WO2020085061A1 - Communication device - Google Patents

Communication device Download PDF

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Publication number
WO2020085061A1
WO2020085061A1 PCT/JP2019/039476 JP2019039476W WO2020085061A1 WO 2020085061 A1 WO2020085061 A1 WO 2020085061A1 JP 2019039476 W JP2019039476 W JP 2019039476W WO 2020085061 A1 WO2020085061 A1 WO 2020085061A1
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WO
WIPO (PCT)
Prior art keywords
signal
antenna
communication device
time
antennas
Prior art date
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PCT/JP2019/039476
Other languages
French (fr)
Japanese (ja)
Inventor
超然 李
Original Assignee
株式会社オートネットワーク技術研究所
住友電装株式会社
住友電気工業株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Application filed by 株式会社オートネットワーク技術研究所, 住友電装株式会社, 住友電気工業株式会社 filed Critical 株式会社オートネットワーク技術研究所
Publication of WO2020085061A1 publication Critical patent/WO2020085061A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R25/00—Fittings or systems for preventing or indicating unauthorised use or theft of vehicles
    • B60R25/20—Means to switch the anti-theft system on or off
    • B60R25/24—Means to switch the anti-theft system on or off using electronic identifiers containing a code not memorised by the user
    • E—FIXED CONSTRUCTIONS
    • E05—LOCKS; KEYS; WINDOW OR DOOR FITTINGS; SAFES
    • E05B—LOCKS; ACCESSORIES THEREFOR; HANDCUFFS
    • E05B49/00—Electric permutation locks; Circuits therefor ; Mechanical aspects of electronic locks; Mechanical keys therefor
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/74—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
    • G01S5/02—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using radio waves
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
    • G01S5/02—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using radio waves
    • G01S5/12—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using radio waves by co-ordinating position lines of different shape, e.g. hyperbolic, circular, elliptical or radial

Definitions

  • the present disclosure relates to communication devices.
  • a crime prevention system is known in which bidirectional wireless communication is performed between an in-vehicle device and a portable device to prevent theft.
  • the security system uses wireless communication to perform mutual authentication between an in-vehicle device and a portable device and to measure a distance from the in-vehicle device to the portable device (hereinafter also referred to as “distance measurement”).
  • the mobile device is an object of distance measurement (hereinafter also referred to as “object of distance measurement”) when viewed from the in-vehicle device.
  • the vehicle-mounted device controls the vehicle in which the vehicle-mounted device is mounted, for example, locks / locks the vehicle door, provided that mutual authentication is established and the measured distance (hereinafter also referred to as “measured distance”) is equal to or less than a predetermined value. Allows unlocking and starting of the engine. The reason for locking / unlocking the vehicle door and starting the engine is that the user carrying the portable device is usually close to the vehicle.
  • mutual authentication is an illegal means, for example, a so-called relay attack in which a wireless relay device is interposed between the vehicle and the portable device. It may be realized by the so-called technology. Although the user carrying the portable device is away from the vehicle, it is possible that a person who does not carry the portable device attempts to lock / unlock the vehicle door or start the engine close to the vehicle. It is advantageous to use the measured distance from the viewpoint of preventing the vehicle from being controlled by such an illegal means.
  • the condition that the measured distance is within the threshold range is included in the condition for determining whether the communication is normal.
  • a plurality of antennas are provided in the vehicle-mounted device, the distance is measured using the time required for communication with the portable device, and the position of the portable device is determined from the plurality of distances. .
  • the present disclosure has an object to provide a technique for performing a plurality of distance measurements even if the communication device that is a distance measurement object transmits only once.
  • the communication device of the present disclosure obtains the position of the second communication device.
  • the second communication device transmits a second signal in response to the first signal, a predetermined time after receiving the first signal.
  • the communication device includes an antenna group, a transmission / reception unit, and a control unit.
  • the antenna group has a plurality of antennas.
  • the transmitter / receiver unit transmits the first signal from at least one of the plurality of antennas and receives the second signal from the antenna group.
  • the control unit is configured to transmit a signal between a specific antenna, which is an antenna to which the first signal is transmitted in response to the second signal among the plurality of antennas, and the second communication device.
  • the first propagation time which is the time required, and the time required for a signal to propagate between the non-specific antenna, which is an antenna different from the specific antenna among the plurality of antennas, and the second communication device.
  • the second propagation time is obtained.
  • the first propagation time is obtained using the predetermined time, a first time point when the specific antenna transmits the first signal, and a second time point when the specific antenna receives the second signal.
  • the second propagation time is obtained using the first propagation time, the predetermined time, the first time point, and the third time point when the non-specific antenna receives the second signal.
  • Another communication device of the present disclosure includes an antenna, a transmission / reception unit, and a control unit.
  • the antenna receives a first signal, transmits a second signal in response to the first signal, the controller extracts information indicating a source of the first signal, and the second signal A signal is generated including the information, and the transmitting / receiving unit causes the antenna to transmit the second signal after a lapse of a predetermined time after receiving the first signal.
  • the present disclosure can be realized not only as a communication device including such a characteristic control unit, but also as a communication method having such characteristic processing as a step, or such a step as a computer (step). It can be realized as a program to be executed by a computer. Further, it can be realized as a semiconductor integrated circuit that realizes a part or all of the communication device or a communication system including the communication device.
  • a plurality of distance measurements are performed even if there is one transmission from the communication device that is the object of distance measurement.
  • FIG. 1 is a schematic view illustrating the arrangement of two communication devices used in this embodiment.
  • FIG. 2 is a block diagram illustrating the configuration of the first communication device 1.
  • FIG. 3 is a block diagram illustrating the configuration of the second communication device 2.
  • FIG. 4 is a timing chart showing transmission and reception of signals in distance measurement.
  • FIG. 5 is a flowchart showing the operation adopted in the distance measurement in the first communication device.
  • FIG. 6 is a flowchart showing the operation adopted in the distance measurement in the second communication device.
  • the communication device of the present disclosure determines the position of the second communication device.
  • the second communication device transmits a second signal in response to the first signal, a predetermined time after receiving the first signal.
  • the communication device includes an antenna group, a transmission / reception unit, and a control unit.
  • the antenna group has a plurality of antennas.
  • the transmitter / receiver unit transmits the first signal from at least one of the plurality of antennas and receives the second signal from the antenna group.
  • the control unit is configured to transmit a signal between a specific antenna, which is an antenna to which the first signal is transmitted in response to the second signal among the plurality of antennas, and the second communication device.
  • the first propagation time which is the time required, and the time required for a signal to propagate between the non-specific antenna, which is an antenna different from the specific antenna among the plurality of antennas, and the second communication device.
  • the second propagation time is obtained.
  • the first propagation time is obtained using the predetermined time, a first time point when the specific antenna transmits the first signal, and a second time point when the specific antenna receives the second signal.
  • the second propagation time is obtained using the first propagation time, the predetermined time, the first time point, and the third time point when the non-specific antenna receives the second signal.
  • the first propagation time and the second propagation time are obtained, and therefore, the distance from the specific antenna and the non-specific antenna to the second communication device, and thus the distance between the second communication device and the second communication device. Two-dimensional positions are specified. Moreover, one second signal is sufficient for obtaining the first propagation time and the second propagation time.
  • the antenna group has three or more antennas
  • the control unit obtains the second propagation time for each of the non-specific antennas, and each of the second propagation times includes the first propagation time.
  • it is determined using time, the predetermined time, the first time point, and the third time point for each of the non-specific antennas. This is because the two-dimensional position of the second communication device can be specified with higher accuracy.
  • the first signal is transmitted from two or more of the plurality of antennas at different timings, the first transmitted first signal is transmitted, and the last transmitted first signal is transmitted. It is preferable that the time interval from the time when the signal is transmitted is shorter than the predetermined time. This is because the signal processing is not complicated.
  • Another communication device of the present disclosure includes an antenna, a transmission / reception unit, and a control unit.
  • the antenna receives a first signal, transmits a second signal in response to the first signal, the controller extracts information indicating a source of the first signal, and the second signal A signal is generated including the information, and the transmitting / receiving unit causes the antenna to transmit the second signal after a lapse of a predetermined time after receiving the first signal.
  • the second signal Since the second signal is transmitted after a lapse of a predetermined time after receiving the first signal, by receiving the second signal by a plurality of antennas including the antenna that has transmitted the first signal, Distances between the plurality of antennas and the communication device are calculated.
  • the second signal is transmitted in response to the first signal received first. This is because the second signal need only be transmitted once, and power consumption can be suppressed.
  • FIG. 1 is a schematic diagram illustrating the arrangement of two communication devices used in this embodiment.
  • the first communication device 1 is mounted on the vehicle body 9.
  • the first communication device 1 includes a main body 10 and antennas a1, a2, a3, a4, a5.
  • the main body 10 is applied to a body control module (hereinafter also referred to as “BCM”) which is an in-vehicle device, for example.
  • BCM body control module
  • the second communication device 2 is provided in, for example, a portable device called fob or FOB.
  • the black triangles indicate that the antennas a1, a2, a3, a4, and a5 are located near the right front door, near the left front door, near the right rear door, near the left rear door, and near the rear trunk, respectively.
  • the antennas a1, a2, a3, a4, a5 may be arranged at positions other than the above positions.
  • the case where the second communication device 2 is located outside the vehicle body 9 is exemplified.
  • Ultra-wide band (UWB: Ultra Wide Band) signals are transmitted and received between the first communication device 1 and the second communication device 2 to perform distance measurement.
  • UWB Ultra Wide Band
  • FIG. 2 is a block diagram illustrating the configuration of the first communication device 1.
  • the antennas a1, a2, a3, a4 and a5 are collectively referred to as an antenna group 104.
  • the main body 10 includes an in-vehicle control unit 101 and a UWB transmitting / receiving unit 103.
  • the UWB transmitting / receiving unit 103 can transmit / receive an ultra-wideband signal via any of the antennas a1, a2, a3, a4, a5.
  • the in-vehicle control unit 101 controls various in-vehicle devices.
  • a plurality of vehicle-mounted devices are collectively illustrated as a vehicle-mounted device group 105.
  • the in-vehicle device group 105 includes a door lock device that controls locking / unlocking of a door and an engine control device that controls an engine.
  • the in-vehicle control unit 101 also generates information included in the signal transmitted by the UWB transmitting / receiving unit 103, acquires information included in the signal received by the UWB transmitting / receiving unit 103, and collates the information.
  • the vehicle-mounted control unit 101 has a memory 102, and the memory 102 stores an ID code (code), a distance measurement code, and an encryption key.
  • the ID code is information for identifying the first communication device 1.
  • the ranging code is information that identifies the antenna used for transmission.
  • the encryption key is information used for at least one of encryption of a transmitted signal and decryption of a received signal.
  • the signal s2 transmitted from the antenna a2 includes an ID code for identifying the first communication device 1, a distance measurement code for identifying the antenna a2, and information for requesting a reply (hereinafter referred to as "reply request"). It is included, encrypted with the encryption key, and transmitted by the UWB transmitting / receiving unit 103.
  • the second communication device 2 that has received the signal s2 transmits the signal c2 in response to the reply request included in the signal s2.
  • the signal c2 received by the UWB transmission / reception unit 103 via the antenna group 104 is decrypted by an encryption key (an encryption key different from decryption and encryption can be used), and the ID code and the measurement included in the signal c2 are measured. Distance codes and are extracted.
