JP2011033413A - Wireless device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wireless device capable of acquiring highly-accurate position information. <P>SOLUTION: This wireless device 10 loaded on a vehicle CA1 operates a pseudo distance P1 between the vehicle CA1 and GPS satellites R1, R3-R6 based on GPS signals received from the GPS satellites R1, R3-R6 for transmitting the GPS signals receivable in common by a wireless device 10 loaded on a vehicle CA2, and receives a pseudo distance P2 between the vehicle CA2 and the GPS satellites R1, R3-R6 from a wireless device 10 loaded on the vehicle CA2. The wireless device 10 loaded on the vehicle CA1 further operates a pseudo distance difference which is a difference between the pseudo distance P1 and the pseudo distance P2, and detects an altitude difference between the vehicle CA1 and the vehicle CA2 by using a three-dimensional electronic map. The wireless device 10 loaded on the vehicle CA1 furthermore operates a relative position between the vehicle CA1 and the vehicle CA2 based on the pseudo distance difference and the altitude difference. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a wireless device, and more particularly to a wireless device that estimates the position of a moving object.

  In a vehicle-to-vehicle communication network, it has been studied to improve driving safety by exchanging position information between vehicles.

  Each vehicle can reduce traffic accidents by maintaining a safe distance based on the relative distance between vehicles calculated based on position information obtained through inter-vehicle communication. In addition, by utilizing the position information, not only cars but also pedestrians can be protected if the distance between the person and the car is maintained. Such an application requires highly accurate position information within 1 m.

  A GPS (Global Positioning System) receiver of each vehicle needs to receive signals from four or more satellites in order to calculate position information of the own vehicle. In an urban area where many tall buildings are adjacent to each other, signals from GPS satellites are often shielded by the buildings, and the number of satellites that transmit GPS signals that can be received by the GPS receiver is often three or less. In such a case, it is difficult to maintain the accuracy of the position information by GPS single positioning.

  Therefore, it has been proposed to improve the accuracy of position information using differential GPS (Non-Patent Document 1). More specifically, it has been proposed to remove the influence of the ionosphere and improve the accuracy of position information by using spatial correlation of signals received by a plurality of GPS receivers.

  There is also a technique for temporarily predicting the position of a vehicle using the speed and movement speed of the vehicle in a place where the number of satellites transmitting GPS signals that can be received by the GPS receiver is small and GPS independent positioning is not possible. It has been proposed (Non-Patent Document 2).

  Furthermore, in RTK (Real Time Kinetic) -GPS, a technique for reducing the search range of a FIX solution (again, a least-squares solution) using a highly accurate three-dimensional electronic map has been proposed (Non-patent Document 3).

B. Hoffmann-Wellenhof, H. Lichtenegger and J. Collins, “GPS Theory and Practice,” Third edition, Springer-Verlag Wien New York, 1994. Oliver J. Woodman, “An introduction to inertial navigation,” University of Cambridge, Technical report, UCAM-CL-TR-696, 2007. Nobuaki Kubo, Akio Yasuda, "Precision positioning of mobile objects using advanced information in ITS," IEICE Transactions, Vol. J91-A, no. 1, pp. 122-129.

  However, in Non-Patent Document 1, since the differential GPS is used, the accuracy of the position information deteriorates in a place where the differential GPS correction signal does not reach. In addition, when the moving body moves away from the reference station, the accuracy of the position information deteriorates.

  Further, in Non-Patent Document 2, the accuracy is not so high, but errors in position information are accumulated.

  Furthermore, in Non-Patent Document 3, RTK-GPS does not operate normally in places where differential GPS signals do not reach or where the number of GPS satellites that transmit GPS signals that can be received by the GPS receiver is small.

  Accordingly, the present invention has been made to solve such a problem, and an object of the present invention is to provide a radio apparatus capable of acquiring position information with high accuracy.

  According to this invention, the wireless device is mounted on the first moving body, and the relative position between the second moving body adjacent to the first moving body and the first moving body or the absolute value of the first moving body. A wireless device for obtaining a position, comprising a GPS receiver, a map holding means, a selection means, and a calculation means. The GPS receiver receives GPS signals from GPS satellites. The map holding means holds a three-dimensional electronic map in which the coordinate values obtained by adding the slope of the road to the altitude, longitude, and latitude from the ellipsoid representing the earth are used as the position of each moving body on the map. Based on the GPS signal received by the GPS receiver, the selection unit transmits a GPS signal that can be received by both the wireless device and the other wireless device mounted on the second mobile unit m (m is Select an integer of 4 or more GPS satellites. The computing means is based on m GPS signals received by the GPS receiver from m GPS satellites, and has a reference point as the origin and is perpendicular to the ellipsoid representing the east direction, the north direction, and the earth from the reference point. In a horizon Cartesian coordinate system defined by three axes oriented in a direction, a first pseudorange indicating a distance between m GPS satellites and a first mobile body, m GPS satellites and a second A second pseudo distance indicating a distance to the moving object is calculated, and a pseudo distance difference between the calculated first pseudo distance and the second pseudo distance is calculated, and the first pseudo distance indicated by longitude and latitude is calculated. The height of the first moving body at the position of the moving body and the height of the second moving body at the position of the second moving body indicated by the longitude and latitude are detected with reference to the three-dimensional electronic map, and the detected The altitude of the first mobile and the second mobile The difference between degrees is calculated as a relative position component between the first moving body and the second moving body in a direction perpendicular to the ellipsoid representing the earth in the horizon orthogonal coordinate system, and the calculated relative position component and the calculated pseudo position Based on the distance difference, an error difference between the error of the first pseudo distance and the error of the second pseudo distance is calculated, the calculated error difference is subtracted from the pseudo distance difference, and the GPS signal from the reference point is added to the subtraction result. The relative position between the first moving body and the second moving body in the east and north directions of the horizon orthogonal coordinate system is calculated by multiplying the inverse matrix of the matrix indicating the error of the true distance to the satellite.

  Preferably, the wireless device further includes position calculation means and reception means. The position calculation means is a first positioning unit that indicates a position of the first moving body in a positioning coordinate system composed of altitude, longitude, and latitude, based on m GPS signals received from m GPS satellites by the GPS receiver. The position information and the first pseudo distance are calculated. The receiving means receives a position information message including the second positioning position information indicating the position of the second moving body in the positioning coordinate system and the second pseudo distance from another wireless device. The calculating means calculates a pseudo distance difference based on the first pseudo distance calculated by the position calculating means and the second pseudo distance included in the position information message, and calculates the first distance calculated by the position calculating means. Based on the positioning position information and the three-dimensional electronic map, the altitude of the first moving body at the position indicated by the longitude and latitude included in the first positioning position information is detected, and the second positioning included in the position information message Based on the position information and the three-dimensional electronic map, the altitude of the second moving body at the position indicated by the longitude and latitude included in the second positioning position information is detected.

  Preferably, the wireless device further includes a position predicting unit and a receiving unit. Based on m GPS signals received by the GPS receiver from m GPS satellites, the position prediction means uses the north pole direction of the earth's rotation axis as the z axis and the direction of the Greenwich meridian perpendicular to the z axis as the x axis. And a first fixed position indicating a position of the first moving body at a first timing in a fixed orthogonal coordinate system in which the direction determined by using the right-hand system so as to be orthogonal to the z axis and the x axis is the y axis. Information is calculated, and the calculated first fixed position information is used as a reference point to calculate first horizon position information indicating the position of the first moving body at the first timing in the horizon orthogonal coordinates, and the calculated first The second horizon position information indicating the position of the first moving body at the second timing after the first timing is predicted using the first horizon position information, the speed and the moving method of the first moving body. . The receiving means receives a position information message including the second positioning position information indicating the position of the second moving body in the positioning coordinate system and the second pseudo distance from another wireless device. Then, the calculation means converts the second horizon position information into second fixed position information indicating the position of the first moving body in the fixed orthogonal coordinate system, and the converted second fixed position information is determined by the positioning coordinate system. Is further converted into first positioning position information indicating the position of the first mobile body, and the longitude and latitude included in the first positioning position information based on the converted first positioning position information and the three-dimensional electronic map Is detected as the altitude of the first mobile body, and the longitude included in the second positioning position information based on the second positioning position information and the three-dimensional electronic map included in the position information message The altitude at the position indicated by the latitude is detected as the altitude of the second moving body.

  Preferably, the second positioning position information includes positioning position information actually measured by another wireless device or positioning position information predicted by another wireless device.

  Preferably, the calculation means further calculates the absolute position of the first moving body based on the calculated relative position and the absolute position of the second moving body.

  According to the present invention, the wireless device is mounted on the first moving body, has the reference point as the origin, and faces the direction perpendicular to the east, north, and ellipsoid representing the earth from the reference point. A wireless device for obtaining an absolute position of a first moving body in a horizon orthogonal coordinate system defined by three axes, comprising a GPS receiver, a map holding means, and a computing means. The GPS receiver receives GPS signals from GPS satellites. The map holding means holds a three-dimensional electronic map in which the coordinate values obtained by adding the slope of the road to the altitude, longitude, and latitude from the ellipsoid representing the earth are used as the position of each moving body on the map. The calculating means calculates a first pseudo distance indicating a distance between the four or more GPS satellites and the first moving body in the horizon orthogonal coordinate system based on the GPS signal received by the GPS receiver, The error of pseudorange in the horizon orthogonal coordinate system of k (k is an integer greater than or equal to 4) second mobile bodies and the first mobile body and the GPS satellite group adjacent to the mobile body from the first pseudorange The first corrected pseudorange corrected by subtraction is calculated, and the absolute position of the first moving body is calculated based on the calculated first corrected pseudorange and the positions of four or more GPS satellites. Then, the error of the pseudorange is the first movement detected based on the first positioning position information indicating the position of the first moving body in the positioning coordinate system composed of altitude, longitude and latitude, and the three-dimensional electronic map. The first altitude difference of the body and the k second positioning position information indicating the positions of the k second moving bodies in the positioning coordinate system and the k second positions detected based on the three-dimensional electronic map. A first change rate that is a change rate at a reference point of a first true distance between the first mobile object and four or more GPS satellites; K second change rates that are change rates at reference points of k second true distances that are true distances between each of the second mobile units and four or more GPS satellites. Based on. In addition, four or more GPS satellites that are targets of the first true distance and the k second true distances are defined between the first true distance and the k second true distances. It is different.

  Preferably, the calculation means further includes the pseudo distance based on the k second height differences, the first height difference, the first true distance, and the k second true distances. An error is calculated, and the absolute position of the first moving body is calculated using the calculated pseudo-range error.

