JP2008128728A - Radio positioning system and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a system for accurately positioning a position coordinate of a mobile object moving at high speed, and a radio positioning method. <P>SOLUTION: In the invention, the mobile object multicasts a positioning request signal to a plurality of marker apparatuses as positioning references. When a plurality of the marker apparatuses receive the positioning request signal, they transmit positioning data to the mobile object by using communication channels specific to them. The mobile object uses the radio positioning system for determining the current position coordinate of the mobile object by using the coordinates of the marker apparatuses obtained from the positioning data and round-trip propagation times between the marker apparatus. A communication time for positioning between the mobile object and a plurality of the markers is reduced, and the mobile object can be accurately positioned. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wireless positioning system and a wireless positioning method for determining a position coordinate of a moving body using a plurality of marker devices serving as positioning reference points.

  In order to measure the position of a vehicle on a road or the like, a GPS (Global Positioning System) is generally used. However, with GPS, the position cannot be measured correctly in a place where the four GPS satellites cannot be seen directly, such as in a valley of a building. Further, it is known that a large error occurs in the valley of the building due to the multipath effect due to reception of radio waves reflected on the building or the like. Therefore, there is a method in which a positioning wireless device (hereinafter referred to as a marker) is installed on the ground instead of a GPS satellite and the vehicle is positioned using radio waves.

  An example of a conventional positioning system that uses a marker to measure the current position of a vehicle is shown in FIG.

  In FIG. 1, 101 is a vehicle, 102 is a marker A, 103 is a marker B, 104 is a marker C, and <1> is a step in which radio waves propagate.

  In FIG. 1, radio waves are transmitted from a plurality of markers 102, 103, 104 fixedly installed on a road or the like at the same time or shifted by a known time, and the position of the vehicle is obtained from the arrival time difference of radio waves from each marker to the vehicle 101. This is the same positioning method as GPS, and it is necessary to directly receive radio waves from at least three markers within the line of sight in order to specify the position in two dimensions. In particular, in order to accurately determine the position in the traveling direction, it is necessary to directly receive radio waves from the markers before and after the vehicle 101 within the line of sight. However, when a large vehicle is traveling in front of and behind the vehicle 101, one of the radio waves from the markers 102, 103, and 104 may be shielded, and the front and rear markers may not be seen at the same time and positioning may not be possible. If the marker is installed at a high position from the road surface, it will not be shielded by a large vehicle. However, it is not desirable to install the marker at a high position because the installation cost increases.

  There is a method called a TWR (Two Way Ranging) method in which a positioning signal is reciprocated between a vehicle and a marker. The principle of positioning by TWR is shown in FIG.

  In FIG. 2, 201 is an in-vehicle device, 202 is a marker, and <1> and <2> are steps in which radio waves propagate.

As shown in FIG. 2, the distance between the in-vehicle device 201 and the marker 202 can be measured by reciprocating the radio wave between the in-vehicle device 201 and the marker 202. A radio wave is transmitted from the vehicle-mounted device 201 at the transmission time T _t0 , and the reception time T _r1 that propagates through the propagation path <1> and reaches the marker 202 is measured.

Next, a radio wave is returned from the marker 202 at the transmission time T _t1 , and the time T _r01 that propagates through the propagation path <2> and reaches the vehicle-mounted device 201 is measured. When the distance between the vehicle-mounted device 201 and the marker 201 is L ₁ , the offset of the clock of the vehicle-mounted device 201 and the marker 202 is T ₀₁ , and the speed of light is V _c , the relations of the expressions (1) and (2) are established.

- equation (2) Clearing the _{T 01} from the equation, the distance _{L 1} of the vehicle-mounted device 201 and the marker 202 is obtained by the formula.

  An example of a prior art positioning system using the TWR system is shown in FIG.

  In FIG. 3, 301 is a vehicle, 302 is a marker A, 303 is a marker B, 304 is a marker C, and <1> to <6> are steps in which radio waves propagate.

  In FIG. 3, the electric wave is reciprocated between the vehicle 301 and the marker A302 using the signal channel CH1 in steps <1> and <2>, and the step <1> is performed between the vehicle 301 and the marker B303 at the next measurement time. 3> and step <4> to reciprocate the radio wave using the signal channel CH1, and between the vehicle 301 and the marker C304, at the next measurement time, the radio wave is transmitted using the signal channel CH1 by the step <5> and step <6>. , And the distance between the vehicle 301 and the markers 302, 303, 304 is sequentially measured by the equation (3). In order to determine the position coordinates of one planar point, if the distance to at least two markers can be measured, the vehicle can be positioned by the intersection of circles centered on each marker.

  In addition, as a method of positioning the vehicle position on the road, two types of markers are installed on the road surface at predetermined intervals, and the width direction position and the traveling direction position of the lane are measured separately using signals from the marker. There is a method to do (see Patent Document 1).

  This system transmits a road width direction inquiry radio wave and a road traveling direction inquiry radio wave from the traveling vehicle toward the road surface at different frequencies.

Position information transmission markers arranged at predetermined intervals on the road surface return radio waves having the same frequency as the received road width direction inquiry radio wave. The vehicle is provided with three antennas, and determines the position in the width direction of the lane indicating the peak from the three radio wave levels received from the return radio wave from the position information transmission marker on the road. On the other hand, a road information transmission marker arranged at a predetermined interval on the road surface returns a radio wave having the same frequency as the received road traveling direction inquiry radio wave. The vehicle receives the return radio wave from the road information transmission marker on the road with the same three antennas as described above, and detects the position coordinates of the road information transmission marker in the road traveling direction. The vehicle combines these two pieces of information to determine the current position.
JP 2002-260158 A

  When the TWR method shown in FIG. 3 is used, positioning with each marker is performed in order, so the vehicle 301 moving at high speed performs positioning communication with one marker A302, and the next marker There is a problem that accurate positioning cannot be performed because the position of the vehicle 301 moves during the communication time of positioning with B303.

  In addition, many vehicles are traveling on the road, and radio waves may be shielded by other vehicles. When positioning, it is necessary to use direct propagation waves within the line of sight because radio waves reflected on the road surface (hereinafter referred to as multipath) cannot be used for correct positioning. If this is done, there is a problem that line-of-sight communication with the marker is not possible.

  In addition, the method according to Patent Document 1 requires that road information transmission markers and position information transmission markers be installed on the road surface at intervals of positioning accuracy in order to increase positioning accuracy in the lane travel direction and width direction. Equipment costs are required.

  Accordingly, one of the objects of the present invention is to provide a wireless positioning system and a wireless positioning method for accurately positioning the position of a moving body that moves at high speed.

  In addition, it is a result derived | led-out by each structure shown in the best form for implementing invention mentioned later not only the said objective, Comprising: The effect which is not acquired by the prior art is also one of the other objectives of this invention. Can be positioned.

(1) In the present invention, the mobile body broadcasts a positioning request signal to a plurality of marker devices serving as positioning reference points, and the plurality of marker devices receive positioning data when receiving the positioning request signal. It transmits to the said mobile body using a communication channel, and the said mobile body uses the radio | wireless positioning system which determines the present position coordinate of a mobile body using the coordinate of the said marker apparatus by the said positioning data, and the round trip time to a marker apparatus. Communication time for positioning between the moving body and the plurality of markers is shortened, and accurate positioning of the moving body becomes possible.

  Preferably, the positioning request signal and the positioning data signal can improve the accuracy of time measurement for positioning by using impulse radio waves.

  The positioning data signal is a signal whose pulse position is modulated by a different pseudo-random code for each marker device, and the pulse position time is controlled by a different pseudo-random code each time transmission of the positioning data is repeated. Can reduce data collisions.

  The positioning data includes first positioning data common to the mobile body and second positioning data that differs depending on the mobile body, and the first positioning data is a predetermined value regardless of reception of the positioning request signal. The second positioning data is transmitted in response to the reception of the positioning request signal. As a result, the communication time between the moving body and the marker device is shortened, and highly accurate positioning is possible.

  In addition, the positioning request data is transmitted from the mobile body only when the mobile body receives the first positioning data, and unnecessary radio waves are not transmitted outside the positioning area, thereby reducing radio wave congestion.