  • the ID code included in the signal c2 is information for identifying the second communication device 2, and the distance measurement code is, for example, the distance measurement code included in the signal s2.
  • the in-vehicle control unit 101 confirms that the received signal c2 is transmitted from the second communication device 2 according to the reply request included in the signal s2 transmitted from the antenna a2. To know.
  • FIG. 3 is a block diagram illustrating the configuration of the second communication device 2.
  • the second communication device 2 includes an electronic key control unit 201, a UWB transmitting / receiving unit 203, and an antenna b1.
  • the UWB transmitting / receiving unit 203 can transmit / receive an ultra wideband signal via the antenna b1.
  • the electronic key control unit 201 also generates information to be included in the signal transmitted by the UWB transmitting / receiving unit 203, obtains information included in the signal received by the UWB transmitting / receiving unit 203, and collates the information.
  • the electronic key control unit 201 has a memory 202, and the memory 202 stores an ID code, a distance measurement code, and an encryption key.
  • the ID code is information for identifying the second communication device 2.
  • the ranging code is, for example, a ranging code included in the received signal.
  • the encryption key is information used for at least one of encryption of a transmitted signal and decryption of a received signal.
  • FIG. 4 is a timing chart showing signal transmission / reception in distance measurement. Time is used on the horizontal axis, and a straight line showing the antenna is arranged along the vertical axis.
  • the transmission from the antenna group 104 is indicated by a downward arrow starting from a straight line showing each antenna.
  • Reception by the antenna b1 is indicated by a downward arrow whose end is a straight line indicating the antenna b1.
  • the transmission from the antenna b1 is indicated by an upward arrow starting from the straight line showing the antenna b1.
  • Reception by the antenna group 104 is indicated by an upward arrow having a straight line indicating each antenna as an end point.
  • Signals s1, s2, s3, s4, s5 are transmitted from the antennas a1, a2, a3, a4, a5, respectively.
  • the signal s2 is received by the antenna b1 as the signal r2.
  • the second communication device 2 having received the signal r2 transmits the signal c2 as a reply to the signal s2.
  • the signal c2 is received by the antennas a2, a3 and a4 as signals d2, d3 and d4, respectively.
  • the starting point at the time of transmission of the signals s1, s2, s3, s4, s5 is explained as time T0.
  • the signals s1, s2, s3, s4, and s5 are transmitted from the antennas a1, a2, a3, a4, and a5, respectively, at times t1, t2, t3, t4, and t5 after the time T0. That is, the time points at which the signals s1, s2, s3, s4, and s5 are transmitted are represented as (T0 + t1), (T0 + t2), (T0 + t3), (T0 + t4), and (T0 + t5), respectively.
  • the time T2r at which the signal r2 is received by the antenna b1 can be expressed as (T0 + t2 + ⁇ t2).
  • the time point Ta2 when the signal d2 is received by the antenna a2 can be expressed as (T2s + ⁇ t2).
  • the time Ta3 when the signal d3 is received by the antenna a3 can be expressed as (T2s + ⁇ t3).
  • the time Ta4 at which the signal d4 is received by the antenna a4 by introducing the time ⁇ t4 for the signal c2 to reach the antenna a4 can be expressed as (T2s + ⁇ t4).
  • the time ⁇ tm obtained by the equation (2) can be substituted in the last term on the right side of the equation (3). Therefore, the time ⁇ tm is also obtained.
  • the first signal sk is transmitted from at least one antenna ak of the first communication device 1;
  • the second signal ck is transmitted from the antenna b1 after a lapse of a predetermined time td after the first signal sk is received as the signal rk by the antenna b1 of the second communication device 2;
  • the second signal cm is received as the signal dm by the antenna am that has transmitted the first signal sm, so that the signal propagates between the antenna am (hereinafter also referred to as “specific antenna”) and the antenna b1.
  • the time ⁇ tm required to do is determined; (iv) The second signal cm is received as the signal dn by the antenna an other than the one that has transmitted the first signal sm (that is, an antenna different from the specific antenna: hereinafter also referred to as “non-specific antenna”), so that the antenna
  • the time ⁇ tn required for a signal to propagate between an and the antenna b1 is obtained for each of the non-specific antennas by using each time Tan.
  • the times ⁇ tk, ⁇ tm, and ⁇ tn are also referred to as propagation times.
  • the distance between the specific antenna am and the antenna b1 is obtained by using the propagation time ⁇ tm, and the distance between the non-specific antenna an and the antenna b1 is obtained by using the propagation time ⁇ tn. The distance is obtained.
  • the position of the second communication device 2 is specified on one circumference in three dimensions and two points in two dimensions. If the distance between the antenna b1 and the two non-specific antennas is obtained, the position of the second communication device 2 is specified in two points in three dimensions and in one point in two dimensions.
  • the above-described distance measurement using the antenna group 104 is sufficient for one specific antenna and two non-specific antennas.
  • the transmission from the second communication device 2 is sufficient with only one signal ck as a reply based on any one of the signals sk. Therefore, the number of transmissions required for a plurality of distance measurements, particularly the number of transmissions from the second communication device 2, is reduced. This is advantageous from the viewpoint that the second communication device 2 is applied to a portable device, its power consumption is suppressed, and battery consumption is delayed.
  • FIG. 5 and 6 are flowcharts showing the operation adopted in the above distance measurement.
  • FIG. 5 shows the operation of the first communication device 1, mainly the operation of the vehicle-mounted control unit 101.
  • FIG. 6 shows the operation of the second communication device 2, mainly the operation of the electronic key control unit 201.
  • step S11 the distance measurement is actually started when a positive result is obtained in the determination in step S11.
  • step S11 it is determined that the operation of the unlock button has been detected.
  • the unlock button is included in, for example, the in-vehicle device group 105, and its operation is detected by the in-vehicle control unit 101.
  • step S12 the signals s1, s2, s3, s4 and s5 are sequentially transmitted from the antennas a1, a2, a3, a4 and a5.
  • Such transmission is performed by the operation of the vehicle-mounted control unit 101, specifically, the control of the vehicle-mounted control unit 101, from the UWB transmitting / receiving unit 103 via the antennas a1, a2, a3, a4, a5.
  • “sequentially” means that the transmission timings from the respective antennas are different, and is expressed by t1 ⁇ t2 ⁇ t3 ⁇ t4 ⁇ t5 in the case of FIG.
  • step S12 includes processing necessary for transmitting the signal sk. Specifically, for example, an in-vehicle control for encrypting a signal including an ID code for identifying the first communication device 1, a distance measurement code for identifying the antenna ak, and a reply request with an encryption key to generate a signal sk.
  • the processing of the unit 101 is also included.
  • the receiving operation is first started in step S21.
  • Such reception is performed by the operation of the electronic key control unit 201, specifically, the control of the electronic key control unit 201, from the UWB transmission / reception unit 203 via the antenna b1.
  • the transmission signal means a signal rk that is known to be a transmission from the first communication device 1.
  • the transmission signal specifically means a signal including an ID code indicating that it is the first communication device 1, and is the signal r2 in the above example.
  • the transmission signal is a signal in which the above-described first signal is received by the second communication device 2.
  • step S22 includes processing required as a premise for the determination. Specifically, for example, the processing of the electronic key control unit 201 that decodes the signal rk, extracts a reply request, an ID code, and a distance measurement code is also included.
  • Step S22 is repeatedly executed until the determination result becomes affirmative. If the determination result is affirmative, the process proceeds to step S23.
  • the distance measurement code of the received transmission signal is stored in the memory 202.
  • the signal r2 corresponds to the transmission signal
  • the ranging code extracted from the signal is the transmission source of the signal received as the signal r2 (specifically, the signal s2). It shows that it is the antenna a2.
  • a response signal is transmitted by step S24.
  • the response signal specifically means a signal including an ID code indicating that it is the second communication device 2 and a distance measurement code stored in the memory 202, and the response signal is the signal in the above example. c2 or signal cm.
  • the response signal corresponds to the above-mentioned second signal, and is transmitted in response to the first signal sk received by the second communication device 2 as the transmission signal rk.
  • the process related to the distance measurement of the second communication device 2 ends by executing step S24.
  • the signal s1 is not received by the antenna b1, but the signal s2 is received as the signal r2. Even if the signal s3 is received by the antenna b1, the process related to distance measurement is not performed. That is, the second communication device 2 transmits the signal ck in response to the signal sk initially received as the signal rk. This is because the second communication device 2 can receive the signal rk and thus the first communication device 1 can also receive the signal dk.
  • the receiving operation is started in step S13. Such reception is performed by the operation of the vehicle-mounted control unit 101, specifically, the control of the vehicle-mounted control unit 101, from the UWB transceiver unit 103 via the antennas a1, a2, a3, a4, a5.
  • the receiving operation is started in step S13, it is determined in step S14 whether the response signal is received.
  • step S14 it is determined whether or not the signal in which the response signal propagates through the plurality of antennas including the specific antenna is received.
  • the signals are the signal d2 or the signal dm and the signals d3, d4 or the signal dn in the above example. These signals are simply abbreviated as “response signals” in FIG.
  • response signals are simply abbreviated as "response signals” in FIG.
  • step S14 includes processing required as a premise for the determination. Specifically, for example, the processing of the vehicle-mounted control unit 101 that decodes the signal dk and extracts the ID code and the ranging code is also included.
  • the UWB transmission / reception unit 103 detects which of the antennas ak the received response signal has passed through, and transmits the information to the vehicle-mounted control unit 101 together with the response signal and the time Tak at which the response signal is received.
  • the signal cm and thus the signals dm and dn, include the ranging code.
  • the in-vehicle control unit 101 determines whether the signal dk received by each of the antennas ak is a reply to the signal sm transmitted from a certain antenna am. Therefore, it can be determined whether or not the response signal is received by one specific antenna and two non-specific antennas.
  • Step S14 is repeatedly executed until the determination result becomes affirmative. If the determination result is affirmative, the process proceeds to step S15.
  • step S15 the propagation time ⁇ tm for the specific antenna is calculated. Since the time Tam when the antenna am receives the signal dm is obtained from the UWB transmitting / receiving unit 103, and the time T0, the time tm, and the predetermined time td are known, the propagation time ⁇ tm is calculated from the equation (2). According to the above example, the propagation time ⁇ t2 is calculated for the specific antenna a2.
  • step S16 is executed.
  • step S16 the propagation time ⁇ tn for the non-specific antenna is calculated.
  • the time Tan when the antenna an receives the signal dm is obtained from the UWB transceiver 103, and the time T0, the time tn, and the predetermined time td are known. Therefore, the propagation time ⁇ tn is calculated from the propagation time ⁇ tm obtained in step S16 and the equation (3).
  • Step S16 is executed corresponding to the number of non-specific antennas that require distance measurement. According to the above example, the propagation times ⁇ t3 and ⁇ t4 are calculated for the two non-specific antennas a3 and a4, respectively.
  • Step S17 calculates the position of the second communication device 2, for example, the position of the FOB, using the propagation times ⁇ tm and ⁇ tn.
  • the position is two-dimensionally specified at two positions, and when there are two non-specific antennas, the position is two-dimensionally specified at one position.
  • the position is specified three-dimensionally at one position.
  • the plurality of non-specific antennas is advantageous from the viewpoint of increasing the accuracy of specifying the position of the second communication device 2 as compared with the case of a single antenna.
  • Mutual authentication can be performed by communication between the first communication device 1 and the second communication device 2.
  • another band of ultra-wide band can be adopted.
