JP2009174964A - Apparatus and system for specifying position - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a position specification apparatus and a position specification system, capable of accurately specifying the position of a mobile body, such as, vehicle. <P>SOLUTION: A time lag computation part 51 computes the time lags between a reference communication part 10 and communication parts 20, 30, and 40, on the basis of the times of receipt of signals for time correction transmitted by the communication parts 20, 30, and 40 and received by the reference communication part 10 and transmission times included in received signals for time correction. A time correction part 52 corrects time so that the time lags between the reference communication part 10 and the communication parts 20, 30, and 40 should be zero. When the communication parts 10-40 each have received positioning signals transmitted from an on-vehicle apparatus, an arrival time difference computing part 53 computes the differences of the time of receipt between the positioning signals at the communication parts 10-40 as their differences of the time of arrival between the positioning signals. A position specifying part 54 specifies the position of the on-vehicle apparatus, on the basis of the differences of the time of arrival. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a position specifying device that receives a predetermined signal transmitted from a terminal device and specifies the position of the terminal device, and a position specifying system including the position specifying device.

2. Description of the Related Art Conventionally, a system for detecting the position of a radio wave source called an unknown station such as a moving body that radiates radio waves has been developed. For example, radio waves emitted from a radio wave source are received by a plurality of sensor stations, and each sensor station takes out a radio wave for a fixed time using a reference time output from a GPS receiver as a trigger, and performs a Fourier transform to obtain a complex frequency component. The extracted complex frequency component is transmitted to the center station. A position detection system has been proposed in which the center station calculates the complex conjugate product between the complex frequency components transmitted from each sensor station, calculates the arrival time difference between the sensor stations, and detects the position of the radio wave source ( Patent Document 1).
Japanese Patent No. 3739078

  However, in the system of Patent Document 1, although the reference time of each sensor station is set using GPS, the reference time between the sensor stations is about 100 to 200 nanoseconds due to the performance of the GPS receiver. The error of about several tens of meters occurs in the position detection of the moving body. Further, there is no function for monitoring whether or not the time of each sensor station is shifted, and a specific method for synchronizing the time between the sensor stations is not disclosed. For this reason, a system capable of accurately detecting the position of the moving body has been desired.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a position specifying device that can accurately specify the position of a moving body such as a vehicle and a position specifying system including the position specifying device. And

  The position specifying device according to the first aspect of the present invention includes at least two communication units with known separation distances, and each of the communication units receives a predetermined signal transmitted by the terminal device and specifies the position of the terminal device. And each communication part is provided with a time measuring means, and other communication parts except one communication part are constituted so that a signal for time correction including a transmission time point may be transmitted to the one communication part, The one communication unit is configured to receive a time correction signal, and based on the reception time and the transmission time of the received time correction signal and the separation distance between the communication units, A time lag calculating means for calculating a time lag between the predetermined signal and the time lag calculated by the time lag calculating means based on the reception time of the predetermined signal transmitted by the terminal device at each communication unit and the time lag calculated by the time lag calculating means. Time to calculate the time difference in arrival time to the communication unit And calculating means, characterized in that it comprises a specifying means for specifying the position of the terminal device based on the time difference calculated by said time difference calculating means.

  According to a second aspect of the present invention, in the first aspect of the invention, the position specifying device includes a correction unit that corrects the time measured by each time measuring unit according to the time difference calculated by the time difference calculating unit, and the time difference calculating unit includes a terminal The time difference between the arrival times of the signals to the communication unit is calculated based on the reception time of the predetermined signal transmitted by the device at each communication unit and the time corrected by the correction unit. And

  According to a third aspect of the present invention, in the first or second aspect, the predetermined signal includes information indicating that the predetermined signal is a signal for identifying the position of the terminal device and an identifier unique to the terminal device. And

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the position specifying device includes storage means for storing road shape information of an area for specifying the position of the terminal device, and the specifying means stores The position of the terminal device is specified using the road shape information.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the position specifying device includes storage means for storing the height information of the position of the terminal device, and the specifying means stores the height information stored therein. The position of the terminal device is specified by using.

  A position specifying system according to a sixth aspect of the present invention includes a terminal device that transmits a predetermined signal and a position specifying device according to any one of the first to fifth aspects of the invention, and specifies the position of the terminal device. It is comprised by these.

