may make it acquire the positional information on an own apparatus using the positioning function which the portable information terminal device 2 has.

  The communication unit 12 transmits and receives messages to and from the in-vehicle terminal device 3 by inter-vehicle communication. In this inter-vehicle communication, wireless communication is performed using the frequency band adopted in the safe driving support wireless system using ITS.

  The input / output unit 13 inputs / outputs information to / from the portable information terminal device 2. Based on the information output from the input / output unit 13, the portable information terminal device 2 performs an output operation for alerting a pedestrian or the like.

  The information storage unit 15 stores map information and a program executed by the control unit 14. The map information is automatically updated according to the user's operation and at a predetermined timing. The update information of the map information may be downloaded from the server using the communication function of the portable information terminal device 2 in addition to using an appropriate storage medium. In addition, you may make it acquire map information from the portable information terminal device 2. FIG.

  The clock 16 outputs the current time. Based on the output time of the timepiece 16, the communication unit 12 acquires the reception time at the timing when the message transmitted from the in-vehicle terminal device 3 is received.

  The control unit 14 includes a reference point surveying unit 21, a map matching processing unit 22, and a risk determination unit 23. The control unit 14 includes a processor, and each unit of the control unit 14 is realized by causing the processor to execute a program stored in the information storage unit 15.

  The reference point surveying unit 21 obtains the position of the pedestrian terminal device 1 by the trilateral survey method based on the position information of the in-vehicle terminal device 3 included in the message received by the communication unit 12. The danger determination unit 23 determines whether or not it is necessary to call attention based on the position, moving speed, traveling direction, and the like of the pedestrian and the vehicle, that is, whether or not the vehicle is likely to collide with the pedestrian. .

  The reference point surveying unit 21 includes a reference point setting unit 25, a three-side distance measuring unit 26, a position calculating unit 27, and a position determining unit 28.

  The reference point setting unit 25 sets the in-vehicle terminal device 3 serving as two reference points by the trilateral survey method from the in-vehicle terminal device 3 that has received the message by the communication unit 12. In this process, the in-vehicle terminal device 3 of the stopped vehicle is preferentially selected, and when there are no two stopped vehicles, the in-vehicle terminal device 3 of the traveling vehicle is selected, and at this time, the speed is The vehicle-mounted terminal device 3 for a low vehicle is preferentially selected.

  The three-side distance measuring unit 26 obtains the distance between the two in-vehicle terminal devices 3 serving as a reference point based on the position information of the in-vehicle terminal device 3 included in the message received by the communication unit 12. Further, the radio wave arrival time is calculated based on the transmission time included in the message and the reception time acquired by the communication unit 12, and the radio wave arrival time is multiplied by the radio wave speed, that is, 2 The distance between each of the two in-vehicle terminal devices 3 and its own device is calculated.

  In the position calculation unit 27, the position information of the in-vehicle terminal device 3 included in the message received by the communication unit 12, the distance between the two in-vehicle terminal devices 3 acquired by the three-side distance measurement unit 26, and the two in-vehicle units Based on the distance between each of the terminal devices 3 and the own device, the position of the own device is calculated using the cosine theorem and the Pythagorean theorem. Here, the positions of two candidate points are obtained as the position of the own device.

  The position determination unit 28 determines the position of the own apparatus from the two candidate points calculated as the position of the own apparatus by the position calculation unit 27 based on the position information acquired by the satellite positioning unit 11.

  The map matching processing unit 22 corrects the position information acquired by the reference point surveying unit 21 by map matching based on the map information stored in the information storage unit 15. The map matching processing unit 22 performs processing for matching the position of a pedestrian to map information on the basis of the positions and moving directions of a plurality of vehicles. At this time, the reference line for map matching is not necessary, and the flow direction of a plurality of vehicles can be used as the reference line.

  Next, a schematic configuration of the in-vehicle terminal device 3 will be described. FIG. 4 is a block diagram illustrating a schematic configuration of the in-vehicle terminal device 3.

