JP6739052B2 - Pedestrian terminal device, communication system, and pedestrian position acquisition method - Google Patents

Description

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

2. Description of the Related Art In recent years, studies have been conducted for practical application and spread of a safe driving support wireless system using ITS (Intelligent Transport System). In this safe driving assistance wireless system, vehicle-to-vehicle communication that communicates between vehicle-mounted terminal devices mounted on the vehicle, or road-vehicle communication that communicates between a roadside device and a vehicle-mounted terminal device installed on the road, Vehicle position information is communicated to alert the driver of the vehicle to avoid an accident.

In recent years, in order to prevent accidents of pedestrians, pedestrian-to-vehicle communication has been proposed in which communication is performed between a pedestrian terminal device carried by a pedestrian and a vehicle-mounted terminal device. In this pedestrian-to-vehicle communication, direct communication between the pedestrian terminal device and the in-vehicle terminal device can alert both the pedestrian and the driver of the vehicle at an appropriate timing. It is expected to have a great effect in preventing such accidents.

In such pedestrian-to-vehicle communication, in a pedestrian terminal device and a vehicle-mounted terminal device, position information of a pedestrian and a vehicle is acquired by using a satellite positioning system such as GPS, and the position information is obtained. 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 error in the position information causes an erroneous judgment in the risk judgment. Therefore, there is a demand for a technology that compensates for the deterioration of the accuracy of the position information by the satellite positioning system.

As a technique for compensating for the deterioration of the accuracy of position information by such a satellite positioning system, conventionally, an index object such as a road marking or a landmark is detected by a sensor such as a radar or a camera, and the position of the index object detected here is detected. There is known a technique for calculating a positional deviation amount from a deviation from the position of the index object in the map information and correcting the vehicle positional information (see Patent Document 1).

JP 2012-212843 A

However, in the above-mentioned 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 improved. There is a problem that you can not. Such a problem can be solved by creating detailed map information including position information of a large number of indicators, but this requires a huge cost, and there is a technology for improving the accuracy of position information at low cost. desired.

Further, in the pedestrian terminal device, the size of the antenna for satellite positioning is small in order to ensure portability, and the way of carrying the device is different, such as putting it in a pocket of clothes or storing it in the back. , Because pedestrians walk near the building at the edge of the road, satellite positioning is greatly affected by the building, and the degree of freedom of movement is high. Become. Therefore, it is particularly desired to improve the accuracy of pedestrian position information.

The present invention has been devised to solve the above-mentioned problems of the conventional technology, and its main purpose is to improve the accuracy of pedestrian position 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 is carried by a pedestrian and wirelessly communicates with at least one of a vehicle-mounted terminal device and a roadside device, and a communication unit that performs the wireless communication, A controller, the communication unit receives position information transmitted from at least one of the vehicle-mounted terminal device and the roadside device, and the controller controls the vehicle-mounted terminal device that receives the position information; From among the roadside devices, at least two devices are preferentially selected as reference points from devices that are determined to have high accuracy in position information based on the moving speed of the device, and the position of the device serving as the reference point is selected. The position information of the own device is acquired by the reference point survey method based on the information.

Further, a communication system of the present invention is a communication system that performs wireless communication between a pedestrian terminal device and at least one of a vehicle-mounted terminal device and a roadside device, wherein the vehicle-mounted terminal device and the roadside device are the wireless devices. The communication unit includes a communication unit that performs communication, the communication unit transmits position information of the own device 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 vehicle-mounted terminal device and the roadside device, and the control unit includes the vehicle-mounted terminal device and the roadside device that have received the position information. Therefore, at least two devices are preferentially selected as the reference points from the devices that are determined to have high accuracy in the position information based on the moving speed of the device, and the reference point based on the position information of the device serving as the reference point is selected. The position information of the device itself is acquired by the survey method.

