JP2011144624A - Communication-terminal position-determination device - Google Patents

Communication-terminal position-determination device Download PDF

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Publication number
JP2011144624A
JP2011144624A JP2010214427A JP2010214427A JP2011144624A JP 2011144624 A JP2011144624 A JP 2011144624A JP 2010214427 A JP2010214427 A JP 2010214427A JP 2010214427 A JP2010214427 A JP 2010214427A JP 2011144624 A JP2011144624 A JP 2011144624A
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Prior art keywords
magnetic field
electronic key
vehicle
antenna
field strength
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Hirokazu Itakura
広和 板倉
Katsuhide Kumagai
勝秀 熊谷
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Tokai Rika Co Ltd
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Tokai Rika Co Ltd
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Priority to JP2010214427A priority Critical patent/JP2011144624A/en
Priority to DE201110104230 priority patent/DE102011104230A1/en
Priority to CN201110172853XA priority patent/CN102419431A/en
Publication of JP2011144624A publication Critical patent/JP2011144624A/en
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    • 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
    • G01S11/00—Systems for determining distance or velocity not using reflection or reradiation
    • G01S11/02—Systems for determining distance or velocity not using reflection or reradiation using radio waves
    • G01S11/06—Systems for determining distance or velocity not using reflection or reradiation using radio waves using intensity measurements
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C23/00—Devices for measuring, signalling, controlling, or distributing tyre pressure or temperature, specially adapted for mounting on vehicles; Arrangement of tyre inflating devices on vehicles, e.g. of pumps or of tanks; Tyre cooling arrangements
    • B60C23/02—Signalling devices actuated by tyre pressure
    • B60C23/04—Signalling devices actuated by tyre pressure mounted on the wheel or tyre
    • B60C23/0408—Signalling devices actuated by tyre pressure mounted on the wheel or tyre transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver
    • B60C23/0415—Automatically identifying wheel mounted units, e.g. after replacement or exchange of wheels
    • B60C23/0416—Automatically identifying wheel mounted units, e.g. after replacement or exchange of wheels allocating a corresponding wheel position on vehicle, e.g. front/left or rear/right
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C23/00—Devices for measuring, signalling, controlling, or distributing tyre pressure or temperature, specially adapted for mounting on vehicles; Arrangement of tyre inflating devices on vehicles, e.g. of pumps or of tanks; Tyre cooling arrangements
    • B60C23/02—Signalling devices actuated by tyre pressure
    • B60C23/04—Signalling devices actuated by tyre pressure mounted on the wheel or tyre
    • B60C23/0408—Signalling devices actuated by tyre pressure mounted on the wheel or tyre transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver
    • B60C23/0422—Signalling devices actuated by tyre pressure mounted on the wheel or tyre transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver characterised by the type of signal transmission means
    • B60C23/0433—Radio signals
    • B60C23/0435—Vehicle body mounted circuits, e.g. transceiver or antenna fixed to central console, door, roof, mirror or fender
    • B60C23/0438—Vehicle body mounted circuits, e.g. transceiver or antenna fixed to central console, door, roof, mirror or fender comprising signal transmission means, e.g. for a bidirectional communication with a corresponding wheel mounted receiver
    • B60C23/044—Near field triggers, e.g. magnets or triggers with 125 KHz
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C23/00—Devices for measuring, signalling, controlling, or distributing tyre pressure or temperature, specially adapted for mounting on vehicles; Arrangement of tyre inflating devices on vehicles, e.g. of pumps or of tanks; Tyre cooling arrangements
    • B60C23/02—Signalling devices actuated by tyre pressure
    • B60C23/04—Signalling devices actuated by tyre pressure mounted on the wheel or tyre
    • B60C23/0408—Signalling devices actuated by tyre pressure mounted on the wheel or tyre transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver
    • B60C23/0422—Signalling devices actuated by tyre pressure mounted on the wheel or tyre transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver characterised by the type of signal transmission means
    • B60C23/0433—Radio signals
    • B60C23/0447—Wheel or tyre mounted circuits
    • B60C23/045—Means for detecting electromagnetic field changes being not part of the signal transmission per se, e.g. strength, direction, propagation or masking
    • 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
    • B60R25/245—Means to switch the anti-theft system on or off using electronic identifiers containing a code not memorised by the user where the antenna reception area plays a role
    • 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
    • G01S1/00—Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith
    • G01S1/02—Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith using radio waves
    • G01S1/08—Systems for determining direction or position line
    • G01S1/14—Systems for determining direction or position line using amplitude comparison of signals transmitted simultaneously from antennas or antenna systems having differently oriented overlapping directivity-characteristics
    • G—PHYSICS
    • G07—CHECKING-DEVICES
    • G07C—TIME OR ATTENDANCE REGISTERS; REGISTERING OR INDICATING THE WORKING OF MACHINES; GENERATING RANDOM NUMBERS; VOTING OR LOTTERY APPARATUS; ARRANGEMENTS, SYSTEMS OR APPARATUS FOR CHECKING NOT PROVIDED FOR ELSEWHERE
    • G07C9/00—Individual registration on entry or exit
    • G07C9/00174—Electronically operated locks; Circuits therefor; Nonmechanical keys therefor, e.g. passive or active electrical keys or other data carriers without mechanical keys
    • G07C9/00309—Electronically operated locks; Circuits therefor; Nonmechanical keys therefor, e.g. passive or active electrical keys or other data carriers without mechanical keys operated with bidirectional data transmission between data carrier and locks
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/27—Adaptation for use in or on movable bodies
    • H01Q1/32—Adaptation for use in or on road or rail vehicles
    • H01Q1/3208—Adaptation for use in or on road or rail vehicles characterised by the application wherein the antenna is used
    • H01Q1/3233—Adaptation for use in or on road or rail vehicles characterised by the application wherein the antenna is used particular used as part of a sensor or in a security system, e.g. for automotive radar, navigation systems
    • H01Q1/3241—Adaptation for use in or on road or rail vehicles characterised by the application wherein the antenna is used particular used as part of a sensor or in a security system, e.g. for automotive radar, navigation systems particular used in keyless entry systems
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q21/00—Antenna arrays or systems
    • H01Q21/29—Combinations of different interacting antenna units for giving a desired directional characteristic
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q7/00—Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
    • G—PHYSICS
    • G07—CHECKING-DEVICES
    • G07C—TIME OR ATTENDANCE REGISTERS; REGISTERING OR INDICATING THE WORKING OF MACHINES; GENERATING RANDOM NUMBERS; VOTING OR LOTTERY APPARATUS; ARRANGEMENTS, SYSTEMS OR APPARATUS FOR CHECKING NOT PROVIDED FOR ELSEWHERE
    • G07C2209/00—Indexing scheme relating to groups G07C9/00 - G07C9/38
    • G07C2209/60—Indexing scheme relating to groups G07C9/00174 - G07C9/00944
    • G07C2209/63—Comprising locating means for detecting the position of the data carrier, i.e. within the vehicle or within a certain distance from the vehicle

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  • Engineering & Computer Science (AREA)
  • Remote Sensing (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • Electromagnetism (AREA)
  • Computer Security & Cryptography (AREA)
  • Lock And Its Accessories (AREA)

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication-terminal position-determination device capable of detecting the position of a communication terminal more accurately. <P>SOLUTION: A magnetic-field-intensity calculation part 20 calculates the magnetic field intensity on a driver side when an electronic key 2 receives a radio wave from a driver-side antenna 11 and the magnetic field intensity on a front-seat-passenger-side when the electronic key 2 receives a radio wave from a front-seat-passenger-side antenna 13, and notifies a vehicle 1 of these calculated values of the magnetic field intensity. A coefficient multiplication part 23 multiplies the magnetic field intensity on the driver side by a coefficient, and also multiplies the magnetic field intensity on the front-seat-passenger-side by the coefficient. A position-determination part 24 calculates a difference in the magnetic field intensities multiplied by the coefficients, so as to determine the position of the electronic key 2 according to the difference in the magnetic field intensities. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

本発明は、通信端末（通信機）の位置を判定する通信端末位置判定装置に関する。   The present invention relates to a communication terminal position determination apparatus that determines the position of a communication terminal (communication device).

従来、車両キーとしての電子キーから無線によりＩＤコードを車両に送信してＩＤ照合を実行する電子キーシステムが広く使用されている。この電子キーシステムには、車両からＩＤコード返信要求としてリクエストを送信し、このリクエストに応答して電子キーが返信してきたＩＤコードによりＩＤ照合を行うキー操作スマートシステムがある。キー操作フリーシステムには、車外でＩＤ照合が成立すると、ドアロック施解錠が許可又は実行されるスマートエントリーシステムと、車内でＩＤ照合が成立すると、車内のエンジンスイッチの単なる押し操作のみでエンジン始動が可能となるワンプッシュエンジンスタートシステムとがある。   2. Description of the Related Art Conventionally, an electronic key system that performs ID collation by transmitting an ID code wirelessly from an electronic key as a vehicle key has been widely used. This electronic key system includes a key operation smart system that transmits a request as an ID code return request from a vehicle and performs ID collation using an ID code returned from the electronic key in response to the request. The key operation-free system includes a smart entry system in which door lock locking / unlocking is permitted or executed when ID verification is established outside the vehicle, and when the ID verification is established in the vehicle, the engine can be started simply by pressing the engine switch inside the vehicle. There is a one-push engine start system.

この電子キーシステムの一種には、図１０に示すように、車両８０の運転席ドア８１側（車体右側）にアンテナ８３を配置し、助手席ドア８２側（車体左側）にアンテナ８４を設置し、これらアンテナ８３，８４からの送信電波に対して電子キー８５が返してきた応答の論理判定によってキー位置を判定する技術（特許文献１，２等）が考案されている。この論理判定キー位置検出方式は、車体右側に設置された運転席アンテナ８３と、車体左側に設置された助手席アンテナ８４とから順にリクエストを送信して、運転席アンテナエリア８６と助手席アンテナエリア８７とを順に形成し、これらリクエストに対して電子キー８５が返信するＩＤコード、即ち応答の論理判定によってキー位置を判定する。   As shown in FIG. 10, the electronic key system includes an antenna 83 arranged on the driver's seat door 81 side (vehicle body right side) of the vehicle 80 and an antenna 84 installed on the passenger seat door 82 side (vehicle body left side). A technique (Patent Documents 1, 2, etc.) for determining the key position by logical determination of the response returned from the electronic key 85 to the radio waves transmitted from the antennas 83 and 84 has been devised. In this logical determination key position detection method, a request is transmitted in order from the driver's seat antenna 83 installed on the right side of the vehicle body and the passenger's seat antenna 84 installed on the left side of the vehicle body, and the driver's seat antenna area 86 and the passenger seat antenna area are transmitted. 87 are formed in order, and the key position is determined by the ID code returned by the electronic key 85 in response to these requests, that is, the logical determination of the response.

例えば、運転席アンテナ８３のリクエストに対して電子キー８５からの応答があり、助手席アンテナ８４のリクエストに対して電子キー８５から応答がないと、電子キー８５が車外に位置すると判定する。また、運転席アンテナ８３のリクエストに対して電子キー８５からの応答がなく、助手席アンテナ８４からのリクエストに対して電子キー８５の応答があれば、電子キー８５が車外に位置すると判定する。さらに、運転席アンテナ８３のリクエストと助手席アンテナ８４のリクエストとに対して両方とも応答があれば、電子キー８５が車内に位置していると判定する。   For example, if there is a response from the electronic key 85 to the request for the driver's seat antenna 83 and there is no response from the electronic key 85 to the request for the passenger seat antenna 84, it is determined that the electronic key 85 is located outside the vehicle. If there is no response from the electronic key 85 to the request from the driver's seat antenna 83 and there is a response from the electronic key 85 to the request from the passenger seat antenna 84, it is determined that the electronic key 85 is located outside the vehicle. Furthermore, if there is a response to both the request for the driver's seat antenna 83 and the request for the passenger's seat antenna 84, it is determined that the electronic key 85 is located in the vehicle.

図１０に示す論理判定キー位置検出方式は、車体右側と車体左側とに設けた一対のアンテナで車外と車内との両方の位置を見ることができる。よって、論理判定キー位置検出方式は、例えば車外アンテナとして各ドアにアンテナを設置しつつ、更に車内アンテナとして車内に複数のアンテナを設置して電子キーの位置を検出する場合に比べて、アンテナを車体の左右にのみ設置すればよい分だけ、アンテナ本数を少なく抑えることができる利点がある。   In the logic determination key position detection method shown in FIG. 10, the positions of both the outside and the inside of the vehicle can be seen with a pair of antennas provided on the right side and the left side of the vehicle. Therefore, the logical determination key position detection method is, for example, compared with the case where an antenna is installed at each door as an antenna outside the vehicle and a plurality of antennas are installed inside the vehicle as antennas inside the vehicle to detect the position of the electronic key. There is an advantage that the number of antennas can be reduced to the extent that it only needs to be installed on the left and right of the vehicle body.

特開２００４−８４４０６号公報JP 2004-84406 A 特開２００５−７６３２９号公報JP 2005-76329 A

ところで、論理判定キー位置検出方式は、少ないアンテナで車外又は車内を判定するため、アンテナエリア８６，８７を極力広くとらなければならない現状がある。しかし、アンテナエリア８６，８７を広くとると、図１１に示すように、アンテナ搭載側に対して反対側に電波が漏れて、漏れ通信エリア８８が形成されることがある。この場合、電子キー２が漏れ通信エリア８８に位置すると、電子キー２がアンテナ反対側に位置するにも拘らず、通信が成立してしまうので、電子キー２の位置が誤検出される。よって、これがドアロック施解錠の誤動作に繋がっていた。   By the way, in the logical determination key position detection method, there is a current situation where the antenna areas 86 and 87 must be made as wide as possible in order to determine whether the vehicle is outside or inside the vehicle with a small number of antennas. However, if the antenna areas 86 and 87 are widened, as shown in FIG. 11, radio waves may leak to the opposite side of the antenna mounting side, and a leaky communication area 88 may be formed. In this case, if the electronic key 2 is located in the leakage communication area 88, communication is established even though the electronic key 2 is located on the opposite side of the antenna, so that the position of the electronic key 2 is erroneously detected. Therefore, this led to a malfunction of door lock locking / unlocking.

なお、この問題は、電子キーシステムに限るものではなく、２者が無線により通信を行う種々のシステムでも同様に言えることである。
本発明の目的は、通信端末の位置をより精度よく検出することができる通信端末位置判定装置を提供することにある。 Note that this problem is not limited to the electronic key system, and can be similarly applied to various systems in which two parties communicate wirelessly.
The objective of this invention is providing the communication terminal position determination apparatus which can detect the position of a communication terminal more accurately.