  • the signals s1, s2, s3, s4, s5 may be transmitted at equal intervals.
  • the value k ⁇ t0 can be adopted as the time tk.
  • the predetermined time td includes the processing time in the second communication device 2.
  • the processing time includes decoding the signal rk, extracting information, collating ID code, storing ranging code, and generating signal ck.
  • the predetermined time td may include a delay time. By using such a delay time, the time from the reception of the signal rk to the transmission of the signal ck can be set to a fixed predetermined time td.
  • the antenna group 104 transmits all the signals sk and then receives the signals dk from the viewpoint of not complicating the signal processing in the first communication device 1. From this point of view, of the series of signals sk sequentially transmitted for distance measurement, from the time when the first one (signal s1 in the above example) is transmitted (time point (T0 + t1) in the above example) to the end It is desirable that the time interval up to the time point (the time point (T0 + t5) in the above example) at which the signal (signal s5 in the above example) is transmitted is shorter than the predetermined time td. It is clear that such a relationship is independent of the distance between the first communication device 1 and the second communication device 2 and can be set in advance.
  • the signal sk may be transmitted from at least one antenna.
  • the plurality of antennas including the specific antenna can receive the signals dm and dn. Reception at all antennas a1, a2, a3, a4, a5 is not necessary.
  • Both the in-vehicle control unit 101 and the electronic key control unit 201 include a computer including a microprocessor (micro processor), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like.
  • a microprocessor micro processor
  • ROM Read Only Memory
  • RAM Random Access Memory
  • the arithmetic processing unit such as a microprocessor stores a computer program (computer program) including some or all of the steps of the timing chart or the flowchart from a storage unit such as a ROM or a RAM as shown in FIGS. Read and execute.
  • a computer program computer program including some or all of the steps of the timing chart or the flowchart from a storage unit such as a ROM or a RAM as shown in FIGS. Read and execute.
  • the computer programs of these multiple devices can be installed from an external server device or the like. Also, such computer programs are in a state of being respectively stored in a recording medium such as a CD-ROM (Compact Disc Read Only Memory), a DVD-ROM (Digital Versatile Disk Only Memory), and a semiconductor memory (memory). Be distributed.
  • a recording medium such as a CD-ROM (Compact Disc Read Only Memory), a DVD-ROM (Digital Versatile Disk Only Memory), and a semiconductor memory (memory).

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  • Engineering & Computer Science (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Mechanical Engineering (AREA)
  • Lock And Its Accessories (AREA)
  • Position Fixing By Use Of Radio Waves (AREA)
  • Radar Systems Or Details Thereof (AREA)

Abstract

A second communication device transmits a second signal responding to a first signal, at a predetermined time after receiving the first signal. Provided is a communication device provided with: an antenna group including a plurality of antennas; a transmission and reception unit for transmitting the first signal from at least one of the plurality of antennas and receiving the second signal from the antenna group; and a control unit for determining a first propagation time for which signals propagate between the second communication device and a specific antenna of the plurality of antennas corresponding to the antenna from which the first signal to which the second signal responds is transmitted and a second propagation time for which signals propagate between the second communication device and a nonspecific antenna of the plurality of antennas that is different from the specific antenna. The first propagation time is determined using a predetermined time, a first point in time when the specific antenna transmits the first signal, and a second point in time when the specific antenna receives the second signal. The second propagation time is determined using the first propagation time, the predetermined time, the first point in time, and a third point in time when the nonspecific antenna receives the second signal.

Description

通信装置Communication device
　本開示は通信装置に関する。 The present disclosure relates to communication devices.
　車載装置と携帯機との間で双方向に無線通信を行い、盗難を防止する防犯システム（ｓｙｓｔｅｍ）が公知である。例えば当該防犯システムは無線通信を利用して、車載装置及び携帯機の間での相互認証と、車載装置から携帯機までの距離の測定（以下「測距」とも称す）とが行われる。車載装置から見て携帯機は測距の対象（以下「測距対象」とも称す）である。 A crime prevention system (system) is known in which bidirectional wireless communication is performed between an in-vehicle device and a portable device to prevent theft. For example, the security system uses wireless communication to perform mutual authentication between an in-vehicle device and a portable device and to measure a distance from the in-vehicle device to the portable device (hereinafter also referred to as “distance measurement”). The mobile device is an object of distance measurement (hereinafter also referred to as “object of distance measurement”) when viewed from the in-vehicle device.
　車載装置は、相互認証が成立し、かつ測定された距離（以下「測定距離」とも称す）が所定値以下であることを条件として、車載装置を搭載する車両の制御、例えば車両ドアの施錠／解錠、エンジンの始動を可能にする。車両ドアの施錠／解錠、エンジンの始動は、携帯機を携帯する使用者が車両に近接していることが通常だからである。 The vehicle-mounted device controls the vehicle in which the vehicle-mounted device is mounted, for example, locks / locks the vehicle door, provided that mutual authentication is established and the measured distance (hereinafter also referred to as “measured distance”) is equal to or less than a predetermined value. Allows unlocking and starting of the engine. The reason for locking / unlocking the vehicle door and starting the engine is that the user carrying the portable device is usually close to the vehicle.
　相互認証が成立しても測定距離が所定値を超えていれば、相互認証は不正な手段、例えば車両と携帯機との間に無線中継器を介在させた、いわゆるリレーアタック（ｒｅｌａｙ　ａｔｔａｃｋ）と称される技術によって実現されている可能性がある。携帯機を携帯する使用者が車両から離れているにも拘わらず、携帯機を携帯しない者が車両に近接して車両ドアの施錠／解錠、エンジンの始動を試みている可能性がある。かかる不正な手段を用いた車両の制御を防止する観点で、測定距離を利用することは有利である。 If the measured distance exceeds the specified value even if mutual authentication is established, mutual authentication is an illegal means, for example, a so-called relay attack in which a wireless relay device is interposed between the vehicle and the portable device. It may be realized by the so-called technology. Although the user carrying the portable device is away from the vehicle, it is possible that a person who does not carry the portable device attempts to lock / unlock the vehicle door or start the engine close to the vehicle. It is advantageous to use the measured distance from the viewpoint of preventing the vehicle from being controlled by such an illegal means.
　特許文献１に記載の技術では、測定距離が閾値の範囲内にあることを、通信が正規であるか否かを判定する条件に含めている。 In the technique described in Patent Document 1, the condition that the measured distance is within the threshold range is included in the condition for determining whether the communication is normal.
　特許文献２に記載の技術では、車載装置に複数のアンテナを設け、携帯機との間での通信に要した時間を用いて距離の測定を行い、複数の距離から携帯機の位置を判定する。 In the technology described in Patent Document 2, a plurality of antennas are provided in the vehicle-mounted device, the distance is measured using the time required for communication with the portable device, and the position of the portable device is determined from the plurality of distances. .
特開２０１８－７１１９０号公報JP, 2018-71190, A 米国特許出願公開第２０１４／０３３０４４９号明細書U.S. Patent Application Publication No. 2014/0330449
　特許文献２の技術では、車載装置に複数のアンテナと携帯機との間での通信がアンテナ毎に行われて測距され、その結果が携帯機の位置の判定に供される。携帯機が複数のアンテナのそれぞれに対して信号を送信して測距する場合、かかる判定は携帯機での電力消費が大きい観点で不利である。携帯機の電源は通常、電池で実現されるので、携帯機から複数のアンテナに信号を送信する頻度が高いことは、電池が早く消耗する観点で不利である。従って測距対象である通信装置から送信される信号の送信頻度が小さくても複数の測距が行えることが望まれる。 In the technology of Patent Document 2, communication is performed between a plurality of antennas in the in-vehicle device and the mobile device for each antenna to measure the distance, and the result is used for determining the position of the mobile device. When the portable device transmits a signal to each of the plurality of antennas to measure the distance, such determination is disadvantageous in that the portable device consumes a large amount of power. Since the power supply of the portable device is usually realized by a battery, the high frequency of transmitting signals from the portable device to the plurality of antennas is disadvantageous in that the battery is exhausted quickly. Therefore, it is desirable that a plurality of distances can be measured even if the frequency of the signal transmitted from the communication device that is the object of distance measurement is low.
　そこで、本開示は、測距対象である通信装置からの送信が一回であっても、複数の測距を行う技術を提供することを目的とする。 Therefore, the present disclosure has an object to provide a technique for performing a plurality of distance measurements even if the communication device that is a distance measurement object transmits only once.
　本開示の通信装置は第２の通信装置の位置を求める。前記第２の通信装置は、第１の信号に応答する第２の信号を、前記第１の信号を受信してから所定時間後に送信する。前記通信装置は、アンテナ群と、送受信部と、制御部とを備える。前記アンテナ群は複数のアンテナを有する。前記送受信部は前記複数のアンテナの少なくとも一つから前記第１の信号を送信し、前記アンテナ群から前記第２の信号を受信する。前記制御部は、前記複数のアンテナのうち前記第２の信号が応答した前記第１の信号が送信されたアンテナである特定アンテナと前記第２の通信装置との間で信号が伝搬するのに要する時間である第１の伝搬時間と、前記複数のアンテナのうち前記特定アンテナとは異なるアンテナである非特定アンテナと前記第２の通信装置との間で信号が伝搬するのに要する時間である第２の伝搬時間とを求める。前記第１の伝搬時間は、前記所定時間、前記特定アンテナが前記第１の信号を送信した第１の時点、及び前記特定アンテナが前記第２の信号を受信した第２の時点を用いて求められる。前記第２の伝搬時間は、前記第１の伝搬時間、前記所定時間、前記第１の時点、及び前記非特定アンテナが前記第２の信号を受信した第３の時点を用いて求められる。 The communication device of the present disclosure obtains the position of the second communication device. The second communication device transmits a second signal in response to the first signal, a predetermined time after receiving the first signal. The communication device includes an antenna group, a transmission / reception unit, and a control unit. The antenna group has a plurality of antennas. The transmitter / receiver unit transmits the first signal from at least one of the plurality of antennas and receives the second signal from the antenna group. The control unit is configured to transmit a signal between a specific antenna, which is an antenna to which the first signal is transmitted in response to the second signal among the plurality of antennas, and the second communication device. The first propagation time, which is the time required, and the time required for a signal to propagate between the non-specific antenna, which is an antenna different from the specific antenna among the plurality of antennas, and the second communication device. The second propagation time is obtained. The first propagation time is obtained using the predetermined time, a first time point when the specific antenna transmits the first signal, and a second time point when the specific antenna receives the second signal. To be The second propagation time is obtained using the first propagation time, the predetermined time, the first time point, and the third time point when the non-specific antenna receives the second signal.
　本開示の他の通信装置は、アンテナと、送受信部と、制御部とを備える。前記アンテナは第１の信号を受信し、前記第１の信号に応答する第２の信号を送信し、前記制御部は前記第１の信号の送信元を示す情報を抽出し、前記第２の信号を前記情報を含めて生成し、前記送受信部は前記第１の信号を受信した後、所定時間が経過してから前記第２の信号を前記アンテナに送信させる。 Another communication device of the present disclosure includes an antenna, a transmission / reception unit, and a control unit. The antenna receives a first signal, transmits a second signal in response to the first signal, the controller extracts information indicating a source of the first signal, and the second signal A signal is generated including the information, and the transmitting / receiving unit causes the antenna to transmit the second signal after a lapse of a predetermined time after receiving the first signal.