Further, the pedestrian position acquisition method of the present invention is a pedestrian position acquisition method for acquiring position information of a pedestrian in a pedestrian terminal device carried by a pedestrian, and is at least one of an in-vehicle terminal device and a roadside device. From the in-vehicle terminal device and the roadside device that received the position information transmitted from the device, the device that is determined to have high accuracy of the position information based on the moving speed of the device is preferentially At least two devices are selected as the reference points, and the position information of the pedestrian is acquired by the reference point survey method based on the position information of the devices serving as the reference points.

According to the present invention, the position information of the vehicle-mounted terminal device or the roadside device is highly accurate, and the position information of the pedestrian terminal device is acquired based on the position information of the vehicle-mounted terminal device or the roadside device. The accuracy of position information can be improved. Further, since it is only necessary to set the on-vehicle terminal device of the vehicle stopped and running on the road or the roadside device installed on the road as the reference point, it is possible to improve the accuracy of the pedestrian position information at low cost. ..

Overall configuration diagram of the communication system according to the first embodiment Explanatory drawing which shows the outline of the process which acquires the positional information on the pedestrian terminal device 1. Block diagram showing a schematic configuration of the pedestrian terminal device 1. Block diagram showing a schematic configuration of the vehicle-mounted terminal device 3 A flow chart showing a procedure of processing performed in pedestrian terminal device 1 and in-vehicle terminal device 3. Explanatory drawing which shows the outline of the communication system which concerns on 2nd Embodiment. A flow chart showing a procedure of processing performed in pedestrian terminal device 1 and in-vehicle terminal device 3. Explanatory drawing which shows the outline 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 problems is a pedestrian terminal device that is carried by a pedestrian and wirelessly communicates with at least one of an in-vehicle terminal device and a roadside device. And a control unit, wherein the communication unit receives position information transmitted from at least one of the vehicle-mounted 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 a reference point survey method based on the position information of the devices serving as the reference points. And

According to this, the position information of the vehicle-mounted terminal device or the roadside device is highly accurate, and the position information of the pedestrian terminal device is obtained based on the position information of the vehicle-mounted terminal device or the roadside device. The accuracy of can be improved. Further, since it is only necessary to set the on-vehicle terminal device of the vehicle stopped and running on the road or the roadside device installed on the road as the reference point, it is possible to improve the accuracy of the pedestrian position information at low cost. ..

Also, in the second invention, the control unit obtains a first distance between two devices serving as the reference points based on position information of the devices serving as the two reference points, and 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 measured by the trilateration method. It is configured to acquire position information.

According to this, the position information of the pedestrian terminal device can be accurately acquired by the trilateration 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 wave signal transmitted from each of the two reference point devices to the own device, and the radio wave arrival time is calculated. The radio wave arrival distance is calculated by multiplying the time by the radio wave speed, and the radio wave arrival distance is acquired as the second and third distances.

According to this, it is possible to accurately obtain the second and third distances, that is, the distances between each of the two reference point devices and the pedestrian terminal device.

Further, in a fourth aspect, the communication unit receives measurement result information regarding at least one of a distance and an angle defining a relative position of a pedestrian with respect to the vehicle, which is acquired by a measuring device mounted on the vehicle, The control unit is configured to acquire the position information of the own device by the reference point survey method based on the measurement result information.

According to this, the position information of the pedestrian terminal device can be accurately acquired by the trilateration method or the triangulation method.

A fifth aspect of the invention is a pedestrian terminal device that is carried by a pedestrian and wirelessly communicates with at least one of an on-vehicle terminal device and a roadside device, and a pedestrian terminal device that performs the wireless communication, and a control unit. And a communication unit that receives position information transmitted from at least one of the vehicle-mounted terminal device and the roadside device, and uses at least one of the vehicle-mounted 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 its own device by the reference point survey method is received, and the control unit controls the in-vehicle terminal device, the roadside device, and the other pedestrian terminal. At least two devices are selected as the reference points from the devices, and the position information of the device itself is acquired by the reference point survey method based on the position information of the devices serving as the reference points.

According to this, the position information of the vehicle-mounted terminal device or the roadside device is highly accurate, and the position information of another pedestrian terminal device acquired based on the position information of the vehicle-mounted terminal device or 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.