In the first invention, the position specifying device includes at least two communication units with known separation distances, and each communication unit includes a time measuring unit. The position specifying device transmits a time correction signal including a transmission time from another communication unit other than one communication unit (hereinafter referred to as a reference communication unit) to the reference communication unit, and the reference communication unit corrects the time measurement. Receive a signal. The position specifying device determines whether the reference communication unit and the other communication unit are based on the reception time of the timing correction signal received by the reference communication unit, the transmission time of the other communication unit, and the separation distance between the communication units. The time difference between them is calculated. For example, if the transmission time is t1, the reception time is t2, and the propagation time of the radio wave between the two communication units is ΔT12, if the time t2 is delayed from the time (t1 + ΔT12), the time of the other communication unit is When the time is ahead of the time of the reference communication unit and the time t2 is ahead of the time (t1 + ΔT12), the time of the other communication unit is behind the time of the reference communication unit. The time difference Δt can be obtained by (t2−t1) −ΔT12. When Δt> 0, the time of the other communication unit is ahead of the time of the reference communication unit, and when Δt <0, the time of the other communication unit is delayed from the time of the reference communication unit. ing. The radio wave propagation time ΔT12 between the two communication units can be obtained by dividing the distance between the communication units by the radio wave propagation speed (3 × 10 ⁸ m / s).

  The position specifying device is a communication of a predetermined signal transmitted by a terminal device (for example, an in-vehicle device mounted on a moving body such as a vehicle, a mobile communication device such as a mobile phone carried by a moving person such as a pedestrian). The time difference of the arrival time of the predetermined signal to the communication unit is calculated based on the reception time at the unit and the calculated time lag. For example, assuming that the reception time at the reference communication unit is tm1, the reception time at the other communication unit is tm2, and the time lag between both communication units is Δt, the arrival time difference ΔT12 is obtained by | tm1−tm2 | −Δt. Can do. The position specifying device specifies the position of the terminal device based on the calculated time difference. For example, a rotational hyperboloid having the same propagation path difference obtained by integrating the propagation speed of the radio wave with the arrival time difference between the two communication units with the position of the two communication units as a focus can be specified. Such a rotation hyperboloid can be specified for each pair of communication units, and the position of the terminal device can be specified as an intersection of the rotation hyperboloid.

  Thereby, the time lag between communication units can be monitored in real time, and when a predetermined signal transmitted by the terminal device is received by each communication unit, the reception time point at each communication unit can be accurately obtained. . For this reason, the arrival time difference between the communication units can be accurately calculated without including information on the transmission time point in the predetermined signal transmitted from the terminal device, and the position of the terminal device can be accurately identified.

  In the second invention, the position specifying device corrects the time measurement according to the calculated time lag. The position specifying device calculates the time difference between the arrival times of the predetermined signals to the communication unit based on the reception times of the predetermined signals transmitted by the terminal devices at the respective communication units and the corrected timing. Thus, even when a time lag occurs in each communication unit, the time difference of the arrival time of the predetermined signal to the communication unit can be accurately obtained by correcting the time lag of each communication unit.

  In the third invention, the predetermined signal includes information indicating that the signal is for identifying the position of the terminal device and an identifier unique to the terminal device. As a result, the position specifying device is understood to be a signal from the terminal device when each communication unit receives a predetermined signal. In addition, even when a predetermined signal is transmitted from a large number of terminal devices, the position specifying device can determine which terminal device is the signal transmitted from the identifier, and can determine the position of each terminal device. Can be accurately identified.

  In the fourth invention, the position specifying device stores road shape information of an area for specifying the position of the terminal device, and specifies the position of the terminal device using the stored road information. For example, the position specifying device specifies a virtual traveling surface of the terminal device based on road shape information. The position specifying device specifies a rotating hyperboloid centered on a pair of communication units, and specifies an intersection line between the specified rotating hyperboloid and the running surface as the position of the terminal device. Thereby, the position of a terminal device can be specified with high precision by installing two communication parts.

  In the fifth invention, the position specifying device stores the height information of the position of the terminal device (for example, the mounting position of the vehicle-mounted device, the mounting position of the portable communication device, etc.), and the stored height information is stored. To identify the position of the terminal device. By using the height information, the position of the terminal device can be specified with higher accuracy.