The marker device is installed on a traffic signal on a road or above both ends of a plurality of lanes on which the moving body travels and above a boundary line of a lane, and a small vehicle for positioning communicates with a marker device in a large sized radio wave in an adjacent lane. It can be prevented from being blocked by a car.
(2) In the present invention, a plurality of moving bodies calculated using a moving body traveling on a one-way road, a round-trip time of radio waves between a plurality of marker devices serving as positioning reference points, and coordinates of the marker devices. Among the coordinates, a wireless positioning method including a step of selecting, as coordinates of the moving body, a coordinate whose time change of the coordinate coincides with the one-way direction is used.

Preferably, the coordinates of the moving body determined using the positioning data of the other marker device centered on the coordinates of the moving body determined using the positioning data of the two marker devices with the shortest round trip time are If it is outside the predetermined range, a wireless positioning method including a step not used for positioning is used.
(3) In the present invention, the step of positioning the moving body with a first plurality of marker devices installed at a position away from the end of the intersection and facing the vehicle direction toward the intersection; A step of positioning the moving body by a second plurality of marker devices installed at an end and facing the vehicle direction entering the intersection, and a second plurality of markers passing through a positioning area by the first marker device The section until the device enters the positioning area uses a wireless positioning method including a step of determining coordinates by an autonomous sensor built in the moving body. A vehicle entering at high speed can be detected in advance, ignoring signals at intersections.
(4) a step of positioning the movable body by a first plurality of marker devices installed at a position separated from the end of the intersection by a first distance and facing the vehicle direction toward the intersection; and from the end of the intersection Positioning the movable body with a second plurality of marker devices installed at positions separated by a second distance and having radio wave directivity in both directions opposite to the direction of the intersection and the intersection; and Positioning at the end of the intersection and positioning the moving body with a third plurality of marker devices facing the direction of the vehicle entering the intersection; passing through a positioning area by the first marker device; A wireless positioning method including a step of determining coordinates by an autonomous sensor built in the moving body is used for a section before entering a positioning area by a plurality of marker devices. The positioning accuracy in the vicinity of the intersection can be improved.

  According to the present invention, it is possible to provide a wireless positioning system and a wireless positioning method for positioning the position coordinates of a moving body that moves at high speed with high accuracy.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Example 1)
In the first embodiment, a traveling vehicle transmits a positioning request signal to a plurality of markers through a broadcast channel, and each marker performs positioning of the vehicle by returning a positioning response signal to the vehicle through a marker-specific channel.

FIG. 4 shows a positioning system configuration in the first embodiment.
In FIG. 4, 401 denotes a vehicle, 402 denotes a marker A, 403 denotes a marker B, 404 denotes a marker C, and <1> denotes a step in which radio waves propagate.

  In FIG. 4, a vehicle 401 uses a broadcast channel CH0 and transmits a positioning request signal to marker A 402, marker B 403, and marker C 404 at the same time in step <1>. The marker A 402, the marker B 403, and the marker C 403 return the positioning response signals of the respective markers using the channels CH1, CH2, and CH3 specific to the marker to the vehicle 401 in the step <2>. The step <2> for returning from each marker has a difference in transmission time depending on a propagation delay time from the vehicle 401 to each marker or a delay time specific to the marker, but does not wait for a time when each marker receives a positioning request signal. Shows the steps to reply immediately.

The vehicle 401 receives the positioning request signal at the time T _t0 , the positioning response signal reception time T _r01 received from the marker A 402, the positioning request signal reception time T _{r1 at the} marker A 402 included in the positioning response signal, and the positioning response signal. using the transmission time _{T t1} of calculating the distance _{L 1} between the vehicle 401 and the marker a by (3). Similarly, the distance L ₂ between the vehicle 401 and the marker B 403 and the distance L ₃ between the vehicle 401 and the marker C 404 are calculated using the time data of each marker included in the positioning response signals from the markers B 403 and C 404.

  In order to determine the position coordinates of one planar point, if the distance to at least two markers can be measured, the vehicle can be positioned by the intersection of circles centered on each marker. In this case, two intersections are obtained, but a correct solution is determined according to the traveling direction of the vehicle 401, and a specific description will be given later with reference to FIG.

  FIG. 5 shows the positioning device configuration of the vehicle 401, FIG. 6 shows the positioning device configuration of the marker A 402, and FIG. 7 shows the communication frame configuration.

In FIG. 5, 500 is an in-vehicle device, 501 is an MPU (microprocessor unit), 502 is a transmission unit, 503 is a transmission data unit, 504 is a PPM (pulse position modulation) data modulation unit, 505 is a CH0PN sequence generation unit, and 506 is Impulse generation unit, 507 is a transmission time holding unit, 508 is a BPF, 509 is a PA (power amplifier), 510 is a transmission antenna, 511 is a timer, 512 is a reception unit, 512 ₁ is a reception unit A, 512 ₂ is a reception unit B 512 _n is a reception unit n, 513 is a reception antenna, 514 is a BPF, 515 is an LNA (low noise amplifier), 516 is a pulse detection unit, 517 is a correlator A, 518 is a CH1PN sequence generation unit, and 519 is a reception time holding unit Portions A and 520 are PPM data demodulator portions A, 521 are reception data portions A and 522 are external interfaces, respectively.

  In FIG. 6, 600 is a marker A, 601 is an MPU (microprocessor unit), 602 is a transmission unit, 603 is a transmission data unit, 604 is a PPM (pulse position modulation) data modulation unit, 605 is a PN sequence generation unit for CH1, 606 is a delay unit, 607 is a transmission time holding unit, 608 is a subtractor, 609 is an impulse generation unit, 610 is a BPF, 611 is a PA (power amplifier), 612 is a transmission antenna, 613 is a timer, 614 is a reception unit, 615 Is a receiving antenna, 616 is a BPF, 617 is an LNA (low noise amplifier), 618 is a pulse detector, 619 is a correlator, 620 is a CH0PN sequence generator, 621 is a reception time holding unit, 622 is a PPM data demodulator, 623 Indicates a received data portion, and 624 indicates an external interface.

In FIG. 7, D701 is a transmission pulse waveform and an output waveform of the impulse generator 506, D702 is TH (time hopping) data and an output waveform of the PN sequence generator 605, D703 is transmission data and an output waveform of the transmission data 603, D703 ₁ the preamble part (unmodulated), D703 ₂ data unit (PPM modulation), D704 and D705 indicate one chip pulse position modulation, respectively.

  FIG. 7 shows the frame configuration of the vehicle-mounted device. Regarding the frame configuration of the marker, the PN code D702 is different from the transmission pulse waveform D701, and the delay time described later is controlled to prevent collisions. Therefore, the description with drawings is omitted.

  The operation of the positioning system in the first embodiment will be described with reference to FIGS. 4, 5, 6, and 7.

  First, the positioning request signal transmitted by the vehicle-mounted device 500 mounted on the vehicle 401 shown in FIG. 5 will be described.

Under the control of the MPU 501, transmission data D703 is output from the transmission data unit 503 as a pulse of 1 μsec. The first part of the transmission data D703 is a section of the preamble D703 _1, section 7 pulses 7μsec is all zeros.

  In FIG. 5, the PPM data modulation unit 504 does not change the time position of the pulse chip input from the CH0PN sequence generation unit 505 when the transmission data D703 sent from the transmission data unit 503 by the control of the MPU 501 is 0. In this case, pulse position modulation which changes (hops) for one chip is performed.

  The CH0PN sequence generator 505 generates an 8-level RS (Reed-Solomon) sequence code sequence, which is a kind of PN (pseudo-random code) sequence, as a broadcast channel CH0, and generates a pulse of 100 nsec per chip with a period of 1 μsec. Each time, a pulse waveform arranged at a time corresponding to the generated code is generated. For example, corresponding to the code of 576421 shown in D702, a pulse of 100 nsec is positioned at 500 nsec in the first 1 μs section for the first 5 and 700 nsec in the next 1 μsec for the next 7 The waveforms are arranged at positions corresponding to the following 6, 3,.

The transmission data D703 shown in FIG. 7 is a pulse code of 1 .mu.sec, a transmitting a preamble part D703 ₁ of arranged for synchronization at the beginning of the data D703, the data unit D703 ₂ Metropolitan subsequent thereto.