Further, the sixth invention represents that the position information transmitted from the other pedestrian terminal device that has acquired the position information of the own device by the reference point survey method has acquired the position information by the reference point survey method. It is configured to include information.

According to this, it is possible to easily identify that the position information transmitted from another pedestrian terminal device is obtained by the reference point survey method.

A seventh aspect of the present invention is a communication system for performing wireless communication between a pedestrian terminal device and at least one of a vehicle-mounted terminal device and a roadside device, wherein the vehicle-mounted terminal device and the roadside device are the wireless communication devices. And a communication unit that transmits the position information of the own device 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 vehicle-mounted terminal device and the roadside device, and the control unit selects from among the vehicle-mounted terminal device and the roadside device that have received the position information. At least two devices are selected as the reference points, and the position information of the device itself is acquired by the reference point survey method based on the position information of the devices serving as the reference points.

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

An eighth aspect of the present invention is a pedestrian position acquisition method for acquiring position information of a pedestrian in a pedestrian terminal device carried by a pedestrian, which is transmitted from at least one of a vehicle-mounted terminal device and a roadside device. At least two devices are selected as reference points from the in-vehicle terminal device and the roadside device that have received the position information, and the reference point survey based on the position information of the devices that are the reference points. The pedestrian position information is acquired by the method.

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

Embodiments of the present invention will be described below 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 carried by a pedestrian, an in-vehicle terminal device 3 and a car navigation device 4 mounted on a vehicle.

The pedestrian terminal device 1 has a positioning function for acquiring position information of the own device and a communication function for performing inter-pedestrian communication with the vehicle-mounted terminal device 3, and the pedestrian and the pedestrian acquired by these functions Danger determination is performed based on the position, traveling direction, moving speed, etc. of the vehicle to determine whether or not the vehicle is likely to collide with a pedestrian who owns the device.

The mobile 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, and when the pedestrian terminal device 1 determines that there is a high possibility of collision, the pedestrian is alerted to avoid 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 the alerting output operation.

The in-vehicle terminal device 3 has 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 and the pedestrian acquired by these functions Based on the position of the vehicle, the traveling direction, the moving speed, and the like, a risk determination is performed to determine whether 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 there is a high possibility of a collision, an output operation for alerting the driver to avoid an accident ( For example, the car navigation device 4 is caused to perform voice output or screen display. The in-vehicle terminal device 3 itself may perform the alerting output operation.

The in-vehicle terminal device 3 may be connected to the portable information terminal device 2 owned by the driver to cause the portable information terminal device 2 to perform an output operation such as a warning to the driver.

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

Now, in this communication system, the information such as the position, the traveling direction, and the moving speed of the pedestrian and the vehicle, which are necessary for the risk determination, are mutually exchanged between the pedestrian terminal device 1 and the vehicle-mounted terminal device 3, and Information is exchanged by pedestrian-to-vehicle communication using a frequency band (eg, 700 MHz band or 5.8 GHz band) adopted in a safe driving support wireless system using ITS (Intelligent Transport System).

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

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

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

Here, in the pedestrian terminal device 1, the size of the antenna for satellite positioning is small in order to ensure portability, and the pedestrian terminal device 1 is carried in various ways such as being put in a pocket of clothes or stored in a bag. Moreover, since the pedestrian walks near the building at the end of the road, the 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. It will be about 5 m.

On the other hand, in the vehicle-mounted terminal device 3, the size of the antenna for satellite positioning is large, and highly accurate and stable positioning can be performed. Further, since the vehicle runs on a road away from the building, the satellite positioning is Since it is less affected and the vehicle travels along the traveling lane of the road, the accuracy of the position information can be improved by the correction by the map matching, so that the horizontal error of the position information is small, for example, 1 m. It becomes a degree.