前記問題点を解決するために、本発明では、通信マスタからの問い合せに通信端末が応答して、これらが双方向通信する無線システムに使用される通信端末位置判定装置において、前記通信マスタの一アンテナ及び他アンテナから交互に電波が送信された際、前記一アンテナからの電波を前記通信端末が受信した際の第１受信強度と、前記他アンテナからの電波を前記通信端末が受信した際の第２受信強度とを算出する受信強度算出手段と、２つの前記受信強度の少なくとも一方に、位置誤判定をキャンセルできる係数を乗算し、該乗算の後、２つの当該受信強度の差を算出し、この強度差を基に前記通信端末の位置を判定する位置判定手段とを備えたことを要旨とする。   In order to solve the above problems, in the present invention, a communication terminal responds to an inquiry from a communication master, and in a communication terminal position determination apparatus used in a wireless system in which these two-way communication is performed, When radio waves are alternately transmitted from the antenna and the other antenna, the first reception intensity when the communication terminal receives the radio wave from the one antenna and the radio terminal when the communication terminal receives the radio wave from the other antenna. A reception strength calculation means for calculating the second reception strength, a coefficient capable of canceling position error determination is multiplied by at least one of the two reception strengths, and after the multiplication, a difference between the two reception strengths is calculated. The gist of the present invention is that it comprises position determination means for determining the position of the communication terminal based on the intensity difference.

この構成によれば、一アンテナからの電波を通信端末が受信したときの受信強度と、他アンテナからの電波を通信端末が受信したときの受信強度との強度差を算出する際、受信強度に計数を乗算してから強度差を算出し、係数乗算を経た後の強度差に基づき、通信マスタに対する通信端末の位置を判定する。ところで、もし２つの受信強度を単にそのまま引いて強度差を算出し、この強度差で以て通信端末を位置判定しただけでは、正しく位置を判定できないエリア（誤判定エリア）が生じてしまい、位置を正確に判定できない可能性が生じ得る。しかし、本構成のように、係数乗算を経てから強度差を算出するようにすれば、誤判定エリアがキャンセルされるので、より正確に通信端末の位置を判定することが可能となる。   According to this configuration, when calculating the intensity difference between the reception intensity when the communication terminal receives a radio wave from one antenna and the reception intensity when the communication terminal receives a radio wave from another antenna, the reception intensity is calculated. The strength difference is calculated after multiplying the count, and the position of the communication terminal with respect to the communication master is determined based on the strength difference after the coefficient multiplication. By the way, if the intensity difference is calculated by simply subtracting the two received intensities, and the communication terminal is determined based on the intensity difference, an area where the position cannot be correctly determined (an erroneous determination area) is generated. May not be accurately determined. However, if the intensity difference is calculated after the coefficient multiplication as in this configuration, the erroneous determination area is canceled, so that the position of the communication terminal can be determined more accurately.

本発明では、前記通信マスタのアンテナは、少なくとも３つ以上設けられ、前記位置判定手段は、少なくとも３つ以上設けた前記アンテナにおいて、各々の２つずつを組みとして該組み同士の前記強度差を算出し、当該強度差から前記通信端末の位置を細分して判定することを要旨とする。   In the present invention, at least three or more antennas of the communication master are provided, and the position determination means is configured to calculate the intensity difference between the two sets of each of the antennas provided at least three or more. The gist is to calculate and subdivide the position of the communication terminal from the intensity difference.

この構成によれば、例えば通信マスタに３つのアンテナが設置された場合、これらアンテナを第１アンテナ、第２アンテナ、第３アンテナとすると、第１アンテナ及び第２アンテナを組みとして、通信端末がどちら側にあるのかを判定し、また第１アンテナ及び第３アンテナを組みとして、通信端末がどちら側にあるのかを判定し、さらに第２アンテナ及び第３アンテナを組として、通信端末がどちら側にあるのかを判定することが可能となる。よって、通信端末の位置をより細分化して見ることが可能となるので、より精度よく通信端末の位置を判定することが可能となる。   According to this configuration, for example, when three antennas are installed in the communication master, when these antennas are defined as the first antenna, the second antenna, and the third antenna, the first antenna and the second antenna are combined, and the communication terminal Determine which side is, and determine which side is the communication terminal with the first antenna and the third antenna as a set, and further determine which side the communication terminal is with the second antenna and the third antenna as a set. It is possible to determine whether or not Therefore, since the position of the communication terminal can be viewed in more detail, the position of the communication terminal can be determined with higher accuracy.

本発明では、前記通信端末は、電子キーであり、前記無線システムは、前記通信マスタが前記電子キーとＩＤ照合する電子キーシステムであり、前記位置判定手段は、前記電子キーの位置を判定することを要旨とする。
この構成によれば、電子キーの位置を精度よく判定することが可能となる。 In the present invention, the communication terminal is an electronic key, the wireless system is an electronic key system in which the communication master performs ID verification with the electronic key, and the position determination unit determines the position of the electronic key. This is the gist.
According to this configuration, the position of the electronic key can be accurately determined.

本発明では、前記通信端末は、車両の各タイヤに取り付けられたタイヤ通信機であり、前記無線システムは、前記タイヤ通信機からタイヤ空気圧を無線により取得するタイヤ空気圧監視システムであり、前記位置判定手段は、前記タイヤ通信機の位置を判定することにより、タイヤの位置を特定することを要旨とする。
この構成によれば、通信成立したタイヤ通信機がどのタイヤに設置されたものなのかを、精度よく判定することが可能となる。 In the present invention, the communication terminal is a tire communication device attached to each tire of a vehicle, and the wireless system is a tire pressure monitoring system that wirelessly acquires tire pressure from the tire communication device, and the position determination The means is to determine the position of the tire by determining the position of the tire communication device.
According to this configuration, it is possible to accurately determine in which tire the tire communication device for which communication has been established is installed.

本発明では、前記通信端末としての電子キーとＩＤ照合する前記無線システムとしての電子キーシステムと、前記通信端末としてのタイヤ通信機から無線によりタイヤ空気圧を取得する前記無線システムとしてのタイヤ空気圧監視システムとは、１つの前記通信マスタを共用することを要旨とする。   In the present invention, an electronic key system as the wireless system that collates ID with the electronic key as the communication terminal, and a tire pressure monitoring system as the wireless system that acquires tire pressure wirelessly from a tire communication device as the communication terminal The gist is to share one communication master.

この構成によれば、共通の部品を電子キーシステムとタイヤ空気圧監視システムとの両方で使用することが可能となるので、部品点数を削減することが可能となる。   According to this configuration, common parts can be used in both the electronic key system and the tire pressure monitoring system, so that the number of parts can be reduced.

本発明によれば、通信端末の位置をより精度よく検出することができる。   According to the present invention, the position of a communication terminal can be detected with higher accuracy.

第１実施形態におけるキー操作フリーシステムの概略構成を示すブロック図。The block diagram which shows schematic structure of the key operation free system in 1st Embodiment. 車両のアンテナエリアのイメージを示す概念図。The conceptual diagram which shows the image of the antenna area of a vehicle. （ａ）は電子キーが運転席側車外に位置する状態を示す概念図、（ｂ）は電子キーが助手席側車外に位置する状態を示す概念図、（ｃ）は電子キーが車内に位置する状態を示す概念図。(A) is a conceptual diagram showing a state in which the electronic key is located outside the driver's seat side vehicle, (b) is a conceptual diagram showing a state in which the electronic key is located outside the passenger seat side vehicle, and (c) is a diagram showing the electronic key being located in the vehicle. The conceptual diagram which shows the state to do. 磁界強度差から求まるキー位置判定のための見かけ上の判定エリアを示す概念図。The conceptual diagram which shows the apparent determination area for the key position determination calculated | required from a magnetic field intensity difference. （ａ）は判定エリアに誤判定エリアが含まれた状態を示す磁界強度のマップ図、（ｂ）は判定エリアから誤判定エリアがキャンセルされた状態を示す磁界強度マップ図。(A) is a magnetic field strength map showing a state in which an erroneous determination area is included in the determination area, and (b) is a magnetic field strength map showing a state in which the erroneous determination area is canceled from the determination area. スマート通信の通信シーケンスを示すタイミングチャート。The timing chart which shows the communication sequence of smart communication. 第２実施形態における判定エリアの形成分布を示す概念図。The conceptual diagram which shows the formation distribution of the determination area in 2nd Embodiment. 第３実施形態におけるタイヤ空気圧監視システムの概念図。The conceptual diagram of the tire pressure monitoring system in 3rd Embodiment. タイヤ空気圧監視システムの具体的動作を示す表。The table | surface which shows the specific operation | movement of a tire pressure monitoring system. 従来における電子キーシステムの概略構成を示す模式図。The schematic diagram which shows schematic structure of the conventional electronic key system. 車両にアンテナの漏れエリアが形成された状態を示す模式図。The schematic diagram which shows the state in which the leak area of the antenna was formed in the vehicle.

（第１実施形態）
以下、本発明を具体化した通信端末位置判定装置の第１実施形態を図１〜図６に従って説明する。 (First embodiment)
Hereinafter, a first embodiment of a communication terminal position determination device embodying the present invention will be described with reference to FIGS.

図１及び図２に示すように、車両１には、無線によりキー照合を行う電子キーシステムの一種として、電子キー２が車両１に近づくと自動でＩＤ（Identification）照合を実行するキー操作フリーシステム３が設けられている。このキー操作フリーシステム３には、実際のキー操作を行うことなくドア開閉の一連の操作過程の中でドアロックの施解錠が実行されるスマートエントリーシステムと、車内に設置されたプッシュ式のエンジンスイッチ４を押し操作するのみでエンジンを始動することが可能なワンプッシュエンジンスタートシステムとがある。なお、電子キー２が通信端末を構成し、キー操作フリーシステム３が無線システム及び電子キーシステムを構成する。   As shown in FIG. 1 and FIG. 2, the vehicle 1 is a kind of electronic key system that performs wireless key verification. As the electronic key 2 approaches the vehicle 1, ID (Identification) verification is automatically performed. A system 3 is provided. This key operation free system 3 includes a smart entry system in which a door lock is unlocked and unlocked in a series of door opening and closing operations without actually performing a key operation, and a push type engine installed in the vehicle. There is a one-push engine start system that can start the engine only by pressing the switch 4. The electronic key 2 constitutes a communication terminal, and the key operation free system 3 constitutes a wireless system and an electronic key system.

この場合、車両１には、電子キー２との間でＩＤ照合を実行するキー照合装置５と、ドアロック動作を管理するドアロック装置６と、エンジンの動作を管理するエンジン始動装置７とが設けられ、これらが車内バス８によって接続されている。キー照合装置５には、同装置５のコントロールユニットとして照合ＥＣＵ（Electronic Control Unit）９が設
けられている。照合ＥＣＵ９のメモリ（図示略）には、車両１と組みをなす電子キー２のＩＤコードが登録されている。 In this case, the vehicle 1 includes a key verification device 5 that performs ID verification with the electronic key 2, a door lock device 6 that manages a door lock operation, and an engine start device 7 that manages the operation of the engine. These are provided and connected by an in-vehicle bus 8. The key verification device 5 is provided with a verification ECU (Electronic Control Unit) 9 as a control unit of the device 5. In the memory (not shown) of the verification ECU 9, the ID code of the electronic key 2 that forms a pair with the vehicle 1 is registered.

照合ＥＣＵ９には、運転席ドア１０（図２参照）の周囲にＬＦ（Low Frequency）帯の電波を発信する運転席側車外発信機（以降、運転席アンテナ１１と記す）と、助手席ドア１２（図２参照）の周囲にＬＦ帯の電波を発信する助手席側車外発信機（以降、助手席アンテナ１３と記す）と、ＵＨＦ（Ultra High Frequency）帯の電波を受信する車両チューナ１４とが接続されている。これらアンテナ１１，１３は、例えば車体左右のピラーにそれぞれ設けられ、電子キー２に対するＩＤ返信要求としてリクエスト信号Ｓrqを送信可能となっている。なお、照合ＥＣＵ９が通信マスタに相当する。   The verification ECU 9 includes a driver-side vehicle-side transmitter (hereinafter referred to as a driver-seat antenna 11) that transmits radio waves in the LF (Low Frequency) band around the driver-seat door 10 (see FIG. 2), and a passenger-seat door 12 (See FIG. 2) A passenger-side outside transmitter (hereinafter referred to as a passenger seat antenna 13) that transmits LF band radio waves and a vehicle tuner 14 that receives UHF (Ultra High Frequency) band radio waves. It is connected. These antennas 11 and 13 are provided, for example, on the left and right pillars of the vehicle body, respectively, and can transmit a request signal Srq as an ID reply request to the electronic key 2. The verification ECU 9 corresponds to a communication master.

図２に示すように、運転席アンテナ１１は、運転席側車外及び車内に通信エリア（運転席アンテナエリアＫｄ）を形成する送信強度で電波送信する。助手席アンテナ１３は、助手席側車外及び車内に通信エリア（助手席アンテナエリアＫｐ）を形成する送信強度で電波送信する。本例の場合、電子キー２の基本的な位置判定として、運転席アンテナ１１からの電波を電子キー２が強く受信する際、電子キー２の位置が運転席側車外と判定され、助手席アンテナ１３からの電波を電子キー２が強く受信する際、電子キー２の位置が運転席側車外と判定される。また、運転席アンテナ１１からの電波と、助手席アンテナ１３からの電波とを、同程度の強さで受信する際、電子キー２の位置が車内と判定される。なお、アンテナ１１，１３が一アンテナ及び他アンテナを構成する。   As shown in FIG. 2, the driver's seat antenna 11 transmits a radio wave with a transmission intensity that forms a communication area (driver's seat antenna area Kd) outside and inside the driver's seat. The passenger seat antenna 13 transmits radio waves at a transmission intensity that forms a communication area (passenger seat antenna area Kp) outside and inside the passenger seat side vehicle. In the case of this example, as a basic position determination of the electronic key 2, when the electronic key 2 strongly receives a radio wave from the driver's seat antenna 11, the position of the electronic key 2 is determined to be outside the driver's seat side vehicle, and the passenger's seat antenna When the electronic key 2 strongly receives the radio wave from 13, the position of the electronic key 2 is determined to be outside the driver's seat side vehicle. Further, when the radio wave from the driver's seat antenna 11 and the radio wave from the passenger seat antenna 13 are received with the same strength, the position of the electronic key 2 is determined to be in the vehicle. The antennas 11 and 13 constitute one antenna and another antenna.