  In the sixth invention, the terminal device and the position specifying device are provided, whereby the position of the terminal device can be specified with high accuracy.

  In the present invention, the time lag between the communication units can be monitored in real time, and when the predetermined signal transmitted by the terminal device is received by each communication unit, the reception time point at each communication unit is accurately determined. Can be sought. In addition, the arrival time difference between the communication units can be calculated with high accuracy without including information on the transmission point in a predetermined signal transmitted from the terminal device, and the position of the terminal device can be specified with high accuracy.

Embodiment 1
Hereinafter, the present invention will be described with reference to the drawings illustrating embodiments. FIG. 1 is a block diagram showing an example of a configuration of a roadside machine 100 as a position specifying device according to the present invention. The roadside machine 100 constitutes a road-vehicle communication system (position specifying system) with an in-vehicle device mounted on a vehicle. The roadside device 100 includes a first communication unit (reference communication unit) 10, a second communication unit 20, a third communication unit 30, a fourth communication unit 40, a control unit 50, a time shift calculation unit 51, a time correction unit 52, An arrival time difference calculating unit 53, a position specifying unit 54, a storage unit 55, and the like are provided.

  The control unit 50 controls the operation of the entire roadside device 100.

  Each communication part 10-40 is isolate | separated from the roadside machine 100 main body, and can communicate with a roadside machine 100 main body by radio | wireless or a wire communication. The communication units 10 to 40 are separated from each other by a required distance, and information on the installation positions or the separation distances of the communication units 10 to 40 are stored in the storage unit 55.

  FIG. 2 is a schematic diagram illustrating an example of installation of the communication units 10 to 40. As shown in FIG. 2, the communication units 10, 20, 30, and 40 are installed at points A, B, C, and D, for example, between points AC, points AB, points CD, and points. The distance between BDs is 300 m, and the distance between points AD and BC is 450 m. In addition, the area surrounded by the points A, B, C, and D and the surrounding area are areas set for specifying the position of the in-vehicle device 200. In addition, the installation example of each communication part 10-40 is not limited to this.

  Each communication part 10-40 is equipped with the communication function which communicates with the vehicle equipment 200 while being provided with the communication function which mutually communicates in the frequency band of a VHF / UHF band, for example. Each of the communication units 10 to 40 includes a crystal oscillator that generates a reference clock signal, a timepiece mechanism such as a clock 11, 21, 31, 41 (or a timer or a counter) that operates based on the reference clock signal, a modulation circuit, A time correction signal transmitted by another communication unit and a positioning signal transmitted by the in-vehicle device 200 are received, and a demodulating circuit or the like is received, and the received signal is demodulated to extract original information. Each of the communication units 10 to 40 calculates a signal reception time and outputs the calculated reception time to the control unit 50.

  FIG. 3 is an explanatory diagram showing an example of a data structure included in the time correction signal. The time correction signal is, for example, a signal transmitted from each communication unit 20, 30, 40 to the reference communication unit 10, in order to calculate a time shift in each communication unit 10 to 40 and correct the time shift. Are repeatedly transmitted and received at appropriate intervals. As shown in FIG. 3, the time correction signal includes, for example, data such as a pilot signal indicating a time correction signal, a communication unit ID of a transmission source, and a signal transmission time. The pilot signal is a known signal among the communication units 10-40. Thereby, it can be seen that the reference communication unit 10 is a time correction signal.

The time lag calculation unit 51 is configured to generate a reference communication unit based on the reception time when the time communication signal transmitted by the second communication unit 20 is received by the reference communication unit 10 and the transmission time included in the received time correction signal. The time difference between 10 and the second communication unit 20 is calculated. For example, when the transmission time is t1, the reception time is t2, and the propagation time of the radio wave between the communication units 10 and 20 is ΔT12, the second communication unit 20 is set when the time t2 is delayed from the time (t1 + ΔT12). The time of the second communication unit 20 is later than the time of the reference communication unit 10 when the time of the second communication unit 20 is advanced from the time of the reference communication unit 10 and the time t2 is advanced from the time (t1 + ΔT12). ing. The time difference Δt can be obtained by (t2−t1) −ΔT12. When Δt> 0, the time of the second communication unit 20 is ahead of the time of the reference communication unit 10, and when Δt <0, the time of the second communication unit 20 is that of the reference communication unit 10. It is later than the time. The radio wave propagation time ΔT12 between the communication units 10 and 20 can be obtained by dividing the distance between the communication units 10 and 20 by the radio wave propagation speed (3 × 10 ⁸ m / s).