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

Particularly, in the present embodiment, as shown in FIGS. 2A and 2B, the position of the pedestrian terminal device 1 is set as the measurement point MP, and the positions of the vehicle-mounted terminal devices 3 of the two vehicles V1 and V2 are set as the reference point RP1. , RP2, the position of the pedestrian terminal device 1 which is the measurement point MP is obtained by the trilateration method. That is, the lengths L1, L2, L3 of the three sides of the triangle formed 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 determined. The position of the measurement point MP is obtained from the positions of RP1 and RP2.

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

At this time, the in-vehicle terminal device 3 adds the transmission time information (time stamp) to the message and transmits the message, 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 multiplied by the radio wave speed to obtain the radio wave arrival distance, that is, each of the two vehicle-mounted terminal devices 3 and the pedestrian terminal device 1. Calculate the distance between.

In this way, when the position of the pedestrian terminal device 1 is obtained by the trilateration method, two candidate points CP are obtained at positions that are line-symmetrical with the straight line connecting the two reference points RP1 and RP2 as the axis of symmetry. Of the two candidate points CP, the one closer to the position acquired by satellite positioning by the pedestrian terminal device 1 may be selected.

Here, when selecting the two vehicle-mounted terminal devices 3 serving as the reference points RP1 and RP2, the vehicle-mounted terminal device 3 of the stopped vehicle is preferentially selected, and when the two stopped vehicles are not present. May select the vehicle-mounted terminal device 3 of the traveling vehicle. While the vehicle is traveling, the error in the radio wave arrival time becomes large, but the error in the position information due to this is small compared to the error in the position information obtained by 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 showing a schematic configuration of the pedestrian terminal device 1.

The pedestrian terminal device 1 includes a satellite positioning unit (positional 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 the position information of its own device by a satellite positioning system such as GPS, QZSS, and GLONASS. The position information of the own device may be acquired using the positioning function of the mobile information terminal device 2.

The communication unit 12 transmits/receives a message to/from the vehicle-mounted terminal device 3 by pedestrian-vehicle communication. In this inter-pedestrian 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 mobile 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. The map information may be acquired from the mobile information terminal device 2.

The clock 16 outputs the current time. Based on the output time of the clock 16, the communication unit 12 acquires the reception time at the timing when the message transmitted from the vehicle-mounted 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 is composed of a processor, and each unit of the control unit 14 is realized by causing the processor to execute the 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 trilateration method based on the position information of the vehicle-mounted terminal device 3 included in the message received by the communication unit 12. The risk determination unit 23 determines whether or not attention is required, that is, whether or not there is a high possibility that the vehicle will collide with a pedestrian, based on the positions of the pedestrian and the vehicle, the moving speed, the traveling direction, and the like. ..

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

The reference point setting unit 25 sets, from the vehicle-mounted terminal devices 3 that have received the message by the communication unit 12, the vehicle-mounted terminal devices 3 that serve as two reference points by the trilateration method. 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. The in-vehicle terminal device 3 of a low vehicle is selected preferentially.

The three-sided distance measuring unit 26 determines the distance between the two vehicle-mounted terminal devices 3 serving as a reference point based on the position information of the vehicle-mounted 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, that is, 2 The distance between each of the onboard terminal devices 3 and its own device is calculated.

In the position calculation unit 27, the position information of the vehicle-mounted terminal device 3 included in the message received by the communication unit 12, the distance between the two vehicle-mounted terminal devices 3 acquired by the three-sided distance measuring unit 26, and the two vehicle-mounted devices. The position of the terminal device 3 is calculated using the cosine theorem and the Pythagoras theorem based on the distance between each terminal device 3 and the device itself. 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 device from the two candidate points calculated as the position of the own device 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 a process of matching the position of a pedestrian with the map information based on the positions and moving directions of a plurality of vehicles. At this time, the reference line for map matching becomes unnecessary, and the flow directions of a plurality of vehicles can be used as the reference line.

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

The vehicle-mounted terminal device 3 includes a satellite positioning unit (positional 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.

The satellite positioning unit 31, like the satellite positioning unit 11 of the pedestrian terminal device 1, acquires the position information of its own device by the satellite positioning system. The position information of the own device may be acquired by using the positioning function of the car navigation device 4.