図１に示すように、電子キー２には、電子キー２の動作を統括制御する通信制御部１５が設けられている。通信制御部１５のメモリ（図示略）には、キー固有のＩＤとしてＩＤコードが登録されている。通信制御部１５には、ＬＦ帯の電波を受信可能なＬＦ受信機１６と、ＵＨＦ帯の電波を送信可能なＵＨＦ送信機１７とが接続されている。ＬＦ受信機１６は、Ｘ軸アンテナとＹ軸アンテナとＺ軸アンテナとを備えた３軸受信アンテナであって、各アンテナがコイルアンテナにより形成されている。電子キー２は、ＬＦ受信機１６でリクエスト信号Ｓrqを受信すると、ＩＤコードを含むＩＤ信号ＳidをＵＨＦ送信機１７によりＵＨＦ帯の電波で送信する。   As shown in FIG. 1, the electronic key 2 is provided with a communication control unit 15 that performs overall control of the operation of the electronic key 2. An ID code is registered in the memory (not shown) of the communication control unit 15 as an ID unique to the key. The communication control unit 15 is connected to an LF receiver 16 capable of receiving LF band radio waves and a UHF transmitter 17 capable of transmitting UHF band radio waves. The LF receiver 16 is a three-axis receiving antenna including an X-axis antenna, a Y-axis antenna, and a Z-axis antenna, and each antenna is formed by a coil antenna. When the electronic key 2 receives the request signal Srq by the LF receiver 16, the electronic signal 2 transmits the ID signal Sid including the ID code by the UHF transmitter 17 using radio waves in the UHF band.

照合ＥＣＵ９は、リクエスト信号Ｓrqに対する応答として電子キー２からＩＤ信号Ｓidを受信すると、ＩＤ照合としてスマート照合を実行する。照合ＥＣＵ９は、車外の電子キー２とスマート照合、即ち車外照合が成立することを確認すると、ドアロック装置６によるドアロック施解錠を実行又は許可する。また、照合ＥＣＵ９は、車内の電子キー２とスマート照合、即ち車内照合が成立することを確認すると、エンジンスイッチ４のプッシュ操作によるエンジン始動及び電源遷移を許可する。   When the verification ECU 9 receives the ID signal Sid from the electronic key 2 as a response to the request signal Srq, the verification ECU 9 executes smart verification as ID verification. When the collation ECU 9 confirms that smart collation with the electronic key 2 outside the vehicle, that is, collation outside the vehicle, is established, the door lock device 6 performs door lock / unlock operation or permits. Further, the verification ECU 9 permits the engine start and the power supply transition by the push operation of the engine switch 4 when confirming that the smart verification with the electronic key 2 in the vehicle, that is, the vehicle verification, is established.

図１に示すように、本例のキー操作フリーシステム３には、運転席アンテナ１１からの電波を電子キー２が受信したときと、助手席アンテナ１３からの電波を電子キー２が受信したときとの磁界強度差Ｈdpを算出し、この磁界強度差Ｈdpから電子キー２の位置を判定する位置判定装置１８が設けられている。位置判定装置１８は、運転席アンテナ１１からのリクエスト信号Ｓrqを電子キー２が受信したときの磁界強度（運転席側磁界強度Ｈｄ）と、助手席アンテナ１３からのリクエスト信号Ｓrqを電子キー２が受信したときの磁界強度（助手席側磁界強度Ｈｐ）との磁界強度差（磁界強度差Ｈdp）を算出し、この磁界強度差Ｈdpからキー位置を判定する。また、本例の位置判定装置１８は、これら磁界強度Ｈｄ，Ｈｐに、キー位置の誤判定をキャンセルできる係数α，βを乗算して、その乗算後の磁界強度Ｈｄ，Ｈｐから磁界強度差Ｈdpを算出する。なお、運転席側磁界強度Ｈｄ及び助手席側磁界強度Ｈｐが第１受信強度及び第２受信強度を構成する。   As shown in FIG. 1, in the key operation free system 3 of this example, when the electronic key 2 receives the radio wave from the driver's seat antenna 11 and when the electronic key 2 receives the radio wave from the passenger seat antenna 13. Is provided, and a position determination device 18 for determining the position of the electronic key 2 from the magnetic field strength difference Hdp is provided. The position determination device 18 uses the electronic key 2 to receive the request signal Srq from the driver's seat antenna 11 by the electronic key 2 and the request signal Srq from the passenger seat antenna 13 by the electronic key 2. The magnetic field strength difference (magnetic field strength difference Hdp) from the received magnetic field strength (passenger side magnetic field strength Hp) is calculated, and the key position is determined from this magnetic field strength difference Hdp. Further, the position determination device 18 of the present example multiplies the magnetic field strengths Hd and Hp by coefficients α and β that can cancel erroneous determination of the key position, and the magnetic field strength difference Hdp from the multiplied magnetic field strengths Hd and Hp. Is calculated. The driver's seat side magnetic field strength Hd and the passenger seat side magnetic field strength Hp constitute the first reception strength and the second reception strength.

この場合、照合ＥＣＵ９には、一対の運転席アンテナ１１及び助手席アンテナ１３を交互に電波送信させる交互送信動作部１９が設けられている。交互送信動作部１９は、例えば車両１が終車状態の際や、車外ドアハンドルノブのロックボタンが押されて施錠操作された際、これらアンテナ１１，１３からリクエスト信号Ｓrqを交互送信して車外通信を開始する。また、交互送信動作部１９は、例えばカーテシスイッチ等により運転者の乗車を確認すると、このときもアンテナ１１，１３からリクエスト信号Ｓrqを交互送信して車内通信を開始する。   In this case, the verification ECU 9 is provided with an alternate transmission operation unit 19 that alternately transmits radio waves to the pair of driver seat antennas 11 and the passenger seat antenna 13. The alternate transmission operation unit 19 alternately transmits request signals Srq from these antennas 11 and 13 when the vehicle 1 is in an end state, or when the lock button of the door handle knob on the outside of the vehicle is pushed and locked. To start. Further, when the alternate transmission operation unit 19 confirms the ride of the driver by, for example, a courtesy switch or the like, the request signal Srq is alternately transmitted from the antennas 11 and 13 at this time to start in-vehicle communication.

通信制御部１５には、電子キー２で受信した電波の受信強度（RSSI：Received Signal Strength Indicator）を、磁界強度Ｈｘとして算出する磁界強度算出部２０が設けられている。磁界強度算出部２０は、運転席アンテナ１１からのリクエスト信号Ｓrqを電子キー２で受信した際、このときの磁界強度Ｈｘを運転席側磁界強度Ｈｄとして算出し、助手席アンテナ１３からのリクエスト信号Ｓrqを電子キー２で受信した際、このときの磁界強度Ｈｘを助手席側磁界強度Ｈｐとして算出する。また、磁界強度算出部２０は、ＬＦ受信機１６（３軸アンテナ）の３軸の受信強度のベクトル合成値を使用して、これら磁界強度Ｈｄ，Ｈｐを算出する。なお、磁界強度算出部２０が受信強度算出手段を構成する。   The communication control unit 15 is provided with a magnetic field strength calculation unit 20 that calculates a received signal strength indicator (RSSI) received by the electronic key 2 as a magnetic field strength Hx. When the request signal Srq from the driver's seat antenna 11 is received by the electronic key 2, the magnetic field strength calculation unit 20 calculates the magnetic field strength Hx at this time as the driver's seat side magnetic field strength Hd, and the request signal from the passenger seat antenna 13. When Srq is received by the electronic key 2, the magnetic field strength Hx at this time is calculated as the passenger seat side magnetic field strength Hp. Further, the magnetic field strength calculation unit 20 calculates the magnetic field strengths Hd and Hp by using the vector composite value of the three-axis reception strengths of the LF receiver 16 (three-axis antenna). The magnetic field strength calculation unit 20 constitutes reception strength calculation means.

通信制御部１５には、電子キー２で受信した磁界強度Ｈｄ，Ｈｐをスマート通信の過程で車両１に通知する磁界強度通知部２１が設けられている。磁界強度通知部２１は、電子キー２がリクエスト信号Ｓrqに応答してＩＤ信号Ｓidを車両１に送信する際、このＩＤ信号Ｓidに磁界強度Ｈｘのデータを含ませて送信する。即ち、ＩＤ信号Ｓidには、電子キー２のＩＤコードと、磁界強度Ｈｘのデータ（デジタル値）とが含まれている。磁界強度通知部２１は、運転席アンテナ１１からのリクエスト信号Ｓrqに応答してＩＤ信号Ｓidを返信する際、このＩＤ信号Ｓidに運転席側磁界強度Ｈｄを乗せて車両１に通知し、助手席アンテナ１３からのリクエスト信号Ｓrqに応答してＩＤ信号Ｓidを返信する際、このＩＤ信号Ｓidに助手席側磁界強度Ｈｐを乗せて車両１に通知する。なお、磁界強度通知部２１が受信強度算出手段を構成する。   The communication control unit 15 is provided with a magnetic field strength notification unit 21 that notifies the vehicle 1 of the magnetic field strengths Hd and Hp received by the electronic key 2 in the process of smart communication. When the electronic key 2 transmits the ID signal Sid to the vehicle 1 in response to the request signal Srq, the magnetic field strength notification unit 21 transmits the ID signal Sid including the data of the magnetic field strength Hx. That is, the ID signal Sid includes the ID code of the electronic key 2 and the data (digital value) of the magnetic field strength Hx. When returning the ID signal Sid in response to the request signal Srq from the driver's seat antenna 11, the magnetic field strength notifying unit 21 notifies the vehicle 1 by putting the driver's seat side magnetic field strength Hd on the ID signal Sid, and the passenger seat. When the ID signal Sid is returned in response to the request signal Srq from the antenna 13, the passenger's seat side magnetic field strength Hp is put on the ID signal Sid and notified to the vehicle 1. The magnetic field strength notification unit 21 constitutes reception strength calculation means.

照合ＥＣＵ９には、スマート通信の際に電子キー２から磁界強度Ｈxを取得する磁界強
度取得部２２が設けられている。磁界強度取得部２２は、スマート通信の際、ＩＤ信号Ｓidに含まれる磁界強度Ｈｘを参照して、磁界強度Ｈｘを取得する。磁界強度取得部２２は、運転席アンテナ１１を車両送信アンテナとして使用したときの運転席側磁界強度Ｈｄと、助手席アンテナ１３を車両送信アンテナとして使用したときの助手席側磁界強度Ｈｐとを取得する。なお、磁界強度取得部２２が受信強度算出手段を構成する。 The verification ECU 9 is provided with a magnetic field strength acquisition unit 22 that acquires the magnetic field strength Hx from the electronic key 2 during smart communication. The magnetic field strength acquisition unit 22 refers to the magnetic field strength Hx included in the ID signal Sid and acquires the magnetic field strength Hx during smart communication. The magnetic field strength acquisition unit 22 acquires a driver seat side magnetic field strength Hd when the driver seat antenna 11 is used as a vehicle transmission antenna and a passenger seat side magnetic field strength Hp when the passenger seat antenna 13 is used as a vehicle transmission antenna. To do. The magnetic field strength acquisition unit 22 constitutes reception strength calculation means.

ところで、図３（ａ）に示すように、電子キー２が運転席側車外に位置したり、或いは図３（ｂ）に示すように、電子キー２が助手席側車外に位置したりする場合、電子キー２は、運転席アンテナ１１及び助手席アンテナ１３のうち、一方側に極端に近づく。このため、結果として、運転席側磁界強度Ｈｄ及び助手席側磁界強度Ｈｐは、一方が他方に対して極端に高い値をとるので、運転席側磁界強度Ｈｄと助手席側磁界強度Ｈｐとの磁界強度差Ｈdpは、高い値をとるはずである。よって、車内外判定の基準値である判定閾値Ｈｋより磁界強度差Ｈdpが高くなることが確認できれば、電子キー２が車外に位置することが分かる。   By the way, as shown in FIG. 3A, the electronic key 2 is located outside the driver's seat side vehicle, or as shown in FIG. 3B, the electronic key 2 is located outside the passenger seat side vehicle. The electronic key 2 is extremely close to one side of the driver seat antenna 11 and the passenger seat antenna 13. For this reason, as a result, the driver's seat side magnetic field strength Hd and the passenger seat side magnetic field strength Hp have extremely high values with respect to the other, so that the driver seat side magnetic field strength Hd and the passenger seat side magnetic field strength Hp The magnetic field strength difference Hdp should take a high value. Therefore, if it can be confirmed that the magnetic field strength difference Hdp is higher than the determination threshold value Hk, which is a reference value for determining the inside / outside of the vehicle, it can be understood that the electronic key 2 is located outside the vehicle.

一方、図３（ｃ）に示すように、電子キー２が車内に位置する場合、電子キー２は、運転席アンテナ１１と助手席アンテナ１３とに対して、ほぼ均等に近づく。このため、結果として、運転席側磁界強度Ｈｄと助手席側磁界強度Ｈｐは、互いに似た様な値に落ち着くので、磁界強度差Ｈdpは低い値をとるはずである。よって、磁界強度差Ｈdpが判定閾値Ｈｋよりも低くなることが確認できれば、電子キー２が車内に位置することが分かる。   On the other hand, as shown in FIG. 3C, when the electronic key 2 is located in the vehicle, the electronic key 2 approaches the driver seat antenna 11 and the passenger seat antenna 13 almost equally. Therefore, as a result, the driver's seat side magnetic field strength Hd and the passenger seat side magnetic field strength Hp settle to values similar to each other, so that the magnetic field strength difference Hdp should take a low value. Therefore, if it can be confirmed that the magnetic field strength difference Hdp is lower than the determination threshold value Hk, it can be seen that the electronic key 2 is located in the vehicle.

ここで、磁界強度差Ｈdpが判定閾値Ｈｋよりも高くなる点をプロットしていくと、このプロット点の集まりは、図４に示すように、電子キー２が車外に位置すると割り出すことが可能な見かけ上の判定エリアＥとして表すことができる。この判定エリアＥは、磁界強度差Ｈdpの正負を考慮に入れずに見ると、運転席側及び助手席側の両側に一対形成される。よって、磁界強度差Ｈdpが判定閾値Ｈｋよりも高い場合、電子キー２が判定エリアＥの中のいずれかの場所に位置し、結果として電子キー２が車両１の近くに存在すること分かる。   Here, if the points where the magnetic field strength difference Hdp is higher than the determination threshold value Hk are plotted, the set of plotted points can be determined when the electronic key 2 is located outside the vehicle as shown in FIG. It can be expressed as an apparent determination area E. A pair of determination areas E are formed on both sides of the driver's seat and the passenger's seat when viewed without considering the positive / negative magnetic field strength difference Hdp. Therefore, when the magnetic field strength difference Hdp is higher than the determination threshold value Hk, it can be seen that the electronic key 2 is located anywhere in the determination area E, and as a result, the electronic key 2 exists near the vehicle 1.