  The time lag can be calculated in the same manner between the reference communication unit 10 and the third communication unit 30 and the fourth communication unit 40.

  FIG. 4 is an explanatory diagram illustrating an example of calculating the reception time of the time correction signal. The example of FIG. 4 shows a case where a time correction signal is transmitted from the communication unit 20 to the reference communication unit 10, but a time correction signal is transmitted from the communication unit 30 or the communication unit 40 to the reference communication unit 10. The same applies to the case. 4A shows an example of a pilot signal of the time correction signal transmitted by the communication unit 20, and FIG. 4B is for performing correlation processing (pattern matching) stored in advance in the reference communication unit 10. Is a replica signal. FIG. 4C shows a received signal when the reference communication unit 10 receives the time correction signal transmitted by the communication unit 20. As shown in FIG. 4C, the received signal is sampled at a predetermined time interval, and the time when the sampled waveform and the replica signal waveform match is measured as the received time.

  The time correction unit 52 corrects the time so that the time difference between the reference communication unit 10 and the other communication units 20, 30, and 40 is zero. For example, if the time lag between the reference communication unit 10 and the other communication units 20, 30, 40 is Δt 12, Δt 13, Δt 14, the time correction unit 52 is connected to the clocks of the other communication units 20, 30, 40. Are corrected, and Δt12, Δt13, and Δt14 are set to zero. In this case, the time correction unit 52 notifies the other communication units 20, 30, and 40 of the time lags Δt12, Δt13, and Δt14, and sets the time lags notified by the communication units 20, 30, and 40 to zero. Correct the time accordingly.

  The arrival time difference calculation unit 53, when the time is corrected by the time correction unit 52, when the positioning signal transmitted by the in-vehicle device 200 is received by each communication unit 10-40, the positioning by each communication unit 10-40 A difference in reception time of the signal for use is calculated as a difference in arrival time of the positioning signal. In this case, when receiving the positioning signals from the plurality of vehicle-mounted devices 200, the arrival time difference calculating unit 53 calculates the arrival time difference of the positioning signals having the same vehicle-mounted device ID based on the vehicle-mounted device IDs included in the positioning signals. calculate. Thus, even if positioning signals are transmitted from a large number of in-vehicle devices 200, it is determined which in-vehicle device 200 is the positioning signal.

  FIG. 5 is a schematic diagram illustrating an example in which the in-vehicle device 200 transmits a positioning signal, and FIG. 6 is an explanatory diagram illustrating an example of a data structure included in the positioning signal. As illustrated in FIG. 5, when the in-vehicle device 200 transmits a positioning signal at an arbitrary time, each communication unit 10-40 receives the transmitted positioning signal and measures the reception time. As shown in FIG. 6, the positioning signal includes data such as a pilot signal indicating that it is a positioning signal and an in-vehicle device ID that is a unique identifier for identifying the in-vehicle device 200. In addition, a pilot signal is a known signal between the vehicle equipment 200 and each communication part 10-40. Thereby, it turns out that each communication part 10-40 is a signal for positioning. The reception time can be measured in the same manner as in the example of FIG. 4 based on the pilot signal.

  In the example of FIG. 5, if the reception time of the positioning signal in each of the communication units 10 to 40 is tm1, tm2, tm3, and tm4, respectively, the time difference between the reference communication unit 10 and the communication unit 20 becomes zero. Therefore, the arrival time difference ΔT12 of the positioning signal between the reference communication unit 10 and the communication unit 20 can be obtained by, for example, ΔT12 = | tm1−tm2 |. Similarly, the arrival time differences ΔT13 and ΔT14 between the reference communication unit 10 and the other communication units 30 and 40 can be obtained by ΔT13 = | tm1−tm3 | and ΔT14 = | tm1−tm4 |.