  Preferably, the wireless device further includes receiving means. The receiving means receives an error in pseudorange from any one of the k second moving bodies. Then, the calculation means further calculates the absolute position of the first moving body using the error of the pseudo distance received by the reception means.

  The wireless device according to the present invention is based on a GPS signal received from a GPS satellite, and a first pseudo-range between the first mobile unit and the GPS satellite and a first pseudo-range between the second mobile unit and the GPS satellite. A pseudo distance difference which is a difference from the pseudo distance of 2 is calculated, and a relative position between the first moving body and the second moving body is calculated using the calculated pseudo distance difference. As a result, the relative position between the first moving body and the second moving body is calculated while suppressing the influence of the ionosphere and the troposphere.

  Therefore, according to the present invention, the accuracy of the relative position can be increased.

  The wireless device according to the present invention calculates a pseudorange error that is an error of a pseudorange between the moving body and the GPS satellite, and subtracts the calculated pseudorange error from the pseudorange to obtain a corrected pseudorange. The absolute position of the moving body on which the wireless device is mounted is calculated using the calculated correction pseudorange and the position of the GPS satellite. As a result, the absolute position of the moving body on which the wireless device is mounted is calculated using a pseudo distance with high accuracy.

  Therefore, according to the present invention, the accuracy of the absolute position can be improved.

It is a block diagram of the radio | wireless apparatus by Embodiment 1 of this invention. 1 is a model diagram of a vehicle-to-vehicle communication network according to an embodiment of the present invention. It is a conceptual diagram of the coordinate system in embodiment of this invention. 3 is a conceptual diagram of a location information message in the first embodiment. FIG. It is a conceptual diagram for demonstrating the premise when calculating | requiring a relative position. It is a figure which shows the specific example of a positional info message. 5 is a flowchart for illustrating a method for obtaining a relative position between adjacent vehicles according to the first embodiment. 6 is a configuration diagram of a radio apparatus according to Embodiment 2. FIG. 10 is a flowchart for explaining a method for obtaining a relative position between adjacent vehicles according to the second embodiment. FIG. 6 is a configuration diagram of a radio apparatus according to a third embodiment. 10 is a flowchart for illustrating a method of calculating the absolute position of a vehicle according to a third embodiment. FIG. 10 is a configuration diagram of a radio apparatus according to a fourth embodiment. FIG. 16 is a conceptual diagram of a location information message in the fourth embodiment. 10 is a flowchart for illustrating a method for obtaining an absolute position of a vehicle according to a fourth embodiment.

  Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[Embodiment 1]
FIG. 1 is a configuration diagram of a radio apparatus according to Embodiment 1 of the present invention. Referring to FIG. 1, radio apparatus 10 according to Embodiment 1 of the present invention includes antenna 1, transmission / reception means 2, processing means 3, map holding means 4, GPS receiver 5, and message generation means 6. With.

  The wireless device 10 is mounted on a vehicle. The antenna 1 receives a position information message from another wireless device and outputs the received position information message to the transmission / reception means 2. Further, the antenna 1 receives the position information message from the transmission / reception means 2 and transmits the received position information message.

  The transmission / reception means 2 receives the position information message from the message generation means 6 and broadcasts the received position information message via the antenna 1. Further, the transmission / reception means 2 receives the position information message via the antenna 1 and outputs the received position information message to the processing means 3.

  The processing unit 3 receives a position information message from the transmission / reception unit 2, reads a three-dimensional electronic map from the map holding unit 4, and receives a GPS signal from the GPS receiver 5. Then, the processing means 3 calculates the position of the vehicle CA1 on which the wireless device 10 is mounted based on the GPS signal by a method described later. In addition, the processing unit 3 calculates a pseudo distance between the GPS satellite and the wireless device 10 using a propagation time during which the GPS signal propagates from the GPS satellite to the wireless device 10. Then, the processing means 3 outputs the position information indicating the calculated position of the vehicle CA1 and the pseudo distance to the message generating means 6.

  Further, the processing means 3 calculates a relative position between the vehicle CA1 and a vehicle adjacent to the vehicle CA1 by a method described later based on the position information message, the GPS signal, and the three-dimensional electronic map.

  Map holding means 4 holds a three-dimensional electronic map. This three-dimensional electronic map is a map of coordinate values (λ, φ, h, β) obtained by adding the slope β of the road on which the vehicle travels to the positioning coordinate values (λ, φ, h) measured by RTK-GPS. It consists of a structure corresponding to the position of each vehicle in the above.

  Here, λ is longitude, φ is latitude, and h is altitude in the vertical direction from the ellipsoid representing the earth. The coordinate system represented by (λ, φ, h) constitutes a “positioning coordinate system”.

  The GPS receiver 5 receives a GPS signal from a GPS satellite and detects a reception time when the GPS signal is received. Then, the GPS receiver 5 associates the received GPS signal with the GPS satellite that transmitted the GPS signal, and outputs the associated GPS signal: GPS satellite and reception time to the processing means 3. Signal: A GPS satellite is output to the message generator 6.

  The message generation means 6 receives the position information and pseudo distance of the vehicle CA1 from the processing means 3, and receives GPS signals: GPS satellites from the GPS receiver 5. Then, the message generation means 6 generates a position information message by a method described later based on the received position information, pseudo distance and GPS signal: GPS satellite of the vehicle CA1, and transmits / receives the generated position information message. Output to 2.

  FIG. 2 is a model diagram of the inter-vehicle communication network according to the embodiment of the present invention. Referring to FIG. 2, each of vehicles CA <b> 1 to CAk (k is an integer equal to or greater than 4 and i is an integer satisfying 1 ≦ i ≦ k) is equipped with radio apparatus 10. The vehicles CA1 to CAk are traveling on the road.

  The radio apparatus 10 mounted on the vehicle CAi receives GPS signals from m (m is an integer of 4 or more) GPS satellites R1 to Rm, and based on the received GPS signals, the vehicle is The relative position between the vehicle adjacent to CAi and the vehicle CAi is calculated.

  Similarly to the wireless device 10 mounted on the vehicle CAi, the wireless device 10 mounted on each of the vehicles CA1 to CAi-1 and CAi + 1 to CAk other than the vehicle CAi is similar to the vehicle mounted on the vehicle CAi and the adjacent vehicle. The relative position between is calculated.

  FIG. 3 is a conceptual diagram of a coordinate system in the embodiment of the present invention. Referring to FIG. 3, the earth-centered earth fixed orthogonal coordinate (ECFF) is a coordinate system including an X axis, a Y axis, and a Z axis. In this case, the Z-axis faces the north pole direction of the earth's rotation axis, and the X-axis faces the Greenwich meridian direction perpendicular to the Z-axis. The Y axis is an axis determined by the right-hand system so as to be orthogonal to the X axis and the Z axis. That is, when the right thumb, middle finger, and index finger are opened so as to be orthogonal to each other, the thumb is directed in the Z-axis direction, and the index finger is directed in the X-axis direction, the direction toward the middle finger is the Y-axis.

  In the following, the earth-centered earth fixed orthogonal coordinates are simply referred to as “fixed orthogonal coordinates”.

In addition, the horizon orthogonal coordinate is based on a reference point r ₀ , which is an arbitrary point on the ground surface, where e is the east direction, n is the north direction, and u is the direction perpendicular to the ellipsoid representing the earth. e, n, u).

  Further, the positioning coordinates are composed of (λ, φ, h) as described above.

  FIG. 4 is a conceptual diagram of a location information message in the first embodiment. Referring to FIG. 4, location information message PSM includes a header and payloads 1 and 2. The header (Header) includes a transmission source (SRC) and a transmission destination (DST). The source (SRC) consists of the address of the wireless device that transmits the location information message. The transmission destination (DST) consists of a broadcast address (= 0xff).

  Payload 1 consists of a vehicle position. The vehicle position consists of positioning coordinate values (λ, φ, h).

  The payload 2 consists of a satellite bitmap and a pseudorange. The satellite bitmap represents whether or not the GPS receiver 5 receives GPS signals from the GPS satellites R1 to Rm. In FIG. 4, the satellite bitmap represents, for example, the presence or absence of reception of GPS signals from 30 GPS satellites. A is “1” when the GPS receiver 5 can receive the GPS signal, and “0” when the GPS receiver 5 cannot receive the GPS signal.

  The pseudo distance represents a distance between each vehicle and each GPS satellite, and is a distance calculated using a propagation time when the GPS signal propagates from the GPS satellite to the wireless device 10. More specifically, the pseudorange is composed of the distance between each vehicle and the GPS satellite that has transmitted the GPS signal received by the wireless device 10, and the number of pseudoranges is “1” stored in the satellite bitmap. It is the same as the number of "".

  FIG. 5 is a conceptual diagram for explaining the premise for obtaining the relative position. FIG. 6 is a diagram showing a specific example of the location information message.

  Referring to FIG. 5, radio device 10 mounted on vehicle CA1 receives GPS signals from GPS satellites R1, R3-R7 among GPS satellites R1-Rm, and radio device 10 mounted on vehicle CA2 The GPS signals are received from the GPS satellites R1 to R6 among the GPS satellites R1 to Rm.

  The method for obtaining the relative position according to the first embodiment will be described by taking as an example the case where the radio apparatus 10 mounted on the vehicle CA1 obtains the relative position between the vehicle CA2 adjacent to the vehicle CA1 and the vehicle CA1.

  The GPS receiver 5 of the wireless device 10 mounted on the vehicle CA1 receives the GPS signals GPS1, GPS3 to GPS7 from the GPS satellites R1, R3 to R7, respectively, and receives the GPS signals GPS1, GPS3 to GPS7. Receive times tr1, tr3 to tr7 are detected.

  The GPS receiver 5 of the wireless device 10 mounted on the vehicle CA1 corresponds to the received GPS signals GPS1, GPS3 to GPS7, and the GPS satellites R1, R3 to R7 that transmitted the GPS signals GPS1, GPS3 to GPS7. The associated GPS signal: GPS satellite = GPS1: R1, GPS3: R3-GPS7: R7 and reception times tr1, tr3-tr7 are output to the processing means 3, and the GPS signal: GPS satellite = GPS1: R1, GPS3: R3 to GPS7: R7 are output to the message generator 6.

  The processing means 3 of the wireless device 10 mounted on the vehicle CA1 receives the GPS signal: GPS satellite = GPS1: R1, GPS3: R3 to GPS7: R7 and reception times tr1, tr3 to tr7 from the GPS receiver 5. In this case, each of the GPS signals GPS1, GPS3 to GPS7 includes the parameters shown in Table 1.