  The in-vehicle terminal device 3 includes a satellite positioning unit (position information acquisition unit) 31, a communication unit 32, an input / output unit 33, a control unit 34, an information storage unit 35, and a clock 36.

  Similarly to the satellite positioning unit 11 of the pedestrian terminal device 1, the satellite positioning unit 31 acquires the position information of the own device by the satellite positioning system. In addition, you may make it acquire the positional information on an own apparatus using the positioning function which the car navigation apparatus 4 has.

  The communication unit 32 transmits and receives messages to and from the pedestrian terminal device 1 by inter-walk communication. In this inter-vehicle communication, similarly to the communication unit 12 of the pedestrian terminal device 1, wireless communication is performed using the frequency band adopted in the safe driving support wireless system using ITS.

  The input / output unit 33 inputs / outputs information to / from the car navigation device 4. Based on the information output from the input / output unit 33, the car navigation device 4 performs an output operation for alerting the driver.

  The information storage unit 35 stores map information and programs executed by the control unit 34. The map information is automatically updated according to the user's operation and at a predetermined timing. The update information of the map information may be downloaded from the server using the communication function of the in-vehicle terminal device 3 and the car navigation device 4 in addition to using an appropriate storage medium. The map information may be acquired from the car navigation device 4.

  The clock 36 outputs the current time. Based on the output time of the clock 36, the communication unit 32 acquires the transmission time at the timing of transmitting the message, and transmits the message with the transmission time information (time stamp) added thereto.

  The control unit 34 includes a danger determination unit 41. The control unit 34 is configured by a processor, and the risk determination unit 41 is realized by causing the processor to execute a program stored in the information storage unit 35. The risk determination unit 41 determines whether or not it is necessary to call attention based on the position, moving speed, traveling direction, and the like of the pedestrian and the vehicle, that is, whether or not the vehicle is likely to collide with the pedestrian. .

  Next, the procedure of the process performed by the pedestrian terminal device 1 and the vehicle-mounted terminal device 3 will be described. FIG. 5 is a flowchart showing a procedure of processes performed in the pedestrian terminal device 1 and the in-vehicle terminal device 3.

  In the in-vehicle terminal device 3 serving as the reference point, first, the satellite positioning unit 31 acquires the position information of the own device (ST101). Then, in communication unit 32, a message is transmitted by inter-step communication (ST102). This message includes the position information of the own device acquired by the satellite positioning unit 31 and transmission time information (time stamp) based on the output time of the clock 36.

  In the pedestrian terminal device 1, first, the communication unit 12 receives a message transmitted from the in-vehicle terminal device 3 (ST201). At this time, the reception time information of the message is acquired based on the output time of the clock 16.

  Next, in the reference point setting unit 25, two in-vehicle terminal devices 3 serving as reference points are selected from the in-vehicle terminal devices 3 that have received the message (ST202). At this time, the in-vehicle terminal device 3 of the parked vehicle is preferentially selected, and if there are no two parked vehicles, the in-vehicle terminal device 3 of the traveling vehicle is selected, and the vehicle having a low speed is selected. The vehicle-mounted terminal device 3 may be preferentially selected. Moreover, when there are three or more vehicles as selection candidates, the in-vehicle terminal devices 3 of two vehicles close to the own device may be selected.

  Next, the three-side distance measuring unit 26 calculates the distance between the two in-vehicle terminal devices 3 from the position information acquired from the two in-vehicle terminal devices 3 serving as reference points (ST203). Further, the radio wave arrival time is calculated from the transmission time and reception time of each message of the two in-vehicle terminal devices 3 serving as the reference points (ST204), and the radio wave arrival time is calculated by multiplying the radio wave arrival time by the radio wave speed. That is, the distance between each of the two in-vehicle terminal devices 3 and its own device is calculated (ST205).

  Next, in the position calculation unit 27, the distance between the two in-vehicle terminal devices 3 serving as a reference point acquired by the three-side distance measuring unit 26, and the distance between each of the two in-vehicle terminal devices 3 and the own device. Based on the distance, the position of the device itself is calculated (ST206).