In the preamble part D703 ₁ in FIG. 7, the transmission data D703 has all the pulses within one period of 7 μsec being zero. At this time, since all the modulation inputs are 0, the PPM data modulation unit 504 outputs the pulse position of the pattern waveform from the CH0 PN sequence generation unit 505 as it is.

The data unit D703 ₂ of FIG. 7, the transmission data D703 has any code within a predetermined period. For example, when the transmission data is 0110..., The PPM data modulation unit 504 causes the pulse position of the chip to be 0110 due to the pattern waveform 5763421... (Usually more than 7 signs of the preamble part) from the PN sequence generation unit 505. .. Corresponding to... Hopping by 1 chip (indicated by D704 and D705 in FIG. 7), modulated as 5873..., And hopped to positions of 500 nsec, 800 nsec, 700 nsec, 300 nsec. , the pulse signal waveform indicated in the data D703 ₂ of FIG.

  The pulse signal modulated by the PPM in the PPM data modulation unit 504 is sent to the impulse generation unit 506, and a very thin impulse is generated at the rising edge of the pulse by the step recovery diode. The as-generated impulse has a very wide frequency band spectrum, but the BPF508 (bandpass filter, eg, 3.4 GHz to 4.8 GHz or 7.25 GHz to 10.25 GHz pass. By passing the (bandwidth), spectrum components outside the allowable band (for example, 3.4 GHz or less and 4.8 GHz or more, or 7.25 GHz or less and 10.25 GHz or more) can be removed. After passing through the BPF 508, the signal is amplified by the PA 509 (power amplifier), and a radio wave is radiated from the transmitting antenna 510.

When transmitting the positioning request signal, the vehicle-mounted device 500 of the vehicle 401 stores the time T _{t0 at} which the first pulse of the data part after the preamble part D703 ₁ is generated in the transmission time holding part 507.

The broadcast radio wave CH0 transmitted from the vehicle-mounted device 500 of the vehicle 401 is received by the receiving unit of each marker. In the marker A 402 receiving unit 614 of FIG. 6, the impulse radio wave received from the receiving antenna 615 is amplified by the low noise amplifier amplifier 617 after unnecessary frequency components are removed by the band pass filter BPF 616, and the pulse detecting unit 618 Presence or absence is detected. The circuit of the pulse detection unit 618 can be realized by a known diode envelope detection circuit and a comparator. The detected pulse is compared with the RS sequence code of the broadcast CH0 generated by the CH0PN sequence generation unit 620 by the correlator 619 using a digital matched filter. If the preamble portion D703 ₁ is detected by the correlator 619, as the synchronization has been established, the PPM data demodulator 622, the subsequent data unit D703 ₂ of the PPM signal to generate a received data demodulated received data Input to the MPU 601 via the unit 623. After detecting the first pulse of the data unit D703 _2, and holds the time _{T r1} to the reception time holding unit 621.

  When the received data input to the MPU 601 is determined as a positioning request signal from the vehicle 401, it is returned as a positioning response signal of the marker A402. At this time, a different channel is used for each marker, and channel 1 (hereinafter referred to as CH1) is used in the marker A402. The transmission unit 602 of the marker A 402 includes a CH1PN sequence generation unit 605, and generates a code string 4672530 different from CH0 as an RS sequence of CH1. Although the frame structure is the same as that in FIG. 7, the only difference is that 5762421 in D702 in FIG. Also, a random delay amount designated by MPU 601 is added to the sequence generated by CH1PN sequence generation unit 605 in delay unit 606.

  The purpose of adding a random delay amount will be described with reference to FIGS.

  In FIG. 8, CH1, CH2, CH3, and CH4 indicate time waveforms of positioning response signal channels transmitted by different markers.

  In FIG. 9, CH1, CH2, CH3, and CH4 indicate time waveforms in which the pulse position of the positioning response signal that is individually transmitted by each marker in FIG. 8 is delayed at random.

  When a positioning response signal is returned from each marker, a different RS sequence is used for each marker, so the pulses transmitted from each marker are pseudo-randomized so that they do not collide continuously even if they collide once. Yes. However, very rarely, as shown in FIG. 8, the pulses of CH1 and CH2 collide, then the pulses of CH1 and CH3 collide, and then the pulses of CH1 and CH4 collide, Since CH1 continuously collides with other channels, error correction cannot be performed, and correct data transfer and positioning may not be performed. As a countermeasure against this inconvenience, when each marker responds to a positioning request signal from the vehicle 401 during repeated positioning in the first embodiment, a random delay is given to each marker for each repeated positioning as shown in FIG. To have.

For example, the marker A 402 has a delay of α ₁ , the marker B 403 has a delay of α ₂ , and similarly, when there are n markers, the n-th marker has a delay of α _n . With this method, as shown in FIG. 8, even if one positioning is failed due to a collision of pulses, in the next positioning, the CH1 pulse shifts by α ₂ −α _{1 with} respect to CH2. As a result, a shift of α ₃ -α ₁ occurs for CH3, a shift of α ₄ -α ₁ occurs for CH4, and there is no collision between CH1 and other channels.

The marker A 402 holds the first pulse generation time T _t1 of the data part D703 ₂ after the transmission data preamble part D703 _{1 in} the transmission time holding part 607, and subtracts it from the positioning request signal reception time T _r1 in the subtractor 608. To obtain time difference data (T _t1 -T _r1 ). The marker A 402 returns the time difference data (T _t1 -T _r1 ) and the position coordinate data of the marker A 402 to the in-vehicle device 500 as positioning response signal data in response to the positioning request signal from the in-vehicle device 500.

Since the positioning response signal is simultaneously returned from each marker, the in-vehicle device 500 includes the receiving units 512 ₁ , 512 ₂ ,..., 512 _n for the number of channels, and performs reception processing in parallel.

5, the positioning response signal from the marker A402 is received by the receiving unit A512 _1, by the balanced signal correlation between CH1 PN sequence by the marker A402, receiving time _{T r01} is held by the reception time holding unit 519, The positioning response signal data is demodulated by the PPM data demodulator 520 and sent to the MPU 501 via the reception data A521.

The MPU 501 of the in-vehicle device 500 includes the response time included in the reception data demodulated from the time T _t0 held in the transmission time holding unit 507, T _r0 held in the reception time holding unit A519, and the positioning response signal from the marker A402. Using the data (T _t1 -T _r1 ), the distance L ₁ between the vehicle 401 and the marker A 402 is calculated based on the equation (3).

In the same manner, positioning response signals received from other markers including the marker B403 and the marker C404 are received by the receiving unit B512 ₂ ,..., Respectively, and the time difference data and the position of each marker at each marker are received. The positioning response signal data including the coordinate data and the reception time from each marker in the vehicle-mounted device 500 are sent to the MPU 501.

The MPU 501 uses the response time at each marker sent from each marker, the transmission time T _t0 of the vehicle-mounted device 500 and the reception time from each marker, and in the same manner as in equation (3), between the vehicle 401 and each marker. distance _{L 2, L 3,} to calculate the ··· _{L n.}

Using the position coordinate data of each marker and the distances L ₁ , L ₂ ,... Ln from the vehicle 401 to each marker, the position coordinates of the vehicle 401 are obtained by a calculation method described later.

  FIG. 10 shows the format of the output signal data of the vehicle-mounted device and the plurality of markers, FIG. 11 shows the flow of positioning request signals and positioning response signals from the markers, and FIG. 12 shows the positioning processing procedure.

In FIG. 10, D101 is positioning request signal, D101 ₁ request header, D101 ₂ vehicle ID, D102 is the positioning response signal, D102 ₁ response header, D102 ₂ vehicle ID, D102 ₃ is a marker ID, D102 ₄ response time, D102 ₅ is a marker of latitude, D102 ₆ is a marker of longitude, D102 ₇ the markers height, D102 ₈ road information, D103 individual positioning response signal, D103 ₁ response header, D103 ₂ vehicle ID, D103 ₃ is a marker ID, D103 ₄ is a response time, D104 is data common to each car, D104 ₁ is a response header, D104 ₂ is a marker ID, D104 ₃ is a marker latitude, D104 ₄ is a marker longitude, and D104 ₅ is a marker height. is, D104 ₆ denotes a road information.