  When the time lag has already been calculated but the time lag has not been corrected, for example, the reception time at the reference communication unit 10 is tm1, the reception time at the communication unit 20 is tm2, and both If the time difference between the communication units 10 and 20 is Δt12, the arrival time difference ΔT12 can be obtained by | tm1−tm2 | −Δt12. When Δt12> 0, the time of the second communication unit 20 is ahead of the time of the reference communication unit 10, and when Δt12 <0, the time of the second communication unit 20 is the reference communication unit. It is later than 10 time.

The position specifying unit 54 specifies the position of the in-vehicle device 200 based on the arrival time differences ΔT12, ΔT13, and ΔT14 calculated by the arrival time difference calculation unit 53. For example, the propagation path difference obtained by integrating the propagation speed (3 × 10 ⁸ m / s) of the radio wave with the arrival time difference ΔT12 between the two communication units 10 and 20 with the position of the two communication units 10 and 20 as a focus. Rotating hyperboloids with the same can be identified. Such a rotational hyperboloid can be specified for each pair of the reference communication unit 10 and the other communication units 20, 30, 40, and the position of the vehicle-mounted device 200 can be specified as an intersection of the rotary hyperboloids. it can. Even when positioning signals are transmitted from a large number of in-vehicle devices 200, it is possible to determine which in-vehicle device 200 is the positioning signal transmitted from the in-vehicle device ID. ,... Can be accurately identified.

  FIG. 7 is a schematic diagram illustrating an example of a method for specifying the position of the in-vehicle device 200. As shown in FIG. 7, the rotation hyperboloid AB can be identified based on the arrival time difference ΔT12 between the reference communication unit 10 and the communication unit 20, and similarly, the reference communication unit 10 and the communication unit 30. The rotation hyperboloid AC can be specified based on the arrival time difference ΔT13 between the reference communication unit 10 and the rotation hyperboloid AD based on the arrival time difference ΔT13 between the reference communication unit 10 and the communication unit 30. Can do. The position of the in-vehicle device 200 can be specified as an intersection of the rotation hyperboloid AB, the rotation hyperboloid AC, and the rotation hyperboloid AD.

  The storage unit 55 is a replica signal of a pilot signal of the time correction signal and the positioning signal, the time lag of each communication unit calculated by the time lag calculation unit 51, the processing data processed by the roadside device 100, and the communication units 10 to 10. 40 installation positions or separation distances are stored.

  FIG. 8 is a schematic diagram illustrating an installation example of the roadside machine 100. In the example of FIG. 8, the communication units 10 to 40 are installed in a vehicle that travels in the vicinity of the intersection by, for example, installing the communication units 10 to 40 at positions corresponding to the vertices of a square having a side of about 30 m. The position of the mounted on-vehicle device 200 (vehicle) can be specified. In addition, the installation example of the roadside machine 100 is an example, and is not limited thereto. For example, the communication units 10 to 40 can be installed so as to surround a plurality of intersections. Moreover, what is necessary is just to determine the installation position of the main body of the roadside machine 100 suitably.

  Next, the operation of the roadside machine 100 will be described. 9 is a flowchart showing the time correction processing procedure of the roadside device 100. The control unit 50 determines whether or not the reference communication unit 10 has received a time correction signal from the other communication units 20, 30, and 40 (S11), and has not received the time correction signal (S11). NO), the process of step S11 is continued. In addition, the control part 50 can control each communication part 20,30,40 so that the signal for positioning may be transmitted in a predetermined time interval in order to monitor the time lag in each communication part 10-40.

  When the reference communication unit 10 receives a time correction signal (YES in S11), the control unit 50 measures the reception time (S12), and the reception time and the time transmitted from each communication unit 20, 30, 40 A time difference from the transmission time included in the correction signal is calculated (S13).

  The control unit 50 determines whether or not the calculated time difference is equal to a predetermined value (S14). Here, the predetermined value is a propagation time of radio waves between the reference communication unit 10 and each of the other communication units 20, 30, and 40. When the calculated time difference is equal to the radio wave propagation time, it can be determined that there is no time difference between the communication units.

  When the calculated time difference is not equal to the predetermined value (NO in S14), the control unit 50 determines a time lag between the communication units based on the calculated time difference (S15), performs time correction (S16), and processing Exit. When the calculated time difference is equal to the predetermined value (YES in S14), the control unit 50 ends the process on the assumption that time correction is not necessary.