The communication unit 32 transmits/receives a message to/from the pedestrian terminal device 1 by inter-pedestrian communication. In this inter-pedestrian 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 by using the communication function of the vehicle-mounted terminal device 3 or 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 to which the information (time stamp) of the transmission time is added.

The control unit 34 includes a risk determination unit 41. The control unit 34 is configured by a processor, and the danger determination unit 41 is realized by causing the processor to execute the program stored in the information storage unit 35. The risk determination unit 41 determines whether or not attention is required, that is, whether or not there is a high possibility that the vehicle will collide with a pedestrian, based on the positions, moving speeds, and directions of travel of the pedestrian and the vehicle. ..

Next, a procedure of processing 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 processing performed by the pedestrian terminal device 1 and the in-vehicle terminal device 3.

In the vehicle-mounted terminal device 3 serving as the reference point, first, the satellite positioning unit 31 acquires the position information of the device itself (ST101). Then, the communication unit 32 transmits the message by pedestrian communication (ST102). This message includes the position information of the own device acquired by the satellite positioning unit 31 and the 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 the message transmitted from the vehicle-mounted 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, the reference point setting unit 25 selects two vehicle-mounted terminal devices 3 serving as reference points from the vehicle-mounted terminal devices 3 that have received the message (ST202). At this time, 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 the vehicle having a low speed is selected. It is advisable to preferentially select the on-vehicle terminal device 3. If there are three or more vehicles that are candidates for selection, the in-vehicle terminal devices 3 of two vehicles close to the own device may be selected.

Next, the three-sided distance measuring unit 26 calculates the distance between the two vehicle-mounted terminal devices 3 from the position information acquired from the two vehicle-mounted 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 vehicle-mounted terminal devices 3 serving as the reference points (ST204), and the radio wave arrival time is multiplied by the radio wave speed to obtain the radio wave arrival distance, That is, the distance between each of the two vehicle-mounted terminal devices 3 and its own device is calculated (ST205).

Next, in the position calculation unit 27, the distance between the two vehicle-mounted terminal devices 3 serving as the reference point, which is acquired by the three-sided distance measurement unit 26, and the distance between each of the two vehicle-mounted terminal devices 3 and the self-device. The position of the own device is calculated based on the distance (ST206).

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

The process of the reference point surveying unit 21 may be performed at all times, or may be performed when the vehicle enters an area where the satellite positioning accuracy decreases, 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 decreases.

Further, in the present embodiment, since the radio wave arrival time is obtained from the transmission time and the reception time of the message transmitted from the vehicle-mounted terminal device 3 to the pedestrian terminal device 1, the clocks 16 of the pedestrian terminal device 1 and the vehicle-mounted terminal device 3 are obtained. , 36 need to be synchronized with high accuracy, the clocks 16 and 36 may be radio wave clocks, and the time information included in the signals from the satellites received by the satellite positioning units 11 and 31 may be used. You may use it.

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

In addition, 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 position of the own device calculated in each combination is used. You may do it.

(Second embodiment)
Next, a second embodiment will be described. The points not particularly mentioned here are the same as those in the above-described embodiment.

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

In the first embodiment, the position information of the pedestrian terminal device 1 is acquired by the reference point survey method using the two vehicle-mounted terminal devices 3 as reference points. However, in the second embodiment, the position information of the pedestrian terminal device 1 is different from that of the first embodiment. Similarly, the next pedestrian terminal device 1 with the first pedestrian terminal device 1 and the one in-vehicle terminal device 3 whose position information were acquired by the reference point surveying method using the on-vehicle terminal device 3 as a reference point as the reference point. The position information of the next pedestrian terminal device 1 is acquired using the two pedestrian terminal devices 1 that have acquired the position information by the reference point survey method as reference points.