Then, the processing unit 3 of the wireless device 10 mounted on a vehicle CA1 detects the transmission time _{t t} 1 of the GPS signal GPS1 included in the GPS signal GPS1, reception of transmission time _{t t} 1 and the GPS signal GPS1 that the detected The difference from the time tr1 is calculated to obtain the propagation time of the GPS signal GPS1 from the GPS satellite R1 to the vehicle CA1, and the obtained propagation time is multiplied by the light velocity c to calculate the pseudo distance P between the GPS satellite R1 and the vehicle CA1. _{Find 1} and ₁ .

Further, the processing unit 3 of the wireless device 10 mounted on a vehicle CA1, similarly, obtains a pseudorange _P 1, 3 _{to P 1, 7} of the GPS satellite R3~R7 and vehicle CA1.

Further, the processing means 3 of the wireless device 10 mounted on the vehicle CA1 substitutes the parameter included in the GPS signal GPS1 into the equation (1), and the fixed orthogonal coordinate value (= ECFF) = (X _k , Y _k , Z _k ) is calculated.

Hereinafter, in order to clarify that it is the fixed orthogonal coordinate value of the GPS satellite R1, the fixed orthogonal coordinate value (= ECFF) = (X _k , Y _k , Z _k ) is changed to (X ₁ , Y ₁ , Z ₁ ). Is written.

Similarly, the processing means 3 of the wireless device 10 mounted on the vehicle CA1 is based on the GPS signals GPS3 to GPS7, and the ECFF coordinate values of the GPS satellites R3 to R7 = (X ₃ , Y ₃ , Z ₃ ) to ( X ₇ , Y ₇ , Z ₇ ) are calculated.

Then, the processing means 3 of the wireless device 10 mounted on the vehicle CA1 has four pseudo distances selected from the pseudo distances P _1,1 , P _{1,3 to} P _1,7 (for example, P _1,1 , P ₁ , ₃ , P _1,4 , P _1,5 ) and GPS satellites R ₁ corresponding to the selected four pseudoranges P _1,1 , P _1,3 , P _1,4 , P _1,5 R3, R4, R5 of ECFF coordinate value _{= (X 1, Y 1,} Z 1), (X 3, Y 3, Z 3), (X 4, Y 4, Z 4), (X 5, Y 5, Based on Z ₅ ), a fixed orthogonal coordinate value = (x ₁ , y ₁ , z ₁ ) indicating the position of the vehicle CA1 is obtained.

In this case, ECFF coordinate values = (X ₁ , Y ₁ , Z ₁ ), (X ₃ , Y ₃ , Z ₃ ), (X ₄ , Y ₄ , Z ₄ ), (X ₅ , Y ₅ , Z ₅ ) To calculate the coordinate value of the intersection point when four spheres whose radii are centered at quasi-distances P _1,1 , P _1,3 , P _1,4 , P _1,5 intersect at one point Thus, the fixed orthogonal coordinate value = (x ₁ , y ₁ , z ₁ ) can be obtained.

Note that the processing means 3 includes four pseudo distances other than the pseudo distances P _1,1 , P _1,3 , P _1,4 , P _1,5 and ECFF coordinate values = (X ₁ , Y ₁ , Z ₁ ). , (X ₃ , Y ₃ , Z ₃ ), (X ₄ , Y ₄ , Z ₄ ), (X ₅ , Y ₅ , Z ₅ ), using the four ECFF coordinate values, the ECFF coordinate value of the vehicle CA1 The ECFF coordinate value of the vehicle CA1 may be obtained using five or more pseudo distances and five or more ECFF coordinate values.

When the processing means 3 of the wireless device 10 mounted on the vehicle CA1 obtains the position (x ₁ , y ₁ , z ₁ ) of the vehicle CA1, the obtained position (x ₁ , y ₁ , z ₁ ) To convert the fixed orthogonal coordinate values into positioning coordinate values (λ ₁ , φ ₁ , h ₁ ).

  In equation (2), a is the equator radius and b is the polar radius. N is N shown in FIG. That is, N is a distance between an intersection where a perpendicular is drawn from the vehicle to the earth plane and the perpendicular intersects the earth plane, and an intersection where the perpendicular intersects the Z axis.

Thereafter, the processing means 3 of the wireless device 10 mounted on the vehicle CA1 reads the three-dimensional electronic map from the map holding means 4. Then, the processing unit 3 of the wireless device 10 mounted on a vehicle CA1 refers to three-dimensional electronic map, the positioning coordinates _{(λ 1, φ 1, h} 1) coordinate values (λ _1, φ ₁₎ by The altitude h ′ at the indicated position is detected. That is, the processing means 3 of the wireless device 10 mounted on the vehicle CA1 is the same as the coordinate values (λ ₁ , φ ₁ ) among the coordinate values (λ, φ, h, β) stored in the three-dimensional electronic map. A coordinate value (λ ₁ , φ ₁ , h, β) having (λ, φ) is selected, and an altitude h is extracted by extracting the altitude h from the selected coordinate values (λ ₁ , φ ₁ , h, β). Detect '.

Then, the processing means 3 of the radio apparatus 10 mounted on the vehicle CA1 sends the positioning coordinate values (λ ₁ , φ ₁ , h ₁ ) and the pseudo distances P _1,1 , P _{1,3 to} P _1,7 as messages. Output to the generating means 6.

The message generation means 6 of the wireless device 10 mounted on the vehicle CA1 receives GPS signals: GPS satellites = GPS1: R1, GPS3: R3 to GPS7: R7 from the GPS receiver 5, and determines the positioning coordinate values (λ ₁ , φ ₁ , H ₁ ) and pseudoranges P _1,1 , P _{1,3 to} P _1,7 are received from the processing means 3.

  And the message generation means 6 of the radio | wireless apparatus 10 mounted in vehicle CA1 is based on GPS signal: GPS satellite = GPS1: R1, GPS3: R3-GPS7: R7, GPS receiver 5 is GPS satellite R1-Rm. Among these, it is detected that GPS signals can be received from the GPS satellites R1, R3 to R7.

  Thereafter, the message generator 6 of the wireless device 10 mounted on the vehicle CA1 stores the address Add1 of the wireless device 10 in the transmission source (SRC) and stores the broadcast address 0xff in the transmission destination (DST).

The message generation means 6 of the wireless device 10 mounted on the vehicle CA1 stores the positioning coordinate values (λ ₁ , φ ₁ , h ₁ ) in the vehicle position of the payload 1.

  Further, the message generator 6 of the wireless device 10 mounted on the vehicle CA1 sets the bitmap = [101111100000000000000000000] based on the fact that the GPS receiver 5 can receive GPS signals from the GPS satellites R1, R3 to R7. The generated bitmap = [101111100000000000000000000] is stored in the bitmap of the satellite of payload 2.

Further, the message generation means 6 of the wireless device 10 mounted on the vehicle CA1 stores the pseudo distances P _1,1 , P _{1,3 to} P _1,7 in the pseudo distance of the payload 2.

  Thereby, the message generation means 6 of the wireless device 10 mounted on the vehicle CA1 generates the position information message PSM1 (see FIG. 6A). Then, the message generation means 6 of the wireless device 10 mounted on the vehicle CA1 outputs the position information message PSM1 to the transmission / reception means 2, and the transmission / reception means 2 broadcasts the position information message PSM1 via the antenna 1.

  Similarly to the wireless device 10 mounted on the vehicle CA1, the wireless device 10 mounted on the vehicle CA2 generates the position information message PSM2 (see FIG. 6B) by the method described above, and the generated position. Broadcast information message PSM2.

  The transmission / reception means 2 of the wireless device 10 mounted on the vehicle CA1 receives the position information message PSM2 via the antenna 1, and outputs the received position information message PSM2 to the processing means 3.

The processing means 3 of the wireless device 10 mounted on the vehicle CA1 receives the position information message PSM2 from the transmission / reception means 2, and from the received position information message PSM2, the vehicle position (λ ₂ , φ ₂ , h ₂ ) of the vehicle CA2; Then, pseudo distances P _{2,1 to} P _2,6 are extracted.

  Further, the processing means 3 of the wireless device 10 mounted on the vehicle CA1 refers to the satellite bitmap of the position information message PSM2, and the wireless device 10 mounted on the vehicle CA2 is a GPS satellite among the GPS satellites R1 to Rm. It is detected that GPS signals can be received from the satellites R1 to R6.

  Then, the processing means 3 of the wireless device 10 mounted on the vehicle CA1 includes the GPS satellites R1, R3 to R7 that allow the wireless device 10 mounted on the vehicle CA1 to receive GPS signals, and the wireless device 10 mounted on the vehicle CA2. GPS satellite R1 that transmits a GPS signal that can be received by both radio apparatus 10 mounted on vehicle CA1 and radio apparatus 10 mounted on vehicle CA2 based on GPS satellites R1 to R6 that can receive GPS signals. , R3 to R6 are extracted.

Then, the processing means 3 of the wireless device 10 mounted on the vehicle CA1 simulates the pseudo distances P _1,1 , P _{1,3 to} P _1,7 in response to the extraction of the GPS satellites R1, R3 to R6. distance _P 1, _1, as well as select _P 1,3 _{~P 1,6,} select pseudorange _{P 2,1, P} 2,3 _{~P 2,6} from pseudorange _P 2,1 _{to P 2, 6} To do. That is, the processing means 3 of the wireless device 10 mounted on the vehicle CA1 is a pseudo distance P ₁ between the GPS satellites R1, R3 to R6 that transmit GPS signals that can be received by both the vehicles CA1 and CA2 and the vehicles CA1 and CA2. _{, 1} , P _{1,3 to} P _1,6 ; P _2,1 , P _{2,3 to} P _2,6 are selected.

Thereafter, the processing means 3 of the wireless device 10 mounted on the vehicle CA1 uses the pseudo distance matrix <P1> = [P _1,1 , P based on the pseudo distances P _1,1 , P _{1,3 to} P _1,6 . _P1,3 , _P1,4 , _P1,5 , _P1,6 ] ^T is generated. Further, the processing unit 3 of the wireless device 10 mounted on a vehicle CA1 is pseudoranges _{P 2,1,} based on P 2,3 _{to P 2, 6,} pseudorange matrix <P2> = _{[P 2,1, P 2,3, P 2,4, P 2,5} , and generates a _P ^{2,6] T.}

  In this specification, the notation <A> represents the matrix A.