さらに、磁界強度差Ｈdpを正負で区分けして見れば、これら一対の判定エリアＥ，Ｅのうち、どちらに位置しているのかも分かる。ところで、磁界強度差Ｈdpは、運転席側判定エリアＥｄと、助手席側判定エリアＥｐとで正負が逆転する値として割り出される。よって、磁界強度差Ｈdpを正負まで考慮に入れて見れば、それは即ち、電子キー２が運転席側に位置するのか、或いは助手席側に位置するのかが分かることになる。よって、例えば判定閾値Ｈｋを正値（＋Ｈｋ）として、磁界強度差Ｈdpが＋Ｈｋよりも高い値をとっていれば、電子キー２が運転席側判定エリアＥｄ、即ち運転席側車外に位置することが分かる。また、逆に、判定閾値Ｈｋを負値（−Ｈｋ）として、磁界強度差Ｈdpが−Ｈｋよりも低い値をとっていれば、電子キー２が助手席側判定エリアＥｐ、即ち助手席側車外に位置することが分かる。   Further, if the magnetic field intensity difference Hdp is divided into positive and negative, it can be determined which of the pair of determination areas E and E is located. By the way, the magnetic field strength difference Hdp is calculated as a value in which the sign is reversed between the driver seat side determination area Ed and the passenger seat side determination area Ep. Therefore, if the magnetic field strength difference Hdp is taken into consideration up to the positive and negative, it can be seen whether the electronic key 2 is located on the driver's seat side or the passenger's seat side. Therefore, for example, if the determination threshold value Hk is a positive value (+ Hk) and the magnetic field strength difference Hdp is higher than + Hk, the electronic key 2 is positioned outside the driver seat side determination area Ed, that is, the driver seat side vehicle. I understand. Conversely, if the determination threshold value Hk is a negative value (−Hk) and the magnetic field strength difference Hdp is lower than −Hk, the electronic key 2 is in the passenger seat side determination area Ep, that is, the passenger seat side outside the vehicle. It can be seen that

ところで、例えば単に運転席側磁界強度Ｈｄから助手席側磁界強度Ｈｐを引いて算出した磁界強度差Ｈdpで、判定閾値Ｈｋとの比較判定を行うと、場合によっては、図５（ａ）に示すように、アンテナ搭載側と反対側にも判定エリア（誤判定エリアＥer）が形成されてしまう可能性がある。これは、各アンテナ１１，１３の通信エリアを細かく設定しようとしても、設定には限界があり、どうしても電波漏れが発生してしまうためである。この場合、もし仮に電子キー２が誤判定エリアＥerに位置してしまうと、電子キー２が運転席側車外に無いにも拘らず、運転席側車外に位置すると誤判定される問題に繋がる。   By the way, for example, when the magnetic field strength difference Hdp calculated by simply subtracting the passenger-side magnetic field strength Hp from the driver-seat-side magnetic field strength Hd is compared with the determination threshold value Hk, in some cases, as shown in FIG. Thus, there is a possibility that a determination area (erroneous determination area Eer) may be formed on the side opposite to the antenna mounting side. This is because even if the communication areas of the antennas 11 and 13 are to be set finely, there is a limit to the setting, and radio wave leakage inevitably occurs. In this case, if the electronic key 2 is positioned in the misjudgment area Eer, it is erroneously determined that the electronic key 2 is located outside the driver's seat side vehicle even though the electronic key 2 is not located outside the driver's seat side vehicle.

ここで、磁界強度Ｈｄ，Ｈｐに係数を乗算してから磁界強度差Ｈdpを算出し、この磁界強度差Ｈdpと判定閾値Ｈｋとを比較する判定形式を採用すると、図５（ｂ）に示すように、係数の分だけ判定エリアＥが縮小し、結果として誤判定エリアＥerをキャンセルできることが分かる。これは、磁界強度Ｈｄ，Ｈｐに係数を乗算することによって、見かけ上、判定エリアＥが小さくなるからである。よって、本例の位置判定装置１８は、磁界強度Ｈｄ，Ｈｐに係数を乗算してから算出した磁界強度差Ｈdpで判定閾値Ｈｋとの比較判定を行うと、誤判定エリアＥerをキャンセルできることを利用して、電子キー２の位置判定を行う。   Here, when a magnetic field strength difference Hdp is calculated after multiplying the magnetic field strengths Hd and Hp by a coefficient, and a determination format for comparing the magnetic field strength difference Hdp with the determination threshold value Hk is adopted, as shown in FIG. In addition, it can be seen that the determination area E is reduced by the coefficient, and as a result, the erroneous determination area Eer can be canceled. This is because the judgment area E is apparently reduced by multiplying the magnetic field strengths Hd and Hp by a coefficient. Therefore, the position determination device 18 of this example utilizes the fact that the erroneous determination area Eer can be canceled by performing a comparison determination with the determination threshold value Hk using the magnetic field strength difference Hdp calculated after multiplying the magnetic field strengths Hd and Hp by a coefficient. Then, the position of the electronic key 2 is determined.

本例の場合、図１に示すように、照合ＥＣＵ９には、運転席側磁界強度Ｈｄと助手席側磁界強度Ｈｐとに係数α，βを乗算する係数乗算部２３が設けられている。係数乗算部２３は、運転席側磁界強度Ｈｄに係数αを乗算するとともに、助手席側磁界強度Ｈｐに係数βを乗算する。係数α，βは、本例の位置判定装置１８が搭載される車両１に応じて、適宜設定される値である。なお、係数乗算部２３が位置判定手段を構成する。   In the case of this example, as shown in FIG. 1, the verification ECU 9 is provided with a coefficient multiplier 23 that multiplies the driver seat side magnetic field strength Hd and the passenger seat side magnetic field strength Hp by the coefficients α and β. The coefficient multiplying unit 23 multiplies the driver seat side magnetic field strength Hd by a factor α and also multiplies the passenger seat side magnetic field strength Hp by a factor β. The coefficients α and β are values that are appropriately set according to the vehicle 1 on which the position determination device 18 of this example is mounted. The coefficient multiplier 23 constitutes a position determination unit.

照合ＥＣＵ９には、係数乗算を経て算出された磁界強度差Ｈdpと判定閾値Ｈｋとの比較結果を基に、電子キー２の位置を判定する位置判定部２４が設けられている。本例の位置判定部２４は、係数乗算後の運転席側磁界強度Ｈｄと、係数除算後の助手席側磁界強度Ｈｐとの差（α×Ｈｄ−β×Ｈｐ）を磁界強度差Ｈdpとして算出する。そして、位置判定部２４は、この磁界強度差Ｈdpと判定閾値Ｈｋとを比較して、電子キー２が車外及び車内のどちらに位置しているのかを判定する。判定閾値Ｈｋは、電子キー２を車内外判定する際の基準になる値であって、例えば実測により定義付けられる。なお、位置判定部２４が位置判定手段を構成する。   The verification ECU 9 is provided with a position determination unit 24 that determines the position of the electronic key 2 based on the comparison result between the magnetic field strength difference Hdp calculated through coefficient multiplication and the determination threshold value Hk. The position determination unit 24 of this example calculates the difference (α × Hd−β × Hp) between the driver-side magnetic field strength Hd after the coefficient multiplication and the passenger-side magnetic field strength Hp after the coefficient division as the magnetic field strength difference Hdp. To do. Then, the position determination unit 24 compares the magnetic field strength difference Hdp and the determination threshold value Hk to determine whether the electronic key 2 is located outside the vehicle or inside the vehicle. The determination threshold value Hk is a reference value for determining whether the electronic key 2 is inside or outside the vehicle, and is defined by actual measurement, for example. The position determination unit 24 constitutes a position determination unit.

ここで、電子キー２が運転席側車外にあるか否かを見る式を第１判定式とし、電子キー２が助手席側車外にあるか否かを見る式を第２判定式とすると、これら判定式は、次式により表される。
第１判定式：（α×Ｈｄ−β×Ｈｐ）＞＋Ｈｋ
第２判定式：（α×Ｈｄ−β×Ｈｐ）＜−Ｈｋ Here, a formula for checking whether or not the electronic key 2 is outside the driver's seat side vehicle is a first judgment formula, and a formula for checking whether or not the electronic key 2 is outside the passenger seat side vehicle is a second judgment formula, These judgment formulas are represented by the following formulas.
First determination formula: (α × Hd−β × Hp)> + Hk
Second determination formula: (α × Hd−β × Hp) <− Hk

位置判定部２４は、運転席側の車外照合の際、第１判定式を使用してキー位置を判定し、同式が成立することを確認すると、電子キー２が運転席側車外に位置すると判定する。位置判定部２４は、助手席側の車外照合の際、第２判定式を使用してキー位置を判定し、同式が成立することを確認すると、電子キー２が助手席側車外に位置すると判定する。また、位置判定部２４は、車内照合の際、第１判定式及び第２判定式の両方を使用してキー位置を判定し、第１判定式及び第２判定式ともに成立しないことを確認すると、電子キー２が車内に位置すると判定する。   When the position determination unit 24 determines the key position using the first determination formula at the time of driver side verification outside the vehicle, and confirms that the formula is satisfied, the electronic key 2 is positioned outside the driver side vehicle. judge. The position determination unit 24 determines the key position using the second determination formula at the time of outside passenger side collation on the passenger seat side, and confirms that the same formula is satisfied, the electronic key 2 is positioned outside the passenger seat side vehicle. judge. In addition, the position determination unit 24 determines the key position using both the first determination formula and the second determination formula at the time of in-vehicle verification, and confirms that neither the first determination formula nor the second determination formula is satisfied. It is determined that the electronic key 2 is located in the vehicle.

次に、本例の位置判定装置１８の動作を図６に従って説明する。
ここで、最初に、車両１が駐車状態（ドアロック施錠、エンジン停止）の際、運転者が運転席ドア１０から乗車する場合を想定する。このとき、交互送信動作部１９は、運転席ドアの車外ドアハンドルノブが運転者によってタッチ操作されたことを確認すると、待機状態をとる電子キー２を起動状態に切り換えるために、運転席アンテナ１１及び助手席アンテナ１３からウェイク信号２６を交互送信する。このとき、交互送信動作部１９は、まずは最初に運転席アンテナ１１から第１ウェイク信号２６ａを送信する。 Next, the operation of the position determination device 18 of this example will be described with reference to FIG.
Here, first, it is assumed that the driver gets on the driver's seat door 10 when the vehicle 1 is in a parked state (door lock locking, engine stop). At this time, when the alternate transmission operation unit 19 confirms that the outside door handle knob of the driver's seat door is touch-operated by the driver, the driver's seat antenna 11 switches the electronic key 2 in the standby state to the activated state. The wake signal 26 is alternately transmitted from the passenger seat antenna 13. At this time, the alternate transmission operation unit 19 first transmits the first wake signal 26 a from the driver's seat antenna 11.

電子キー２は、運転席アンテナエリアＫｄ内に入っているので、第１ウェイク信号２６ａを受信可能である。電子キー２は、第１ウェイク信号２６ａを受信すると、この第１ウェイク信号２６ａによって起動状態に切り換わる。このとき、磁界強度算出部２０は、第１ウェイク信号２６ａの受信強度、即ち運転席側磁界強度Ｈｄを算出する。また、電子キー２は、起動状態に切り換わると、第１アック信号２７を車両１に送信する。   Since the electronic key 2 is in the driver's seat antenna area Kd, the first wake signal 26a can be received. When the electronic key 2 receives the first wake signal 26a, the electronic key 2 is switched to the activated state by the first wake signal 26a. At this time, the magnetic field strength calculation unit 20 calculates the reception strength of the first wake signal 26a, that is, the driver seat side magnetic field strength Hd. In addition, when the electronic key 2 switches to the activated state, the electronic key 2 transmits a first ACK signal 27 to the vehicle 1.

照合ＥＣＵ９は、第１ウェイク信号２６ａを送信した際、制限時間内にアック応答を受信すると、車両周囲に電子キー２が存在すると認識し、運転席アンテナ１１を送信アンテナとする動作を継続する。照合ＥＣＵ９は、車両周囲に電子キー２が存在することを確認すると、運転席アンテナ１１からビークルＩＤ２８を送信する。ビークルＩＤ２８は、車両１の固有ＩＤである。電子キー２は、ビークルＩＤ２８を受信すると、ビークルＩＤ照合を実行し、このときの通信相手の車両１が正規通信相手か否かを確認する。電子キー２は、ビークルＩＤ照合が成立することを確認すると、第２アック信号２９を車両１に送信する。   When the verification ECU 9 transmits the first wake signal 26a and receives an ACK response within the time limit, the verification ECU 9 recognizes that the electronic key 2 exists around the vehicle and continues the operation using the driver's seat antenna 11 as the transmission antenna. When the verification ECU 9 confirms that the electronic key 2 is present around the vehicle, the verification ECU 9 transmits a vehicle ID 28 from the driver's seat antenna 11. The vehicle ID 28 is a unique ID of the vehicle 1. When the electronic key 2 receives the vehicle ID 28, the electronic key 2 executes vehicle ID verification, and confirms whether or not the communication partner vehicle 1 at this time is a regular communication partner. When the electronic key 2 confirms that vehicle ID verification is established, the electronic key 2 transmits a second ACK signal 29 to the vehicle 1.

照合ＥＣＵ９は、ビークルＩＤ２８の送信後の制限時間内に第２アック信号２９を受信すると、続いてチャレンジ３０を運転席アンテナ１１から送信する。チャレンジ３０には、電子キー２が何番目の登録キーかを問い合せるためのキー番号と、チャレンジレスポンス認証用のチャレンジコードとが含まれている。電子キー２は、チャレンジ３０を受信すると、チャレンジ３０内のキー番号で番号照合を実行し、番号照合が成立することを確認すると、チャレンジコードを自身の暗号鍵に通してレスポンスコードを演算する。電子キー２は、レスポンスコードの演算が完了すると、レスポンス３１を車両１に送信する。レスポンス３１には、電子キー２のＩＤコードと、演算したレスポンスコードとが含まれている。電子キー２は、レスポンス３１の送信が完了すると、元の待機状態に戻る。   When the verification ECU 9 receives the second ACK signal 29 within the time limit after the transmission of the vehicle ID 28, the verification ECU 9 subsequently transmits a challenge 30 from the driver's seat antenna 11. The challenge 30 includes a key number for inquiring what registration key the electronic key 2 is and a challenge code for challenge response authentication. When the electronic key 2 receives the challenge 30, the electronic key 2 executes number verification with the key number in the challenge 30. When the electronic key 2 confirms that the number verification is established, the electronic key 2 passes the challenge code through its own encryption key and calculates a response code. When the calculation of the response code is completed, the electronic key 2 transmits a response 31 to the vehicle 1. The response 31 includes the ID code of the electronic key 2 and the calculated response code. When the transmission of the response 31 is completed, the electronic key 2 returns to the original standby state.