　本開示は、このような特徴的な制御部を備える通信装置として実現することができるのみならず、かかる特徴的な処理をステップとする通信方法として実現したり、かかるステップ（ｓｔｅｐ）をコンピュータ（ｃｏｍｐｕｔｅｒ）に実行させるためのプログラム（ｐｒｏｇｒａｍ）として実現したりすることができる。また、通信装置の一部または全部を実現する半導体集積回路として実現したり、通信装置を含む通信システムとして実現したりすることができる。 The present disclosure can be realized not only as a communication device including such a characteristic control unit, but also as a communication method having such characteristic processing as a step, or such a step as a computer (step). It can be realized as a program to be executed by a computer. Further, it can be realized as a semiconductor integrated circuit that realizes a part or all of the communication device or a communication system including the communication device.
　本開示によれば、測距対象である通信装置からの送信が一回であっても、複数の測距が行われる。 According to the present disclosure, a plurality of distance measurements are performed even if there is one transmission from the communication device that is the object of distance measurement.
図１は本実施形態において採用される二つの通信装置の配置を例示する模式図である。FIG. 1 is a schematic view illustrating the arrangement of two communication devices used in this embodiment. 図２は第１の通信装置１の構成を例示するブロック図である。FIG. 2 is a block diagram illustrating the configuration of the first communication device 1. 図３は第２の通信装置２の構成を例示するブロック図である。FIG. 3 is a block diagram illustrating the configuration of the second communication device 2. 図４は測距における信号の送受信を示すタイミングチャートである。FIG. 4 is a timing chart showing transmission and reception of signals in distance measurement. 図５は第１の通信装置において測距で採用される動作を示すフローチャートである。FIG. 5 is a flowchart showing the operation adopted in the distance measurement in the first communication device. 図６は第２の通信装置において測距で採用される動作を示すフローチャートである。FIG. 6 is a flowchart showing the operation adopted in the distance measurement in the second communication device.
　［本開示の実施形態の説明］
　最初に本開示の実施態様が列記して説明される。本開示の通信装置は、第２の通信装置の位置を求める。前記第２の通信装置は、第１の信号に応答する第２の信号を、前記第１の信号を受信してから所定時間後に送信する。 [Description of Embodiments of the Present Disclosure]
First, the embodiments of the present disclosure will be listed and described. The communication device of the present disclosure determines the position of the second communication device. The second communication device transmits a second signal in response to the first signal, a predetermined time after receiving the first signal.
　（１）前記通信装置は、アンテナ群と、送受信部と、制御部とを備える。前記アンテナ群は複数のアンテナを有する。前記送受信部は前記複数のアンテナの少なくとも一つから前記第１の信号を送信し、前記アンテナ群から前記第２の信号を受信する。前記制御部は、前記複数のアンテナのうち前記第２の信号が応答した前記第１の信号が送信されたアンテナである特定アンテナと前記第２の通信装置との間で信号が伝搬するのに要する時間である第１の伝搬時間と、前記複数のアンテナのうち前記特定アンテナとは異なるアンテナである非特定アンテナと前記第２の通信装置との間で信号が伝搬するのに要する時間である第２の伝搬時間とを求める。前記第１の伝搬時間は、前記所定時間、前記特定アンテナが前記第１の信号を送信した第１の時点、及び前記特定アンテナが前記第２の信号を受信した第２の時点を用いて求められる。前記第２の伝搬時間は、前記第１の伝搬時間、前記所定時間、前記第１の時点、及び前記非特定アンテナが前記第２の信号を受信した第３の時点を用いて求められる。 (1) The communication device includes an antenna group, a transmission / reception unit, and a control unit. The antenna group has a plurality of antennas. The transmitter / receiver unit transmits the first signal from at least one of the plurality of antennas and receives the second signal from the antenna group. The control unit is configured to transmit a signal between a specific antenna, which is an antenna to which the first signal is transmitted in response to the second signal among the plurality of antennas, and the second communication device. The first propagation time, which is the time required, and the time required for a signal to propagate between the non-specific antenna, which is an antenna different from the specific antenna among the plurality of antennas, and the second communication device. The second propagation time is obtained. The first propagation time is obtained using the predetermined time, a first time point when the specific antenna transmits the first signal, and a second time point when the specific antenna receives the second signal. To be The second propagation time is obtained using the first propagation time, the predetermined time, the first time point, and the third time point when the non-specific antenna receives the second signal.
　本開示にかかる通信装置によると、第１の伝搬時間と第２の伝搬時間とが求められるので、特定アンテナと非特定アンテナから第２の通信装置までの距離、ひいては第２の通信装置の二次元的な位置が二箇所に特定される。しかも第１の伝搬時間と第２の伝搬時間とが求められるのに一つの第２の信号で足りる。 According to the communication device of the present disclosure, the first propagation time and the second propagation time are obtained, and therefore, the distance from the specific antenna and the non-specific antenna to the second communication device, and thus the distance between the second communication device and the second communication device. Two-dimensional positions are specified. Moreover, one second signal is sufficient for obtaining the first propagation time and the second propagation time.
　（２）前記アンテナ群は３以上のアンテナを有し、前記制御部は前記非特定アンテナの各々について前記第２の伝搬時間を求め、前記第２の伝搬時間の各々は、前記第１の伝搬時間、前記所定時間、前記第１の時点、及び前記非特定アンテナの各々についての前記第３の時点を用いて求められることが好ましい。第２の通信装置の二次元的な位置がより精度良く特定されるからである。 (2) The antenna group has three or more antennas, the control unit obtains the second propagation time for each of the non-specific antennas, and each of the second propagation times includes the first propagation time. Preferably, it is determined using time, the predetermined time, the first time point, and the third time point for each of the non-specific antennas. This is because the two-dimensional position of the second communication device can be specified with higher accuracy.
　（３）前記第１の信号は前記複数のアンテナの二つ以上から異なるタイミングで送信され、最初に送信される前記第１の信号が送信される時点と、最後に送信される前記第１の信号が送信される時点との時間間隔は、前記所定時間よりも短いことが好ましい。信号処理が煩雑にされないからである。 (3) The first signal is transmitted from two or more of the plurality of antennas at different timings, the first transmitted first signal is transmitted, and the last transmitted first signal is transmitted. It is preferable that the time interval from the time when the signal is transmitted is shorter than the predetermined time. This is because the signal processing is not complicated.
　（４）本開示の他の通信装置は、アンテナと、送受信部と、制御部とを備える。前記アンテナは第１の信号を受信し、前記第１の信号に応答する第２の信号を送信し、前記制御部は前記第１の信号の送信元を示す情報を抽出し、前記第２の信号を前記情報を含めて生成し、前記送受信部は前記第１の信号を受信した後、所定時間が経過してから前記第２の信号を前記アンテナに送信させる。 (4) Another communication device of the present disclosure includes an antenna, a transmission / reception unit, and a control unit. The antenna receives a first signal, transmits a second signal in response to the first signal, the controller extracts information indicating a source of the first signal, and the second signal A signal is generated including the information, and the transmitting / receiving unit causes the antenna to transmit the second signal after a lapse of a predetermined time after receiving the first signal.
　第１の信号を受信した後、所定時間が経過してから第２の信号が送信されるので、第２の信号を第１の信号を送信したアンテナを含む複数のアンテナで受信することにより、当該複数のアンテナと通信装置との距離が算出される。 Since the second signal is transmitted after a lapse of a predetermined time after receiving the first signal, by receiving the second signal by a plurality of antennas including the antenna that has transmitted the first signal, Distances between the plurality of antennas and the communication device are calculated.
　（５）最初に受信した前記第１の信号に応答して前記第２の信号が送信されることが好ましい。第２の信号の送信が一回で足り、電力消費が抑制されるからである。 (5) It is preferable that the second signal is transmitted in response to the first signal received first. This is because the second signal need only be transmitted once, and power consumption can be suppressed.
　［本開示の実施形態の詳細］
　本開示の通信装置の具体例が、以下に図面を参照して説明される。なお、本発明はこれらの例示に限定されず、請求の範囲によって示され、請求の範囲と均等の意味および範囲内における全ての変更が含まれることが意図される。 [Details of the embodiment of the present disclosure]
Specific examples of the communication device of the present disclosure will be described below with reference to the drawings. It should be noted that the present invention is not limited to these exemplifications, and is shown by the scope of the claims, and is intended to include meanings equivalent to the scope of the claims and all modifications within the scope.
　［構成］
　図１は、本実施形態において採用される二つの通信装置の配置を例示する模式図である。車体９には第１の通信装置１が搭載される。第１の通信装置１は、本体１０とアンテナａ１，ａ２，ａ３，ａ４，ａ５とを備える。本体１０は、例えば車載装置であるボディ・コントール・モジュール（Ｂｏｄｙ　Ｃｏｎｔｒｏｌ　Ｍｏｄｕｌｅ：以下「ＢＣＭ」とも称す）に適用される。第２の通信装置２は、例えばｆｏｂあるいはＦＯＢと称される携帯機に備えられる。 [Constitution]
FIG. 1 is a schematic diagram illustrating the arrangement of two communication devices used in this embodiment. The first communication device 1 is mounted on the vehicle body 9. The first communication device 1 includes a main body 10 and antennas a1, a2, a3, a4, a5. The main body 10 is applied to a body control module (hereinafter also referred to as “BCM”) which is an in-vehicle device, for example. The second communication device 2 is provided in, for example, a portable device called fob or FOB.
　図１においてアンテナａ１，ａ２，ａ３，ａ４，ａ５は、それぞれ右前ドア近傍、左前ドア近傍、右後ドア近傍、左後ドア近傍、後部トランク近傍に位置することを、黒三角の記号で示した。もちろん、アンテナａ１，ａ２，ａ３，ａ４，ａ５が上述の位置以外に配置されてもよい。第２の通信装置２は車体９の外部に位置する場合が例示される。 In FIG. 1, the black triangles indicate that the antennas a1, a2, a3, a4, and a5 are located near the right front door, near the left front door, near the right rear door, near the left rear door, and near the rear trunk, respectively. . Of course, the antennas a1, a2, a3, a4, a5 may be arranged at positions other than the above positions. The case where the second communication device 2 is located outside the vehicle body 9 is exemplified.
　超広帯域（ＵＷＢ：Ｕｌｔｒａ　Ｗｉｄｅ　Ｂａｎｄ）の信号が、第１の通信装置１と第２の通信装置２との間で送受信されて、測距が行われる。図１ではアンテナａ２から信号ｓ２が送信され、第２の通信装置２から信号ｃ２が送信される態様が例示される。 Ultra-wide band (UWB: Ultra Wide Band) signals are transmitted and received between the first communication device 1 and the second communication device 2 to perform distance measurement. In FIG. 1, a mode in which the signal s2 is transmitted from the antenna a2 and the signal c2 is transmitted from the second communication device 2 is illustrated.
　図２は第１の通信装置１の構成を例示するブロック図である。図２においてアンテナａ１，ａ２，ａ３，ａ４，ａ５は纏めてアンテナ群１０４としても標記される。本体１０は、車載制御部１０１及びＵＷＢ送受信部１０３を含む。 FIG. 2 is a block diagram illustrating the configuration of the first communication device 1. In FIG. 2, the antennas a1, a2, a3, a4 and a5 are collectively referred to as an antenna group 104. The main body 10 includes an in-vehicle control unit 101 and a UWB transmitting / receiving unit 103.