In FIG. 11, the same signal as that in FIG. 10 is given the same symbol, T _1a is the communication time between the vehicle 1 and the marker, T _2a is the communication time between the vehicle 2 and the marker, and T _3a is the vehicle 3 Communication time with the marker, T _na is the communication time between the vehicle n and the marker, T ₀ is the time for simultaneous transmission from the marker to each vehicle, T _1b is the communication time between the vehicle 1 and the marker, and T _2b is the vehicle 2 and the marker , T _3b is the communication time between the vehicle 3 and the marker, and T _nb is the communication time between the vehicle n and the marker.

In FIG. 10, a positioning request signal D101 is broadcast from each onboard device 500 to each marker using CH0. A positioning response signal D102 is returned from each marker. However, in the data D102, the vehicle ID 102 ₂ and the response time 102 ₄ is the different data for each vehicle that issued the positioning request signal D101, D102 ₃ and marker latitude D102 ₅ after the data markers Marker ID This is road information data indicating coordinate data and marker installation positions on the road, and is common to each vehicle.

  In this embodiment, therefore, the positioning response signal D102 from the marker is divided into different individual positioning response signals D103 and different vehicle common data D104 for each vehicle, and D103 is used as an individual positioning response signal for each vehicle. And each marker transmits each vehicle common data D104 for every fixed period.

  The in-vehicle device 500 receives the common data D104 for each vehicle and uses it to calculate the position coordinates of the vehicle 402.

FIG. 11A shows the signal flow when positioning a plurality of vehicles 1, vehicles 2, vehicles 3,..., Vehicle n using positioning request signal D101 and positioning response signal D102. In this case, so that the interference of each vehicle on the signal does not occur, the communication markers A402 and each vehicle is time-divided, each _{T 1a, T 2a, T 3a} , ···, performed _{T na.}

On the other hand, (b) of FIG. 11 shows signals for positioning of a plurality of vehicles 1, vehicles 2, vehicles 3,..., Vehicle n based on the positioning request signal D101 and the signals D103 and D104 as positioning response signals. Show the flow. In this case, the communication between the marker A 402 and each vehicle is time-divided so that signal interference does not occur for each vehicle in the same manner as described above, and T _1b , T _2b , T _{3b ,.} To be done. Each vehicle common data D104 is broadcasted to each vehicle at an appropriate cycle instead of the communication time for each vehicle.

In the method using the individual positioning response signal shown in FIG. 11 (b), since T _1b , T _2b , T _3b ,..., T _nb does not include data common to each vehicle, T _1a according to FIG. , T _2a , T _3a ,..., T _na can be compared with a method in which common data is included in all, and a single positioning time is shortened.

  That is, in FIG. 11B, the occupied time of the channel transmitted from the marker is reduced, so the time for each vehicle to perform positioning at a time is shortened, and the positioning cycle in the case of repeated positioning is shortened.

  When positioning repeatedly while each vehicle is moving, if the positioning cycle is shortened, the distance to be measured next after the positioning is shortened, and the positioning accuracy of the moving vehicle is improved.

  When a plurality of vehicles communicate with a plurality of markers, each vehicle uses the same broadcast channel CH0. Therefore, in order to prevent radio wave interference, a CSMA / CA (Carrier Sense Multiple Access Avidance) system is used. The CSMA / CA method has been used conventionally, and is a signal collision prevention method in which data is transmitted after confirming that a communication path is continuously available for a certain time or more.

FIG. 12 shows a positioning processing procedure using the CSMA / CA method.
12, the same components as those in FIGS. 4 and 5 are denoted by the same reference numerals. Further, S1201 is a step in which the marker A402 transmits each vehicle common data A, S1202 is a step in which the vehicle-mounted device 500 holds each vehicle common data A of the marker A402, and S1203 is a step in which the marker B403 transmits each vehicle common data B. , S1204 is a step in which the vehicle-mounted device 500 holds the vehicle common data B of the marker B403, S1205 is a step for waiting until all the CHs are free, S1206 is a step for waiting for a random time interval from the time when all the CHs are free, and S1207 is a positioning request. Broadcasting the signal using CH0, S1208 is a step in which the marker A402 receives the positioning request signal, S1209 is a step in which the marker A402 transmits the positioning response signal A, and S1210 is a step in which the marker B403 receives the positioning request signal Step, S1211 is marker B40 Transmitting a positioning response signal B, S1212 is a step in which the in-vehicle device 500 receives the positioning response signal A, S1213 is a step in which the in-vehicle device 500 receives the positioning response signal B, S1214 is a step in which positioning calculation is performed, and S1215 is in step S1215. Steps for returning to S1202 and performing the next positioning will be shown.

FIG. 13 shows a flow of positioning operation including determination as to whether or not the in-vehicle device 500 has entered the positioning service area where the marker is installed.
In FIG. 13, S1301 is a step in which the vehicle-mounted device 500 starts a positioning operation, S1302 is a step in which all CHs are monitored, and S1302 is a step in which it is determined whether or not each vehicle common data D104 is detected in any one of CH1 to CHn. , S1304 is a step of determining whether or not all the CHs are free, S1305 is a step of waiting for a random time, S1306 is a step of requesting positioning with CH0, S1307 is a step of determining whether or not there is a response using CH1 to CHn, S1308 Indicates a step of performing positioning with respect to the marker of the CH that has responded in S1307, and S1309 indicates a step of determining whether or not there is no response continuously for a predetermined time.

  Positioning is started in step S1301 of FIG. Since no marker is installed outside the positioning area, the in-vehicle device 500 does not need to issue the positioning request signal D101 on the channel CH0, and unnecessary radio wave emission should be suppressed in order to reduce interference with other systems. In step S1302, the vehicle common data signal D104 in CH1 to CHn transmitted by the marker is monitored.

  In step S1303, it is determined whether each company common data D104 has been received.

  The marker installed in the positioning area transmits the signal of the common data D104 for each vehicle regardless of the presence or absence of the positioning request signal from the traveling vehicle. Therefore, when the in-vehicle device 500 enters the positioning area, the common data for each vehicle is transmitted. Received by any one of CH1 to CHn. When the in-vehicle device 500 is out of the positioning area, the in-vehicle device 500 cannot receive any of the common vehicle data D104 for any of CH1 to CHn, so the process returns to S1302 and repeats until the common vehicle data D104 can be received.

  If the common vehicle data D104 can be received, it is determined in step S1304 how long all the CHs are available. However, the data of each vehicle common data D104 is transmitted in a long cycle, and the vacant time of each vehicle common data D104 is long, and CH0 and CH1 to CHn for other vehicles are not transmitted during this vacant time. Judging. If there is free time, the in-vehicle device 500 waits for a random time in step S1305 and transmits the positioning request signal D101 using CH0. In step S1307, it is determined whether or not the individual positioning response signal D103 from the marker has been received. In the case of yes in step S1307, positioning is performed using the data of the individual positioning response signal D103 in step S1308, and while the positioning response signal is returned to CH1 to CHn, it is in the positioning area. repeat.

  In the case of no in step S1307, since there is no positioning response signal from any of CH1 to CHn, a positioning request signal is transmitted within a certain time by step S1309, but in the case of yes by step S1309, even after the elapse of the certain time, Since there is no positioning response signal from any of CH1 to CHn, it is determined that the signal has gone out of the positioning area, the transmission of the positioning request signal is stopped, and the process returns to the first monitoring of CH1 to CHn. If NO in step S1309, the process returns to step S1306, and a positioning request signal is transmitted on CH0 to the CH marker that has responded.

Next, a method for installing a plurality of markers will be described.
FIG. 14 shows an example of marker installation.
14, 1401 is an intersection, 1402 is a vehicle, 1403 is a vehicle-mounted device, 1404 is a marker, 1405 is a marker, 1406 is a marker, and 1407 is a marker.