また、電子キー２がレスポンス３１を車両１に送信する際、磁界強度通知部２１は、レスポンス３１にＩＤコード及びレスポンスコードとともに、運転席側磁界強度Ｈｄのデータを含ませて送信させる。即ち、レスポンス３１として、ＩＤコードとレスポンスコードと運転席側磁界強度Ｈｄとが電子キー２から車両に送信される。   In addition, when the electronic key 2 transmits the response 31 to the vehicle 1, the magnetic field strength notification unit 21 causes the response 31 to include the ID code and the response code together with data on the driver's seat side magnetic field strength Hd. That is, as the response 31, the ID code, the response code, and the driver's seat side magnetic field strength Hd are transmitted from the electronic key 2 to the vehicle.

照合ＥＣＵ９は、チャレンジ３０の送信の際、自身もチャレンジコードを自らの暗号鍵に通してレスポンスコードを演算する。そして、照合ＥＣＵ９は、電子キー２からレスポンス３１を受信すると、レスポンス３１に含まれるレスポンスコードでレスポンス照合を行い、この照合が成立することを確認すると、レスポンス３１に含まれるＩＤコードでＩＤコード照合を実行する。照合ＥＣＵ９は、両照合がともに成立することを確認すると、スマート照合を成立として処理する。   When transmitting the challenge 30, the verification ECU 9 also passes the challenge code through its encryption key and calculates the response code. When the verification ECU 9 receives the response 31 from the electronic key 2, the verification ECU 9 performs response verification using the response code included in the response 31. If it is confirmed that the verification is established, the verification ECU 9 verifies the ID code using the ID code included in the response 31. Execute. When the verification ECU 9 confirms that both verifications are established, the verification ECU 9 processes the smart verification as establishment.

さらに、磁界強度取得部２２は、スマート照合が成立することを確認すると、レスポンス３１に含まれる運転席側磁界強度Ｈｄを取得し、この運転席側磁界強度Ｈｄを位置判定部２４に出力する。即ち、磁界強度取得部２２は、このときに受信したレスポンス３１が、運転席アンテナ１１からの問い合せに対する電子キー２の応答であると把握しているので、このレスポンス３１に含まれる受信強度データを運転席側磁界強度Ｈｄとして取り込み、これを位置判定部２４に通知する。   Further, when confirming that the smart verification is established, the magnetic field strength acquisition unit 22 acquires the driver seat side magnetic field strength Hd included in the response 31 and outputs the driver seat side magnetic field strength Hd to the position determination unit 24. That is, the magnetic field strength acquisition unit 22 recognizes that the response 31 received at this time is the response of the electronic key 2 to the inquiry from the driver's seat antenna 11, so the received strength data included in the response 31 is obtained. This is taken in as the driver's seat side magnetic field strength Hd, and this is notified to the position determination unit 24.

交互送信動作部１９は、運転席アンテナ１１によるスマート照合が完了することを確認すると、今度は助手席アンテナ１３から第２ウェイク信号２６ｂの送信を開始して、助手席アンテナ１３を車両送信アンテナとして電子キー２とスマート通信する。電子キー２は、第２ウェイク信号２６ｂを受信すると、この第２ウェイク信号２６ｂによって再度起動状態に入る。このとき、磁界強度算出部２０は、第２ウェイク信号２６ｂの受信強度、即ち助手席側磁界強度Ｈｐを算出する。   When the alternate transmission operation unit 19 confirms that the smart collation by the driver's seat antenna 11 is completed, the alternate transmission operation unit 19 starts transmission of the second wake signal 26b from the passenger seat antenna 13 and uses the passenger seat antenna 13 as a vehicle transmission antenna. Smart communication with the electronic key 2 is performed. When receiving the second wake signal 26b, the electronic key 2 enters the activated state again by the second wake signal 26b. At this time, the magnetic field strength calculation unit 20 calculates the reception strength of the second wake signal 26b, that is, the passenger seat side magnetic field strength Hp.

また、電子キー２は、第２ウェイク信号２６ｂにより起動状態に切り換わると、第３アック信号３２を車両１に送信する。照合ＥＣＵ９は、第２ウェイク信号２６ｂを送信した際、制限時間内にアック応答を受信すると、助手席アンテナ１３を車両送信アンテナとしたスマート通信を継続する。   Further, when the electronic key 2 is switched to the activated state by the second wake signal 26b, the electronic key 2 transmits a third ack signal 32 to the vehicle 1. When the verification ECU 9 transmits the second wake signal 26b and receives an ACK response within the time limit, the verification ECU 9 continues the smart communication using the passenger seat antenna 13 as the vehicle transmission antenna.

以降のスマート通信は、運転席アンテナ１１を車両送信アンテナとしたときと同様の通信シーケンスにより実行される。即ち、第３アック信号３２が車両１に届くと、助手席アンテナ１３からビークルＩＤ３３が送信され、ビークルＩＤ照合が実行される。そして、ビークルＩＤ照合成立通知として第４アック信号３４が電子キー２から車両１に届くと、助手席アンテナ１３からチャレンジ３５が送信される。   The subsequent smart communication is executed by the same communication sequence as when the driver's seat antenna 11 is a vehicle transmission antenna. That is, when the third ACK signal 32 reaches the vehicle 1, the vehicle ID 33 is transmitted from the passenger seat antenna 13, and the vehicle ID verification is executed. When the fourth ACK signal 34 arrives from the electronic key 2 to the vehicle 1 as a vehicle ID verification establishment notification, a challenge 35 is transmitted from the passenger seat antenna 13.

電子キー２は、チャレンジ３５を受信すると、同チャレンジ３５でキー番号照合と、レスポンスコード演算とを実行する。電子キー２は、レスポンスコード演算が完了すると、レスポンス３６を車両１に送信する。このレスポンス３６には、電子キー２のＩＤコードと、演算したレスポンスコードと、助手席側磁界強度Ｈｐのデータとが含まれている。   When the electronic key 2 receives the challenge 35, the electronic key 2 executes key number verification and response code calculation in the challenge 35. When the response code calculation is completed, the electronic key 2 transmits a response 36 to the vehicle 1. The response 36 includes the ID code of the electronic key 2, the calculated response code, and data on the passenger seat side magnetic field strength Hp.

照合ＥＣＵ９は、レスポンス３６を受信すると、レスポンス認証とＩＤコード照合とを行い、これら両照合が成立することを確認すると、スマート照合を成立として処理する。また、磁界強度取得部２２は、スマート照合が成立することを確認すると、このレスポンス３６から助手席側磁界強度Ｈｐを取得し、助手席側磁界強度Ｈｐを位置判定部２４に出力する。即ち、磁界強度取得部２２は、このときに受信したレスポンス３６が、助手席アンテナ１３からの問い合せに対する電子キー２の応答であると把握しているので、このレスポンス３６に含まれる受信強度を助手席側磁界強度Ｈｐとして取り込み、これを位置判定部２４に出力する。   When the verification ECU 9 receives the response 36, the verification ECU 9 performs response authentication and ID code verification. When the verification ECU 9 confirms that both verifications are established, the verification ECU 9 processes the smart verification as establishment. Further, when confirming that the smart verification is established, the magnetic field strength acquisition unit 22 acquires the passenger seat side magnetic field strength Hp from the response 36 and outputs the passenger seat side magnetic field strength Hp to the position determination unit 24. That is, the magnetic field strength acquisition unit 22 recognizes that the response 36 received at this time is the response of the electronic key 2 to the inquiry from the passenger seat antenna 13, and therefore the reception strength included in the response 36 is determined as the assistant. This is taken in as the seat-side magnetic field strength Hp and output to the position determination unit 24.

係数乗算部２３は、磁界強度取得部２２から運転席側磁界強度Ｈｄと助手席側磁界強度Ｈｐと取得すると、運転席側磁界強度Ｈｄに係数αを乗算し、助手席側磁界強度Ｈｐに係数βを乗算し、これら磁界強度Ｈｄ，Ｈｐを位置判定部２４に出力する。位置判定部２４は、係数乗算部２３から係数乗算後の磁界強度Ｈｄ，Ｈｐを取得すると、これら磁界強度Ｈｄ，Ｈｐの磁界強度差Ｈdpを算出する。そして、位置判定部２４は、磁界強度差Ｈdpと判定閾値Ｈｋとを比較することにより、電子キー２の位置を判定する。   When the coefficient multiplication unit 23 obtains the driver seat side magnetic field strength Hd and the passenger seat side magnetic field strength Hp from the magnetic field strength obtaining unit 22, the coefficient multiplication unit 23 multiplies the driver seat side magnetic field strength Hd by a coefficient α, and the passenger seat side magnetic field strength Hp is a coefficient. β is multiplied and these magnetic field strengths Hd and Hp are output to the position determination unit 24. When the position determination unit 24 acquires the magnetic field strengths Hd and Hp after the coefficient multiplication from the coefficient multiplication unit 23, the position determination unit 24 calculates a magnetic field strength difference Hdp between the magnetic field strengths Hd and Hp. Then, the position determination unit 24 determines the position of the electronic key 2 by comparing the magnetic field strength difference Hdp with the determination threshold value Hk.

ここで、位置判定部２４は、車外ドアハンドルノブのタッチ操作をトリガとして開始されたスマート通信であることを以て、このときのスマート通信が車外通信であることを認識している。また、位置判定部２４は、タッチ操作された車外ドアハンドルが、運転席側であることを把握しているので、運転席側に電子キー２が位置すべきであることも認識している。   Here, the position determination unit 24 recognizes that the smart communication at this time is the out-of-vehicle communication because the smart communication is triggered by the touch operation of the out-of-vehicle door handle knob. Further, the position determination unit 24 recognizes that the touched outside door handle is on the driver's seat side, and therefore recognizes that the electronic key 2 should be positioned on the driver's seat side.

よって、位置判定部２４は、運転席側の車外ドアハンドルノブのタッチ操作により開始されたスマート通信であることを認識すると、第１判定式が成立するか否かを確認する。即ち、Ｈdp＞＋Ｈｋが成立するか否かを確認する。このとき、位置判定部２４は、Ｈdp＞＋Ｈｋが成立することを確認すると、電子キー２が運転席側車外に位置すると認識し、車外照合を成立として処理する。照合ＥＣＵ９は、電子キー２との間のスマート照合が成立し、かつ車外位置判定も正しいということを確認すると、ドアロック装置６にドアロックの解錠を実行させる。   Therefore, when the position determination unit 24 recognizes that the smart communication is started by the touch operation of the vehicle exterior door handle knob on the driver's seat side, the position determination unit 24 checks whether or not the first determination formula is satisfied. That is, it is confirmed whether or not Hdp> + Hk is satisfied. At this time, when the position determination unit 24 confirms that Hdp> + Hk is established, the position determination unit 24 recognizes that the electronic key 2 is located outside the driver's seat side vehicle, and processes the vehicle outside verification as establishment. When the collation ECU 9 confirms that the smart collation with the electronic key 2 is established and the position determination outside the vehicle is correct, the collation ECU 9 causes the door lock device 6 to unlock the door.

続いて、ドアロックの解錠後、運転者が車内に乗車した場合を想定する。照合ＥＣＵ９は、運転者が車内に乗車したことを例えばカーテシスイッチ等により確認すると、ドアロックを解錠したときと同じ通信シーケンスで、同様のスマート通信を実行する。よって、この場合も、運転席アンテナ１１を車両送信アンテナとして電子キー２とスマート通信を行ったときの電子キー２の受信強度を運転席側磁界強度Ｈｄとして取得し、助手席アンテナ１３を車両送信アンテナとして電子キー２とスマート通信を行ったときの電子キー２の受信強度を助手席側磁界強度Ｈｐとして取得し、前述した係数乗算を経た磁界強度差Ｈdpを算出する。   Subsequently, it is assumed that the driver gets into the vehicle after unlocking the door lock. When the verification ECU 9 confirms that the driver has entered the vehicle by using, for example, a courtesy switch or the like, the verification ECU 9 executes the same smart communication in the same communication sequence as when the door lock is unlocked. Therefore, also in this case, the reception intensity of the electronic key 2 when performing smart communication with the electronic key 2 using the driver's seat antenna 11 as a vehicle transmission antenna is acquired as the driver's seat side magnetic field strength Hd, and the passenger's seat antenna 13 is transmitted to the vehicle. The reception strength of the electronic key 2 when performing smart communication with the electronic key 2 as an antenna is acquired as the passenger-side magnetic field strength Hp, and the magnetic field strength difference Hdp through the coefficient multiplication described above is calculated.

位置判定部２４は、車内照合時に磁界強度差Ｈdpを取得すると、電子キー２が車内に位置するか否かを確認するために、第１判定式及び第２判定式の両式成立可否を確認する。ｋのとき、位置判定部２４は、Ｈdp＞＋Ｈｋが成立せず、さらにＨdp＜−Ｈｋも成立しないことを確認すると、電子キー２が車内にあると認識して、車内照合を成立として処理する。照合ＥＣＵ９は、電子キー２との間のスマート通信が成立し、かつ車内位置判定も成立することを確認すると、エンジン始動装置７による電源遷移操作及びエンジン始動操作を許可する。   When the position determination unit 24 acquires the magnetic field strength difference Hdp at the time of in-vehicle verification, the position determination unit 24 confirms whether or not both of the first determination expression and the second determination expression are established in order to check whether or not the electronic key 2 is positioned in the vehicle. To do. When k, the position determination unit 24 recognizes that the electronic key 2 is in the vehicle when it confirms that Hdp> + Hk is not satisfied and further Hdp <−Hk is not satisfied, and processes in-vehicle verification as established. . When the verification ECU 9 confirms that the smart communication with the electronic key 2 is established and the in-vehicle position determination is also established, the verification ECU 9 permits the power supply transition operation and the engine start operation by the engine start device 7.

続いて、降車した運転者がドアロックを施錠する場合を想定する。照合ＥＣＵ９は、車両１が停車状態（ドアロック解錠、エンジン停止）の際、運転席ドア１０の車外ドアハンドルノブのロックボタン（図示略）が押し操作されたことを検出すると、前述した通信シーケンスと同様のスマート照合を実行する。このときも、運転席アンテナ１１及び助手席アンテナ１３により交互にスマート通信を実行して、運転席側磁界強度Ｈｄと助手席側磁界強度Ｈｐとを取得し、前述した係数乗算を経た磁界強度差Ｈdpを算出する。   Then, the case where the driver who got off locks a door lock is assumed. When the verification ECU 9 detects that the lock button (not shown) of the outside door handle knob of the driver's door 10 is pressed when the vehicle 1 is stopped (door lock unlocked, engine stopped), the communication described above is performed. Performs smart matching similar to a sequence. Also at this time, smart communication is alternately performed by the driver's seat antenna 11 and the passenger's seat antenna 13 to acquire the driver's seat side magnetic field strength Hd and the passenger seat side magnetic field strength Hp, and the magnetic field strength difference that has undergone the coefficient multiplication described above. Calculate Hdp.