In the example shown in FIG. 6, the pedestrian terminal device 1 of the pedestrians P1 and P2 acquires the position information with the vehicle-mounted 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 with the pedestrian terminal device 1 of the pedestrian P1 and the vehicle-mounted terminal device 3 of the vehicle V1 as reference points. The pedestrian terminal device 1 of the pedestrian P4 acquires position information by 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 by using the pedestrian terminal devices 1 of the two pedestrians P1 and P2 as reference points.

In this way, a method of acquiring the position information of the next pedestrian terminal device 1 by the reference point surveying method using the vehicle-mounted terminal device 3 or the pedestrian terminal device 1 whose position information is obtained by the reference point surveying method as a reference point If the pedestrian terminal device 1 existing within the range where the inter-pedestrian communication is possible is repeatedly performed, the newly acquired position information of the pedestrian terminal device 1 is based on the highly accurate position information of the vehicle-mounted terminal device 3. Therefore, the accuracy of the position information of the pedestrian terminal devices 1 existing in the entire area 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 vehicle-mounted terminal devices 3 that have received the message, the vehicle-mounted terminal device 3 is selected as a reference point. There is only one vehicle-mounted terminal device 3 that has received the message, and at least one pedestrian terminal device 1 that has received position information by the reference point survey method among the pedestrian terminal devices 1 that have received the message If it exists, the pedestrian terminal device 1 and the vehicle-mounted terminal device 3 are selected as reference points. In addition, there is no vehicle-mounted terminal device 3 that has received the message, and at least 2 of the pedestrian terminal devices 1 that have received the message and have acquired position information by the reference point survey method. If there is one, the pedestrian terminal device 1 is selected as a reference point.

Since the pedestrian terminal device 1 whose position information has been acquired by the reference point survey method is selected as the 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 is added. Send from 1.

Next, a procedure of processing 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 processing performed by the pedestrian terminal device 1 and the in-vehicle terminal device 3. Here, a case will be described in which another pedestrian terminal device 1 that has acquired position information by the reference point surveying method and one vehicle-mounted terminal device 3 are set as reference points.

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

Further, the pedestrian terminal device 1 serving as the reference point performs the positioning process by the reference point surveying method in the procedure shown in FIG. 5 to determine the position of the own device (ST208). Then, the communication unit 12 transmits the message by inter-pedestrian communication (ST301). In this message, the position information of the device itself acquired by the reference point survey method, information indicating that this position information was 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 that acquires position information, the communication unit 12 receives the message transmitted from the vehicle-mounted terminal device 3 (ST401), and is transmitted from another pedestrian terminal device 1. The message is received (ST402). At this time, the reception time of the message is acquired based on the output time of the clock 16.

Next, in the reference point setting unit 25, from the in-vehicle terminal device 3 that has received the message and another pedestrian terminal device 1 that has received the message, the in-vehicle terminal device 3 that is the reference point and the pedestrian terminal that is the reference point The device 1 is selected (ST403). At this time, when there are three or more vehicle-mounted 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-sided distance measuring unit 26, based on the position information acquired from the vehicle-mounted terminal device 3 serving as the reference point and the pedestrian terminal device 1 serving as the reference point, the vehicle-mounted terminal device 3 serving as the reference point and the walking 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 the reception time of each message of the vehicle-mounted terminal device 3 which is the reference point and the pedestrian terminal device 1 which is the reference point (ST405), and the radio wave speed is set to the radio wave arrival time. By multiplying, the radio wave arrival distance, that is, the distance between each of the vehicle-mounted terminal device 3 serving as the reference point and the pedestrian terminal device 1 serving as the reference point, and its own device is calculated (ST406).

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

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

In addition, in FIG. 7, the case where another pedestrian terminal device 1 and the in-vehicle terminal device 3 which have acquired the position information by the reference point survey method are set as the reference points has been described, but the position information is acquired by the reference point survey method. When setting the other two pedestrian terminal devices 1 as the reference points, the vehicle-mounted terminal device 3 in FIG. 7 may be replaced with another pedestrian terminal device 1.

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

(Third Embodiment)
Next, a third embodiment will be described. The points not particularly mentioned here are the same as those in the above-described embodiment.