Subsequently, the processing means 3 of the wireless device 10 mounted on the vehicle CA1 performs the already calculated ECFF coordinate values (X ₁ , Y ₁ , Z ₁ ), (X ₃ , Y ₃ , Z ₃ ), (X ₄ , Y ₄ , Z ₄ ), (X ₅ , Y ₅ , Z ₅ ), (X ₆ , Y ₆ , Z ₆ ) are converted into horizonal orthogonal coordinate values (E ₁ , N ₁ , U ₁ ), (E ₃ , N ₃ , U ₃ ), (E ₄ , N ₄ , U ₄ ), (E ₅ , N ₅ , U ₅ ), (E ₆ , N ₆ , U ₆ ) Convert to

In equation (3), (x ₀ , y ₀ , z ₀ ) = r ₀ is the coordinate value of the reference point.

Further, the processing means 3 of the wireless device 10 mounted on the vehicle CA1 determines the position (x ₁ , y ₁ , z ₁ ) consisting of the ECFF coordinate values of the vehicle CA1 from the horizon orthogonal coordinate value (e ₁ , n ₁ , u ₁ ).

Let P _{ij be} the pseudorange between the vehicle CAi and the GPS satellite Rj (j is an integer satisfying 1 ≦ j ≦ m), and the influence of the measurement error (Δt _i ) of the propagation time of the GPS signal on the pseudorange P _ij Assuming that δ _i = c × Δt _i and the error of pseudorange due to the effect on the propagation of GPS signals in the ionosphere and troposphere as ε _ij , the vehicle CAi and the GPS satellite Rj in the fixed orthogonal coordinate system (ECFF coordinate system) The following formula holds during

Then, _{<d (r i)>} the true distance to all of the GPS satellites R1~Rm from the vehicle _{CAi = [d 1 (r i} ), d 2 (r i), ···, d m (r i )] If ^T is a pseudorange from the vehicle CAi to all GPS satellites R1 to Rm, <P _i > = [P _i1 , P _i2 , P _i3 ,..., P _im ] ^T , Equation (4) Is given by

  In equation (5), matrix <1> is a unit matrix.

  Also in the horizon orthogonal coordinate system, Expression (5) is established, and the following expression is obtained for the vehicles CA1 and CA2.

In equation (6), the matrix <d (r ₀ )> is from the reference point r ₀ = (x ₀ , y ₀ , z ₀ ) to the GPS satellite (the GPS satellite from which the wireless device 10 receives a GPS signal). The matrix <D (r ₀ )> represents a change rate of the distance d (r ₀ ). Moreover, _{r 1} represents the position of the vehicle CA1, _{r 2} represents the position of the vehicle CA2.

  Then, the following two formulas are obtained from formula (6).

The processing means 3 of the wireless device 10 mounted on the vehicle CA1 converts the ECFF coordinate values (x ₁ , y ₁ , z ₁ ) into horizon orthogonal coordinate values (e ₁ , n ₁ , u ₁ ) according to equation (3). Then, a three-dimensional electronic map is read out from the map holding means 4 and is represented by (λ ₁ , φ ₁ ) of positioning coordinate values (λ ₁ , φ ₁ , h ₁ ) with reference to the read-out three-dimensional electronic map. The altitude h ₁ ′ at the position is detected, and the altitude h ₂ ′ at the position represented by (λ ₂ , φ ₂ ) of the positioning coordinate values (λ ₂ , φ ₂ , h ₂ ) is detected.

Then, the processing unit 3 of the wireless device 10 mounted on a vehicle CA1 is highly _{h 1} altitude difference by subtracting the 'altitude _{h 2} from' _{h 1} obtains a '-h _2', the determined altitude difference _{h 1} ' Let −h ₂ ′ be u ₁ −u ₂ (= h ₁ ′ −h ₂ ′).

Then, the processing means 3 of the radio apparatus 10 mounted on the vehicle CA1 calculates the error δ ₁₂ by substituting the altitude difference h ₁ ′ −h ₂ ′ into u ₁ −u ₂ in the equation (8). That is, the processing unit 3 of the wireless device 10 mounted on a vehicle CA1, in formula (8) comprising a matrix of 3 rows × 1 column, obtaining an error [delta] ₁₂ using the third row.

Thereafter, the processing means 3 of the wireless device 10 mounted on the vehicle CA1 substitutes the obtained error δ ₁₂ into the equation (8), and calculates the first and second rows on the right side of the equation (8). Thus, Δe ₁₂ = e ₁ -e ₂ and Δn ₁₂ = n ₁ -n ₂ are obtained.

Then, the processing unit 3 of the wireless device 10 mounted on the vehicle CA1 sets the obtained Δe ₁₂ = e ₁ -e ₂ and Δn ₁₂ = n ₁ -n ₂ as the relative positions of the vehicle CA1 and the vehicle CA2.

  FIG. 7 is a flowchart for explaining a method for obtaining a relative position between adjacent vehicles according to the first embodiment.

  Referring to FIG. 7, when a series of operations is started, radio apparatus 10 mounted on vehicle CAi receives GPS signals from four or more GPS satellites and detects the reception time of GPS signals ( Step S1).

Then, the wireless device 10 mounted on the vehicle CAi calculates the pseudo distances P _{i, 1 to} P _{i, j} between the vehicle CAi and the GPS satellite based on the transmission time and reception time of the GPS signal (step S2). .

  Thereafter, the wireless device 10 mounted on the vehicle CAi calculates an ECFF coordinate value indicating the position of the GPS satellite that has transmitted the GPS signal using Expression (1) based on the GPS signal (step S3).

Subsequently, the radio apparatus 10 mounted on the vehicle CAi calculates an ECFF coordinate value indicating the position of the vehicle CAi based on the pseudo distances P _{i, 1 to} P _{i, j} and the ECFF coordinate value of the GPS satellite (step S4). ).

The radio device 10 mounted on a vehicle CAi converts ECFF coordinate values of the vehicle CAi positioning coordinates using equation _{(2) (λ i, φ} i, h i) (step S5).

Then, the wireless device 10 mounted on the vehicle CAi can receive the pseudo distances P _{i, 1 to} P _{i, j} , the positioning coordinate values (λ _i , φ _i , h _i ) of the vehicle CAi and the GPS receiver 5. The position information message 1 including the GPS satellite (= bit map of the GPS satellite) that transmitted the GPS signal is generated and broadcast (step S6).

  Thereafter, the wireless device 10 mounted on the vehicle CAi receives the position information message 2 from the wireless device mounted on the vehicle CAi + 1 adjacent to the vehicle CAi (step S7).

Then, the wireless device 10 mounted on the vehicle CAi detects the pseudo distances P _{i + 1,1 to} P _{i + 1, j} and the positioning coordinate values (λ _{i + 1} , φ _{i + 1} , h _{i + 1} ) of the vehicle CAi + 1 from the position information message 2 ( Step S8).

Subsequently, the radio device 10 mounted on the vehicle CAi is mounted on the vehicle CAi and the vehicle CAi + 1 based on the pseudo distances P _{i, 1 to} P _{i, j} and the pseudo distances P _{i + 1,1 to} P _{i + 1, j} . The pseudo-ranges P _{i, 1 to} P _{i, J} , P _{i + 1,1 to} P _{i + 1, J} between the GPS satellites that have transmitted GPS signals that can be commonly received by the two wireless devices 10 are extracted (step S9). .

After that, the radio apparatus 10 mounted on the vehicle CAi uses the positioning coordinate values (λ _i , φ _i , h _i ), the positioning coordinate values (λ _{i + 1} , φ _{i + 1} , h _{i + 1} ), and the three-dimensional electronic map. And the difference between the altitude of the vehicle CAi + 1 and the altitude of the vehicle CAi + 1 is detected (step S10).

Then, the radio device 10 mounted on the vehicle CAi includes a pseudo distance P _i = [P _{i, 1 to} P _{i, J} ] between the vehicle CAi and the GPS satellite, and a pseudo distance P _{i + 1} = [P _{i + 1} between the vehicle CAi + 1 and the GPS satellite. Based on P _{i + 1,1 to} P _{i + 1, J} ] and the altitude difference, the relative position between vehicle CAi and vehicle CAi + 1 is calculated using equation (8) (step S11). As a result, a series of operations is completed.

As described above, in the first embodiment of the present invention, the difference between the pseudo distance P _i between the vehicle CAi and the GPS satellite and the pseudo distance P _{i + 1} between the vehicle CAi + 1 and the GPS satellite is calculated to calculate the vehicle CAi and the vehicle CAi + 1. The relative position is calculated while suppressing the influence of the ionosphere and the troposphere.

  Therefore, according to the first embodiment, the accuracy of the relative position between adjacent vehicles can be increased.

  In the first embodiment, the altitude difference between adjacent vehicles is obtained using a highly accurate three-dimensional electronic map, and the relative position between adjacent vehicles is obtained using the obtained altitude difference. Can be improved.

  Furthermore, even when the number of GPS satellites that transmitted GPS signals that can be received by the wireless device 10 is small (three), the relative position can be calculated.

  In the first embodiment, a GPS satellite that transmits a GPS signal that can be commonly received by the wireless device 10 mounted on the vehicle CA1 and the wireless device 10 mounted on the vehicle CA2 based on the satellite bitmap. The processing means 3 to be selected constitutes “selection means”.

  Further, in the first embodiment, the processing means 3 for calculating the relative position between the vehicle CAi and the vehicle CAi + 1 according to the flowchart shown in FIG. 7 constitutes “calculation means”.

Furthermore, in the first embodiment, the processing means 3 for calculating the pseudo distances P _{i, 1 to} P _{i, j} and the positioning coordinate values (λ _i , φ _i , h _i ) of the vehicle CAi is “position calculation means”. Is configured.

  Further, in the first embodiment, the transmission / reception means 2 that receives the location information message 2 constitutes a “reception means”.

[Embodiment 2]
FIG. 8 is a configuration diagram of a radio apparatus according to the second embodiment. Referring to FIG. 8, radio apparatus 10A according to the second embodiment is the same as radio apparatus 10 except that processing unit 3 of radio apparatus 10 shown in FIG.

The processing means 3A uses the same method as the processing means 3 to calculate the ECFF coordinate values (x _i (t ₀ ), y _i (t ₀ ), z _i (t ₀ ) at the time t ₀ of the vehicle CAi on which the wireless device 10A is mounted. )) Is calculated.

Then, the processing means 3A uses the equation (3) to convert the ECFF coordinate values (x _i (t ₀ ), y _i (t ₀ ), z _i (t ₀ )) to the ENU coordinate values (e _i (t _0). ), N _i (t ₀ ), u _i (t ₀ )). Further, the processing means 3A uses the equation (2) to convert the ECFF coordinate values (x _i (t ₀ ), y _i (t ₀ ), z _i (t ₀ )) into the positioning coordinate values (λ _i (t _0). ), Φ _i (t ₀ ), h _i (t ₀ )).