  Note that the process of FIG. 9 can be repeated as appropriate. Thereby, while monitoring the time lag between each communication part in real time, the time lag can be eliminated and the time between each communication part can be maintained at the same time.

  FIG. 10 is a flowchart illustrating a processing procedure of the position specifying process of the in-vehicle device 200 of the roadside device 100. The control unit 50 determines whether or not a positioning signal has been received from the in-vehicle device 200 (S21). When the positioning signal has not been received (NO in S21), the process of step S21 is continued.

  When the positioning signal is received (YES in S21), the control unit 50 measures the reception time at each of the communication units 10 to 40 (S22), and calculates the arrival time difference of the positioning signal between the communication units (S23). ). Based on the calculated arrival time difference, the control unit 50 focuses on the position of the two communication units, and the rotation hyperboloid having the same propagation path difference obtained by adding the propagation speed of the radio wave to the arrival time difference between the two communication units. Is specified (S24). Note that the control unit 50 identifies such a rotational hyperboloid for each pair of communication units.

  The controller 50 specifies the intersection of the rotating hyperboloid as the position of the in-vehicle device 200 (S25). The control unit 50 determines whether or not there is an instruction to end the process (S26). If there is no end instruction (NO in S26), the control unit 50 continues the process after step S21, and if there is an end instruction (YES in S26), performs the process. finish.

Embodiment 2
In Embodiment 1 described above, the configuration includes four communication units, but the number of communication units is not limited to this. For example, the number of communication units can be limited to two by considering the road shape information of the road on which the vehicle on which the vehicle-mounted device 200 is mounted, the height information of the mounting position of the vehicle-mounted device 200, and the like. Hereinafter, the case of the roadside machine 100 provided with the two communication parts 10 and 20 is demonstrated. In this case, the roadside device 100 is configured to exclude the third communication unit 30 and the fourth communication unit 40 in the example of FIG.

  FIG. 11 is an explanatory diagram showing the structure of road shape information. As shown in FIG. 11, the road shape information is configured by dividing a road into sections of a predetermined distance (for example, 20 m) by a plurality of nodes, and information such as distance, gradient, and curvature for each section. When the road is a straight line, nodes are set on one straight line along the road, and when the road is a curve, nodes (for example, two nodes) are set on a plurality of straight lines along the road. Thereby, even when the road is inclined by the curve, the plane determined by the two straight lines can be specified.

  The road shape information may be stored in advance in the storage unit 55, and information relating to a road existing in an area where the position of the in-vehicle device 200 is specified by the roadside device 100 may be stored.

  FIG. 12 is an explanatory diagram illustrating an example of specifying the position of the in-vehicle device 200 according to the second embodiment. In this case, the reference communication unit 10 and the communication unit 20 are installed with appropriate length separation (separation distance is known). When a positioning signal is received from the in-vehicle device 200 at a certain point P1 on the road, the control unit 50 calculates the arrival time ΔT1 of the positioning signal in each of the communication units 10 and 20. The control unit 50 calculates the distance corresponding to the arrival time difference ΔT1 by adding the speed of light to the arrival time difference ΔT1 of the positioning signal, and makes the calculated distances equal to each other with the positions of the communication units 10 and 20 as the focal point. The hyperboloid W1 is specified. That is, it can be seen that the position of the vehicle-mounted device 200 is on the rotating hyperboloid W1.

  On the other hand, the control unit 50 specifies the virtual traveling surface of the vehicle based on the road shape information of the road (link: road between intersections) on which the vehicle on which the vehicle-mounted device 200 is mounted and the height information of the vehicle-mounted device 200. . When the road is a straight road, the traveling surface is a plane, and when the road is curved, the traveling surface is a curved surface.

  The control unit 50 specifies the position of the in-vehicle device 200 as an intersection line intersecting the rotating hyperboloid W1 and the traveling surface. Thereby, it becomes possible to specify the position of the vehicle-mounted device 200 with high accuracy only by providing the two communication units 10 and 20.

  If the vehicle continues to travel and transmits a positioning signal at a point P2 on the road, as in the case of the point P1, the control unit 50 adds the speed of light to the arrival time difference ΔT2 of the positioning signal, A distance corresponding to the arrival time difference ΔT2 is calculated, and the rotational hyperboloid W2 having the calculated distances equal to each other with the positions of the communication units 10 and 20 as a focus is specified.