FIG. 8 is an explanatory diagram showing an outline of the communication system according to the third embodiment.

In the first embodiment, the position of the pedestrian terminal device 1 is obtained by the trilateration method, but in the third embodiment, the position of the pedestrian terminal device 1 is obtained by the triangulation method. That is, with the line segment connecting the two reference points RP1 and RP2 as the 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 The position of the pedestrian terminal device 1, which is the measurement point, is obtained from the length L1 and the two vertex angles θ1 and θ2.

A camera (measuring device) 51 is mounted on each of the vehicles V1 and V2, and a pedestrian is imaged by the camera 51. The camera 51 detects a pedestrian in the captured image using an image recognition technique such as person detection, obtains the direction in which the pedestrian exists, and determines the apex angles θ1 and 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 to walk. In the person terminal device 1, the position of the pedestrian terminal device 1 is obtained by the triangulation method based on the measurement result information acquired from each in-vehicle terminal device 3. 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 modified example of the third embodiment will be described.

In the third embodiment shown in FIG. 8, the apex angles θ1 and θ2 are obtained from the image captured by the camera 51, but from the image captured by the camera 51, 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 distances from the two vehicles V1 and V2 to the pedestrian P1 and P2 are measured, and three 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 to the pedestrian from the image picked up by the camera 51, the camera 51 provided with a distance image sensor such as a TOF (Time Of Flight) system or a stereo camera may be used.

By the way, in the third embodiment and its modified example, a camera (measuring device) 51 is mounted on a vehicle, and an angle and a distance defining a relative position of a pedestrian viewed from the vehicle are measured from an image captured 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 viewed from the vehicle by the radar device. In this case, the radar device may measure the distance between the two vehicles serving as the reference points.

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 measuring device such as the camera and the radar device mounted on the vehicle. You may make it correct. By doing so, the accuracy of the position information of the pedestrian terminal device 1 can be further improved.

(Fourth Embodiment)
Next, a fourth embodiment will be described. The points not particularly mentioned here are the same as those in the above-described embodiment.

FIG. 9 is an explanatory diagram showing an outline of the communication system according to the fourth embodiment.

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

The roadside device 61 holds position information of its own device, transmits a message including this position information by road-vehicle communication, and the pedestrian terminal device 1 receives the message transmitted from the roadside device 61. In addition, the pedestrian terminal device 1 receives a message transmitted from the vehicle-mounted terminal device 3 by pedestrian-vehicle communication. Then, in the pedestrian terminal device 1, the radio wave arrival distance obtained from the radio wave arrival time of the message is measured as the distance between each of the roadside device 61 and the in-vehicle terminal device 3 and the pedestrian terminal device 1, and three sides are measured. 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 accurately measured. Therefore, when selecting the two devices serving as the reference points, the roadside device 61 is preferentially selected and the roadside device 61 is selected. If there are not two, the in-vehicle terminal device 3 may be selected.

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

Further, the selection of the roadside device 61 as the reference point as in the present embodiment can be applied to the second embodiment. That is, two reference point devices are selected from the roadside device 61, the vehicle-mounted terminal device 3, and the pedestrian terminal device 1 whose position information has been acquired by the reference point surveying method, and the next reference point surveying method is selected. The position information of the pedestrian terminal device 1 may be acquired.

The embodiments have been described above as examples of the technology disclosed in the present application. However, the technology of the present disclosure is not limited to this, and can be applied to embodiments in which changes, replacements, additions, omissions, etc. have been made. Further, it is also possible to combine the respective constituent elements described in the above-described embodiment to form a new embodiment.

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

In addition, in the above-described embodiment, an example in which horizontal position information is acquired as position information of a pedestrian has been described, but it is also possible to acquire position information in the height direction by the reference point survey method. , It is not necessary to provide a pressure sensor for acquiring the position information in the height direction in the pedestrian terminal device, and with the position information acquired by the reference point survey method, by correcting the position information based on the pressure sensor, The accuracy of position information in the height direction can be improved.