  Next, the satellite positioning unit 11 acquires the position information of the own device (ST207). Then, in the position determination unit 28, based on the position information acquired by the satellite positioning unit 11, from the two candidate points (CP in FIG. 2B) calculated by the position calculation unit 27 as the position of the own device. The position of the device itself is determined (ST208).

  The processing of the reference point surveying unit 21 may be performed all the time, or may be performed when entering an area where the accuracy of satellite positioning is reduced, such as a high-rise building street. In this case, it may be determined based on the map information that the vehicle has entered an area where the accuracy of satellite positioning is reduced.

  Moreover, in this embodiment, in order to obtain | require radio wave arrival time from the transmission time and reception time of the message transmitted from the vehicle-mounted terminal device 3 to the pedestrian terminal device 1, each clock 16 of the pedestrian terminal device 1 and the vehicle-mounted terminal device 3 is obtained. 36 and 36 need to be synchronized with high accuracy, the clocks 16 and 36 may be constituted by radio clocks, and the time information included in the signals from the satellites received by the satellite positioning units 11 and 31 is obtained. You may make it use.

  In the present embodiment, the pedestrian terminal device 1 acquires position information from each in-vehicle terminal device 3 and calculates the distance between the two in-vehicle terminal devices 3 based on the position information. At least one of the two in-vehicle terminal devices 3 obtains the position information of the other party through inter-vehicle communication, calculates the distance between the two in-vehicle terminal devices 3, and sends the distance information to the pedestrian terminal device 1. You may make it notify. The inter-vehicle communication is ITS wireless communication common to inter-vehicle communication, that is, wireless communication using a frequency band adopted in a safe driving support wireless system using ITS.

  Further, when there are three or more vehicles (in-vehicle terminal device 3) that are candidates for selection of the reference point, two vehicles are selected in a plurality of combinations, and the average of the position of the own device calculated in each combination is used. You may do it.

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

  FIG. 6 is an explanatory diagram showing an overview of a communication system according to the second embodiment.

  In the first embodiment, the position information of the pedestrian terminal device 1 is obtained by the reference point survey method using the two in-vehicle terminal devices 3 as reference points. In the second embodiment, the first embodiment and the first embodiment are obtained. Similarly, the next pedestrian terminal device 1 with the first pedestrian terminal device 1 that has acquired the position information by the reference point survey method using the in-vehicle terminal device 3 as a reference point and one in-vehicle terminal device 3 as a reference point. The position information of the next pedestrian terminal apparatus 1 is acquired using the two pedestrian terminal apparatuses 1 that have acquired the position information by the reference point survey method as reference points.

  In the example illustrated in FIG. 6, the pedestrian terminal devices 1 of the pedestrians P1 and P2 acquire position information using the in-vehicle terminal devices 3 of the two vehicles V1 and V2 as reference points. The pedestrian terminal device 1 of the pedestrian P3 acquires position information using the pedestrian terminal device 1 of the pedestrian P1 and the in-vehicle terminal device 3 of the vehicle V1 as reference points. The pedestrian terminal device 1 of the pedestrian P4 acquires position information using the pedestrian terminal devices 1 of the two pedestrians P1 and P3 as reference points. The pedestrian terminal device 1 of the pedestrian P5 acquires position information using the pedestrian terminal devices 1 of the two pedestrians P1 and P2 as reference points.

  As described above, a method of acquiring the position information of the next pedestrian terminal device 1 by the reference point surveying method using the in-vehicle terminal device 3 or the pedestrian terminal device 1 having acquired the position information by the reference point surveying method as a reference point. If the pedestrian terminal device 1 existing in a range where inter-pedal communication is possible is repeatedly performed, the newly acquired position information of the pedestrian terminal device 1 is based on the position information of the in-vehicle terminal device 3 with high accuracy. Since it is a thing, the precision of the positional information on the pedestrian terminal device 1 which exists in a belt can be improved as a whole.