  In the marker installation example shown in FIG. 14, since the purpose is to determine the position of the vehicle 1402 in the vicinity of the intersection 1401, a marker is installed at each traffic light at the intersection 1401. Since there are usually four traffic lights at one intersection, four markers 1404, 1405, 1406, and 1407 are installed. Since positioning is possible if at least two markers can be seen from the vehicle-mounted device 1403, positioning can be performed for each approach path of the intersection 1401. For example, by using signal information of a traffic light, it is possible to detect a vehicle that intrudes by ignoring the signal and issue a warning or forcibly stop the vehicle.

  FIG. 15 and FIG. 23 show specific examples of positioning of a traveling vehicle by marker installation.

  In FIG. 15-1, 1501 is a pole, 1502 is a marker M1, 1503 is a marker M2, 1504 is a pole, 1505 is a marker M3, 1503 is a marker M4, 1507 is a large vehicle, 1508 is a small vehicle, 1509 is a large vehicle, 1510 is Lanes, 1511 are lanes, 1512 are lanes, and P1501 to P1506 are propagation paths of radio waves.

  15-2, the same components as those in FIG. 15-1 are assigned the same numbers, 1513 indicates a marker M1, 1514 indicates a marker M2, 1515 indicates a marker M3, and P1507 to P1510 indicate radio wave propagation paths.

  15C, the same components as those in FIG. 15A are denoted by the same reference numerals, and P1511 to P1513 indicate radio wave propagation paths.

  15-4, the same components as those in FIG. 15-1 are denoted by the same reference numerals, 1516 is a small vehicle, 1517 is a large vehicle, 1518 is a small vehicle, and P1514 to P1521 are radio wave propagation paths.

  In FIG. 23, the same components as those in FIG. 15-1 are assigned the same numbers, 2319 is a large vehicle, 2320 is a large vehicle, 2321 is a small vehicle, 2322 is a large vehicle, 2323 is a lane, 2324 is a lane, 2325 is a lane, P2322 to P2326 indicate radio wave propagation paths, respectively.

In FIG. 15A, a marker M1 1502 is installed on the pole 1501 at the road end, a marker M4 1506 is installed on the pole 1504, and the marker M2 1503 and the marker M3 are positioned above the lanes adjacent to the traveling lane 1511 of the small car 1508. The case where 1505 is installed is shown.

  As shown in FIG. 15A, from a small vehicle 1508 sandwiched between a large vehicle 1507 and a large vehicle 1509, propagation paths P1501, P1502 directly looking through the marker M1 1502, M4 1506, M2 1503, M3 1505, All of P1503 and P1504 may be blocked.

  In the case of FIG. 15A, in the small vehicle 1508, the radio wave from the M2 1503 is reflected by the large vehicle 1509 and received by the propagation path P1505 reaching the small vehicle 1508, and the radio wave from the M3 1505 is reflected by the large vehicle 1507. May be received by the propagation path P1506 reaching the small car 1508. In this case, since the propagation paths P1505 and P1506 are not linear distances, a large error occurs in the distance measurement between the marker and the small car 1508. Further, if the height of the large vehicle 1507 in FIG. 15A is slightly low, there may be a direct propagation path P1502 from the marker M2 1503 to the small vehicle 1508 and a reflection propagation path P1505 at the same time. As described above, in the case of a multi-wave transmission path (hereinafter referred to as multi-path) that receives the same radio wave from a plurality of paths, the direct wave and the reflected wave are combined. Therefore, in the distance measurement between the marker M2 1503 and the small car 1508. An error is generated.

  FIG. 15B illustrates a case where a marker M1 1513, a marker M2 1514, and a marker M3 1515 are installed above the lanes 1501, 1511, and 1512. However, also in the case of FIG. 15B, the direct wave of two or more markers is blocked, and only the reflected wave can be received from the marker M1 1513 and the marker M2 1515, resulting in a large positioning error.

  Therefore, in this embodiment, as shown in FIG. 15C, a marker M1 1502 is installed at the end of the lane, and a marker M2 1503 and a marker M3 1505 are installed above the boundary between the lane and the lane. By doing this, even from a small vehicle 1508 sandwiched between large vehicles 1507 and 1508, the minimum two markers M2 1503 and the marker M3 1505 are clearly visible and positioning can be performed correctly, so that positioning errors can be reduced. . At this time, the communication with the marker M1 1502 becomes a reflection wave out of line of sight and the positioning error becomes large. However, as will be described later, the two markers M2 1503 and M3 1505 are selected in order of decreasing distance. Thus, it is possible to avoid using the marker M1 1502 in which the positioning error increases due to the reflection path.

  Similarly, when the large vehicle 1517 travels in the central lane in FIG. 15-4, the small vehicles 1516 and 1518 in both lanes can see at least two markers M1 1502 and 1503 of the marker M2, and direct waves Since it can be received, the positioning error becomes small.

  Further, as shown in FIG. 23, even when the large vehicle 2322 travels in the center lane 2324 of three lanes (2323, 2324, 2325) and the small vehicle 2321 travels in the end lane 2323, at least two markers M1 1502 and the marker The M2 1503 can be seen, and a direct wave can be received, so the positioning error is small.

  Next, a specific positioning method will be described with reference to FIGS. 16-1 and 16-2.

  In FIG. 16A, 1601 is a marker M1, 1602 is a marker M2, 1603 is a marker M3, 1604A is a vehicle-mounted device, 1604B is a virtual image of the vehicle-mounted device, 1605 is a large vehicle, 1606 is a lane, 1607 is a lane, 1608 is a lane, Reference numeral 1609 denotes a lane, 1610 denotes a circle centered on M1, and 1611 denotes a circle centered on M2.

As shown in FIG. 16A, consider a case where two markers 1601 of M1 and 1602 of M2 are line-of-sight. In FIG. 16A, the lane direction is x-coordinate, the lane width direction is y-coordinate, and the height direction is z-coordinate, and the markers M1 1601, M2 1602, and the vehicle-mounted device 1604 are respectively coordinated (X ₁ , Y ₁ , Z ₁ ), (X ₂ , Y ₂ , Z ₂ ), (x, y, 0), and the distances between the vehicle-mounted device 1604 and the markers M1 1601 and M2 1602 are L ₁ and L ₂ , respectively. The relationship between the equations (4) and (5) is established.

If x and y are solved by simultaneous equations (4) and (5), the coordinates (x, y) of the vehicle-mounted device are the coordinates of 1601 of marker M1, the coordinates of 1602 of marker M2, and the distance L ₁ . represented by L _2.

However, in this case, (4) and (5) the solution of equation, the 1601 yen 1610 having a radius _{L 1} around the marker M1, the intersection of the radius _{L 2} of the circle 1611 around the 1602 marker M2 Thus, two points of the position of the in-vehicle device 1604A and the position 1604B of the virtual image are obtained. In one positioning, it cannot be determined whether the actual position of the vehicle-mounted device is 1604A or 1604B. However, when the vehicle-mounted device 1604A is traveling in the direction of the arrow on the lane, if positioning is performed continuously at a predetermined time interval, the 1604A position coordinate moves in the direction of the arrow, but the 1604B virtual image position coordinate is in the direction opposite to the arrow. Move to.

  For example, since the vehicle is a lane that moves in the direction of the arrow in FIG. 16A, the position coordinates of 1604A can be determined as the actual position coordinates of the vehicle-mounted device.

Further, as shown in FIG. 16B, a case is considered where three markers M1, 1601, M2, 1602, and M3, 1603 are visible. Assuming that the distances between the vehicle-mounted device 1604 and the markers M1 1601, M2 1602 and M3 1603 are L ₁ , L ₂ and L ₃ , respectively, in addition to the equations (4) and (5), the following (6 ) Formula is obtained.

  When these relational expressions (4), (5), and (6) are used, as shown in FIG. 16-2, when markers M1 1601, M2 1602 and M3 1603 are in a straight line, Two solutions, 1604A and 1604B, are obtained as in the case of FIG. 16-1, but it can be determined that the actual position of the vehicle-mounted device is 1604A from the traveling direction on the lane. Further, if there are many relational expressions, the error can be reduced by the least square method. Therefore, when three or more distances can be used, positioning is performed by the least square method.

  However, even when positioning can be performed with three or more markers, as shown in FIG. 15-4, the propagation path P1520 of the radio wave from the M3 1505 is an error when reflected.