　ＵＷＢ送受信部１０３は、アンテナａ１，ａ２，ａ３，ａ４，ａ５のいずれを介しても超広帯域の信号の送受信が可能である。 The UWB transmitting / receiving unit 103 can transmit / receive an ultra-wideband signal via any of the antennas a1, a2, a3, a4, a5.
　車載制御部１０１は各種の車載機器を制御する。図２では複数の車載機器が車載機器群１０５として一つに纏めて例示される。例えば車載機器群１０５には、ドアの施錠／解錠を制御するドアロック（ｄｏｏｒ　ｌｏｃｋ）装置や、エンジンの制御を行うエンジン制御装置が含まれる。 The in-vehicle control unit 101 controls various in-vehicle devices. In FIG. 2, a plurality of vehicle-mounted devices are collectively illustrated as a vehicle-mounted device group 105. For example, the in-vehicle device group 105 includes a door lock device that controls locking / unlocking of a door and an engine control device that controls an engine.
　車載制御部１０１は、ＵＷＢ送受信部１０３によって送信される信号に含める情報の生成や、ＵＷＢ送受信部１０３によって受信される信号が含む情報の取得、照合をも行う。 The in-vehicle control unit 101 also generates information included in the signal transmitted by the UWB transmitting / receiving unit 103, acquires information included in the signal received by the UWB transmitting / receiving unit 103, and collates the information.
　例えば、車載制御部１０１はメモリ（ｍｅｍｏｒｙ）１０２を有し、メモリ１０２にはＩＤコード（ｃｏｄｅ）、測距コード、暗号鍵が記憶される。ＩＤコードは第１の通信装置１を識別するための情報である。測距コードは送信に用いるアンテナを特定する情報である。暗号鍵は送信する信号の暗号化と、受信した信号の復号化との少なくとも一方に用いる情報である。 For example, the vehicle-mounted control unit 101 has a memory 102, and the memory 102 stores an ID code (code), a distance measurement code, and an encryption key. The ID code is information for identifying the first communication device 1. The ranging code is information that identifies the antenna used for transmission. The encryption key is information used for at least one of encryption of a transmitted signal and decryption of a received signal.
　例えばアンテナａ２から送信される信号ｓ２は、第１の通信装置１を識別するＩＤコードと、アンテナａ２を特定する測距コードと、返信を要求する情報（以下「返信要求」と称す）とを含み、暗号鍵で暗号化されて、ＵＷＢ送受信部１０３によって送信される。 For example, the signal s2 transmitted from the antenna a2 includes an ID code for identifying the first communication device 1, a distance measurement code for identifying the antenna a2, and information for requesting a reply (hereinafter referred to as "reply request"). It is included, encrypted with the encryption key, and transmitted by the UWB transmitting / receiving unit 103.
　詳細は後述するが、信号ｓ２を受信した第２の通信装置２は、信号ｓ２に含まれた返信要求に応えて信号ｃ２を送信する。アンテナ群１０４を介してＵＷＢ送受信部１０３によって受信された信号ｃ２は、暗号鍵によって復号され（復号と暗号とは異なる暗号鍵を用いることができる）、信号ｃ２に含まれていたＩＤコードと測距コードとが抽出される。信号ｃ２に含まれるＩＤコードは第２の通信装置２を識別するための情報であり、測距コードは例えば信号ｓ２に含まれていた測距コードである。 As will be described in detail later, the second communication device 2 that has received the signal s2 transmits the signal c2 in response to the reply request included in the signal s2. The signal c2 received by the UWB transmission / reception unit 103 via the antenna group 104 is decrypted by an encryption key (an encryption key different from decryption and encryption can be used), and the ID code and the measurement included in the signal c2 are measured. Distance codes and are extracted. The ID code included in the signal c2 is information for identifying the second communication device 2, and the distance measurement code is, for example, the distance measurement code included in the signal s2.
　このような送受信により、車載制御部１０１は、受信した信号ｃ２が、アンテナａ２から送信された信号ｓ２に含まれた返信要求に従って、第２の通信装置２から発信されたものであることを了知する。 Through such transmission and reception, the in-vehicle control unit 101 confirms that the received signal c2 is transmitted from the second communication device 2 according to the reply request included in the signal s2 transmitted from the antenna a2. To know.
　図３は第２の通信装置２の構成を例示するブロック図である。第２の通信装置２は、電子キー制御部２０１、ＵＷＢ送受信部２０３、アンテナｂ１を備える。ＵＷＢ送受信部２０３は、アンテナｂ１を介して超広帯域の信号の送受信が可能である。 FIG. 3 is a block diagram illustrating the configuration of the second communication device 2. The second communication device 2 includes an electronic key control unit 201, a UWB transmitting / receiving unit 203, and an antenna b1. The UWB transmitting / receiving unit 203 can transmit / receive an ultra wideband signal via the antenna b1.
　電子キー制御部２０１は、ＵＷＢ送受信部２０３によって送信される信号に含める情報の生成や、ＵＷＢ送受信部２０３によって受信される信号が含む情報の取得、照合をも行う。 The electronic key control unit 201 also generates information to be included in the signal transmitted by the UWB transmitting / receiving unit 203, obtains information included in the signal received by the UWB transmitting / receiving unit 203, and collates the information.
　例えば、電子キー制御部２０１はメモリ２０２を有し、メモリ２０２にはＩＤコード、測距コード、暗号鍵が記憶される。ＩＤコードは第２の通信装置２を識別するための情報である。測距コードは、例えば受信した信号が含む測距コードである。暗号鍵は送信する信号の暗号化と、受信した信号の復号化との少なくとも一方に用いる情報である。 For example, the electronic key control unit 201 has a memory 202, and the memory 202 stores an ID code, a distance measurement code, and an encryption key. The ID code is information for identifying the second communication device 2. The ranging code is, for example, a ranging code included in the received signal. The encryption key is information used for at least one of encryption of a transmitted signal and decryption of a received signal.
　［動作］
　図４は測距における信号の送受信を示すタイミングチャート（ｔｉｍｉｎｇ　ｃｈａｒｔ）である。横軸には時間が採用され、アンテナを示す直線が縦軸方向に並べられる。 [motion]
FIG. 4 is a timing chart showing signal transmission / reception in distance measurement. Time is used on the horizontal axis, and a straight line showing the antenna is arranged along the vertical axis.
　アンテナ群１０４からの送信は各アンテナを示す直線を始点とする下向きの矢印で示される。アンテナｂ１での受信はアンテナｂ１を示す直線を終点とする下向きの矢印で示される。 The transmission from the antenna group 104 is indicated by a downward arrow starting from a straight line showing each antenna. Reception by the antenna b1 is indicated by a downward arrow whose end is a straight line indicating the antenna b1.
　アンテナｂ１からの送信はアンテナｂ１を示す直線を始点とする上向きの矢印で示される。アンテナ群１０４での受信は各アンテナを示す直線を終点とする上向きの矢印で示される。 The transmission from the antenna b1 is indicated by an upward arrow starting from the straight line showing the antenna b1. Reception by the antenna group 104 is indicated by an upward arrow having a straight line indicating each antenna as an end point.
　アンテナａ１，ａ２，ａ３，ａ４，ａ５からは、それぞれ信号ｓ１，ｓ２，ｓ３，ｓ４，ｓ５が送信される。信号ｓ２は信号ｒ２としてアンテナｂ１に受信される。信号ｒ２を受信した第２の通信装置２は信号ｓ２に対する返信として信号ｃ２を送信する。信号ｃ２はアンテナａ２，ａ３，ａ４において、それぞれ信号ｄ２，ｄ３，ｄ４として受信される。 Signals s1, s2, s3, s4, s5 are transmitted from the antennas a1, a2, a3, a4, a5, respectively. The signal s2 is received by the antenna b1 as the signal r2. The second communication device 2 having received the signal r2 transmits the signal c2 as a reply to the signal s2. The signal c2 is received by the antennas a2, a3 and a4 as signals d2, d3 and d4, respectively.
　信号ｓ１，ｓ２，ｓ３，ｓ４，ｓ５の送信時点の起点が時点Ｔ０として説明される。信号ｓ１，ｓ２，ｓ３，ｓ４，ｓ５は、時点Ｔ０からそれぞれ時間ｔ１，ｔ２，ｔ３，ｔ４，ｔ５が経過した時点で、それぞれアンテナａ１，ａ２，ａ３，ａ４，ａ５から送信される。つまり信号ｓ１，ｓ２，ｓ３，ｓ４，ｓ５が送信される時点は、それぞれ（Ｔ０＋ｔ１），（Ｔ０＋ｔ２），（Ｔ０＋ｔ３），（Ｔ０＋ｔ４），（Ｔ０＋ｔ５）と表される。 The starting point at the time of transmission of the signals s1, s2, s3, s4, s5 is explained as time T0. The signals s1, s2, s3, s4, and s5 are transmitted from the antennas a1, a2, a3, a4, and a5, respectively, at times t1, t2, t3, t4, and t5 after the time T0. That is, the time points at which the signals s1, s2, s3, s4, and s5 are transmitted are represented as (T0 + t1), (T0 + t2), (T0 + t3), (T0 + t4), and (T0 + t5), respectively.
　信号ｓ２がアンテナｂ１に時間Δｔ２で到達するとすれば、信号ｒ２がアンテナｂ１で受信される時点Ｔ２ｒは（Ｔ０＋ｔ２＋Δｔ２）と表せる。 If the signal s2 arrives at the antenna b1 at time Δt2, the time T2r at which the signal r2 is received by the antenna b1 can be expressed as (T0 + t2 + Δt2).
　信号ｃ２がアンテナｂ１から時点Ｔ２ｓで送信される場合を想定する。信号ｃ２がアンテナａ２に到達するのにかかる時間は時間Δｔ２に等しい。よって信号ｄ２がアンテナａ２で受信される時点Ｔａ２は、（Ｔ２ｓ＋Δｔ２）と表せる。信号ｃ２がアンテナａ３に到達するのに要する時間Δｔ３を導入して、信号ｄ３がアンテナａ３で受信される時点Ｔａ３は、（Ｔ２ｓ＋Δｔ３）と表せる。信号ｃ２がアンテナａ４に到達する時間Δｔ４を導入して、信号ｄ４がアンテナａ４で受信される時点Ｔａ４は、（Ｔ２ｓ＋Δｔ４）と表せる。 Assume that signal c2 is transmitted from antenna b1 at time T2s. The time it takes for the signal c2 to reach the antenna a2 is equal to the time Δt2. Therefore, the time point Ta2 when the signal d2 is received by the antenna a2 can be expressed as (T2s + Δt2). By introducing the time Δt3 required for the signal c2 to reach the antenna a3, the time Ta3 when the signal d3 is received by the antenna a3 can be expressed as (T2s + Δt3). The time Ta4 at which the signal d4 is received by the antenna a4 by introducing the time Δt4 for the signal c2 to reach the antenna a4 can be expressed as (T2s + Δt4).