  In this case, the in-vehicle terminal device 3 may be preferentially selected as the reference point. That is, when there are two or more in-vehicle terminal devices 3 that have received the message, the in-vehicle terminal device 3 is selected as a reference point. There is only one in-vehicle terminal device 3 that has received the message, and among the pedestrian terminal devices 1 that have received the message, there is at least one pedestrian terminal device 1 that has acquired position information by the reference point survey method. When it exists, the pedestrian terminal device 1 and the vehicle-mounted terminal device 3 are selected as a reference point. In addition, there is no on-vehicle terminal device 3 that has received the message, and at least two pedestrian terminal devices 1 that have acquired position information by the reference point survey method are among the pedestrian terminal devices 1 that have received the message. If there are two, the pedestrian terminal device 1 is selected as a reference point.

  In addition, in order to select the pedestrian terminal device 1 that has acquired the position information by the reference point survey method as a reference point, information indicating that the position information has been acquired by the reference point survey method is added to the message, and the pedestrian terminal device It is good to transmit from 1.

  Next, the procedure of the process performed by the pedestrian terminal device 1 and the vehicle-mounted terminal device 3 will be described. FIG. 7 is a flowchart showing a procedure of processes performed in the pedestrian terminal device 1 and the in-vehicle terminal device 3. Here, a case where another pedestrian terminal device 1 that has acquired position information by the reference point survey method and one in-vehicle terminal device 3 are set as reference points will be described.

  In the in-vehicle terminal device 3 serving as the reference point, the satellite positioning unit 31 acquires the position information of the own device (ST101). Then, in communication unit 32, a message is transmitted by inter-step communication (ST102). This message includes the position information of the own device acquired by the satellite positioning unit 31 and transmission time information (time stamp) based on the output time of the clock 36.

  Further, the pedestrian terminal device 1 serving as a reference point performs a positioning process by the reference point survey method according to the procedure shown in FIG. 5, and determines the position of the own device (ST208). Then, the communication unit 12 transmits a message by inter-vehicle communication (ST301). This message includes the position information of the own device acquired by the reference point survey method, information indicating that this position information has been acquired by the reference point survey method, and transmission time information (time stamp) based on the output time of the clock 16 It is included.

  On the other hand, in the pedestrian terminal device 1 on the side of acquiring position information, the communication unit 12 receives a message transmitted from the in-vehicle terminal device 3 (ST401), and is transmitted from another pedestrian terminal device 1. A message is received (ST402). At this time, the message reception time is acquired based on the output time of the clock 16.

  Next, in the reference point setting unit 25, the in-vehicle terminal device 3 that serves as a reference point and the pedestrian terminal that serves as a reference point from among the in-vehicle terminal device 3 that has received the message and another pedestrian terminal device 1 that has received the message. The device 1 is selected (ST403). At this time, when there are three or more in-vehicle terminal devices 3 and pedestrian terminal devices 1 that are candidates for the reference point, two devices close to the pedestrian terminal device 1 of the own device may be selected.

  Next, in the three-side distance measuring unit 26, the in-vehicle terminal device 3 serving as the reference point and the walking serving as the reference point from the position information acquired from the in-vehicle terminal device 3 serving as the reference point and the pedestrian terminal device 1 serving as the reference point. The distance to the person terminal device 1 is calculated (ST404). Further, the radio wave arrival time is calculated from the transmission time and reception time of each message of the in-vehicle terminal device 3 serving as the reference point and the pedestrian terminal device 1 serving as the reference point (ST405), and the radio wave velocity is calculated from the radio wave arrival time. By multiplying, the radio wave arrival distance, that is, the distance between each of the in-vehicle terminal device 3 serving as the reference point and the pedestrian terminal device 1 serving as the reference point and the own device is calculated (ST406).

  Next, in the position calculation unit 27, the distance between the in-vehicle terminal device 3 serving as the reference point and the pedestrian terminal device 1 serving as the reference point, acquired by the three-side distance measurement unit 26, and the in-vehicle terminal device 3 and the reference Based on the distance between each of the pedestrian terminal devices 1 serving as points and the own device, the position of the own device is calculated (ST407).