  FIG. 17 shows a positioning processing method for removing the reflected wave when the reflected wave is included.

In FIG. 17, S1701 is a step in which the vehicle-mounted device 500 starts a positioning operation, S1702 is a step in which the positioning coordinates C _i are _obtained by using the two markers with the shortest distance, and S1703 is positioning by using the marker M _k with the next shortest distance. A step of obtaining coordinates C _k , S 1704 is a step of determining whether C _k is within a predetermined distance with respect to C _i , S 1705 is a step of adopting marker M _k as a marker, and S 1706 is a step of not employing marker M _k as a marker S1707 indicates a step of determining whether or not all markers have been accepted, and S1708 indicates a step of positioning by the least square method using the distances to all the employed markers.

In FIG. 17, a positioning process is started by step S1701. In step S1702, the position coordinates (x, y) of the vehicle-mounted device 500 are obtained by the equations (4) and (5) using the distance to the two markers with the shortest distance. At this time, since two solutions including a virtual image are obtained, which solution is determined by the determination based on the traveling direction. In step S1703, the marker _Mk having the next shortest distance is selected, and a solution is obtained by using the distance from the shortest marker and the expressions (4) and (6). In step S1704, it is determined whether the position coordinate (x, y) of the vehicle-mounted device 500 obtained previously matches the position coordinate (x, y) using the marker _Mk within the measurement error range. In the case of yes in step S1704, it is determined that the marker _Mk has been measured by the line-of-sight distance without a reflection path, and is registered as a marker to be used. In the case of no in S1704, the marker _Mk is determined to be positioning based on the non-line-of-sight distance by the reflection path, and is not adopted as the marker used for positioning.

  In step S1707, it is determined whether or not the determination for all markers having a positioning response has been completed. If no in step S1707, the process returns to step S1703 to determine the next marker.

In the case of yes in S1707, the position coordinates (x, y) of the in-vehicle device 500 with a small error are obtained by the least square method using the position coordinates for all the markers registered as usable markers in step S1708.
(Example 2)
The second embodiment provides a wireless positioning system that performs vehicle positioning with high accuracy near an intersection.

  18-1, FIG. 18-2, and FIG. 18-3 show the situation where a small vehicle traveling behind a large vehicle sees a marker over the road.

  18A, 1801 is a pole, 1802 is a marker, 1803 is a large vehicle, 1804 is a small vehicle, 1805 is an in-vehicle device, and P1801 is a propagation path of a radio wave.

  18B, the same components as those in FIG. 18A are denoted by the same reference numerals, and P1802 indicates a radio wave propagation path.

  18-3, the same components as those in FIG. 18-1 are denoted by the same reference numerals, 1806 indicates a pole, 1807 indicates a marker, 1808 indicates a pole, 1809 indicates a marker, and P1803 indicates a radio wave propagation path.

  In the second embodiment, the present invention is applied to a use of stopping a signal ignoring vehicle by a wireless positioning system in the vicinity of an intersection. In order to warn, decelerate, and stop a runaway vehicle ignoring an intersection signal, for example, it is necessary to position the traveling vehicle from about 100 meters before the intersection.

  As shown in FIG. 18A, when the small vehicle 1804 is close to the marker, the elevation angle looking up at the marker is large, and therefore the radio wave propagation path P1801 is not blocked by the large vehicle 1803, and the in-vehicle device 1805 mounted on the small vehicle 1804 is used. Can directly communicate with the marker 1802.

  However, as shown in FIG. 18-2, the elevation angle looking up at the marker 1802 becomes small at the position where the small car 1804 is away from the marker 1802, so that the radio wave propagation path P 1802 is shielded by the large car 1803.

  As a countermeasure, if a large number of markers are installed as shown in FIG. 18-3, a nearby vehicle becomes a line of sight and the problem can be solved, but the markers increase to 1802, 1807, and 1809, There is a problem that the equipment cost including the mounted poles 1801, 1806, and 1808 increases.

FIG. 19 shows a marker layout diagram of the positioning sensor system according to the second embodiment.
In FIG. 19, 1901 is an intersection, 1902 is a marker, 1903 is a marker, 1904 is a marker, 1905 is a marker, 1906 is a real-time positioning area, 1907 is an autonomous sensor area, 1908 is a calibration area, 1909 is a marker, 1910 is a marker, 1911 is a marker, 1912 is a marker, 1913 is a lane, 1914 is a lane, and 1915 is a lane.

  In FIG. 19, an area (hereinafter referred to as a calibration area) 1908 having a length of about 30 m for performing preliminary positioning of a traveling vehicle is set in a lane about 100 m away from an intersection 1901. 1, positioning is performed by impulse radio waves using the in-vehicle device 500 and the marker A 600 described with reference to FIGS. 5 and 6.

  Thereafter, in an autonomous sensor area 1907 in front of the intersection 1901, positioning is performed by an in-vehicle autonomous sensor such as a vehicle speed sensor or a gyro sensor mounted on the traveling vehicle. Then, positioning by the impulse radio wave is performed in a real-time positioning area 1906 having a length of about 30 m before the intersection 1901.

  By this method, the traveling vehicle can be reliably captured from the calibration area 1908 at a position away from the intersection 1901, and high-precision positioning can be performed in the real-time positioning area 1906 near the intersection, and the positioning system shown in FIG. Thus, it is economical because it is not necessary to install many markers.

  Furthermore, since the positioning area can be limited to two narrow areas, the real-time positioning area 1906 near the intersection and the calibration area 1908, the frequency of vacating radio channels in the positioning area increases, The positioning cycle can be shortened.

  In addition, since the positioning area is as narrow as about 30 m, the radio wave output of the vehicle-mounted device and the marker can be lowered, and radio wave interference to other systems can be reduced.

  When positioning of the vehicle position is performed by the TWR method, there is a property that variation in positioning in the lateral direction increases from the vehicle toward the marker as the distance from the vehicle to the two markers increases.

  The reason why the variation in positioning differs depending on the distance from the marker and the positioning direction will be described with reference to FIG.

In FIG. 20, 2001 _A is marker A, 2001 _B is marker B, d is an installation interval between marker _A 2001 _A and marker B 2001 _B , 2002 is a short distance vehicle, 2003 is a short range variation range, and 2004 is a long distance. Vehicle, 2005 is a dispersion range at a long distance, C _A1 and C _A2 are short arcs around the marker A, C _B1 and C _B2 are short arcs around the marker B, and Δr is a radial distance measurement. Variation, Δx ₁ is a short-distance x-direction positioning variation, Δy ₁ is a short-distance y-direction positioning variation, C _A3 and C _A4 are long-distance arcs around the marker A, and C _B3 and C _B4 are long markers B far arc around the, [Delta] x ₂ long distance in the x-direction positioning variation, [Delta] y ₂ represents far in the y direction positioning variations, respectively.

In Figure 20, when the vehicle 2002 is in the same degree of close range position compared to the installation distance d between the markers, the distance between the marker A2001 _A is in the range of the arc _{C A1} and arc _{C A2} around the marker A2001 _A It is measured by a value having a variation Δr.

  In this case, the variation Δr in the measurement distance in the radial direction is a random value regardless of the size of the distance, which is caused by a processing error or time error caused by the positioning system marker or the vehicle-mounted device, and is almost the same for each marker. Assuming variation, Δr is constant.

Next, when the vehicle 2002 at a short distance measures the distance to the marker B2001 _B , the distance is measured with a value having a variation Δr within the range of the arc C _B1 and the arc C _B2 around the marker B2001 _B.

As a result, the vehicle position coordinates are measured as within a variation range of 2003 surrounded by four arcs. Since the x-axis direction length Δx ₁ and the y-axis direction length Δy ₁ of the variation range 2003 are substantially equal to Δr, the variations in the x-axis direction and the y-axis direction are substantially equal.