　第２の通信装置２が信号ｒｍ（ｍ＝１～Ｍ：上述の例ではＭ＝５。以下同様）を受信してから信号ｃｍを送信するまでに一定の所定時間ｔｄが経過し、信号ｃｍが信号ｄｋ（ｋ＝１～Ｍ：以下同様）としてアンテナａｎで時点Ｔａｋで受信されるとすれば、次式が成立する：
Ｔａｋ＝Ｔ０＋ｔｍ＋Δｔｍ＋ｔｄ＋Δｔｋ…（１） The second communication device 2 receives the signal rm (m = 1 to M: M = 5 in the above example, the same applies in the following), and a certain predetermined time td elapses before the signal cm is transmitted. Is received as a signal dk (k = 1 to M: the same below) at the antenna an at the time Tak, the following equation holds:
Tak = T0 + tm + Δtm + td + Δtk (1)
　アンテナａｍが送信した信号ｓｍに対する返信としてアンテナａｍが信号ｄｍを受信した場合（上述の例ではｋ＝ｍ＝２）には次式が成立する：
Δｔｍ＝（Ｔａｍ－Ｔ０－ｔｍ－ｔｄ）／２…（２） When the antenna am receives the signal dm in response to the signal sm transmitted by the antenna am (k = m = 2 in the above example), the following equation holds:
Δtm = (Tam-T0-tm-td) / 2 (2)
　式（２）の右辺は全て既知であるので、式（２）のみで時間Δｔｍが求められる。 Since the right side of equation (2) is already known, the time Δtm can be obtained only by equation (2).
　アンテナａｍが送信した信号ｓｍに対する返信としてアンテナａｎ（ｎ＝１～Ｍ，ｎ≠ｍ：以下同様）が信号ｄｎを受信した場合（上述の例ではｍ＝２，ｎ＝３，４）には次式が成立する：
Δｔｎ＝Ｔａｎ－Ｔ０－ｔｍ－ｔｄ－Δｔｍ…（３） When the antenna an (n = 1 to M, n ≠ m: the same applies hereinafter) receives the signal dn as a reply to the signal sm transmitted by the antenna am (m = 2, n = 3, 4 in the above example). The following expression holds:
Δtn = Tan−T0−tm−td−Δtm (3)
　式（３）の右辺の最後の項には、式（２）で求められた時間Δｔｍが代入され得る。よって時間Δｔｍも求められる。 The time Δtm obtained by the equation (2) can be substituted in the last term on the right side of the equation (3). Therefore, the time Δtm is also obtained.
　このように：
　(i)第１の通信装置１の少なくとも一つのアンテナａｋから第１の信号ｓｋが送信され；
　(ii)第２の通信装置２のアンテナｂ１で第１の信号ｓｋを信号ｒｋとして受信された後、所定時間ｔｄが経過してから、アンテナｂ１から第２の信号ｃｋが送信され；
　(iii)第２の信号ｃｍが第１の信号ｓｍを送信したアンテナａｍで信号ｄｍとして受信されることにより、アンテナａｍ（以下「特定アンテナ」とも称す）とアンテナｂ１との間で信号が伝搬するのに要する時間Δｔｍが求められ；
　(iv)第２の信号ｃｍが第１の信号ｓｍを送信した以外のアンテナａｎ（つまり特定アンテナとは異なるアンテナ：以下「非特定アンテナ」とも称す）で信号ｄｎとして受信されることにより、アンテナａｎとアンテナｂ１との間で信号が伝搬するのに要する時間Δｔｎが、非特定アンテナの各々について、各々の時点Ｔａｎを用いて求められる。以下では時間Δｔｋ，Δｔｍ，Δｔｎを伝搬時間とも称す。 in this way:
(i) The first signal sk is transmitted from at least one antenna ak of the first communication device 1;
(ii) The second signal ck is transmitted from the antenna b1 after a lapse of a predetermined time td after the first signal sk is received as the signal rk by the antenna b1 of the second communication device 2;
(iii) The second signal cm is received as the signal dm by the antenna am that has transmitted the first signal sm, so that the signal propagates between the antenna am (hereinafter also referred to as “specific antenna”) and the antenna b1. The time Δtm required to do is determined;
(iv) The second signal cm is received as the signal dn by the antenna an other than the one that has transmitted the first signal sm (that is, an antenna different from the specific antenna: hereinafter also referred to as “non-specific antenna”), so that the antenna The time Δtn required for a signal to propagate between an and the antenna b1 is obtained for each of the non-specific antennas by using each time Tan. Below, the times Δtk, Δtm, and Δtn are also referred to as propagation times.
　特許文献１，２などで公知のように、伝搬時間Δｔｍを用いて特定アンテナａｍとアンテナｂ１との間の距離が得られ、伝搬時間Δｔｎを用いて非特定アンテナａｎとアンテナｂ１との間の距離が得られる。 As known in Patent Documents 1 and 2, the distance between the specific antenna am and the antenna b1 is obtained by using the propagation time Δtm, and the distance between the non-specific antenna an and the antenna b1 is obtained by using the propagation time Δtn. The distance is obtained.
　第２の通信装置２の位置は三次元的には一つの円周上に特定され、二次元的には二点に特定される。二つの非特定アンテナについてアンテナｂ１との間の距離が得られれば、第２の通信装置２の位置が三次元的には二点に特定され、二次元的には一点に特定される。 The position of the second communication device 2 is specified on one circumference in three dimensions and two points in two dimensions. If the distance between the antenna b1 and the two non-specific antennas is obtained, the position of the second communication device 2 is specified in two points in three dimensions and in one point in two dimensions.
　通常、第２の通信装置２の位置は二次元的に特定すれば足りるので、アンテナ群１０４を用いた上述の測距は、一つの特定アンテナと二つの非特定アンテナについて行えば足りる。 Normally, it is sufficient to specify the position of the second communication device 2 in a two-dimensional manner, so the above-described distance measurement using the antenna group 104 is sufficient for one specific antenna and two non-specific antennas.
　上述の測距において第２の通信装置２からの送信は、信号ｓｋのいずれか一つに基づく返信としての一つの信号ｃｋのみで足りる。よって複数の測距に必要な送信、特に第２の通信装置２からの送信の回数が低減される。これは第２の通信装置２が携帯機に適用されることに鑑みれば、その電力消費を抑制し、電池の消耗を遅らせる観点で有利である。 In the above distance measurement, the transmission from the second communication device 2 is sufficient with only one signal ck as a reply based on any one of the signals sk. Therefore, the number of transmissions required for a plurality of distance measurements, particularly the number of transmissions from the second communication device 2, is reduced. This is advantageous from the viewpoint that the second communication device 2 is applied to a portable device, its power consumption is suppressed, and battery consumption is delayed.
　図５及び図６は上述の測距で採用される動作を示すフローチャートである。図５は第１の通信装置１の動作、主として車載制御部１０１の動作を示す。図６は第２の通信装置２の動作、主として電子キー制御部２０１の動作を示す。 5 and 6 are flowcharts showing the operation adopted in the above distance measurement. FIG. 5 shows the operation of the first communication device 1, mainly the operation of the vehicle-mounted control unit 101. FIG. 6 shows the operation of the second communication device 2, mainly the operation of the electronic key control unit 201.
　図５において測距は、実質的にはステップＳ１１の判断で肯定的な結果が得られて開始する。ここではステップＳ１１として、開錠ボタンの操作が検知されたが判断される。開錠ボタンは、例えば車載機器群１０５に含まれ、その操作は車載制御部１０１において検知される。 In FIG. 5, the distance measurement is actually started when a positive result is obtained in the determination in step S11. Here, in step S11, it is determined that the operation of the unlock button has been detected. The unlock button is included in, for example, the in-vehicle device group 105, and its operation is detected by the in-vehicle control unit 101.
　ステップＳ１１の判断で肯定的な結果が得られれば、つまり開錠ボタンの操作が検知されれば、ステップＳ１２の処理が実行される。ステップＳ１２ではアンテナａ１，ａ２，ａ３，ａ４，ａ５からそれぞれ信号ｓ１，ｓ２，ｓ３，ｓ４，ｓ５が順次に送信される。かかる送信は車載制御部１０１の動作、具体的には車載制御部１０１の制御により、ＵＷＢ送受信部１０３からアンテナａ１，ａ２，ａ３，ａ４，ａ５を介して行われる。ここで「順次に」とはそれぞれのアンテナからの送信のタイミングが異なることを意味し、図４に即して言えばｔ１＜ｔ２＜ｔ３＜ｔ４＜ｔ５で表されている。 If a positive result is obtained in the determination of step S11, that is, if the operation of the unlock button is detected, the process of step S12 is executed. In step S12, the signals s1, s2, s3, s4 and s5 are sequentially transmitted from the antennas a1, a2, a3, a4 and a5. Such transmission is performed by the operation of the vehicle-mounted control unit 101, specifically, the control of the vehicle-mounted control unit 101, from the UWB transmitting / receiving unit 103 via the antennas a1, a2, a3, a4, a5. Here, "sequentially" means that the transmission timings from the respective antennas are different, and is expressed by t1 <t2 <t3 <t4 <t5 in the case of FIG.
　なお、詳細は省略するがステップＳ１２には、信号ｓｋを送信するために必要な処理を含む。具体的には例えば、第１の通信装置１を識別するＩＤコードと、アンテナａｋを特定する測距コードと、返信要求とを含む信号を、暗号鍵で暗号化して信号ｓｋを生成する車載制御部１０１の処理も含む。 Note that although details are omitted, step S12 includes processing necessary for transmitting the signal sk. Specifically, for example, an in-vehicle control for encrypting a signal including an ID code for identifying the first communication device 1, a distance measurement code for identifying the antenna ak, and a reply request with an encryption key to generate a signal sk. The processing of the unit 101 is also included.
　図６において測距は、まずステップＳ２１において受信動作が開始される。かかる受信は電子キー制御部２０１の動作、具体的には電子キー制御部２０１の制御により、ＵＷＢ送受信部２０３からアンテナｂ１を介して行われる。 As for distance measurement in FIG. 6, the receiving operation is first started in step S21. Such reception is performed by the operation of the electronic key control unit 201, specifically, the control of the electronic key control unit 201, from the UWB transmission / reception unit 203 via the antenna b1.
　ステップＳ２１により受信動作が開始されると、ステップＳ２２で送信信号が受信されたかが判断される。ここで送信信号とは、第１の通信装置１からの送信であることがわかる信号ｒｋを意味する。送信信号は、具体的にはその信号に第１の通信装置１であることを示すＩＤコードが含まれている信号を意味し、上述の例では信号ｒ２である。送信信号は上述の第１の信号が第２の通信装置２において受信される信号である。 When the receiving operation is started in step S21, it is determined in step S22 whether the transmission signal is received. Here, the transmission signal means a signal rk that is known to be a transmission from the first communication device 1. The transmission signal specifically means a signal including an ID code indicating that it is the first communication device 1, and is the signal r2 in the above example. The transmission signal is a signal in which the above-described first signal is received by the second communication device 2.
　詳細は省略するが、ステップＳ２２にはその判断の前提として必要な処理を含む。具体的には例えば、信号ｒｋの復号化、返信要求とＩＤコードと測距コードの抽出を行う電子キー制御部２０１の処理も含む。 Although details are omitted, step S22 includes processing required as a premise for the determination. Specifically, for example, the processing of the electronic key control unit 201 that decodes the signal rk, extracts a reply request, an ID code, and a distance measurement code is also included.
　ステップＳ２２は、その判断結果が肯定的となるまで繰り返して実行される。当該判断結果が肯定的となれば、処理はステップＳ２３へ進む。ステップＳ２３では受信した送信信号の測距コードがメモリ２０２に記憶される。図４の例に則して言えば、信号ｒ２が送信信号に該当し、そこから抽出された測距コードは、信号ｒ２として受信された信号（具体的には信号ｓ２）の送信元が、アンテナａ２であることを示す。 Step S22 is repeatedly executed until the determination result becomes affirmative. If the determination result is affirmative, the process proceeds to step S23. In step S23, the distance measurement code of the received transmission signal is stored in the memory 202. According to the example of FIG. 4, the signal r2 corresponds to the transmission signal, and the ranging code extracted from the signal is the transmission source of the signal received as the signal r2 (specifically, the signal s2). It shows that it is the antenna a2.