位置判定部２４は、車外照合時に磁界強度差Ｈdpを取得すると、運転席ドア１０側から乗車したときと同様に、第１判定式が成立するか否かを確認する。このとき、位置判定部２４は、Ｈdp＞＋Ｈｋが成立することを確認すると、電子キー２が運転席側車外に位置すると認識し、車外照合を成立として処理する。照合ＥＣＵ９は、電子キー２との間のスマート照合が成立し、かつ車外位置判定も正しいということを確認すると、ドアロック装置６にドアロックの施錠を実行させる。   When the position determination unit 24 obtains the magnetic field strength difference Hdp at the time of external verification, the position determination unit 24 checks whether or not the first determination formula is satisfied, as in the case of getting on from the driver's seat door 10 side. At this time, when the position determination unit 24 confirms that Hdp> + Hk is established, the position determination unit 24 recognizes that the electronic key 2 is located outside the driver's seat side vehicle, and processes the vehicle outside verification as establishment. When the collation ECU 9 confirms that the smart collation with the electronic key 2 is established and the vehicle exterior position determination is also correct, the collation ECU 9 causes the door lock device 6 to lock the door.

なお、以上は、運転席ドア１０から車両１に乗車する例を説明したが、助手席ドア１２や後部右側ドアや左側ドアから乗降車する場合の動作も、基本的な動作は運転席ドア１０から乗降車する場合と同様であるので、これらの具体例については詳細を省略する。   Although the example in which the vehicle 1 is boarded from the driver's seat door 10 has been described above, the basic operation of the driver's seat door 10 is also the operation when getting on and off the passenger seat door 12, the rear right door, and the left door. Since these are the same as when getting on and off, details of these specific examples are omitted.

以上により、本例においては、係数αを乗算した運転席側磁界強度Ｈｄと、係数βを乗算した助手席側磁界強度Ｈｐとの磁界強度差Ｈdpを算出し、磁界強度差Ｈdpと判定閾値Ｈｋとを比較することにより、電子キー２の位置を判定する。ところで、ただ単に運転席側磁界強度Ｈｄと助手席側磁界強度Ｈｐとをそのまま引いて求める磁界強度差Ｈdpでは、図５（ａ）に示すような誤判定エリアＥerが生じてしまうが、係数α，βを磁界強度Ｈｄ，Ｈｐに乗算して磁界強度差Ｈdpを割り出せば、図５（ａ）に示す誤判定エリアＥerがキャンセルされる。よって、電子キー２の位置を誤判定してしまう要因を無くせるので、より精度よく電子キー２の位置を判定することが可能となる。   As described above, in this example, the magnetic field strength difference Hdp between the driver side magnetic field strength Hd multiplied by the coefficient α and the passenger seat side magnetic field strength Hp multiplied by the coefficient β is calculated, and the magnetic field strength difference Hdp and the determination threshold value Hk are calculated. Is compared to determine the position of the electronic key 2. By the way, in the magnetic field strength difference Hdp obtained by simply subtracting the driver's seat side magnetic field strength Hd and the passenger seat side magnetic field strength Hp as they are, an erroneous determination area Eer as shown in FIG. , Β is multiplied by the magnetic field strengths Hd, Hp to determine the magnetic field strength difference Hdp, the erroneous determination area Eer shown in FIG. Therefore, since the factor that erroneously determines the position of the electronic key 2 can be eliminated, the position of the electronic key 2 can be determined with higher accuracy.

本実施形態の構成によれば、以下に記載の効果を得ることができる。
（１）測定した磁界強度Ｈｄ，Ｈｐに係数α，βを乗算し、係数乗算を経た後の磁界強度Ｈｄ，Ｈｐの磁界強度差Ｈdpと判定閾値Ｈｋとを比較することにより、電子キー２の位置を判定する。よって、ただ単に磁界強度Ｈｄ，Ｈｐの磁界強度差Ｈdpを判定することでキー位置を判定していた場合に発生していた図５（ａ）に示すような誤判定エリアＥerがキャンセルされるので、より精度よくキー位置を検出することができる。 According to the configuration of the present embodiment, the following effects can be obtained.
(1) The measured magnetic field strengths Hd and Hp are multiplied by coefficients α and β, and the magnetic field strength difference Hdp between the magnetic field strengths Hd and Hp after the coefficient multiplication is compared with the determination threshold value Hk. Determine the position. Therefore, the erroneous determination area Eer as shown in FIG. 5A, which has occurred when the key position is determined simply by determining the magnetic field strength difference Hdp between the magnetic field strengths Hd and Hp, is canceled. The key position can be detected with higher accuracy.

（２）磁界強度差Ｈdpと判定閾値Ｈｋとの大小関係を見ることによりキー位置を判定するので、磁界強度差Ｈdpと判定閾値Ｈｋとの大小を単に比較するという簡素な処理によって、電子キー２の位置を判定することができる。   (2) Since the key position is determined by observing the magnitude relationship between the magnetic field strength difference Hdp and the determination threshold value Hk, the electronic key 2 can be simply processed by simply comparing the magnitudes of the magnetic field strength difference Hdp and the determination threshold value Hk. Can be determined.

（３）運転席側に運転席アンテナ１１を設置し、助手席側に助手席アンテナ１３を設置して、これらアンテナ１１，１３からの電波を電子キー２が受信したときの磁界強度差Ｈdpを基に、電子キー２が車外及び車外のどちらに位置するのかを判定する。よって、電子キー２が車外及び車内のどちらに位置するのかを、より精度よく判定することができる。   (3) The driver's seat antenna 11 is installed on the driver's seat side, the passenger's seat antenna 13 is installed on the passenger's seat side, and the magnetic field intensity difference Hdp when the electronic key 2 receives radio waves from these antennas 11 and 13 is obtained. Based on this, it is determined whether the electronic key 2 is located outside the vehicle or outside the vehicle. Therefore, it can be determined more accurately whether the electronic key 2 is located outside the vehicle or inside the vehicle.

（４）磁界強度差Ｈdpを絶対値ではなく正負を持った値で算出し、磁界強度差Ｈdpが正をとる場合、判定閾値としての＋Ｈｋと磁界強度差Ｈdpとの大小比較により、電子キー２が運転席側車外に位置するか否かを判定する。また、磁界強度差Ｈdpが負をとる場合、判定閾値としての−Ｈｋと磁界強度差Ｈdpとの大小比較により、電子キー２が助手席側車外に位置するか否かを判定する。このため、電子キー２が車外に位置する際に、運転席側及び助手席側のどちらに位置するのかまで、細かく判定することができる。   (4) When the magnetic field strength difference Hdp is calculated not as an absolute value but as a positive / negative value, and the magnetic field strength difference Hdp is positive, the electronic key 2 is compared by comparing the + Hk as the determination threshold with the magnetic field strength difference Hdp. Whether or not is located outside the driver's seat side vehicle is determined. Further, when the magnetic field strength difference Hdp is negative, it is determined whether or not the electronic key 2 is located outside the passenger side vehicle by comparing the magnitude of the determination threshold value −Hk with the magnetic field strength difference Hdp. For this reason, when the electronic key 2 is located outside the vehicle, it can be finely determined whether the electronic key 2 is located on the driver seat side or the passenger seat side.

（第２実施形態）
次に、第２実施形態を図７に従って説明する。なお、本例は、車両１の送信アンテナを３つとして電子キー２の位置を細分検出可能とした例であり、第１実施形態と基本的な構成部分は同じである。よって、同一部分は同一符号を付して詳しい説明を省略し、異なる部分についてのみ詳述する。 (Second Embodiment)
Next, a second embodiment will be described with reference to FIG. In addition, this example is an example in which the position of the electronic key 2 can be subdividedly detected by using three transmission antennas of the vehicle 1, and the basic components are the same as those in the first embodiment. Therefore, the same parts are denoted by the same reference numerals, detailed description thereof is omitted, and only different parts are described in detail.

図７に示すように、ラッゲージドア４１には、車両１の一送信アンテナとしてラッゲージドアアンテナ４２が設けられている。ラッゲージドアアンテナ４２は、例えばラッゲージドア４１の内面等に取り付けられ、運転席アンテナ１１や助手席アンテナ１３と同様に、スマート通信の際にリクエスト信号Ｓrqを電子キー２に送信する。なお、ラッゲージドアアンテナ４２が一アンテナ及び他アンテナを構成する。   As shown in FIG. 7, the luggage door 41 is provided with a luggage door antenna 42 as one transmission antenna of the vehicle 1. The luggage door antenna 42 is attached to, for example, the inner surface of the luggage door 41, and transmits a request signal Srq to the electronic key 2 during smart communication, like the driver's seat antenna 11 and the passenger seat antenna 13. The luggage door antenna 42 constitutes one antenna and another antenna.

交互送信動作部１９は、スマート通信時、運転席アンテナ１１と助手席アンテナ１３とラッゲージドアアンテナ４２とから順にリクエスト信号Ｓrqを送信する。このとき、磁界強度算出部２０は、運転席側磁界強度Ｈｄ及び助手席側磁界強度Ｈｐの他に、ラッゲージドア４１からのリクエスト信号Ｓrqを受信した際の磁界強度（ラッゲージドア側磁界強度Ｈｒ）も算出する。そして、磁界強度通知部２１は、それぞれのアンテナ１１，１３，４２ごとのスマート通信の折り返しで、運転席側磁界強度Ｈｄと助手席側磁界強度Ｈｐとラッゲージドア側磁界強度Ｈｒとを車両１に通知する。なお、ラッゲージドア側磁界強度Ｈｒが第１受信強度及び第２受信強度を構成する。   The alternate transmission operation unit 19 transmits the request signal Srq in order from the driver seat antenna 11, the passenger seat antenna 13, and the luggage door antenna 42 during smart communication. At this time, the magnetic field strength calculation unit 20 receives the request signal Srq from the luggage door 41 in addition to the driver seat side magnetic field strength Hd and the passenger seat side magnetic field strength Hp (luggage door side magnetic field strength Hr). Is also calculated. The magnetic field strength notifying unit 21 returns the driver seat side magnetic field strength Hd, the passenger seat side magnetic field strength Hp, and the luggage door side magnetic field strength Hr to the vehicle 1 by turning back the smart communication for each of the antennas 11, 13, and 42. Notice. The luggage door side magnetic field strength Hr constitutes the first reception strength and the second reception strength.

磁界強度取得部２２は、各アンテナ１１，１３，４２のスマート通信で、それぞれ運転席側磁界強度Ｈｄと助手席側磁界強度Ｈｐとラッゲージドア側磁界強度Ｈｒとを取得する。そして、係数乗算部２３は、運転席側磁界強度Ｈｄに係数αを乗算し、助手席側磁界強度Ｈｐに係数βを乗算し、ラッゲージドア側磁界強度Ｈｒに係数γを乗算する。そして、係数乗算部２３は、係数乗算を経た３つの磁界強度Ｈｄ，Ｈｐ，Ｈｒを位置判定部２４に出力する。   The magnetic field strength acquisition unit 22 acquires the driver-seat-side magnetic field strength Hd, the passenger-seat-side magnetic field strength Hp, and the luggage door-side magnetic field strength Hr by smart communication of the antennas 11, 13, and 42, respectively. Then, the coefficient multiplier 23 multiplies the driver seat side magnetic field strength Hd by a factor α, multiplies the passenger seat side magnetic field strength Hp by a factor β, and multiplies the luggage door side magnetic field strength Hr by a factor γ. Then, the coefficient multiplication unit 23 outputs the three magnetic field strengths Hd, Hp, and Hr that have undergone the coefficient multiplication to the position determination unit 24.

位置判定部２４は、係数乗算を経た３つの磁界強度Ｈｄ，Ｈｐ，Ｈｒにおいて、２つずつをそれぞれ組みとして、組みごとに磁界強度差を算出し、キー位置を判定する。即ち、位置判定部２４は、運転席側磁界強度Ｈｄ及び助手席側磁界強度Ｈｐの磁界強度差Ｈdpと、運転席側磁界強度Ｈｄ及びラッゲージドア側磁界強度Ｈｒの磁界強度差Ｈdrと、助手席側磁界強度Ｈｐ及びラッゲージドア側磁界強度Ｈｒの磁界強度差Ｈprとを算出し、これら磁界強度差Ｈdp，Ｈdr，Ｈprをそれぞれの判定閾値と比較することにより、キー位置を判定する。   The position determination unit 24 calculates a magnetic field strength difference for each of the three magnetic field strengths Hd, Hp, and Hr that have undergone coefficient multiplication, and determines a key position. In other words, the position determination unit 24 determines the magnetic field strength difference Hdp between the driver's seat side magnetic field strength Hd and the passenger seat side magnetic field strength Hp, the magnetic field strength difference Hdr between the driver seat side magnetic field strength Hd and the luggage door side magnetic field strength Hr, and the passenger seat. The key position is determined by calculating the magnetic field strength difference Hpr of the side magnetic field strength Hp and the luggage door side magnetic field strength Hr, and comparing these magnetic field strength differences Hdp, Hdr, Hpr with respective determination thresholds.

このとき、位置判定部２４は、磁界強度差Ｈdrの閾値判定により、一対の判定エリアＥr1，Ｅr2のうち電子キー２が判定エリアＥr2に位置すること、又は磁界強度差Ｈprの閾値判定により、一対の判定エリアＥr3，Ｅr4のうち電子キー２が判定エリアＥr4に位置することの何れかを確認すると、電子キー２がラッゲージドア側車外に位置すると判定する。よって、照合ＥＣＵ９は、この状況下でラッゲージドア開ボタン（図示略）が操作されたことを検出すると、ラッゲージドアの電気錠を解錠して、ラッゲージドアを開状態にする。   At this time, the position determination unit 24 determines whether the electronic key 2 is positioned in the determination area Er2 out of the pair of determination areas Er1 and Er2 by threshold determination of the magnetic field strength difference Hdr, or determines threshold by determining the threshold of the magnetic field strength difference Hpr. When it is confirmed that the electronic key 2 is positioned in the determination area Er4 in the determination areas Er3 and Er4, it is determined that the electronic key 2 is positioned outside the luggage door side vehicle. Therefore, when the verification ECU 9 detects that the luggage door open button (not shown) is operated under this condition, the verification ECU 9 unlocks the electric lock of the luggage door and opens the luggage door.