Thereafter, the processing means 3A reads the three-dimensional electronic map from the map holding means 4, and refers to the read three-dimensional electronic map to determine the positioning coordinate values (λ _i (t ₀ ), φ _i (t ₀ ), h _{i. (t} 0)) of (λ _{i (t} 0), to detect the phi _{i (t} 0)) inclination beta _i at time _{t 0} at the position indicated by _{(t 0).} The processing means 3A receives the speed v _i (t ₀ ) of the vehicle CAi at time t ₀ from the speedometer mounted on the vehicle CAi, and the moving direction of the vehicle CAi at time t ₀ from the gyro mounted on the vehicle CAi. Receive α _i (t ₀ ).

Then, the processing means 3A uses the ENU coordinate values (e _i (t ₀ ), n _i (t ₀ ), u _i (t ₀ )), the speed v _i (t ₀ ), the moving direction α _i (t ₀ ) and inclination beta _{i (t 0)} the position of the vehicle CAi at time t is substituted into the following equation to predict _{(e i (t), n} i (t), u i (t)).

Then, the processing means 3A uses the ECFF coordinate values (x _i (t ₀ ), y _i (t ₀ ), z _i (t ₀ )) as reference points and ENU coordinate values (e _i (t), n _i (t ), U _i (t)) are converted into ECFF coordinate values by the following equation, and the converted ECFF coordinate values are further converted into positioning coordinate values (λ _i (t), φ _i (t), h _i (t)).

Then, the processing unit 3A refers to the three-dimensional electronic map, the positioning coordinates _{(λ i (t), φ} i (t), h i (t)) of the _{(λ i (t), φ} i (t )) To detect the altitude h _i ′ at the position indicated by

  Further, if the processing unit 3A of the radio apparatus 10A mounted on the vehicle CAi + 1 adjacent to the vehicle CAi can determine the position of the vehicle CAi + 1 by using a GPS signal, the position information message including the measured position information is mounted on the vehicle CAi. If the position of the vehicle CAi + 1 cannot be measured by the GPS signal transmitted to the wireless device 10A, the position of the vehicle CAi + 1 at the time t is predicted by the above-described method, and a position information message including the predicted position is mounted on the vehicle CAi. To the radio apparatus 10A.

As a result, the processing unit 3A of the wireless device 10A mounted on the vehicle CAi extracts the position information (= positioning coordinate value) from the position information message received from the wireless device 10A mounted on the vehicle CAi + 1, and the extracted positioning coordinates. Based on the value and the three-dimensional electronic map, the altitude h _{i + 1} ′ of the vehicle CAi + 1 is detected by the method described above.

Then, the processing unit 3A of the radio apparatus 10A mounted on the vehicle CAi has a pseudo distance P _i = [P _{i, 1 to} P _{i, J} ] and a pseudo distance P _{i + 1} = [P _{i + 1,1 to} P _{i + 1, J} ]. Based on the ENU coordinate value of the GPS satellite, the ENU coordinate value of the vehicle CAi, the altitude h _i ′, and the altitude h _{i + 1} ′, the relative position between the vehicle CAi and the vehicle CAi + 1 is calculated using Equation (8).

  The processing means 3A performs the same functions as the processing means 3 in other respects.

  FIG. 9 is a flowchart for explaining a method for obtaining a relative position between adjacent vehicles according to the second embodiment.

  The flowchart shown in FIG. 9 is the same as the flowchart shown in FIG. 7 except that steps S4 and S5 in the flowchart shown in FIG. 7 are replaced with steps S4A, 4B, and S5A.

  Referring to FIG. 9, when the operation for obtaining the relative position in the second embodiment is started, the above-described steps S1 to S3 are sequentially executed.

Then, after step S3, the processing means 3A of the wireless device 10A mounted on the vehicle CAi performs the vehicle CAi by the above-described method based on the pseudoranges P _{i, 1 to} P _{i, j} and the ECFF coordinate values of the GPS satellites. The ECFF coordinate value is calculated, and the calculated ECFF coordinate value is set as the ECFF coordinate value (t ₀ ) of the vehicle CAi at time t ₀ (step S4A).

Thereafter, the processing unit 3A of the radio apparatus 10A mounted on the vehicle CAi uses the ECFF coordinate value (t ₀ ) of the vehicle CAi as a reference point, and uses the ECFF coordinate value (t ₀ ) as an ENU coordinate value (t ₀ ), and based on the converted ENU coordinate value (t ₀ ), the speed v _i (t ₀ ), the moving direction α _i (t ₀ ), and the slope β _i (t ₀ ) of the vehicle CAi The position of CAi at time t (= ENU coordinate value (t)) is predicted (step S4B).

Subsequently, the processing means 3A of the radio apparatus 10A mounted on the vehicle CAi converts the ENU coordinate value (t) of the vehicle CAi into an ECFF coordinate value (t) using the equation (10), and the converted ECFF coordinates. The value (t) is further converted into positioning coordinate values (λ _i (t), φ _i (t), h _i (t)) using the equation (2) (step S5A).

  Thereafter, the above-described steps S6 to S11 are sequentially executed, and the relative position between the vehicle CAi and the vehicle CAi + 1 is calculated.

When the flowchart shown in FIG. 9 is executed, the positioning coordinate values (λ _{i + 1} (t), φ _{i + 1} (t), h _{i + 1} (t)) of the vehicle CAi + 1 are the measured positioning coordinate values or the formula (9 ) Is used for the positioning coordinate value predicted.

Thus, in the second embodiment, the wireless device 10A which is mounted on the vehicle CAi at time t ₀ can actually measure the position of the vehicle CAi, when it is not possible to actually measure the position of the vehicle CAi at time t, at time t ₀ The position of the vehicle CAi at the time t is predicted using the measured position of the vehicle CAi, and the relative position between the vehicle CAi and the vehicle CAi + 1 is calculated using the predicted position.

  Therefore, according to the second embodiment, GPS signals can be received only from three GPS satellites, and even when GPS signals cannot be received from four or more GPS satellites, the relative position between vehicle CAi and vehicle CAi + 1 is determined with high accuracy. Can be obtained.

  In the first embodiment, the altitude difference between adjacent vehicles is obtained using a highly accurate three-dimensional electronic map, and the relative position between adjacent vehicles is obtained using the obtained altitude difference. Can be improved.

  In the second embodiment, the processing means 3A that predicts the position of the vehicle at time t by the above-described method constitutes a “position prediction means”.

  In the second embodiment, the processing means 3A for calculating the relative position by the above-described method constitutes “calculation means”.

  Others are the same as in the first embodiment.

[Embodiment 3]
FIG. 10 is a configuration diagram of a radio apparatus according to the third embodiment. Referring to FIG. 10, radio apparatus 10B according to Embodiment 3 is the same as radio apparatus 10 except that processing means 3 of radio apparatus 10 shown in FIG.

  In the third embodiment, the position information message has a configuration in which a positioning error σ is added to the payload 1 of the position information message PSM shown in FIG.

  The processing means 3B incorporates a Kalman filter. Then, based on the GPS signal received from the GPS receiver 5, the processing means 3B obtains the ECFF coordinate values of the GPS satellites R1 to Rm, the pseudo distance between the vehicle CAi and the GPS satellites R1 to Rm, and the ECFF coordinate value of the vehicle CAi. In addition to the calculation, the ECFF coordinate value of the calculated vehicle CAi is processed by a Kalman filter to detect an error σ_self of the ECFF coordinate value.

  Thereafter, the processing unit 3B converts the ECFF coordinate value of the vehicle CAi into a positioning coordinate value using Expression (2), and outputs the converted positioning coordinate value, pseudo distance, and error σ_self to the message generating unit 6.

  Further, the processing means 3B receives a position information message from each of a plurality of wireless devices 10B mounted on a plurality of vehicles adjacent to the vehicle CAi, and detects an error σ_other included in the received position information message.

  Then, when the error σ_self is equal to or less than the reference value σ_std, the processing unit 3B calculates the relative position between the vehicle CAi and the vehicle CAi + 1 adjacent to the vehicle CAi by the method described in the first embodiment. The reference value σ_std is set to 1 m, for example.

  On the other hand, when the error σ_self is larger than the reference value σ_std, the processing unit 3B selects an error σ_other_pre that is equal to or less than the reference value σ_std from the errors σ_other, and selects a vehicle having the selected error σ_other_pre as a reference vehicle.

  Then, the processing unit 3B calculates the relative position between the vehicle CAi and the reference vehicle by the method described in the first embodiment. Thereafter, the processing means 3B calculates the absolute position of the vehicle CAi based on the calculated relative position and the absolute position of the reference vehicle (= the vehicle position included in the position information message from the reference vehicle).

  Further, the processing means 3B calculates the absolute position of the vehicle CAi by the above-described method even when the position of the vehicle CAi cannot be uniquely determined based on the GPS signal from the GPS receiver 5.

  The processing unit 3B performs the same function as the processing unit 3 in other respects.

  A method of calculating the positioning error σ and the relative position error γ in the processing unit 3B will be described.

If [D (r ₀ ) ^T · (D (r ₀ )] ⁻¹ in equation (8) described above is the matrix <A>, the positioning error σ is obtained by the following equation.

In Equation (11), σ _n is a noise error, and is 0.5 m, for example.

Accordingly, the processing means 3B calculates the matrix <A> (= [D (r ₀ ) ^T · (D (r ₀ )] ⁻¹ ) using the ENU coordinate value of the GPS satellite and the eu coordinate value of the vehicle CAi. (See equation (6)), the positioning error σ is calculated using the calculated matrix <A>.

The relative positions Δe and Δu between the vehicles change almost linearly. If Δe is x _i and Δu is y _i , y = ax + b is established (a and b are constants).

Therefore, the processing means 3B obtains constants a and b by substituting n (n is an integer of 2 or more) (Δe, Δu) into y = ax + b, and the obtained constants a, b and the vehicle By substituting the relative position (Δe, Δu) = (x _i , y _i ) into the following equation, the relative position error γ is calculated.

  FIG. 11 is a flowchart for explaining a method of calculating the absolute position of the vehicle according to the third embodiment.

  Referring to FIG. 11, when the operation of calculating the absolute position of the vehicle is started, processing means 3B of radio apparatus 10B mounted on vehicle CAi uses vehicle CAi and GPS satellites by the method described in the first embodiment. Is calculated (step S21).