　ステップＳ２３の処理の後、ステップＳ２４によって、応答信号が送信される。応答信号は、具体的にはその信号に第２の通信装置２であることを示すＩＤコードと、メモリ２０２に記憶された測距コードが含まれている信号を意味し、上述の例では信号ｃ２あるいは信号ｃｍである。応答信号は上述の第２の信号に相当し、第２の通信装置２が送信信号ｒｋとして受信した第１の信号ｓｋに応答して送信される。 After the processing of step S23, a response signal is transmitted by step S24. The response signal specifically means a signal including an ID code indicating that it is the second communication device 2 and a distance measurement code stored in the memory 202, and the response signal is the signal in the above example. c2 or signal cm. The response signal corresponds to the above-mentioned second signal, and is transmitted in response to the first signal sk received by the second communication device 2 as the transmission signal rk.
　第２の通信装置２の測距に関する処理はステップＳ２４の実行によって終了する。上述の例では信号ｓ１はアンテナｂ１で受信されず、信号ｓ２が信号ｒ２として受信された場合が例示される。信号ｓ３がアンテナｂ１で受信されても測距に関する処理は行われない。つまり、第２の通信装置２は、信号ｒｋとして最初に受信した信号ｓｋに応答して信号ｃｋを送信する。第２の通信装置２が信号ｒｋを受信できたので、第１の通信装置１も信号ｄｋを受信できるからである。 The process related to the distance measurement of the second communication device 2 ends by executing step S24. In the above example, the signal s1 is not received by the antenna b1, but the signal s2 is received as the signal r2. Even if the signal s3 is received by the antenna b1, the process related to distance measurement is not performed. That is, the second communication device 2 transmits the signal ck in response to the signal sk initially received as the signal rk. This is because the second communication device 2 can receive the signal rk and thus the first communication device 1 can also receive the signal dk.
　図５に戻って説明が行われる。第１の通信装置１ではステップＳ１３において受信動作が開始される。かかる受信は車載制御部１０１の動作、具体的には車載制御部１０１の制御により、ＵＷＢ送受信部１０３からアンテナａ１，ａ２，ａ３，ａ４，ａ５を介して行われる。ステップＳ１３により受信動作が開始されると、ステップＳ１４で応答信号が受信されたかが判断される。 Returning to FIG. 5, the explanation will be given. In the first communication device 1, the receiving operation is started in step S13. Such reception is performed by the operation of the vehicle-mounted control unit 101, specifically, the control of the vehicle-mounted control unit 101, from the UWB transceiver unit 103 via the antennas a1, a2, a3, a4, a5. When the receiving operation is started in step S13, it is determined in step S14 whether the response signal is received.
　ステップＳ１４では特定アンテナを含む複数のアンテナで応答信号が伝搬した信号を受信したか否かが判断される。当該信号は上述の例では信号ｄ２あるいは信号ｄｍと、信号ｄ３，ｄ４あるいは信号ｄｎである。これらの信号は図５では単に「応答信号」と略記される。上述のように、第２の通信装置２の位置を二次元的に特定する場合には、一つの特定アンテナと二つの非特定アンテナについての判断が行われる。これらのアンテナは図５では単に「３以上のアンテナ」と略記される。 In step S14, it is determined whether or not the signal in which the response signal propagates through the plurality of antennas including the specific antenna is received. The signals are the signal d2 or the signal dm and the signals d3, d4 or the signal dn in the above example. These signals are simply abbreviated as "response signals" in FIG. As described above, when the position of the second communication device 2 is two-dimensionally specified, the determination regarding one specific antenna and two non-specific antennas is performed. These antennas are simply abbreviated as "3 or more antennas" in FIG.
　詳細は省略するが、ステップＳ１４にはその判断の前提として必要な処理を含む。具体的には例えば、信号ｄｋの復号化、ＩＤコードと測距コードの抽出を行う車載制御部１０１の処理も含む。 Although details are omitted, step S14 includes processing required as a premise for the determination. Specifically, for example, the processing of the vehicle-mounted control unit 101 that decodes the signal dk and extracts the ID code and the ranging code is also included.
　ＵＷＢ送受信部１０３は、受信した応答信号がアンテナａｋのいずれを経由したかを検出し、その情報を応答信号及び当該応答信号を受信した時点Ｔａｋと共に車載制御部１０１に伝達する。 The UWB transmission / reception unit 103 detects which of the antennas ak the received response signal has passed through, and transmits the information to the vehicle-mounted control unit 101 together with the response signal and the time Tak at which the response signal is received.
　上述のように、信号ｃｍには、したがって信号ｄｍ，ｄｎには測距コードが含まれる。アンテナａｋのそれぞれが受信した信号ｄｋが、あるアンテナａｍから送信された信号ｓｍに対する返信であるかは、車載制御部１０１で判断される。よって一つの特定アンテナと二つの非特定アンテナにおいて応答信号が受信されたか否かは判断できる。 As described above, the signal cm, and thus the signals dm and dn, include the ranging code. The in-vehicle control unit 101 determines whether the signal dk received by each of the antennas ak is a reply to the signal sm transmitted from a certain antenna am. Therefore, it can be determined whether or not the response signal is received by one specific antenna and two non-specific antennas.
　ステップＳ１４は、その判断結果が肯定的となるまで繰り返して実行される。当該判断結果が肯定的となれば、処理はステップＳ１５へ進む。ステップＳ１５では特定アンテナについての伝搬時間Δｔｍが算出される。アンテナａｍが信号ｄｍを受信した時点ＴａｍはＵＷＢ送受信部１０３から得られており、時点Ｔ０、時間ｔｍ、所定時間ｔｄは既知であるので、式（２）から伝搬時間Δｔｍが算出される。上述の例に則して言えば、特定アンテナａ２について伝搬時間Δｔ２が算出される。 Step S14 is repeatedly executed until the determination result becomes affirmative. If the determination result is affirmative, the process proceeds to step S15. In step S15, the propagation time Δtm for the specific antenna is calculated. Since the time Tam when the antenna am receives the signal dm is obtained from the UWB transmitting / receiving unit 103, and the time T0, the time tm, and the predetermined time td are known, the propagation time Δtm is calculated from the equation (2). According to the above example, the propagation time Δt2 is calculated for the specific antenna a2.
　ステップＳ１５の実行後、ステップＳ１６が実行される。ステップＳ１６では非特定アンテナについての伝搬時間Δｔｎが算出される。アンテナａｎが信号ｄｍを受信した時点ＴａｎはＵＷＢ送受信部１０３から得られており、時点Ｔ０、時間ｔｎ、所定時間ｔｄは既知である。よってステップＳ１６で求められた伝搬時間Δｔｍと式（３）とから伝搬時間Δｔｎが算出される。ステップＳ１６は測距が必要な非特定アンテナの数に対応して実行される。上述の例に則して言えば、二つの非特定アンテナａ３，ａ４についてそれぞれ伝搬時間Δｔ３，Δｔ４が算出される。 After execution of step S15, step S16 is executed. In step S16, the propagation time Δtn for the non-specific antenna is calculated. The time Tan when the antenna an receives the signal dm is obtained from the UWB transceiver 103, and the time T0, the time tn, and the predetermined time td are known. Therefore, the propagation time Δtn is calculated from the propagation time Δtm obtained in step S16 and the equation (3). Step S16 is executed corresponding to the number of non-specific antennas that require distance measurement. According to the above example, the propagation times Δt3 and Δt4 are calculated for the two non-specific antennas a3 and a4, respectively.
　ステップＳ１７は伝搬時間Δｔｍ，Δｔｎを用いて、第２の通信装置２の位置、例えばＦＯＢの位置を算出する。非特定アンテナが一つの場合には当該位置は二次元的に二箇所に特定され、非特定アンテナが二つの場合には当該位置は二次元的に一箇所に特定される。また非特定アンテナが三つの場合には当該位置は三次元的に一箇所に特定される。非特定アンテナが複数であることは、単数である場合と比較して、第２の通信装置２の位置を特定する精度が高まる観点で有利である。 Step S17 calculates the position of the second communication device 2, for example, the position of the FOB, using the propagation times Δtm and Δtn. When there is one non-specific antenna, the position is two-dimensionally specified at two positions, and when there are two non-specific antennas, the position is two-dimensionally specified at one position. When there are three non-specific antennas, the position is specified three-dimensionally at one position. The plurality of non-specific antennas is advantageous from the viewpoint of increasing the accuracy of specifying the position of the second communication device 2 as compared with the case of a single antenna.
　［変形例］
　第１の通信装置１と第２の通信装置２との間の通信によって相互認証を行うことができる。第１の通信装置１と第２の通信装置２との間の通信には超広帯域の他の帯域を採用することができる。 [Modification]
Mutual authentication can be performed by communication between the first communication device 1 and the second communication device 2. For communication between the first communication device 1 and the second communication device 2, another band of ultra-wide band can be adopted.
　信号ｓ１，ｓ２，ｓ３，ｓ４，ｓ５は等間隔で送信されてもよい。例えば時間ｔｋとして値ｋ・ｔ０が採用され得る。 The signals s1, s2, s3, s4, s5 may be transmitted at equal intervals. For example, the value k · t0 can be adopted as the time tk.
　所定時間ｔｄは、第２の通信装置２における処理時間を含む。例えば当該処理時間としては信号ｒｋの復号、情報の抽出、ＩＤコードの照合、測距コードの記憶、信号ｃｋの生成を含む。所定時間ｔｄには遅延時間が含められてもよい。かかる遅延時間を用いることにより、信号ｒｋの受信から信号ｃｋの送信までの時間を一定の所定時間ｔｄにできる。 The predetermined time td includes the processing time in the second communication device 2. For example, the processing time includes decoding the signal rk, extracting information, collating ID code, storing ranging code, and generating signal ck. The predetermined time td may include a delay time. By using such a delay time, the time from the reception of the signal rk to the transmission of the signal ck can be set to a fixed predetermined time td.
　アンテナ群１０４が、信号ｓｋを全て送信してから信号ｄｋを受信することは、第１の通信装置１における信号処理を煩雑にしない観点で望ましい。かかる観点からは、測距のために順次に送信される一連の信号ｓｋのうち、最初のもの（上述の例では信号ｓ１）が送信される時点（上述の例では時点（Ｔ０＋ｔ１））から最後のもの（上述の例では信号ｓ５）が送信される時点（上述の例では時点（Ｔ０＋ｔ５））までの時間間隔が、所定時間ｔｄよりも短いことが望ましい。このような関係は第１の通信装置１と第２の通信装置２との間の距離とは無関係であり、予め設定することが可能であることは明白である。 It is desirable that the antenna group 104 transmits all the signals sk and then receives the signals dk from the viewpoint of not complicating the signal processing in the first communication device 1. From this point of view, of the series of signals sk sequentially transmitted for distance measurement, from the time when the first one (signal s1 in the above example) is transmitted (time point (T0 + t1) in the above example) to the end It is desirable that the time interval up to the time point (the time point (T0 + t5) in the above example) at which the signal (signal s5 in the above example) is transmitted is shorter than the predetermined time td. It is clear that such a relationship is independent of the distance between the first communication device 1 and the second communication device 2 and can be set in advance.