  On the other hand, when the control unit 50 receives a positioning signal from each of the communication units 10 and 20, the control unit 50 uses the road shape information of the road on which the vehicle on which the vehicle-mounted device 200 is mounted and the height information of the vehicle-mounted device 200 to determine the virtual of the vehicle. Specific driving surface.

  The control unit 50 specifies the position of the in-vehicle device 200 as an intersection line intersecting the rotating hyperboloid W2 and the traveling surface. Thereafter, by repeating the same operation, the control unit 50 can continue to specify the position of the in-vehicle device 200 by receiving the positioning signal each time the in-vehicle device 200 transmits the positioning signal. In this case, the width of the running surface corresponds to the lane width (or road width in the case of multiple lanes), but it is considered that the vehicle runs almost in the center of the lane, so the error in the width direction of the running surface is acceptable. Is within.

  Thereby, the position of the vehicle equipment 200 can be specified with high accuracy by installing two communication units. In addition to the road shape information, the position of the in-vehicle device 200 can be specified with higher accuracy by considering the height information of the in-vehicle device 200.

Embodiment 3
In the position specifying device or the position specifying system of the above-described first and second embodiments, the vehicle-mounted device 200 itself may be configured to have an autonomous vehicle presence position measuring function using GPS or the like. In this case, the in-vehicle device 200 can exchange information on the own vehicle presence position measured autonomously with the in-vehicle devices of other vehicles traveling in the vicinity. By transmitting and receiving mutual position information between the vehicle-mounted devices 200, the vehicle-mounted device 200 of each vehicle is how many vehicles exist around the vehicle, how close the vehicle is, and so on. Can be grasped, and it becomes possible to support the driver's safe driving.

  In such an apparatus or system, the vehicle position that each vehicle autonomously recognizes may have an error that is greater than or equal to a predetermined value. If there is an error in the location information that exceeds a certain level, it may be misunderstood that the other vehicle that received the location information is actually separated by some distance, but this increases traffic safety. May not be suitable for the purpose. Therefore, by adopting the configuration in which the roadside device 100 shown in the first and second embodiments is arranged, the position of each vehicle is measured by the roadside device 100, and the position information transmitted and received by the in-vehicle device 200 is determined by the roadside device. 100 is intercepted and roadside device 100 warns vehicle-mounted device 200 when vehicle-side device 100 grasped by roadside device 100 and vehicle-mounted device 200 itself have an error greater than or equal to a predetermined position. You can send information.

  The above warning information includes, for example, information on the position of the vehicle measured by the roadside device 100 and information that can be known to what extent the error is, and the autonomous positioning function of the in-vehicle device 200 itself. It is desirable to be able to immediately grasp that there is a problem with Furthermore, warning information is also sent to the vehicle-mounted device 200 of the vehicle traveling around the vehicle having a problem with the autonomous positioning function, and there is an error in the position information of the specific vehicle transmitted / received by inter-vehicle communication. You can also let them know.

  As described above, in the present invention, positioning by the roadside device 100 can be used as a complement to the autonomous positioning function of the vehicle.

  As described above, in the present invention, the time lag between communication units can be monitored in real time, and when a predetermined signal transmitted by the in-vehicle device is received by each communication unit, each communication unit Can be accurately obtained. For this reason, the arrival time difference between the communication units can be accurately calculated without including information on the transmission time point in the predetermined signal transmitted from the in-vehicle device, and the position of the in-vehicle device can be accurately identified.

  In the above-described embodiment, the roadside unit 100 includes the communication units 10 to 40. However, the communication units 10 to 40 can be configured as separate communication devices. In addition, the control unit 50, the time difference calculation unit 51, the time correction unit 52, the arrival time difference calculation unit 53, the position specifying unit 54, and the storage unit 55 of the roadside device 100 can be configured in the reference communication unit 10. The roadside machine as the position specifying device is an example, and can be realized as another device such as a signal controller.