  Then, the processing unit 3B of the wireless device 10B mounted on the vehicle CAi determines whether or not the absolute position of the vehicle CAi can be measured (step S22). More specifically, the processing means 3B of the radio apparatus 10B mounted on the vehicle CAi can measure the absolute position of the vehicle CAi when it can calculate the positions of four or more pseudoranges and four or more GPS satellites. When it is possible to calculate only the pseudo distances less than four and the positions of less than four GPS satellites, it is determined that the absolute position of the vehicle CAi cannot be measured.

  When it is determined in step S22 that the absolute position of the vehicle CAi cannot be measured, the series of operations proceeds to step S29.

  On the other hand, when it is determined in step S22 that the absolute position of the vehicle CAi can be measured, the processing unit 3B of the wireless device 10B mounted on the vehicle CAi has four or more pseudo distances between the vehicle CAi and the GPS satellite. The position information of the vehicle CAi is calculated by the above-described method using the positions of four or more GPS satellites, and the error σ_self of the position information of the vehicle CAi is detected (step S23).

  Then, the processing means 3B of the radio apparatus 10B mounted on the vehicle CAi generates a position information message 1 including the pseudo distance, the GPS satellite bitmap, the position information of the vehicle CAi, and the error σ_self and outputs the position information message 1 to the transmission / reception means 2. The transmitter / receiver 2 broadcasts the location information message 1 via the antenna 1 (step S24).

  Thereafter, the transmission / reception means 2 of the wireless device 10B mounted on the vehicle CAi receives the position information message 2 from another wireless device 10B mounted on the vehicle adjacent to the vehicle CAi (step S25), and the received position information. Message 2 is output to processing means 3B.

  The processing means 3B of the radio apparatus 10B mounted on the vehicle CAi receives the position information message 2 from the transmission / reception means 2, and detects the pseudo distance, position information, and error σ_other from the received position information message 2 (step S26).

  Then, the processing unit 3B of the wireless device 10B mounted on the vehicle CAi determines whether or not the error σ_self is equal to or less than the reference value σ_std (step S27).

  When it is determined in step S27 that the error σ_self is equal to or less than the reference value σ_std, the processing unit 3B of the wireless device 10B mounted on the vehicle CAi determines that the vehicle adjacent to the vehicle CAi and the vehicle CAi are in accordance with the flowchart shown in FIG. Is calculated (step S28).

  On the other hand, when it is determined in step S27 that the error σ_self is larger than the reference value σ_std, or when it is determined in step S22 that the absolute position of the vehicle CAi cannot be measured, the radio mounted on the vehicle CAi. The processing unit 3B of the apparatus 10B selects an error σ_other_pre that is equal to or less than the reference value σ_std from the error σ_other (step S29).

  Thereafter, the processing unit 3B of the wireless device 10B mounted on the vehicle CAi selects a vehicle having the error σ_other_pre as a reference vehicle (step S30).

  Then, processing means 3B of radio apparatus 10B mounted on vehicle CAi calculates the relative position between vehicle CAi and the reference vehicle according to the flowchart shown in FIG. 7 (step S31).

  Subsequently, the processing means 3B of the wireless device 10B mounted on the vehicle CAi is based on the calculated relative position and the absolute position of the reference vehicle (= the vehicle position included in the position information message 2 from the reference vehicle). Then, the absolute position of the vehicle CAi is calculated (step S32).

  And a series of operation | movement is complete | finished after step S28 or step S32.

  In the flowchart shown in FIG. 11, when the series of operations shifts from “NO” in step S27 to step S29, the processing unit 3B of the wireless device 10B mounted on the vehicle CAi determines that the ENU of the vehicle CAi in step S31. The relative position between the vehicle CAi and the reference vehicle is calculated using the coordinate values.

  On the other hand, in the flowchart shown in FIG. 11, when the series of operations proceeds from “NO” in step S22 to step S29, the processing unit 3B of the wireless device 10B mounted on the vehicle CAi determines in step S31 the ENU of the reference vehicle. The relative position between the vehicle CAi and the reference vehicle is calculated using the coordinate values. In this case, the processing unit 3B of the wireless device 10B mounted on the vehicle CAi indicates that the position of the vehicle included in the position information message 2 from the reference vehicle is represented by the positioning coordinate value, and thus the positioning coordinate value is expressed by the equation (3). Is converted into an ENU coordinate value and the relative position between the vehicle CAi and the reference vehicle is calculated.

  When the series of operations proceeds from “NO” in step S22 to step S29, the processing unit 3B of the wireless device 10B mounted on the vehicle CAi cannot calculate the position information of the vehicle CAi. Is used to calculate the relative position between the vehicle CAi and the reference vehicle.

  In the flowchart shown in FIG. 11, two or more vehicles may be selected as reference vehicles, or one reference vehicle may be selected.

  A method for calculating the absolute position of the vehicle CAi in step S32 of FIG. 11 will be described.

When the vehicle CA1 selects two vehicles CA2 and CA3 as reference vehicles, the absolute position (e ₁ ′, n ₁ ′) of the vehicle CA1 calculated by the method described above is expressed by the following equation.

In the equation _{(13), e 31} is the E component of the ENU coordinate value of the absolute position of the vehicle CA1 and the relative position and the vehicle CA1 computed using the absolute position of the vehicle CA3 of the vehicle _{CA3, e 21} Is an E component of the ENU coordinate value of the absolute position of the vehicle CA1 calculated using the relative position between the vehicle CA1 and the vehicle CA2 and the absolute position of the vehicle CA2, and n ₃₁ is the relative value between the vehicle CA1 and the vehicle CA3. N component of the ENU coordinate value of the absolute position of the vehicle CA1 calculated using the position and the absolute position of the vehicle CA3, and n ₂₁ is the relative position between the vehicle CA1 and the vehicle CA2 and the absolute position of the vehicle CA2. The calculated N component of the ENU coordinate value of the absolute position of the vehicle CA1, Δe ₃₁ is the E component of the ENU coordinate value of the relative position between the vehicle CA1 and the vehicle CA3, and Δe ₂₁ is , The E component of the ENU coordinate value of the relative position between the vehicle CA1 and the vehicle CA2, Δn ₃₁ is the N component of the ENU coordinate value of the relative position between the vehicle CA1 and the vehicle CA3, and Δn ₂₁ is the vehicle CA1. an n component of ENU coordinate values of the relative position between the vehicle _{CA2, e 1, e 2,} e 3 are each a component E of a vehicle CA1, CA2, ENU coordinate value of the absolute position of _{CA3, n} 1, n ₂ and n ₃ are N components of the ENU coordinate values of the absolute positions of the vehicles CA1, CA2, and CA3, respectively, and γ is an error of the relative position.

Further, when there is one reference vehicle, the absolute position of the vehicle CA1 is calculated by an expression in which the terms e ₃₁ , n ₃₁ , and σ ₃₁ are deleted in the expression (13).

Further, when there are three reference vehicles, the absolute position of the vehicle CA1 is calculated by an equation in which terms of e ₄₁ , n ₄₁ , and σ ₄₁ are added in the equation (13). The same applies when there are four or more reference vehicles.

The positioning error of the absolute position obtained by the above method will be described. If γ = 1, σ ₁ = 5, and σ ₂ = σ ₃ = 1, then (σ ₁ ) ² = 25, (σ ₃₁ ) ² = 2 and (σ ₂₁ ) ² = 2. Then, the positioning error σ ₁ ′ in the vehicle CA1 is (2/2 + 2 + 2/2 + 5/25) / (1/2 + 1/2 + 1/25) = 2.1. As a result, the positioning error is reduced from 5 m to 2.1 m.

  As described above, according to the third embodiment, the wireless device 10B mounted on the vehicle CAi cannot independently determine the position of the vehicle CAi, or when the positioning error is larger than the reference value σ_std, the reference value σ_std. The absolute position of the vehicle CAi is calculated using the relative position between the reference vehicle having the following positioning error and the vehicle CAi and the absolute position of the reference vehicle. The relative position between the reference vehicle and the vehicle CAi is a highly accurate position calculated by suppressing the influence of the ionosphere and the troposphere.

  Therefore, according to Embodiment 3, the accuracy of the absolute position can be improved.

  In the second embodiment, the processing means 3B that calculates the absolute position of the vehicle by the method described above constitutes “calculation means”.

  Others are the same as in the first embodiment.

[Embodiment 4]
FIG. 12 is a configuration diagram of a radio apparatus according to the fourth embodiment. Referring to FIG. 12, radio apparatus 10C according to the fourth embodiment is the same as radio apparatus 10 except that processing means 3 of radio apparatus 10 shown in FIG.

The processing means 3C calculates the pseudo distance between the vehicle CAi on which the wireless device 10C is mounted and the GPS satellite by the method described above. Further, the processing means 3C calculates the positioning coordinate values (λ _i , φ _i , h _i ) and the ENU coordinate values (e _i , n _i , u _i ) of the vehicle CAi by the method described above.

Then, the processing means 3C reads the three-dimensional electronic map from the map holding means 4, and based on the read three-dimensional electronic map and positioning coordinate values (λ _i , φ _i , h _i ), (λ _i , φ _i detecting the three-dimensional electronic map advanced h _{i 'at} the position indicated by). Then, the processing unit 3C calculates the altitude difference _{Δu i = u i '-u i} = h i' -h i.

The above-described formula (5) is expressed linearly as the following formula at the reference point r ₀ = (x ₀ , y ₀ , z ₀ ).

Note that ε _i is ignored in the transformation from Equation (5) to Equation (14).

  When the equation (14) is transformed, the following equation is obtained.

According to the equation (15), in the vehicle CAi, the relationship between the altitude difference Δu _i and the pseudorange error ΔP _i is as follows.

  Considering the error generated by the ionosphere, the pseudo-range error in each vehicle is almost the same, and therefore equation (16) is established.

If the number of GPS satellites from which the radio apparatus 10C can receive GPS signals is m, ΔP _i can be obtained from Equation (16) using the altitude difference of k vehicles satisfying k ≧ m.

Therefore, a method for obtaining ΔP _i from equation (16) will be described. FIG. 13 is a conceptual diagram of a location information message in the fourth embodiment. The position information message PSM ′ has a configuration in which a pseudo distance error is added to the payload 2 of the position information message PSM. The pseudorange error is optional.

  Assume that there are five vehicles CA1 to CA5. The five radio apparatuses 10C mounted on the vehicles CA1 to CA5 respectively generate and broadcast position information messages PSM'1 to PSM'5.

  The transmission / reception means 2 of the radio apparatus 10C mounted on the vehicle CA1 receives the position information messages PSM'2 to PSM'5 via the antenna 1, and processes the received position information messages PSM'2 to PSM'5. Output to 3C.