　アンテナ群１０４の全てのアンテナから信号ｓｋを送信することは必須ではない。ある一つのアンテナａｍから送信された信号ｓｍに対応して、アンテナｂ１から信号ｃｍが送信され、信号ｃｍが複数のアンテナａｍ，ａｎにおいてそれぞれ信号ｄｍ，ｄｎとして受信されれば、上記（２），（３）から伝搬時間Δｔｍ，Δｔｎが得られるからである。つまり少なくとも一つのアンテナから信号ｓｋが送信されればよい。 It is not essential to transmit the signal sk from all the antennas of the antenna group 104. When the signal cm is transmitted from the antenna b1 and the signal cm is received as the signals dm and dn at the plurality of antennas am and an, respectively, in response to the signal sm transmitted from one antenna am, the above-mentioned (2) , (3), the propagation times Δtm and Δtn are obtained. That is, the signal sk may be transmitted from at least one antenna.
　またアンテナ群１０４での受信については、上述のように、特定アンテナを含む複数のアンテナで信号ｄｍ，ｄｎが受信できればよい。全てのアンテナａ１，ａ２，ａ３，ａ４，ａ５での受信は必要ではない。 Regarding reception by the antenna group 104, as described above, it is sufficient that the plurality of antennas including the specific antenna can receive the signals dm and dn. Reception at all antennas a1, a2, a3, a4, a5 is not necessary.
　車載制御部１０１、電子キー制御部２０１のいずれもが、マイクロプロセッサ（ｍｉｃｒｏ　ｐｒｏｃｅｓｓｏｒ）、ＲＯＭ（Ｒｅａｄ　Ｏｎｌｙ　Ｍｅｍｏｒｙ）、ＲＡＭ（Ｒａｎｄｏｍ　Ａｃｃｅｓｓ　Ｍｅｍｏｒｙ）等を含み構成されるコンピュータを備える。 Both the in-vehicle control unit 101 and the electronic key control unit 201 include a computer including a microprocessor (micro processor), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like.
　マイクロプロセッサ等の演算処理部は、図４～図６に示すような、タイミングチャートまたはフローチャートの各ステップの一部または全部を含むコンピュータプログラム（ｃｏｍｐｕｔｅｒ　ｐｒｏｇｒａｍ）を、ＲＯＭ、ＲＡＭ等の記憶部からそれぞれ読み出して実行する。 The arithmetic processing unit such as a microprocessor stores a computer program (computer program) including some or all of the steps of the timing chart or the flowchart from a storage unit such as a ROM or a RAM as shown in FIGS. Read and execute.
　これら複数の装置のコンピュータプログラムは、それぞれ、外部のサーバ（ｓｅｒｖｅｒ）装置等からインストール（ｉｎｓｔａｌｌ）することができる。また、このようなコンピュータプログラムは、それぞれ、ＣＤ－ＲＯＭ（Ｃｏｍｐａｃｔ　Ｄｉｓｃ　Ｒｅａｄ　Ｏｎｌｙ　Ｍｅｍｏｒｙ）、ＤＶＤ－ＲＯＭ（Ｄｉｇｉｔａｌ　Ｖｅｒｓａｔｉｌｅ　Ｄｉｓｋ　Ｒｅａｄ　Ｏｎｌｙ　Ｍｅｍｏｒｙ）、半導体メモリ（ｍｅｍｏｒｙ）等の記録媒体に格納された状態にあって流通する。 The computer programs of these multiple devices can be installed from an external server device or the like. Also, such computer programs are in a state of being respectively stored in a recording medium such as a CD-ROM (Compact Disc Read Only Memory), a DVD-ROM (Digital Versatile Disk Only Memory), and a semiconductor memory (memory). Be distributed.
　上記実施形態及び各変形例で説明した各構成は、相互に矛盾しない限り適宜組み合わせることができる。 The respective configurations described in the above-mentioned embodiment and each modification can be appropriately combined unless they contradict each other.
　１　（第１の）通信装置
　２　（第２の）通信装置
　９　車体
　１０　本体
　１０１　制御部（車載制御部）
　１０２，２０２　メモリ
　１０３，２０３　送受信部（ＵＷＢ送受信部）
　１０４　アンテナ群
　１０５　車載機器群
　２０１　制御部（電子キー制御部）
　ａ１，ａ５，ａｋ，ｂ１　アンテナ
　ａ２，ａｍ　（特定）アンテナ
　ａ３，ａ４，ａｎ　（非特定）アンテナ
　ｃ２，ｄ２，ｄ３，ｄ４，ｄｋ，ｄｍ，ｄｎ，ｒ２，ｒｍ，ｓ１，ｓ２，ｓ３，ｓ４，ｓ５　信号
　ｃｋ，ｃｍ　（第２の）信号
　ｒｋ　（送信）信号
　Ｓ１１，Ｓ１２，Ｓ１３，Ｓ１４，Ｓ１５，Ｓ１６，Ｓ１７，Ｓ２１，Ｓ２２，Ｓ２３，Ｓ２４　ステップ
　ｓｋ，ｓｍ　（第１の）信号
　Ｔ０，Ｔ２ｒ，Ｔ２ｓ，Ｔａ２，Ｔａ３，Ｔａ４，Ｔａｋ　時点
　ｔ１，ｔ２，ｔ３，ｔ４，ｔ５，ｔｋ，ｔｍ，ｔｎ，Δｔ４，Δｔｋ　時間
　Ｔａｍ　（第２の）時点
　Ｔａｎ　（第３の）時点
　ｔｄ　所定時間
　Δｔ２，Δｔ３，Δｔｍ，Δｔｎ　（伝搬）時間
　Δｔｍ　（第１の）伝搬時間
　Δｔｎ　（第２の）伝搬時間 1 (First) Communication Device 2 (Second) Communication Device 9 Vehicle Body 10 Main Body 101 Control Unit (Vehicle Control Unit)
102,202 memory 103,203 transceiver unit (UWB transceiver unit)
104 antenna group 105 in-vehicle device group 201 control unit (electronic key control unit)
a1, a5, ak, b1 antenna a2, am (specific) antenna a3, a4, an (non-specific) antenna c2, d2, d3, d4, dk, dm, dn, r2, rm, s1, s2, s3, s4 , S5 signal ck, cm (second) signal rk (transmission) signal S11, S12, S13, S14, S15, S16, S17, S21, S22, S23, S24 step sk, sm (first) signal T0, T2r, T2s, Ta2, Ta3, Ta4, Tak time points t1, t2, t3, t4, t5, tk, tm, tn, Δt4, Δtk time Tam (second) time point Tan (third) time point td predetermined time Δt2 , Δt3, Δtm, Δtn (propagation) time Δtm (first) propagation time Δtn (second) propagation time

Claims (5)

  1. 　第２の通信装置の位置を求める通信装置であって、
    　前記第２の通信装置は、第１の信号に応答する第２の信号を、前記第１の信号を受信してから所定時間後に送信し、
    　前記通信装置は、アンテナ群と、送受信部と、制御部とを備え、
    　前記アンテナ群は複数のアンテナを有し、
    　前記送受信部は前記複数のアンテナの少なくとも一つから前記第１の信号を送信し、前記アンテナ群から前記第２の信号を受信し、
    　前記制御部は、前記複数のアンテナのうち前記第２の信号が応答した前記第１の信号が送信されたアンテナである特定アンテナと前記第２の通信装置との間で信号が伝搬するのに要する時間である第１の伝搬時間と、前記複数のアンテナのうち前記特定アンテナとは異なるアンテナである非特定アンテナと前記第２の通信装置との間で信号が伝搬するのに要する時間である第２の伝搬時間とを求め、
    　前記第１の伝搬時間は、前記所定時間、前記特定アンテナが前記第１の信号を送信した第１の時点、及び前記特定アンテナが前記第２の信号を受信した第２の時点を用いて求められ、
    　前記第２の伝搬時間は、前記第１の伝搬時間、前記所定時間、前記第１の時点、及び前記非特定アンテナが前記第２の信号を受信した第３の時点を用いて求められる、通信装置。     A communication device for determining the position of a second communication device,
    The second communication device transmits a second signal responsive to the first signal after a predetermined time has elapsed after receiving the first signal,
    The communication device includes an antenna group, a transmission / reception unit, and a control unit,
    The antenna group has a plurality of antennas,
    The transmitting / receiving unit transmits the first signal from at least one of the plurality of antennas and receives the second signal from the antenna group,
    The control unit is configured to transmit a signal between a specific antenna, which is an antenna to which the first signal is transmitted in response to the second signal among the plurality of antennas, and the second communication device. The first propagation time, which is the time required, and the time required for a signal to propagate between the non-specific antenna, which is an antenna different from the specific antenna among the plurality of antennas, and the second communication device. And the second propagation time,
    The first propagation time is obtained using the predetermined time, a first time point when the specific antenna transmits the first signal, and a second time point when the specific antenna receives the second signal. The
    The second propagation time is obtained using the first propagation time, the predetermined time, the first time point, and a third time point when the non-specific antenna receives the second signal, communication apparatus.
  2. 　請求項１に記載の通信装置であって、
    　前記アンテナ群は３以上のアンテナを有し、
    　前記制御部は前記非特定アンテナの各々について前記第２の伝搬時間を求め、
    　前記第２の伝搬時間の各々は、前記第１の伝搬時間、前記所定時間、前記第１の時点、及び前記非特定アンテナの各々についての前記第３の時点を用いて求められる、通信装置。     The communication device according to claim 1, wherein
    The antenna group has three or more antennas,
    The control unit obtains the second propagation time for each of the non-specific antennas,
    The communication device, wherein each of the second propagation times is obtained using the first propagation time, the predetermined time, the first time point, and the third time point for each of the non-specific antennas.
  3. 　請求項１または請求項２に記載の通信装置であって、
    　前記第１の信号は前記複数のアンテナの二つ以上から異なるタイミングで送信され、
    　最初に送信される前記第１の信号が送信される時点と、最後に送信される前記第１の信号が送信される時点との時間間隔は、前記所定時間よりも短い、通信装置。     The communication device according to claim 1 or 2, wherein
    The first signal is transmitted from two or more of the plurality of antennas at different timings,
    The communication device, wherein a time interval between a time point at which the first signal transmitted first is transmitted and a time point at which the first signal transmitted last is transmitted is shorter than the predetermined time period.
  4. 　アンテナと、
    　送受信部と、
    　制御部と
    を備え、
    　前記アンテナは第１の信号を受信し、前記第１の信号に応答する第２の信号を送信し、
    　前記制御部は前記第１の信号の送信元を示す情報を抽出し、前記第２の信号を前記情報を含めて生成し、
    　前記送受信部は前記第１の信号を受信した後、所定時間が経過してから前記第２の信号を前記アンテナに送信させる、通信装置。     An antenna,
    A transceiver
    And a control unit,
    The antenna receives a first signal and transmits a second signal responsive to the first signal,
    The control unit extracts information indicating a transmission source of the first signal, and generates the second signal including the information,
    The communication device, wherein the transmission / reception unit causes the antenna to transmit the second signal after a predetermined time elapses after receiving the first signal.
  5. 　請求項４に記載の通信装置であって、
    　最初に受信した前記第１の信号に応答して前記第２の信号を送信する、通信装置。     The communication device according to claim 4, wherein
    A communication device that transmits the second signal in response to the first signal received first.
PCT/JP2019/039476 2018-10-25 2019-10-07 Communication device WO2020085061A1 (en)

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