本実施形態の構成によれば、第１実施形態に記載の（１）〜（４）の効果に加え、以下の効果を得ることができる。
（５）運転席アンテナ１１、助手席アンテナ１３、ラッゲージドアアンテナ４２を車両１に搭載し、運転席アンテナ１１及び助手席アンテナ１３を組みとし、運転席アンテナ１１とラッゲージドアアンテナ４２とを組みとし、助手席アンテナ１３とラッゲージドアアンテナ４２とを組みとする。そして、アンテナ１１，１３の組みから電子キー２が運転席及び助手席のどちら側に位置するのか、アンテナ１１，４２の組みから電子キー２が運転席及びラッゲージのどちら側に位置するのか、アンテナ１３，４２の組みから電子キー２が助手席及びラッゲージのどちら側に位置するのかを確認可能とした。このため、電子キー２がラッゲージドア側車外に位置することも検出可能となるので、車外における電子キー２の位置を、より細分して検出することができる。 According to the configuration of the present embodiment, in addition to the effects (1) to (4) described in the first embodiment, the following effects can be obtained.
(5) The driver's seat antenna 11, the passenger's seat antenna 13, and the luggage door antenna 42 are mounted on the vehicle 1, the driver's seat antenna 11 and the passenger's seat antenna 13 are combined, and the driver's seat antenna 11 and the luggage door antenna 42 are combined. The passenger seat antenna 13 and the luggage door antenna 42 are combined. Whether the electronic key 2 is located on the side of the driver's seat or the passenger's seat from the combination of the antennas 11 and 13, whether the electronic key 2 is located on the side of the driver's seat or the luggage from the combination of the antennas 11 and 42, the antenna From the set of 13, 42, it is possible to confirm on which side of the passenger seat or luggage the electronic key 2 is located. For this reason, since it becomes possible to detect that the electronic key 2 is located outside the luggage door side vehicle, the position of the electronic key 2 outside the vehicle can be detected more finely.

（６）例えば電子キー２が運転席車外に位置する場合、運転席アンテナ１１及び助手席アンテナ１３を組みとした判定と、運転席アンテナ１１とラッゲージドアアンテナ４２とを組みとした判定との２判定で、電子キー２が運転席側に位置することが判定可能となる。よって、両方の判定で電子キー２が運転席側車外に位置していれば、それは確実に電子キー２が運転席側車外に位置していると見なせるので、電子キー２が運転席側車外に位置していることを、より正確に検出することができる。なお、これは、電子キー２が助手席車外、ラッゲージドア側車外、車内に位置しているときも同様に言えることである。   (6) For example, when the electronic key 2 is located outside the driver's seat, the determination is made with the combination of the driver's seat antenna 11 and the passenger's seat antenna 13 and the determination with the combination of the driver's seat antenna 11 and the luggage door antenna 42. In the determination, it can be determined that the electronic key 2 is located on the driver's seat side. Therefore, if the electronic key 2 is located outside the driver's seat side vehicle in both determinations, it can be considered that the electronic key 2 is located outside the driver's seat side vehicle. The position can be detected more accurately. This is also true when the electronic key 2 is located outside the passenger seat vehicle, outside the luggage door side vehicle, or inside the vehicle.

（第３実施形態）
次に、第３実施形態を図８及び図９に従って説明する。なお、本例は、本願発明の技術思想をタイヤ空気圧監視システム５０に応用した実施例であって、本例も前記実施形態と異なる部分についてのみ説明する。 (Third embodiment)
Next, a third embodiment will be described with reference to FIGS. Note that this example is an example in which the technical idea of the present invention is applied to the tire pressure monitoring system 50, and this example will be described only for parts different from the above embodiment.

図８に示すように、車両１には、各タイヤ５１に無線式のバルブ（タイヤセンサ）５２を取り付けて各タイヤ５１の空気圧を監視するタイヤ空気圧監視システム５０が搭載されている。タイヤ空気圧監視システム５０は、タイヤ空気圧が閾値よりも低いタイヤを検出すると、そのタイヤを例えば車内インストルメントパネル等で運転者に通知する。タイヤ５１には、右前タイヤ５１ａ、左前タイヤ５１ｂ、右後タイヤ５１ｃ、左後タイヤ５１ｄがある。なお、タイヤ空気圧監視システム５０が無線システムを構成する。   As shown in FIG. 8, the vehicle 1 is equipped with a tire air pressure monitoring system 50 that monitors the air pressure of each tire 51 by attaching a wireless valve (tire sensor) 52 to each tire 51. When the tire pressure monitoring system 50 detects a tire whose tire pressure is lower than the threshold value, the tire pressure monitoring system 50 notifies the driver of the tire, for example, with an in-vehicle instrument panel. The tire 51 includes a right front tire 51a, a left front tire 51b, a right rear tire 51c, and a left rear tire 51d. The tire pressure monitoring system 50 constitutes a wireless system.

各タイヤ５１ａ〜５１ｄには、タイヤ空気圧情報Ｓtpを無線により送信可能なバルブ５２が取り付けられている。本例のバルブ５２には、ＬＦ電波を受信可能なＬＦ受信機、ＵＨＦ電波を送信可能なＵＨＦ送信機、タイヤ空気圧を検出する圧力センサ、タイヤ温度を検出する温度センサ、タイヤに加わる加速度を検出する加速度センサ、以上の部品を制御するマイクロコンピュータ等が搭載されている。また、各バルブ５２のマイクロコンピュータには、前述したような磁界強度算出部２０や磁界強度通知部２１も設けられている。なお、バルブ５２が通信端末及びタイヤ通信機を構成する。   A valve 52 capable of transmitting tire pressure information Stp by radio is attached to each of the tires 51a to 51d. The valve 52 in this example includes an LF receiver that can receive LF radio waves, a UHF transmitter that can transmit UHF radio waves, a pressure sensor that detects tire air pressure, a temperature sensor that detects tire temperature, and an acceleration applied to the tire. An acceleration sensor that performs this operation, a microcomputer that controls the above components, and the like are mounted. The microcomputer of each valve 52 is also provided with the magnetic field strength calculation unit 20 and the magnetic field strength notification unit 21 as described above. The valve 52 forms a communication terminal and a tire communication device.

バルブ５２は、車体のアンテナ（アンテナ１１，１３等）からトリガ信号Ｓtrを受信したとき、タイヤ空気圧情報ＳtpをＵＨＦ電波により送信する。タイヤ空気圧情報Ｓtpには、例えばバルブ固有の識別ＩＤ、タイヤ空気圧、タイヤ温度、タイヤに付与されている加速度等の情報が含まれている。また、トリガ信号Ｓtrは、ＬＦ電波であって、バルブ５２に電波送信を要求する動作実行要求が含まれている。トリガ信号Ｓtrは、車両走行中において車体のアンテナ（アンテナ１１，１３等）が電子キー２と通信を実行しない所定タイミングで送信される。   When the valve 52 receives the trigger signal Str from the antenna of the vehicle body (antennas 11, 13, etc.), the tire pressure information Stp is transmitted by UHF radio waves. The tire pressure information Stp includes, for example, information such as a valve-specific identification ID, tire pressure, tire temperature, acceleration applied to the tire, and the like. The trigger signal Str is an LF radio wave and includes an operation execution request for requesting the valve 52 to transmit a radio wave. The trigger signal Str is transmitted at a predetermined timing when the antenna of the vehicle body (antennas 11, 13 and the like) does not communicate with the electronic key 2 while the vehicle is running.

車両１の車体後部には、車両後部一帯においてＬＦ電波の通信エリアを形成可能なリヤアンテナ５３が設けられている。リヤアンテナ５３は、車両後部一帯にトリガ信号Ｓtrの通信エリアを形成可能である。また、リヤアンテナ５３は、もちろんスマート通信も実行可能である。   A rear antenna 53 capable of forming an LF radio wave communication area in the entire rear part of the vehicle is provided at the rear of the vehicle body. The rear antenna 53 can form a communication area for the trigger signal Str in the entire rear part of the vehicle. Of course, the rear antenna 53 can also perform smart communication.

次に、本例のタイヤ空気圧監視システム５０の動作を説明する。
照合ＥＣＵ９は、例えば運転席アンテナ１１、助手席アンテナ１３、そしてリヤアンテナ５３から、それぞれ異なるタイミングでトリガ信号Ｓtrを送信する。まず、運転席アンテナ１１がトリガ信号Ｓtrを送信したとき、運転席アンテナ１１に最も近い右前タイヤ５１ａのバルブ５２ａは確実にトリガ信号Ｓtrを受信する。よって、バルブ５２ａは、このトリガ信号Ｓtrに応答してタイヤ空気圧情報Ｓtpを車両チューナ１４に送信する。また、バルブ５２ａは、トリガ信号Ｓtrを受信したときの磁界強度Ｈｄを算出し、これをタイヤ空気圧情報Ｓtpに含めて送信する。つまり、バルブ５２ａのタイヤ空気圧情報Ｓtpには、現状のタイヤ空気圧の他に、磁界強度Ｈｄや、バルブ５２ａの固有ＩＤとして識別ＩＤ１が含まれている。 Next, operation | movement of the tire pressure monitoring system 50 of this example is demonstrated.
The verification ECU 9 transmits trigger signals Str at different timings, for example, from the driver's seat antenna 11, the passenger seat antenna 13, and the rear antenna 53. First, when the driver's seat antenna 11 transmits the trigger signal Str, the valve 52a of the right front tire 51a closest to the driver's seat antenna 11 reliably receives the trigger signal Str. Therefore, the valve 52a transmits the tire pressure information Stp to the vehicle tuner 14 in response to the trigger signal Str. Further, the valve 52a calculates the magnetic field strength Hd when the trigger signal Str is received, and transmits this by including it in the tire pressure information Stp. That is, the tire pressure information Stp of the valve 52a includes the magnetic field strength Hd and the identification ID1 as the unique ID of the valve 52a in addition to the current tire pressure.

なお、他タイヤ５１ｂ〜５１ｄのバルブ５２ｂ〜５２ｄは、運転席アンテナ１１から遠いので、基本的には運転席アンテナ１１のトリガ信号Ｓtrを受信できない。但し、仮にトリガ信号Ｓtrを受信できても、極めて値の低い磁界強度Ｈｄを車両１に通知する。   Since the valves 52b to 52d of the other tires 51b to 51d are far from the driver's seat antenna 11, basically, the trigger signal Str of the driver's seat antenna 11 cannot be received. However, even if the trigger signal Str can be received, the vehicle 1 is notified of the extremely low magnetic field strength Hd.

続いて、助手席アンテナ１３がトリガ信号Ｓtrを送信したとき、助手席アンテナ１３に最も近い左前タイヤ５１ｂのバルブ５２ｂは確実にトリガ信号Ｓtrを受信する。よって、バルブ５２ｂは、このトリガ信号Ｓtrを受信したとき、磁界強度Ｈｐを算出し、この磁界強度Ｈｐを含むタイヤ空気圧情報Ｓtpを車両チューナ１４に送信する。つまり、バルブ５２ｂのタイヤ空気圧情報Ｓtpには、現状のタイヤ空気圧の他に、磁界強度Ｈｐや、バルブ５２ｂの固有ＩＤとして識別ＩＤ２が含まれている。   Subsequently, when the passenger seat antenna 13 transmits the trigger signal Str, the valve 52b of the left front tire 51b closest to the passenger seat antenna 13 reliably receives the trigger signal Str. Therefore, when the valve 52b receives the trigger signal Str, the valve 52b calculates the magnetic field strength Hp and transmits tire pressure information Stp including the magnetic field strength Hp to the vehicle tuner 14. That is, the tire pressure information Stp of the valve 52b includes the magnetic field strength Hp and the identification ID2 as the unique ID of the valve 52b in addition to the current tire pressure.

なお、他タイヤ５１ａ、５１ｃ，５１ｄのバルブ５２ａ、５２ｃ，５２ｄは、助手席アンテナ１３から遠いので、基本的には助手席アンテナ１３のトリガ信号Ｓtrを受信できない。但し、仮にトリガ信号Ｓtrを受信できても、極めて低い値の磁界強度Ｈｐを車両１に通知する。   Since the valves 52a, 52c, 52d of the other tires 51a, 51c, 51d are far from the passenger seat antenna 13, basically, the trigger signal Str of the passenger seat antenna 13 cannot be received. However, even if the trigger signal Str can be received, the vehicle 1 is notified of an extremely low magnetic field strength Hp.

続いて、リヤアンテナ５３がトリガ信号Ｓtrを送信したとき、リヤアンテナ５３に近い後側のタイヤ５１ｃ，５１ｄのバルブ５２ｃ，５２ｄは確実にトリガ信号Ｓtrを受信する。よって、バルブ５２ｃ，５２ｄは、このトリガ信号Ｓtrを受信したとき、磁界強度Ｈｓを算出し、この磁界強度Ｈｓを含むタイヤ空気圧情報Ｓtpを車両チューナ１４に送信する。本例の場合、バルブ５２ｃからのタイヤ空気圧情報Ｓtpには、現状のタイヤ空気圧の他に、磁界強度Ｈｓや、バルブ５２ｃの固有ＩＤとして識別ＩＤ３が含まれている。また、バルブ５２ｄのタイヤ空気圧情報Ｓtpには、現状のタイヤ空気圧の他に、磁界強度Ｈｓや、バルブ５２ｄの固有ＩＤとして識別ＩＤ４が含まれている。   Subsequently, when the rear antenna 53 transmits the trigger signal Str, the valves 52c and 52d of the rear tires 51c and 51d close to the rear antenna 53 reliably receive the trigger signal Str. Therefore, when receiving the trigger signal Str, the valves 52c and 52d calculate the magnetic field strength Hs and transmit the tire pressure information Stp including the magnetic field strength Hs to the vehicle tuner 14. In the case of this example, the tire air pressure information Stp from the valve 52c includes the magnetic field strength Hs and the identification ID 3 as the unique ID of the valve 52c in addition to the current tire air pressure. In addition to the current tire pressure, the tire pressure information Stp of the valve 52d includes the magnetic field strength Hs and the identification ID 4 as the unique ID of the valve 52d.

なお、他タイヤ５１ａ，５１ｂのバルブ５２ａ，５２ｂは、リヤアンテナ５３から遠いので、基本的にはリヤアンテナ５３のトリガ信号Ｓtrを受信できない。但し、仮にトリガ信号Ｓtrを受信できても、極めて低いイ値の磁界強度Ｈｓを車両１に通知する。   Since the valves 52a and 52b of the other tires 51a and 51b are far from the rear antenna 53, basically, the trigger signal Str of the rear antenna 53 cannot be received. However, even if the trigger signal Str can be received, the vehicle 1 is notified of the extremely low magnetic field strength Hs.