  In the above-described embodiment, when the position of the in-vehicle device 200 is specified by the roadside device 100, the specified position may be transmitted to the original in-vehicle device 200. Further, even when there are a large number of vehicle-mounted devices 200, the vehicle-mounted device ID indicates which vehicle-mounted device 200 should be transmitted. In this case, by using the present invention, for example, the display information of the traffic signal ahead can be received by the in-vehicle device 200, and whether or not it can be safely stopped before the intersection based on the received display information, or It is possible to determine with high accuracy whether or not the intersection can be safely passed, and to alert the driver with voice according to the determination result. Moreover, based on the display information of the traffic signal received by the in-vehicle device 200, it can be determined with high accuracy whether or not it is possible to safely pass through the intersection, and the vehicle brake control can be performed according to the determination result, Traffic accidents can be prevented and traffic safety can be improved.

  In the above embodiment, the time lag is calculated and the time lag is corrected. However, the present invention is not limited to this, and the time measuring means may be constituted by a timer or a counter in addition to the clock. It is also possible to calculate the deviation of the count values and correct the deviation of the count values. In other words, the time lag includes these count values.

  In the above-described embodiment, the in-vehicle device has been described as an example of the terminal device. However, the terminal device is not limited to the in-vehicle device, and a portable communication device (for example, a pedestrian or the like) carried by a moving person (for example, It may be a mobile phone, a PDA having a communication function, a music / video playback device, a notebook personal computer, or the like.

  The disclosed embodiments are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a block diagram showing an example of composition of a roadside machine as a position specifying device concerning the present invention. It is a schematic diagram which shows an example of installation of each communication part. It is explanatory drawing which shows the example of the data structure contained in the signal for time correction. It is explanatory drawing which shows the example of calculation of the reception time of the signal for time correction. It is a schematic diagram which shows an example in which a vehicle equipment transmits the signal for positioning. It is explanatory drawing which shows the example of the data structure contained in the signal for positioning. It is a schematic diagram which shows an example of the method of specifying the position of vehicle equipment. It is a schematic diagram which shows the example of installation of a roadside machine. It is a flowchart which shows the process sequence of the time correction of a roadside machine. It is a flowchart which shows the process sequence of the position specific process of the vehicle equipment of a roadside machine. It is explanatory drawing which shows the structure of road shape information. It is explanatory drawing which shows the example which pinpoints the position of the vehicle equipment of Embodiment 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 1st communication part 20 2nd communication part 30 3rd communication part 40 4th communication part 11, 21, 31, 41 Clock 50 Control part 51 Time shift calculation part 52 Time correction part 53 Arrival time difference calculation part 54 Position specification part 55 Storage unit 100 Roadside device 200 In-vehicle device

Claims (6)

A position specifying device that includes at least two communication units with known separation distances, receives a predetermined signal transmitted by a terminal device at each communication unit, and specifies the position of the terminal device,
Each communication department
With timekeeping means,
Other communication departments except for one communication department
It is configured to transmit a timing correction signal including a transmission time point to the one communication unit,
The one communication unit is:
It is configured to receive the time correction signal,
A time lag calculating means for calculating a time lag with another communication unit based on the reception time of the received timing correction signal and the transmission time and the separation distance between the communication units;
Time difference calculation means for calculating a time difference between arrival times of the predetermined signal to the communication unit based on the reception time of the predetermined signal transmitted by the terminal device at each communication unit and the time difference calculated by the time difference calculation means. When,
And a specifying unit that specifies the position of the terminal device based on the time difference calculated by the time difference calculating unit. In accordance with the time lag calculated by the time lag calculating means, the correction means for correcting the time in each time measuring means,
The time difference calculating means includes
The time difference between the arrival times of the signals to the communication unit is calculated based on the reception time of the predetermined signal transmitted by the terminal device at each communication unit and the time corrected by the correction unit. The position specifying device according to claim 1, wherein The predetermined signal is:
The position specifying device according to claim 1 or 2, comprising information indicating that the signal is a signal for specifying the position of the terminal device and an identifier unique to the terminal device. Storage means for storing road shape information of an area for specifying the position of the terminal device;
The specifying means is:
The position specifying device according to any one of claims 1 to 3, wherein the position of the terminal device is specified using the stored road shape information. Comprising storage means for storing height information of the position of the terminal device;
The specifying means is:
The position specifying device according to any one of claims 1 to 4, wherein the position of the terminal device is specified by using the stored height information.   A terminal device that transmits a predetermined signal and the position specifying device according to any one of claims 1 to 5, wherein the position of the terminal device is specified. Location system to do.

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