On the other hand, when the distance from the vehicle 2004 far away from the installation distance d between the markers to the marker A2001 _A is measured, it is measured with a value having a variation width Δr from the arc R _A3 to the arc R _A4 . Further, when the distance from the long-distance vehicle 2004 to the marker B2001 _B is measured, it is measured with a value having a variation width Δr from the arc C _B3 to the arc C _B4 . As a result, the position coordinates of the vehicle 2004 are measured as being within a variation range of 2005 surrounded by four arcs. Although x-axis length [Delta] x ₂ variation range 2005 is approximately equal to [Delta] r, for the y-axis direction, the direction of the arc _{C A3} and the arc _C direction _A4 and the arc _{C B3} and the arc _{C B4} intersect at an acute angle, [Delta] y ₂ is considerably larger than Δx _2. For this reason, the variation in the x-axis direction is almost constant with respect to the distance, whereas the variation in the y-axis direction becomes larger as the distance becomes longer.

  The above-mentioned variation in positioning is measured as a statistical variation in position coordinates because the size varies randomly at each positioning.

FIG. 21-1 shows an example of variation in positioning using two markers.
In FIG. 21A, D2101 is a positional coordinate variation in the lane direction (x-axis direction) of the measured vehicle (hereinafter referred to as 3σ, which is three times the standard deviation σ of the variation), and D2102 is a measured lane width direction (y A variation in position coordinates in the axial direction is shown.

  The variation in the position in the x-axis direction of the vehicle is substantially constant with respect to the distance from the position just below the horizontal axis marker (equal to the value of x), but the variation in the position in the y-axis direction of the vehicle increases in proportion to the horizontal axis. .

  FIG. 22 shows the configuration of a wireless positioning system that solves this increase in variation and improves the positioning accuracy near the intersection.

In Figure 22, 2201 is an intersection, 2202 ₁ marker, 2203 ₁ marker, 2204 ₁ marker, 2205 ₁ marker, 2202 ₂ marker, 2203 ₂ marker, 2204 ₂ marker, 2205 ₂ marker, the 2206 Real-time positioning area, 2206 _a is real-time positioning area a, 2206 _b is real-time positioning area b, 2207 is an autonomous sensor area, 2208 is a calibration area, 2209 is a marker, 2210 is a marker, 2211 is a marker, 2212 is a marker, and 2213 is A lane, 2214 indicates a lane, and 2215 indicates a lane.

In FIG. 22, a vehicle traveling in an area 2206a close to the intersection 2201 within the range of the real-time positioning area 2206 (for example, an area 20 m from the intersection) is at least _one of the forward markers 2202 ₁ , 2203 ₁ , 2204 ₁ , 2205 ₁ . Positioning can be performed by communication between two markers and at least _two of the markers 2202 ₂ , 2203 ₂ , 2204 ₂ , and 2205 _{2 in} the backward direction.

FIG. 21-2 shows an example of variations in positioning using two markers in the forward direction and two markers in the backward direction.
In FIG. 21B, D2103 indicates the positional coordinate variation in the lane direction (x-axis direction) of the measured vehicle, and D2104 indicates the positional coordinate variation in the measured lane width direction (y-axis direction).

  The variation D2103 in the x-axis direction position of the vehicle is substantially constant with respect to the distance (equal to the value of x) from directly below the horizontal axis marker. On the other hand, the variation D2104 in the position in the y-axis direction of the vehicle is shown to be improved as compared with D2102 in FIG. As the distance from the marker at the intersection position (x = 0) increases, the variation in positioning in the y direction due to the intersection position marker increases. However, since the distance from the intersection 2201 to the marker 20 m away is closer, The variation in the y direction decreases. Since the position coordinates are determined by the least square error method using the positioning results obtained by these front and rear markers, an increase in the variation D2104 in the y-axis direction can be suppressed, and highly accurate positioning can be performed in the real-time positioning area 2206a.

  22, in the real-time positioning area 2206b (for example, an area 30 m from the end of the real-time positioning area 2206a), highly accurate positioning equivalent to the real-time positioning area 1906 close to the intersection in FIG. 19 can be performed.

  In the calibration area 2208 (length 30 m) 100 m away from the intersection 2201, preliminary positioning of the traveling vehicle is performed. That is, positioning using impulse radio waves is performed by the markers 2209, 2210, 2211, and 212 and the in-vehicle device of the traveling vehicle.

After that, in the autonomous sensor area 2207 until entering the real-time positioning area 2206 for positioning with high accuracy in front of the intersection 2201, positioning is performed by an autonomous sensor such as a vehicle speed sensor or a gyro sensor mounted on the traveling vehicle.
(Appendix 1)
In a wireless positioning system that determines the coordinates of the moving body using a round-trip time of a radio wave between the moving body and a plurality of marker devices serving as positioning reference points, and the coordinates of the marker device,
When receiving a positioning request signal from the mobile body, the marker device that transmits positioning data used for positioning to the mobile body using a communication channel unique to the marker device;
The positioning request signal is transmitted to the marker device through the same communication channel, the positioning request signal transmission time, the positioning data reception time, the marker device coordinates, the positioning request signal reception time, and the positioning data transmission. The moving body that determines the coordinates of the moving body using the positioning data including time; and
A wireless positioning system comprising:
(Appendix 2)
The wireless positioning system according to supplementary note 1, wherein the positioning request signal and positioning data are impulse radio waves.
(Appendix 3)
The wireless positioning system according to claim 1, wherein the positioning data is a signal whose pulse position is modulated by a pseudo-random code different for each marker device.
(Appendix 4)
The wireless positioning system according to claim 1, wherein the positioning data is controlled by a different delay time of the pulse position by a different pseudo-random code every time transmission of the positioning data is repeated.
(Appendix 5)
The positioning data includes first positioning data common to the mobile body and second positioning data that differs depending on the mobile body, and the first positioning data has a predetermined cycle regardless of reception of the positioning request signal. The wireless positioning system according to claim 1, wherein the second positioning data is transmitted in response to reception of the positioning request signal.
(Appendix 6)
The wireless positioning system according to claim 1, wherein the positioning request data is transmitted from the moving body only when the moving body receives the first positioning data.
(Appendix 7)
The wireless positioning system according to claim 1, wherein the marker device is installed in a traffic signal on a road.
(Appendix 8)
The wireless positioning system according to claim 1, wherein the marker device is installed above both ends of a plurality of lanes on which the moving body travels and above a boundary line between the lanes.
(Appendix 9)
In the wireless positioning method for determining the coordinates of the moving body using a round trip time of radio waves between the moving body traveling on a one-way road and a plurality of marker devices serving as positioning reference points and the coordinates of the marker device,
A wireless positioning method including a step of selecting, as a coordinate of the mobile object, a coordinate whose time change of the coordinate coincides with the traveling direction of the one-way among a plurality of coordinates of the mobile object calculated by the round trip time.
(Appendix 10)
Centering on the coordinates of the moving body determined using the positioning data of the two marker devices with the shortest round-trip time, the coordinates of the moving body determined using the positioning data of other marker devices are within a predetermined range. The wireless positioning method according to supplementary note 9, including a step not used for positioning in the case of outside.
(Appendix 11)
In the wireless positioning method for determining the coordinates of the moving body using the round trip time between the moving body traveling in the lane entering the intersection and a plurality of marker devices serving as positioning reference points and the coordinates of the marker device,
Positioning the movable body with a first plurality of marker devices that are installed at a predetermined distance from the end of the intersection and face the vehicle direction toward the intersection;
Positioning the moving body with a second plurality of marker devices installed at the end of the intersection and facing the vehicle direction entering the intersection;
A step of passing through the positioning area by the first marker device and entering a positioning area by the second plurality of marker devices to determine coordinates by an autonomous sensor built in the moving body;
Wireless positioning method including.
(Appendix 12)
In a wireless positioning system that determines the coordinates of the moving body using a round trip time between a plurality of marker devices serving as positioning reference points and a moving body traveling in a lane that enters an intersection, and the coordinates of the marker device,
Positioning the movable body with a first plurality of marker devices installed at a position away from the end of the intersection by a first distance and facing a vehicle direction toward the intersection;
The mobile object is positioned by a second multi-marker device that is installed at a second distance from the end of the intersection and has radio wave directivity in both the direction of the intersection and the direction opposite to the intersection. Steps to do,
Positioning the moving body with a third multi-marker device installed at the end of the intersection and facing the vehicle direction entering the intersection;
A step of passing through the positioning area by the first marker device and entering a positioning area by the second plurality of marker devices to determine coordinates by an autonomous sensor built in the moving body;
Wireless positioning method including.