Further, in the above embodiment, two devices serving as reference points are set to perform positioning by the reference point survey method, but three or more devices serving as reference points can be set. Thereby, the accuracy of the position information of the 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, positioning by the reference point survey 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, but acquires the position information of the pedestrian terminal device by the reference point survey method. You may make it perform a positioning process in a vehicle-mounted terminal device and notify the pedestrian terminal device of the positional information.

INDUSTRIAL APPLICABILITY 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 position information at low cost, and the pedestrian possesses the in-vehicle terminal device and A pedestrian terminal device that wirelessly communicates with at least one of the roadside devices, a communication system that wirelessly communicates with the pedestrian terminal device and at least one of the vehicle-mounted terminal device and the roadside device, and walking that the pedestrian possesses. It is useful as a pedestrian position acquisition method for acquiring position information of a pedestrian in a person terminal device.

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

Claims (8)

A pedestrian terminal device that is carried by a pedestrian and wirelessly communicates with at least one of an in-vehicle terminal device and a roadside device,
A communication unit that performs the wireless communication,
A control unit,
Equipped with
The communication unit receives position information transmitted from at least one of the vehicle-mounted terminal device and the roadside device,
The control unit preferentially selects at least two devices from among the in-vehicle terminal device and the roadside device that have received the position information, from a device that is determined to have high position information accuracy based on the moving speed of the device. Is selected as a reference point, and the position information of the own device is acquired by a reference point surveying method based on the position information of the device serving as the reference point. The control unit acquires a first distance between two devices serving as the reference points based on position information of the devices serving as the two reference points, and each of the devices serving as the two reference points. Second and third distances between the device and the device itself, and based on the first, second, and third distances, position information of the device itself is acquired by a trilateration method. The pedestrian terminal device according to claim 1. The control unit calculates the radio wave arrival time from the transmission time and the reception time of the radio wave signal transmitted from each of the two reference point devices to the own device, and multiplies the radio wave arrival time by the radio speed to obtain the radio wave. The pedestrian terminal device according to claim 2, wherein an arrival distance is calculated and the arrival distance of the radio wave 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, which is acquired by a measurement device mounted on the vehicle,
The pedestrian terminal device according to claim 1, wherein the control unit acquires the position information of the device itself by the reference point survey method based on the measurement result information. A pedestrian terminal device that is carried by a pedestrian and wirelessly communicates with at least one of an in-vehicle terminal device and a roadside device,
A communication unit that performs the wireless communication,
A control unit,
Equipped with
The communication unit receives position information transmitted from at least one of the vehicle-mounted terminal device and the roadside device, and by a reference point surveying method using at least one of the vehicle-mounted terminal device and the roadside device as a reference point. Receives the position information transmitted from another pedestrian terminal device that has 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 other 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 is characterized in that it 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 for performing wireless communication between a pedestrian terminal device and at least one of a vehicle-mounted terminal device and a roadside device,
The in-vehicle terminal device and the roadside device,
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 that performs the wireless communication,
A control unit,
Equipped with
The communication unit of the pedestrian terminal device receives the position information transmitted from at least one of the vehicle-mounted terminal device and the roadside device,
The control unit preferentially selects at least two devices from among the in-vehicle terminal device and the roadside device that have received the position information, from a device that is determined to have high position information accuracy based on the moving speed of the device. Is selected as a reference point, and the position information of the own device is acquired by a reference point survey method based on the position information of the device that is the reference point. In a pedestrian terminal device carried by a pedestrian, a pedestrian position acquisition method for acquiring position information of a pedestrian,
Receives position information transmitted from at least one of the in-vehicle terminal device and the roadside device,
From the in-vehicle terminal device and the roadside device that have received the position information , at least two devices are preferentially selected as a reference point from devices that are determined to have high position information accuracy based on the moving speed of the device. Then, the pedestrian position acquisition method is characterized in that the position information of the pedestrian is acquired by a reference point survey method based on the position information of the device serving as the reference point.

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