  Next, the satellite positioning unit 11 acquires the position information of its own device (ST408). Then, position determination section 28 determines the position of the own apparatus from the two candidate points calculated as the position of the own apparatus by position calculation section 27 based on the position information acquired by satellite positioning section 11 (ST409). ).

  In addition, although FIG. 7 demonstrated the case where another pedestrian terminal device 1 and the in-vehicle terminal device 3 that acquired the position information by the reference point survey method were set as reference points, the position information was acquired by the reference point survey method. When another two pedestrian terminal devices 1 are set as reference points, the in-vehicle terminal device 3 in FIG. 7 may be replaced with another pedestrian terminal device 1.

  When there are three or more in-vehicle terminal devices 3 and pedestrian terminal devices 1 that are candidates for the reference point, two devices are selected in a plurality of combinations, and the average of the position of the own device calculated in each combination is used. You may do it.

(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. 8 is an explanatory diagram showing an overview of a communication system according to the third embodiment.

  In the first embodiment, the position of the pedestrian terminal device 1 is obtained by the trilateral survey method, but in the third embodiment, the position of the pedestrian terminal device 1 is obtained by the triangulation method. That is, using the line segment connecting the two reference points RP1 and RP2 as a reference line, the length L1 of the reference line and the apex angles θ1 and θ2 at the two reference points RP1 and RP2 are obtained, and the reference line From the length L1 and the two apex angles θ1 and θ2, the position of the pedestrian terminal device 1 that is a measurement point is obtained.

  Each vehicle V1, V2 is equipped with a camera (measuring device) 51, and a pedestrian is imaged by the camera 51. The camera 51 detects a pedestrian in the captured image by using an image recognition technique such as person detection, obtains a direction in which the pedestrian exists, and apex angles θ1, θ2 based on the direction in which the pedestrian exists. Ask for.

  In this way, the measurement result information regarding the apex angles θ1 and θ2 obtained by each of the cameras 51 mounted on the two vehicles V1 and V2 is transmitted from each in-vehicle terminal device 3 to the pedestrian terminal device 1 for walking. In the pedestrian terminal device 1, the position of the pedestrian terminal device 1 is calculated | required by the triangulation method based on the measurement result information acquired from each vehicle-mounted terminal device 3. FIG. Note that the length L1 of the reference line may be obtained from the position information of each in-vehicle terminal device 3 as in the first embodiment.

  Next, a modification of the third embodiment will be described.

  In the third embodiment shown in FIG. 8, the apex angles θ <b> 1 and θ <b> 2 are obtained from the image captured by the camera 51, but from the image captured by the camera 51, 2 as in the first embodiment (see FIG. 2). The lengths L2 and L3 of two sides connecting each of the two reference points RP1 and RP2 and the measurement point MP, that is, the distance from each of the two vehicles V1 and V2 to the pedestrians P1 and P2, are measured. It is also possible to obtain the position of the pedestrian terminal device 1 by the edge survey method.

  Here, in order to calculate the distance from the image captured by the camera 51 to the pedestrian, a camera 51 provided with a distance image sensor such as a TOF (Time Of Flight) method or a stereo camera may be used.

  By the way, in 3rd Embodiment and its modification, the camera (measurement apparatus) 51 is mounted in a vehicle, and the angle and distance which prescribe | regulate the relative position of the pedestrian seen from the vehicle are measured from the captured image by the camera 51. However, it is also possible to mount a radar device (measuring device) on the vehicle and measure the angle and distance that define the relative position of the pedestrian as viewed from the vehicle. In this case, you may make it measure the distance between two vehicles used as a reference point with a radar apparatus.

  In addition, the position information acquired by the configuration according to the first embodiment is obtained based on the measurement result obtained by measuring the angle and the distance defining the relative position of the pedestrian by the measurement device such as the camera or the radar device mounted on the vehicle. You may make it correct | amend. If it does in this way, the precision of the positional information on the pedestrian terminal device 1 can be improved further.