It is a figure which shows the conventional positioning system example 1. FIG. It is a figure which shows the principle of TWR. It is a figure which shows the conventional positioning system example 2. FIG. It is a figure which shows a positioning system structure (Example 1). It is a figure which shows the structure of a vehicle equipment. It is a figure which shows the structure of the marker A. It is a figure which shows the flame | frame structure of a vehicle equipment. It is a figure which shows the example of the collision of a positioning response signal pulse. It is a figure which shows the collision avoidance method of the pulse by delay. It is a figure which shows the format of data. It is a figure which shows the flow of a marker and communication between vehicles when there exists a some traveling vehicle. It is a figure which shows the processing flow of positioning. It is a figure which shows the operation | movement start flow within a positioning area. It is a figure which shows the example of marker installation. It is a figure which shows the example of marker installation. It is a figure which shows a side position method. It is a figure which shows the flow of a positioning process. It is a figure which shows the installation method (Example 2) of a marker. It is a figure which shows the marker installation method (Example 2). It is a figure which shows the dispersion | variation in positioning by distance. It is a figure which shows the positioning dispersion | variation by marker installation. It is a figure which shows the marker installation method (Example 2). It is a figure which shows installing a marker in the sky between a lane edge and a lane (Example 1).

Explanation of symbols

101 Vehicle 102 Marker A
103 Marker B
104 Marker C
201 vehicle-mounted device 202 marker 301 vehicle 302 marker A
303 Marker B
304 Marker C
401 Vehicle 402 Marker A
403 Marker B
404 Marker C
500 On-board unit 501 MPU (microprocessor unit)
502 Transmission Unit 503 Transmission Data Unit 504 PPM (Pulse Position Modulation) Data Modulation Unit 505 CH0PN Sequence Generation Unit 506 Impulse Generation Unit 507 Transmission Time Holding Unit 508 BPF
509 PA (Power Amplifier)
510 transmitting antenna 511 timer 512 receiving unit 512 ₁ receiving unit A
512 ₂ Receiver B
512 _n receiver n
513 Reception antenna 514 BPF
515 LNA (Low Noise Amplifier)
516 Pulse Detection Unit 517 Correlator A
518 CH1PN sequence generation unit 519 Reception time holding unit A
520 PPM data demodulator A
521 Receive data A
522 External interface 600 Marker A
601 MPU (microprocessor unit)
602 Transmission unit 603 Transmission data unit 604 PPM (pulse position modulation) data modulation unit 605 CH1 PN sequence generation unit 606 Delay unit 607 Transmission time holding unit 608 Subtractor 609 Impulse generation unit 610 BPF
611 PA (Power Amplifier)
612 transmitting antenna 613 timer 614 receiving unit 615 receiving antenna 616 BPF
617 LNA (Low Noise Amplifier)
618 Pulse detection unit 619 Correlator 620 CH0PN sequence generation unit 621 Reception time holding unit 622 PPM data demodulation unit 623 Reception data 624 External interface 1401 Intersection 1402 Vehicle 1403 Vehicle-mounted device 1404 Marker 1405 Marker 1406 Marker 1407 Marker 1501 Pole 1502 Marker M1
1503 Marker M2
1504 Paul 1505 Marker M3
1503 Marker M4
1507 Large vehicle 1508 Small vehicle 1509 Large vehicle 1510 Lane 1511 Lane 1512 Lane 1513 Marker M1
1514 Marker M2
1515 Marker M3
1516 Small car 1517 Large car 1518 Small car

1601 Marker M1
1602 Marker M2
1603 Marker M3
1604A Vehicle-mounted device 1604B Vehicle-mounted virtual image 1605 Large vehicle 1606 Lane 1607 Lane 1608 Lane 1608 Lane 1610 M1 center circle 1611 M2 center circle 1801 Pole 1802 Marker 1803 Large vehicle 1804 Small vehicle 1805 Vehicle-mounted device 1806 Pole 1807 Marker 1809 Pole 1809 Intersection 1902 Marker 1903 Marker 1904 Marker 1905 Marker 1906 Real-time positioning area 1907 Autonomous sensor area 1908 Calibration area 1909 Marker 1911 Marker 1911 Marker 1912 Marker 1913 Lane 1914 Lane 1915 Lane 1901 _A marker A
2001 _B Marker B
2002 Short distance vehicle 2003 Short range dispersion range 2004 Long range vehicle 2005 Long range variation range 2201 Intersection 2202 ₁ marker 2203 ₁ marker 2204 ₁ marker 2205 ₁ marker 2202 ₂ marker 2203 ₂ marker 2204 ₂ marker 2205 ₂ marker 2206 Real time Positioning area 2206 _a Real-time positioning area a
2206 _b Real-time positioning area b
2207 Autonomous sensor area 2208 Calibration area 2209 Marker 2210 Marker 2211 Marker 2212 Marker 2213 Lane 2214 Lane 2215 Lane 2319 Large vehicle 2320 Large vehicle 2321 Small vehicle 2322 Large vehicle 2323 Lane 2324 Lane 2325 Lane

Claims (8)

In a wireless positioning system that determines the coordinates of the moving body using a round-trip time of a radio wave between the moving body and a plurality of marker devices serving as positioning reference points, and the coordinates of the marker device,
When receiving a positioning request signal from the mobile body, the marker device that transmits positioning data used for positioning to the mobile body using a communication channel unique to the marker device;
The positioning request signal is transmitted to the marker device through the same communication channel, the positioning request signal transmission time, the positioning data reception time, the marker device coordinates, the positioning request signal reception time, and the positioning data transmission. The moving body that determines the coordinates of the moving body using the positioning data including time; and
A wireless positioning system comprising:   The wireless positioning system according to claim 1, wherein the positioning request signal and positioning data are impulse radio waves.   The wireless positioning system according to claim 1, wherein the positioning data is a signal whose pulse position is modulated by a pseudo-random code different for each marker device.   The positioning data includes first positioning data common to the mobile body and second positioning data that differs depending on the mobile body, and the first positioning data has a predetermined period regardless of reception of the positioning request signal. The wireless positioning system according to claim 1, wherein the second positioning data is transmitted in response to reception of the positioning request signal.   The wireless positioning system according to claim 1, wherein the marker device is installed above both ends of a plurality of lanes on which the moving body travels and above a boundary line of each lane. In the wireless positioning method for determining the coordinates of the moving body using a round trip time of radio waves between the moving body traveling on a one-way road and a plurality of marker devices serving as positioning reference points and the coordinates of the marker device,
A wireless positioning method including a step of selecting, as a coordinate of the mobile object, a coordinate whose time change of the coordinate coincides with the traveling direction of the one-way among a plurality of coordinates of the mobile object calculated by the round trip time. In the wireless positioning method for determining the coordinates of the moving body using a round trip time between a plurality of marker devices serving as positioning reference points and a moving body traveling in a lane that enters an intersection, and the coordinates of the marker device,
Positioning the moving body with a first plurality of marker devices installed at a predetermined distance from an end of the intersection and facing a vehicle direction toward the intersection;
Positioning the movable body with a second plurality of marker devices installed at the end of the intersection and facing the vehicle direction entering the intersection; and
A step of passing through a positioning area by the first marker device and entering a positioning area by a second plurality of marker devices by determining coordinates by an autonomous sensor built in the moving body;
Wireless positioning method including. In a wireless positioning system that determines the coordinates of the moving body using a round trip time between a plurality of marker devices serving as positioning reference points and a moving body traveling in a lane that enters an intersection, and the coordinates of the marker device,
Positioning the movable body with a first plurality of marker devices installed at a position away from the end of the intersection by a first distance and facing a vehicle direction toward the intersection;
The mobile object is positioned by a second multi-marker device that is installed at a second distance from the end of the intersection and has radio wave directivity in both the direction of the intersection and the direction opposite to the intersection. Steps to do,
Positioning the moving body with a third multi-marker device installed at the end of the intersection and facing the vehicle direction entering the intersection;
A step of passing through the positioning area by the first marker device and entering a positioning area by the second plurality of marker devices to determine coordinates by an autonomous sensor built in the moving body;
Wireless positioning method including.

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