The processing means 3C of the radio apparatus 10C mounted on the vehicle CA1 receives the position information messages PSM'2 to PSM'5 from the transmission / reception means 2. Then, the processing unit 3C of the wireless device 10C mounted on the vehicle CA1 receives the positioning coordinate values (λ ₂ , φ ₂ , h ₂ ) and the positioning coordinate values (λ ₃ , φ ₃ , h ₃ ), positioning coordinate values (λ ₄ , φ ₄ , h ₄ ) and positioning coordinate values (λ ₅ , φ ₅ , h ₅ ) are detected.

Then, the processing unit 3C of the radio apparatus 10C mounted on the vehicle CA1 is positioned by (λ ₁ , φ ₁ ) based on the positioning coordinate values (λ ₁ , φ ₁ , h ₁ ) and the three-dimensional electronic map. 'detects the three-dimensional electronic map, altitude difference Δu ₁ = _{u 1'} altitude _{h 1} in computing the _{-u 1 = h 1 '-h 1} .

Similarly, the processing unit 3C of the radio apparatus 10C mounted on the vehicle CA1 is similar to the altitude difference Δu ₂ = u ₂ ′ −u ₂ = h ₂ ′ −h ₂ and the altitude difference Δu ₃ = u ₃ ′ −u. ₃ = h ₃ ′ −h ₃ , altitude difference Δu ₄ = u ₄ ′ −u ₄ = h ₄ ′ −h ₄ , and altitude difference Δu ₅ = u ₅ ′ −u ₅ = h ₅ ′ −h ₅ .

Then, the processing means 3C of the radio apparatus 10C mounted on the vehicle CA1 has a matrix <D (r ₀ )> for obtaining the pseudorange error ΔP _i that is very similar between the vehicles CA1 to CA5. Different GPS satellites are selected among CA5 to obtain the pseudorange error ΔP _i .

  For example, the processing means 3C of the wireless device 10C mounted on the vehicle CA1 refers to the satellite bitmaps of the position information messages PSM'1 to PSM'5 and uses the GPS satellites R2 to R5 as the GPS satellites for the vehicle CA1. Select GPS satellites R1, R3-R5 as GPS satellites for vehicle CA2, select GPS satellites R1, R2, R4, R5 as GPS satellites for vehicle CA3, and GPS satellites as GPS satellites for vehicle CA4 R1, R2, R3, and R5 are selected, and GPS satellites R1 to R4 are selected as GPS satellites for the vehicle CA5.

Thereafter, the processing means 3C of the wireless device 10C mounted on the vehicle CA1 can receive GPS signals from all of the GPS satellites R1 to R5. Therefore, based on the GPS signals GPS1 to GPS5 respectively received from the GPS satellites R1 to R5, The ECFF coordinate values (R1) to ECFF coordinate values (R5) of the GPS satellites R1 to R5 are calculated by the above-described method, and the calculated ECFF coordinate values (R1) to ECFF coordinate values (R5) and the pseudo distance P _{1, 1} , P _1,2 , P _1,3 , P _1,4 , P _1,5 , the ECFF coordinate value (CA1) of the vehicle CA1 is calculated.

Then, the processing means 3C of the wireless device 10C mounted on the vehicle CA1 uses the ECU coordinate values (R1) to ECFF coordinate values (R5) as ENU coordinate values (E ₁ , N ₁ , U ₁ ) to An ENU coordinate value (E ₅ , N ₅ , U ₅ ) is converted, and an ECFF coordinate value (CA1) is converted to an ENU coordinate value (e ₁ , n ₁ , u ₁ ) using Equation (3).

Further, the processing means 3C of the wireless device 10C mounted on the vehicle CA1 uses the following equations to determine positioning coordinate values (λ ₂ , φ ₂ , h ₂ ), positioning coordinate values (λ ₃ , φ ₃ , h ₃ ), The positioning coordinate values (λ ₄ , φ ₄ , h ₄ ) and the positioning coordinate values (λ ₅ , φ ₅ , h ₅ ) are converted into ECFF coordinate values (CA2) to ECFF coordinate values (CA5), respectively.

Then, the processing unit 3C of the wireless device 10C mounted on the vehicle CA1 converts the ECFF coordinate value (CA2) to the ECFF coordinate value (CA5) to ENU coordinate values (e ₂ , n ₂ , u ₂ ) according to the equation (3). ), ENU coordinate values (e ₃ , n ₃ , u ₃ ), ENU coordinate values (e ₄ , n ₄ , u ₄ ), and ENU coordinate values (e ₅ , n ₅ , u ₅ ).

Subsequently, the processing unit 3C of the wireless device 10C mounted on the vehicle CA1 as the reference point _{r 0} ECFF coordinate values (CA1), ENU coordinate values _{(E 2, N 2, U} 2) ~ENU coordinate values (E ₅ , N ₅ , U ₅ ) and ENU coordinate values (e ₁ , n ₁ , u ₁ ) are converted into d _j ′ (e ₀ ), d _j ′ (n ₀ ), d _j ′ (u ₀ ) in equation (6). ) To calculate d ₁₂ ′, d ₁₃ ′, d ₁₄ ′, and d ₁₅ ′. Note that d ₁₂ ′, d ₁₃ ′, d ₁₄ ′, and d ₁₅ ′ are change rates at the reference point of the true distance between the vehicle CA1 and four or more GPS satellites.

The processing unit 3C of the wireless device 10C mounted on the vehicle CA1 as the reference point _{r 0} ECFF coordinate values (CA1), ENU coordinate values _{(E 1, N 1, U} 1), (E 3, N 3 , U ₃ ) to (E ₅ , N ₅ , U ₅ ) and the ENU coordinate values (e ₂ , n ₂ , u ₂ ) are expressed as d _j ′ (e ₀ ), d _j ′ (n ₀ ) in equation (6). , D _j ′ (u ₀ ) and calculate d ₂₁ ′, d ₂₃ ′, d ₂₄ ′, and d ₂₅ ′. Note that d ₂₁ ′, d ₂₃ ′, d ₂₄ ′, and d ₂₅ ′ are change rates at the reference point of the true distance between the vehicle CA2 and four or more GPS satellites.

Further, the processing unit 3C of the wireless device 10C mounted on the vehicle CA1 as the reference point _{r 0} ECFF coordinate values (CA1), ENU coordinate values _{(E 1, N 1, U} 1), (E 2, N 2 , U ₂ ), (E ₄ , N ₄ , U ₄ ), (E ₅ , N ₅ , U ₅ ) and the ENU coordinate values (e ₃ , n ₃ , u ₃ ) are expressed as _dj ′ ( Substituting into the equations of e ₀ ), d _j ′ (n ₀ ), d _j ′ (u ₀ ), d ₃₁ ′, d ₃₂ ′, d ₃₄ ′, d ₃₅ ′ are calculated. Note that d ₃₁ ′, d ₃₂ ′, d ₃₄ ′, and d ₃₅ ′ are change rates at the reference point of the true distance between the vehicle CA3 and four or more GPS satellites.

Further, the processing unit 3C of the wireless device 10C mounted on the vehicle CA1 as the reference point _{r 0} ECFF coordinate values (CA1), ENU coordinate values _{(E 1, N 1, U} 1), (E 2, N 2 , U ₂ ), (E ₃ , N ₃ , U ₃ ), (E ₅ , N ₅ , U ₅ ) and ENU coordinate values (e ₄ , n ₄ , u ₄ ) are expressed as d _j ′ ( Substituting into the equations of e ₀ ), d _j ′ (n ₀ ), d _j ′ (u ₀ ), d ₄₁ ′, d ₄₂ ′, d ₄₃ ′, d ₄₅ ′ are calculated. Note that d ₄₁ ′, d ₄₂ ′, d ₄₃ ′, and d ₄₅ ′ are change rates at the reference point of the true distance between the vehicle CA3 and four or more GPS satellites.

Further, the processing unit 3C of the wireless device 10C mounted on the vehicle CA1 as the reference point _{r 0} ECFF coordinate values (CA1), ENU coordinate values _{(E 1, N 1, U} 1) ~E 4, N 4, U ₄ ) and ENU coordinate values (e ₅ , n ₅ , u ₅ ) are substituted into d _j ′ (e ₀ ), d _j ′ (n ₀ ), d _j ′ (u ₀ ) in equation ( ₆ ). Then, d ₅₁ ′, d ₅₂ ′, d ₅₃ ′, and d ₅₄ ′ are calculated. Note that d ₅₁ ′, d ₅₂ ′, d ₅₃ ′, and d ₅₄ ′ are change rates at the reference point of the true distance between the vehicle CA3 and four or more GPS satellites.

Then, the processing unit 3C of the wireless device 10C mounted on the vehicle CA1 _{is, d 12 ', d 13'} , d 14 ', d 15'; d 21 ', d 23', d 24 ', d 25'; d _{31 ', d 32', d} 34 ', d 35'; d 41 ', d 42', d 43 ', d 45'; d 51 ', d 52', d 53 ', d 54' and altitude difference Δu Substituting _{1 to} Δu ₅ into equation (18), the pseudorange error ΔP _i is calculated.

Thereafter, the processing means 3C of the radio apparatus 10C mounted on the vehicle CA1 calculates the pseudorange error ΔP _i from the pseudoranges P _1,1 , P _1,2 , P _1,3 , P _1,4 , P _1,5. The corrected pseudo distances P _1,1 ′, P _1,2 ′, P _1,3 ′, P _1,4 ′, P _1,5 ′ are obtained by subtraction.

Then, the processing means 3C of the wireless device 10C mounted on the vehicle CA1 includes the ECFF coordinate values (R1) to ECFF coordinate values (R5) of the GPS satellites R1 to R5 and the corrected pseudo distances P _1,1 ′, P _{1, Based on 2} ′, P _1,3 ′, P _1,4 ′, P _1,5 ′, the ECFF coordinate value (CA1) of the vehicle CA1 is calculated as an absolute position. More specifically, the processing means 3C of the wireless device 10C mounted on the vehicle CA1 has the radii around the ECFF coordinate value (R1) to the ECFF coordinate value (R5) as the corrected pseudo distances P _1,1 ′, By calculating the coordinate values of intersection points when five spheres corresponding to P _1,2 ′, P _1,3 ′, P _1,4 ′, P _1,5 ′ intersect at one point, Calculate absolute position.

  Further, the processing means 3C of the wireless device 10C mounted on the vehicles CA2 to CA5 also calculates the absolute positions of the vehicles CA2 to CA5 by the method described above.