(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. 9 is an explanatory diagram showing an overview of a communication system according to the fourth embodiment.

  In the first embodiment, two in-vehicle terminal devices 3 are selected as reference points. However, in this fourth embodiment, in addition to the in-vehicle terminal device 3, a roadside device 61 installed on a road is used as a reference point. Can be selected.

  The roadside device 61 holds the position information of the own device, transmits a message including the position information by road-to-vehicle communication, and receives a message transmitted from the roadside device 61 in the pedestrian terminal device 1. Further, the pedestrian terminal device 1 receives a message transmitted from the in-vehicle terminal device 3 by inter-vehicle communication. And in the pedestrian terminal device 1, the radio wave arrival distance calculated | required from the radio wave arrival time of a message is measured as a distance between each of the roadside device 61 and the vehicle-mounted terminal device 3, and the pedestrian terminal device 1, and three sides The position information of the pedestrian terminal device 1 is acquired by the surveying method.

  In the example shown in FIG. 9, the in-vehicle terminal device 3 and the roadside device 61 are selected one by one as reference points, but it is also possible to select two roadside devices 61 as reference points. Since the roadside device 61 is fixed, the radio wave arrival distance can be measured with high accuracy. Therefore, when selecting two devices as reference points, the roadside device 61 is preferentially selected, and the roadside device 61 is selected. If there are no two, the in-vehicle terminal device 3 may be selected.

  The road-to-vehicle communication is ITS wireless communication that is common to inter-vehicle communication and inter-vehicle communication, that is, wireless communication using a frequency band that is adopted in a safe driving support wireless system using ITS.

  In addition, selecting the roadside device 61 as a reference point as in this embodiment can be applied to the second embodiment. That is, the roadside device 61, the in-vehicle terminal device 3, and the pedestrian terminal device 1 that has acquired the position information by the reference point survey method are selected as two reference points, and the reference point survey method is used to select the next device. You may make it acquire the positional information on the pedestrian terminal device 1. FIG.

  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, an example in which position information is acquired by a pedestrian terminal device possessed by a pedestrian, that is, a person walking on a road, is described. A person riding in a vehicle such as an electric vehicle or an electric wheelchair may be included as a pedestrian in a broad sense.

  In the above-described embodiment, the example in which the horizontal position information is acquired as the position information of the pedestrian has been described. However, the position information in the height direction can also be acquired by the reference point surveying method. In addition, it is no longer necessary to provide a pedestrian terminal device with a barometric sensor for acquiring position information in the height direction, and by correcting the position information based on the barometric sensor with the position information acquired by the reference point survey method, The accuracy of position information in the height direction can be increased.

  Further, in the above-described embodiment, two devices as reference points are set and positioning is performed by the reference point surveying method. However, it is also possible to set three or more devices as reference points. Thereby, the precision of the positional information on a pedestrian terminal device can be improved. In this case, for example, the combination of two reference points selected from three or more reference points is changed, and positioning by the reference point surveying method is performed a plurality of times, and the positioning results are statistically processed (averaging, etc.) ) To find the position.

  In the above embodiment, the pedestrian terminal device acquires the position information of the pedestrian terminal device by the reference point survey method. However, the position information of the pedestrian terminal device is acquired by the reference point survey method. The positioning process may be performed by the in-vehicle terminal device, and the position information may be notified to the pedestrian terminal device.

  The pedestrian terminal device, the communication system, and the pedestrian position acquisition method according to the present invention have the effect of improving the accuracy of the pedestrian location information at low cost, and the pedestrian possesses the in-vehicle terminal device and A pedestrian terminal device that performs wireless communication with at least one of roadside devices, a communication system that performs wireless communication between a pedestrian terminal device and at least one of an in-vehicle terminal device and a roadside device, and a pedestrian's walking This is useful as a pedestrian position acquisition method for acquiring pedestrian position information in a pedestrian terminal device.

DESCRIPTION OF SYMBOLS 1 Pedestrian terminal device 3 In-vehicle terminal device 11 Satellite positioning part 12 Communication part 14 Control part 16 Clock 21 Reference point surveying part 25 Reference point setting part 26 Three side distance measurement part 27 Position calculation part 31 Satellite positioning part 32 Communication part 34 Control Part 36 Clock 51 Camera (measuring device)
61 Roadside device (measuring device)

Claims (8)

A pedestrian terminal device possessed by a pedestrian and performing wireless communication with at least one of an in-vehicle terminal device and a roadside device,
A communication unit for performing the wireless communication;
A control unit;
With
The communication unit receives position information transmitted from at least one of the in-vehicle terminal device and the roadside device,
The control unit selects at least two devices as reference points from the in-vehicle terminal device and the roadside device that have received the position information, and a reference point survey method based on the position information of the device serving as the reference point A pedestrian terminal device characterized by acquiring position information of the device itself.   The control unit obtains a first distance between two reference point devices based on position information of the two reference point devices, and each of the two reference point devices. The second and third distances between the device and the device are acquired, and the position information of the device is acquired by the trilateration method based on the first, second, and third distances. The pedestrian terminal device according to claim 1.   The control unit calculates a radio wave arrival time from a transmission time and a reception time of a radio wave signal transmitted from each of the two reference point devices to the own device, and multiplies the radio wave arrival time by a radio wave velocity to generate a radio wave. The pedestrian terminal device according to claim 2, wherein an arrival distance is calculated and the radio wave arrival distance is acquired as the second and third distances. The communication unit receives measurement result information regarding at least one of a distance and an angle that defines a relative position of a pedestrian with respect to the vehicle, acquired by a measurement device mounted on the vehicle,
The pedestrian terminal device according to claim 1, wherein the control unit acquires position information of the own device by the reference point survey method based on the measurement result information. A pedestrian terminal device possessed by a pedestrian and performing wireless communication with at least one of an in-vehicle terminal device and a roadside device,
A communication unit for performing the wireless communication;
A control unit;
With
The communication unit receives position information transmitted from at least one of the in-vehicle terminal device and the roadside device, and uses a reference point survey method using at least one of the in-vehicle terminal device and the roadside device as a reference point. Receive position information transmitted from another pedestrian terminal device that acquired the position information of its own device,
The control unit selects at least two devices as reference points from the in-vehicle terminal device, the roadside device, and the another pedestrian terminal device, and a reference point based on position information of the device serving as the reference point A pedestrian terminal device characterized by acquiring position information of its own device by a surveying method.   The position information transmitted from the other pedestrian terminal device that has acquired the position information of its own device by the reference point survey method includes information indicating that the position information has been acquired by the reference point survey method. The pedestrian terminal device according to claim 5. A communication system that performs wireless communication between a pedestrian terminal device and at least one of an in-vehicle terminal device and a roadside device,
The in-vehicle terminal device and the roadside device are:
A communication unit for performing the wireless communication;
This communication unit transmits the position information of its own device to the pedestrian terminal device,
The pedestrian terminal device
A communication unit for performing the wireless communication;
A control unit;
With
The communication unit of the pedestrian terminal device receives the position information transmitted from at least one of the in-vehicle terminal device and the roadside device,
The control unit selects at least two devices as reference points from the in-vehicle terminal device and the roadside device that have received the position information, and a reference point survey method based on the position information of the device serving as the reference point A communication system characterized in that the position information of the own device is acquired by the method. In a pedestrian terminal device possessed by a pedestrian, a pedestrian position acquisition method for acquiring pedestrian position information,
Receives position information transmitted from at least one of the in-vehicle terminal device and the roadside device,
The position of the pedestrian is determined by the reference point survey method based on the position information of the device serving as the reference point by selecting at least two devices as the reference points from the in-vehicle terminal device and the roadside device that have received the position information. A pedestrian location acquisition method characterized by acquiring information.

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