In the above description, it has been described that all of the five radio apparatuses 10C mounted on the vehicles CA1 to CA5 calculate the pseudorange error ΔP _i , but in the fourth embodiment, the invention is not limited to this, and the vehicles CA1 to CA1 are calculated. One wireless device 10C out of the five wireless devices 10C mounted on CA5 may calculate the pseudorange error ΔP _i and transmit it to another wireless device 10C.

In this case, for example, a wireless device 10C mounted on a vehicle CA1 with the smallest ID is computed pseudorange error [Delta] P _i by the above-described method, and broadcasts the pseudorange error [Delta] P _i that the operation to another radio device 10C . Then, another wireless device 10C receives the pseudo-range error [Delta] P _i, itself calculates the absolute position of the vehicle equipped with the above-described method using a pseudo-range error [Delta] P _i with the received.

Therefore, the radio apparatus according to the fourth embodiment calculates the pseudo distance error ΔP _i by the above-described method, corrects the pseudo distance using the calculated pseudo distance error ΔP _i, and uses the corrected corrected pseudo distance. What is necessary is just to calculate the absolute position of the vehicle in which the vehicle is mounted.

  FIG. 14 is a flowchart for explaining a method of obtaining the absolute position of the vehicle according to the fourth embodiment.

Referring to FIG. 14, when a series of operations is started, radio device 10C mounted on vehicle CAi acquires pseudorange error ΔP _i (step S41). In this case, the wireless device 10C mounted on the vehicle CAi is pseudoranges may obtain pseudo-range error [Delta] P _i, the other wireless device 10C is calculated by calculating a pseudo-range error [Delta] P _i by the methods described above The pseudo distance error ΔP _i may be acquired by receiving the error ΔP _i from the other radio apparatus 10C.

After step S41, the radio apparatus 10C mounted on the vehicle CAi calculates a corrected pseudo distance P _i ′ by subtracting the pseudo distance error ΔP _i from the pseudo distance P _i in the vehicle CAi (step S42).

Then, the wireless device 10C mounted on the vehicle CAi calculates the absolute position of the vehicle CAi based on the ECFF coordinate value (Rj) of the GPS satellite Rj and the corrected pseudo distance P _i ′ (step S43). Thus, a series of operations is completed.

As described above, in the fourth embodiment, the pseudo distance by subtracting the error [Delta] P _i pseudorange from P _{i 'is} calculated and the calculated correction pseudorange P _i' corrected pseudorange P _i each with Calculate the absolute position of the vehicle. As a result, the absolute position of the vehicle CAi is calculated using a highly accurate correction pseudorange.

  Therefore, the accuracy of the absolute position of each vehicle can be made higher than the absolute position of each vehicle in the third embodiment.

  In the fourth embodiment, the processing means 3C for calculating the absolute position by the method described above constitutes “calculation means”.

  Others are the same as in the first embodiment.

  In the first embodiment described above, the relative position between adjacent vehicles may be calculated using the absolute position calculated in the third and fourth embodiments.

  In the above description, the radio devices 10, 10A, 10B, and 10C have been described as being mounted on a vehicle. However, in the embodiment of the present invention, the radio devices 10, 10A, 10B, and 10C are not limited thereto. May be mounted on a motorcycle, a bicycle and a person, and generally only needs to be mounted on a moving body.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include meanings equivalent to the scope of claims for patent and all modifications within the scope.

  The present invention is applied to a radio apparatus capable of acquiring highly accurate position information.

  DESCRIPTION OF SYMBOLS 1 Antenna 2 Transmission / reception means 3, 3A, 3B, 3C Processing means 4 Map holding means 5 GPS receiver 6 Message generation means 10, 10A, 10B, 10C Radio equipment.

Claims (8)

A wireless device that is mounted on a first moving body and obtains a relative position between a second moving body adjacent to the first moving body and the first moving body or an absolute position of the first moving body. And
A GPS receiver for receiving GPS signals from GPS satellites;
Map holding means for holding a three-dimensional electronic map in which coordinate values obtained by adding the slope of a road to altitude, longitude, and latitude from an ellipsoid representing the earth are used as positions of each moving body on the map;
Based on the GPS signal received by the GPS receiver, m (m is 4 or more) that transmits a GPS signal that can be received by both the wireless device and another wireless device mounted on the second moving body. An integer) selection means for selecting GPS satellites;
Based on m GPS signals received by the GPS receiver from the m GPS satellites, a reference point is the origin, and a direction perpendicular to the ellipsoid representing the east direction, the north direction, and the earth from the reference point In a horizon orthogonal coordinate system defined by three axes facing the first, a first pseudo-range indicating a distance between the m GPS satellites and the first mobile body, the m GPS satellites and the A second pseudo distance indicating a distance to the second moving body is calculated, and a pseudo distance difference between the calculated first pseudo distance and the second pseudo distance is calculated, and the longitude and the latitude are calculated. The three-dimensional representation of the altitude of the first moving body at the position of the first moving body shown and the altitude of the second moving body at the position of the second moving body indicated by the longitude and the latitude. Referring to electronic map Then, the difference between the detected height of the first moving body and the height of the second moving body is calculated by using the first moving body in the direction perpendicular to the ellipsoid representing the earth in the horizon orthogonal coordinate system and the height of the second moving body. Calculated as a relative position component with respect to the second moving body, and based on the calculated relative position component and the calculated pseudorange difference, the error of the first pseudorange and the error of the second pseudorange An error difference is calculated, the calculated error difference is subtracted from the pseudo-range difference, and the subtraction result is multiplied by an inverse matrix of a matrix indicating an error of a true distance from the reference point to the GPS satellite. A wireless apparatus comprising: a computing unit that computes a relative position between the first moving body and the second moving body in the east direction and the north direction of an orthogonal coordinate system. Based on m GPS signals received from the m GPS satellites by the GPS receiver, a first position indicating the position of the first moving body in a positioning coordinate system composed of the altitude, the longitude, and the latitude. Position calculating means for calculating positioning position information and the first pseudo distance;
Receiving means for receiving a position information message including second positioning position information indicating the position of the second moving body in the positioning coordinate system and the second pseudo distance from the other wireless device;
The calculation means calculates the pseudo distance difference based on the first pseudo distance calculated by the position calculation means and the second pseudo distance included in the position information message, and the position calculation means Detecting the altitude of the first moving body at a position indicated by longitude and latitude included in the first positioning position information based on the calculated first positioning position information and the three-dimensional electronic map; Based on the second positioning position information and the three-dimensional electronic map included in the position information message, the altitude of the second moving body at the position indicated by the longitude and the latitude included in the second positioning position information is detected. The wireless device according to claim 1. Based on m GPS signals received by the GPS receiver from the m GPS satellites, the north pole direction of the earth's rotation axis is the z axis, and the direction of the Greenwich meridian perpendicular to the z axis is the x axis, A first fixed position indicating a position of the first moving body at a first timing in a fixed orthogonal coordinate system in which a direction determined using a right-handed system so as to be orthogonal to the z-axis and the x-axis is a y-axis. Calculating position information, calculating the first horizon position information indicating the position of the first moving body at the first timing in the horizon orthogonal coordinates with the calculated first fixed position information as a reference point; The second indicating the position of the first moving body at the second timing after the first timing using the calculated first horizon position information and the speed and moving method of the first moving body. Horizon position A position prediction means for predicting the distribution,
The apparatus further comprises receiving means for receiving, from the other wireless device, a position information message including second positioning position information indicating the position of the second moving body in the positioning coordinate system and the second pseudo distance. Prepared,
The calculation means converts the second horizon position information into second fixed position information indicating the position of the first moving body in the fixed orthogonal coordinate system, and converts the converted second fixed position information into the second fixed position information. Further converted into first positioning position information indicating the position of the first moving body in the positioning coordinate system, and the first positioning position information based on the converted first positioning position information and the three-dimensional electronic map. And detecting the altitude at the position indicated by the longitude and latitude included as the altitude of the first mobile body based on the second positioning position information and the three-dimensional electronic map included in the position information message. The radio apparatus according to claim 1, wherein an altitude at a position indicated by longitude and latitude included in the second positioning position information is detected as an altitude of the second moving body.   4. The wireless device according to claim 3, wherein the second positioning position information includes positioning position information measured in the other wireless device or positioning position information predicted in the other wireless device.   The radio apparatus according to claim 1, wherein the calculating unit further calculates an absolute position of the first moving body based on the calculated relative position and an absolute position of the second moving body. A horizontal Cartesian coordinate system defined by three axes mounted on the first moving body and having a reference point as an origin and facing from the reference point to an east direction, a north direction, and a direction perpendicular to an ellipsoid representing the earth A wireless device for obtaining an absolute position of the first moving body in a system,
A GPS receiver for receiving GPS signals from GPS satellites;
Map holding means for holding a three-dimensional electronic map in which coordinate values obtained by adding the slope of a road to altitude, longitude, and latitude from an ellipsoid representing the earth are used as positions of each moving body on the map;
Based on a GPS signal received by the GPS receiver, a first pseudo distance indicating a distance between four or more GPS satellites and the first moving body is calculated in the horizon orthogonal coordinate system, and the first pseudo distance is calculated. The pseudo-range error in the horizon orthogonal coordinate system between the k second moving bodies adjacent to the moving body (k is an integer of 4 or more) and the first moving body and the GPS satellite group is the first distance. A first corrected pseudorange corrected by subtracting from the pseudorange is calculated, and the absolute value of the first moving body is calculated based on the calculated first corrected pseudorange and the positions of the four or more GPS satellites. Computing means for computing the position,
The pseudorange error is detected based on first positioning position information indicating the position of the first moving body in the positioning coordinate system including the altitude, the longitude, and the latitude, and the three-dimensional electronic map. Based on the first altitude difference of the first moving body, the k second positioning position information indicating the positions of the k second moving bodies in the positioning coordinate system, and the three-dimensional electronic map. The k second height differences of the k second mobile bodies detected and the first true distance between the first mobile body and the four or more GPS satellites at the reference point. The first change rate that is the change rate and the k second true distances that are the true distances between each of the k second moving bodies and four or more GPS satellites at the reference point. Calculated based on the k second change ratios that are the change ratios,
The four or more GPS satellites that are the targets of the first true distance and the k second true distances are defined as the first true distance and the k second true distances. Wireless devices that differ between.   The computing means is further configured to be based on the k second height differences, the first height difference, the first true distance, and the k second true distances. The radio apparatus according to claim 6, wherein an error of a pseudo distance is calculated, and an absolute position of the first moving body is calculated using the calculated pseudo distance error. Receiving means for receiving the error of the pseudorange from any one of the k second moving bodies;
The radio apparatus according to claim 6, wherein the calculating unit further calculates an absolute position of the first moving body using an error in a pseudo distance received by the receiving unit.

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