照合ＥＣＵ９は、車両チューナ１４でタイヤ空気圧情報Ｓtpを受信すると、タイヤ位置を特定する。このとき、位置判定部２４は、それぞれの識別ＩＤ１〜ＩＤ４において、係数αを乗算した磁界強度Ｈｄと、係数γを乗算した磁界強度Ｈｓとの磁界強度差Ｈdsを算出し、Ｈds＞Ｈk1が成立するバルブ５２がどれなのかを確認する（図９参照）。なお、Ｈk1は、タイヤが車体前部側にあるのか否かを見るための閾値である。ここで、Ｈds＞Ｈk1が成立すれば、その識別ＩＤのバルブ５２は、図８に示す判定エリアＥr1に位置していると見なせる。よって、本例では、識別ＩＤ１がこの条件を満たすため、バルブ５２ａが右前タイヤ５１ａに取り付いていると判定される。   When the vehicle tuner 14 receives the tire pressure information Stp, the verification ECU 9 identifies the tire position. At this time, the position determination unit 24 calculates a magnetic field strength difference Hds between the magnetic field strength Hd multiplied by the coefficient α and the magnetic field strength Hs multiplied by the coefficient γ for each of the identifications ID1 to ID4, and Hds> Hk1 is established. Which valve 52 is to be checked is confirmed (see FIG. 9). Hk1 is a threshold value for checking whether the tire is on the front side of the vehicle body. Here, if Hds> Hk1 is established, it can be considered that the valve 52 of the identification ID is located in the determination area Er1 shown in FIG. Therefore, in this example, since the identification ID1 satisfies this condition, it is determined that the valve 52a is attached to the right front tire 51a.

また、位置判定部２４は、左後タイヤ５１ｄがどれなのかを確認するために、Ｈds＜Ｈk2が成立するバルブ５２がどれなのかを確認する。なお、Ｈk2は、タイヤが車体後部側にあるのか否かを見るための閾値である。ここで、Ｈds＜Ｈk2が成立すれば、その識別ＩＤのバルブ５２は、図８に示す判定エリアＥr2に位置していると見なせる。よって、本例では、識別ＩＤ４がこの条件を満たすため、バルブ５２ｄが左後タイヤ５１ｄに取り付いていると判定される。   Further, the position determination unit 24 checks which valve 52 satisfies Hds <Hk2 in order to check which is the left rear tire 51d. Hk2 is a threshold value for checking whether the tire is on the rear side of the vehicle body. Here, if Hds <Hk2 is established, it can be considered that the valve 52 of the identification ID is located in the determination area Er2 shown in FIG. Therefore, in this example, since the identification ID 4 satisfies this condition, it is determined that the valve 52d is attached to the left rear tire 51d.

さらに、位置判定部２４は、左前タイヤ５１ｂがどれなのかを確認するために、係数βを乗算した磁界強度Ｈｐと、係数γを乗算した磁界強度Ｈｓとの磁界強度差Ｈpsを算出し、Ｈps＞Ｈk1が成立するバルブ５２がどれなのかを確認する。ここで、Ｈps>Hk1が成立すれば、その識別ＩＤのバルブ５２は、図８に示す判定エリアＥr3に位置していると見なせる。よって、本例では、識別ＩＤ３がこの条件を満たすため、バルブ５２ｂが左前タイヤ５１ｂに取り付いていると判定される。   Further, the position determination unit 24 calculates the magnetic field strength difference Hps between the magnetic field strength Hp multiplied by the coefficient β and the magnetic field strength Hs multiplied by the coefficient γ in order to confirm which is the left front tire 51b. It is confirmed which valve 52 satisfies> Hk1. Here, if Hps> Hk1 is established, it can be considered that the valve 52 of the identification ID is located in the determination area Er3 shown in FIG. Therefore, in this example, since the identification ID3 satisfies this condition, it is determined that the valve 52b is attached to the left front tire 51b.

また、位置判定部２４は、右後タイヤ５１ｃがどれなのかを確認するために、Ｈps＜Hk2が成立するバルブ５２がどれなのかを確認する。ここで、Ｈps＜Hk2が成立すれば、その識別ＩＤのバルブ５２は、図８に示す判定エリアＥr4に位置していると見なせる。よって、本例では、識別ＩＤ３がこの条件を満たすため、バルブ５２ｃが右後タイヤ５１ｃに取り付いていると判定される。   In addition, the position determination unit 24 checks which valve 52 satisfies Hps <Hk2 in order to check which is the right rear tire 51c. Here, if Hps <Hk2 is established, it can be considered that the valve 52 of the identification ID is located in the determination area Er4 shown in FIG. Therefore, in this example, since the identification ID3 satisfies this condition, it is determined that the valve 52c is attached to the right rear tire 51c.

なお、スペアタイヤ（図示略）の位置特定は、例えばリヤアンテナ５３の単独送信においてその送信強度を抑えたり、後輪タイヤ（右後タイヤ５１ｃや左後タイヤ５１ｄ）とスペアタイヤとが受信する電波の磁界強度差を確認したりすることにより特定可能である。また、磁界強度差Ｈdsの比較結果と、磁界強度差Ｈpsの比較結果とのANDをとることによって特定することも可能である。   Note that the position of the spare tire (not shown) can be specified, for example, by suppressing the transmission intensity in the single transmission of the rear antenna 53, or by radio waves received by the rear wheel tire (the right rear tire 51c and the left rear tire 51d) and the spare tire. It can be specified by checking the magnetic field strength difference. It is also possible to specify by taking the AND of the comparison result of the magnetic field strength difference Hds and the comparison result of the magnetic field strength difference Hps.

本実施形態の構成によれば、前記実施形態に記載の（１）〜（６）の効果に加え、以下の効果を得ることができる。
（７）各タイヤハウスにイニシエータを配置しなくてもタイヤ５１ａ〜５１ｄの位置を特定することが可能となるので、タイヤ空気圧監視システム５０に必要な部品点数を少なく抑えることができる。また、タイヤ特定も精度よく行うことができる。 According to the configuration of the present embodiment, in addition to the effects (1) to (6) described in the embodiment, the following effects can be obtained.
(7) Since it is possible to specify the positions of the tires 51a to 51d without arranging an initiator in each tire house, the number of parts required for the tire pressure monitoring system 50 can be reduced. In addition, tire specification can be performed with high accuracy.

（８）キー操作フリーシステム３における車体側の通信インフラ（主に照合ＥＣＵ９、アンテナ１１，１３、車両チューナ１４等）をタイヤ空気圧監視システム５０にも共用するので、車両１に搭載される部品点数を削減することができる。   (8) Since the communication infrastructure on the vehicle body side (mainly, the verification ECU 9, the antennas 11 and 13, the vehicle tuner 14, etc.) in the key operation free system 3 is also shared with the tire pressure monitoring system 50, the number of components mounted on the vehicle 1 Can be reduced.

なお、実施形態はこれまでに述べた構成に限らず、以下の態様に変更してもよい。
・第１及び第２実施形態において、係数は、運転席側磁界強度Ｈｄと助手席側磁界強度Ｈｐとの両方に乗算することに限定されず、磁界強度Ｈｄ，Ｈｐの一方のみに乗算されるものでもよい。なお、これは第３実施形態の場合でも同様に言える。 Note that the embodiment is not limited to the configuration described so far, and may be modified as follows.
In the first and second embodiments, the coefficient is not limited to multiplying both the driver's seat side magnetic field strength Hd and the passenger seat side magnetic field strength Hp, but only one of the magnetic field strengths Hd and Hp. It may be a thing. This also applies to the third embodiment.

・第１〜第３実施形態において、係数α，β，γの値は、車両１の種類に応じて適宜変更可能としてもよい。
・第１〜第３実施形態において、係数α，βは、互いに異なる値をとることに限定されず、同じ値であってもよい。 In the first to third embodiments, the values of the coefficients α, β, and γ may be appropriately changed according to the type of the vehicle 1.
In the first to third embodiments, the coefficients α and β are not limited to taking different values, and may be the same value.

・第１〜第３実施形態において、電子キー２の車外位置は、運転席側及び助手席側のどちらにあるのかを細分して見ることに限らず、例えば車内外判定のみとしてもよい。
・第１及び第２実施形態において、アンテナは、運転席アンテナ１１と助手席アンテナ１３とラッゲージドアアンテナ４２の３つに限定されない。例えば、通信エリアのヌル点を埋める他のアンテナ設けて、車両アンテナを４本以上としてもよい。なお、これは第３実施形態にも応用可能である。 In the first to third embodiments, the position outside the vehicle of the electronic key 2 is not limited to subdividing whether it is on the driver's seat side or the passenger's seat side, and for example, only the inside / outside determination may be performed.
In the first and second embodiments, the number of antennas is not limited to three, that is, the driver's seat antenna 11, the passenger seat antenna 13, and the luggage door antenna 42. For example, another antenna that fills the null point in the communication area may be provided to provide four or more vehicle antennas. This can also be applied to the third embodiment.

・第１〜第３実施形態において、キー位置判定は、車内外又は車外位置を見ることに限定されない。即ち、電子キー２の位置を見るものであれば、位置判定の対象位置は特に限定しないものとする。   In the first to third embodiments, the key position determination is not limited to seeing the inside / outside or outside position of the vehicle. That is, if the position of the electronic key 2 is viewed, the position determination target position is not particularly limited.

・第１〜第３実施形態において、キー位置判定は、車内外及び車外位置の両方を見ることに限らず、どちらか一方でもよい。
・第１〜第３実施形態において、ウェイク信号２６は、運転者の所定操作をトリガとして送信が開始されることに限定されない。例えば、車両１が駐車状態の際、車両１に近づく電子キー２を常に監視するために、常時送信としてもよい。 In the first to third embodiments, the key position determination is not limited to viewing both the inside and outside of the vehicle and the outside position of the vehicle, and may be either one.
-In 1st-3rd embodiment, the wake signal 26 is not limited to starting transmission by a driver | operator's predetermined operation as a trigger. For example, when the vehicle 1 is in a parked state, the electronic key 2 approaching the vehicle 1 may be constantly monitored so that the transmission is always performed.

・第１〜第３実施形態において、磁界強度Ｈｄ，Ｈｐは、３軸のベクトル合成値を使用して算出されることに限らず、例えば３軸の中の最大値を使用してもよい。
・第１〜第３実施形態において、電子キー２やバルブ５２の受信アンテナは、３軸アンテナに限定されず、例えば１軸アンテナでもよい。 In the first to third embodiments, the magnetic field strengths Hd and Hp are not limited to being calculated using the three-axis vector composite value, and for example, the maximum value among the three axes may be used.
-In 1st-3rd embodiment, the receiving antenna of the electronic key 2 or the valve | bulb 52 is not limited to a triaxial antenna, For example, a uniaxial antenna may be sufficient.

・第１及び第２実施形態において、磁界強度Ｈｘの算出は、ウェイク信号２６ａ，２６ｂで行うことに限らず、例えばビークルＩＤ２８，３３やチャレンジ３０，３５により算出してもよい。また、第３実施形態においては、トリガ信号Ｓtrで磁界強度を求めることに限らず、他の信号でもよい。   In the first and second embodiments, the calculation of the magnetic field strength Hx is not limited to the wake signals 26a and 26b, and may be calculated by the vehicle IDs 28 and 33 and the challenges 30 and 35, for example. In the third embodiment, not only the magnetic field strength is obtained by the trigger signal Str but other signals may be used.

・第１及び第２実施形態において、キー位置判定は、電子キー２から磁界強度Ｈｘのデータを車両１が受け付けて、車両１側で行う形式に限定されない。例えば、キー位置判定までを全て電子キー２側で行い、その判定結果を車両１に通知する形式でもよい。なお、これは第３実施形態でも応用可能である。   -In 1st and 2nd embodiment, key position determination is not limited to the format which the vehicle 1 receives the data of the magnetic field strength Hx from the electronic key 2, and performs on the vehicle 1 side. For example, the key position determination may be performed entirely on the electronic key 2 side, and the determination result may be notified to the vehicle 1. This can also be applied to the third embodiment.

・第１〜第３実施形態において、受信強度は、受信電波の磁界強度Ｈｘに限定されず、電界強度としてもよい。
・第１〜第３実施形態において、スマート照合は、運転席アンテナ１１及び助手席アンテナ１３の両方で成立を条件とすることに限らず、どちらか一方のみとしてもよい。 In the first to third embodiments, the reception intensity is not limited to the magnetic field intensity Hx of the received radio wave, and may be an electric field intensity.
In the first to third embodiments, the smart verification is not limited to the condition that both the driver's seat antenna 11 and the passenger's seat antenna 13 are established, and only one of them may be used.

・第１〜第３実施形態において、リクエスト信号Ｓrqは、ＩＤ返信要求に限らず、電子キー２に応答を求める信号であればよい。
・第１〜第３実施形態において、電子キー２は、車両キーに限定されず、種々の端末（携帯電話、ＩＣカード等）が使用可能である。また、電子キー２は、必ずしもキー機能を持つものに限らず、広義として認証行為が必要な通信端末（認証端末）を広く含むものとする。 In the first to third embodiments, the request signal Srq is not limited to an ID reply request, and may be a signal that requests a response from the electronic key 2.
-In 1st-3rd embodiment, the electronic key 2 is not limited to a vehicle key, Various terminals (a mobile phone, an IC card, etc.) can be used. Further, the electronic key 2 is not necessarily limited to one having a key function, and widely includes communication terminals (authentication terminals) that require an authentication action in a broad sense.

・第１〜第３実施形態において、キー操作フリーシステム３は、相互通信の往路と復路とで周波数が異なることに限定されず、同じ周波数としてもよい。また、キー操作フリーシステム３の通信周波数は、ＬＦやＵＨＦに限らず、例えばＨＦ（High Frequency）等の他の周波数を使用してもよい。   In the first to third embodiments, the key operation free system 3 is not limited to having different frequencies in the forward path and the return path of mutual communication, and may have the same frequency. The communication frequency of the key operation free system 3 is not limited to LF and UHF, and other frequencies such as HF (High Frequency) may be used.

・第１〜第３実施形態において、無線システムや問い合せは、実施形態に述べた例に限定されず、本願思想の適用先に応じて適宜変更可能である。
・第１〜第３実施形態において、スマート通信の過程で車両１から電子キー２の電力電波を送信し、この電力電波により電子キー２を駆動させることで、電子キー２を電池レスとしてもよい。 -In 1st-3rd embodiment, a radio | wireless system and an inquiry are not limited to the example described in embodiment, It can change suitably according to the application place of this thought.
-In 1st-3rd embodiment, the electric key 2 of the electronic key 2 is transmitted from the vehicle 1 in the process of smart communication, and the electronic key 2 is driven by this electric power electric wave, and it is good also considering the electronic key 2 as a battery-less. .

・第１〜第３実施形態において、電子キーシステムは、キー操作フリーシステム３に限定されず、車両１と電子キー２とが相互無線通信によりＩＤ照合を行うものであればよい。   -In 1st-3rd embodiment, an electronic key system is not limited to the key operation free system 3, What is necessary is just what the vehicle 1 and the electronic key 2 perform ID collation by mutual wireless communication.

・各実施形態に記載の各種閾値、設定値、パラメータ、判定値等は、適宜変更可能である。
・第３実施形態において、車両チューナ１４は、タイヤ位置特定に際して同じバルブ５２から何度も同様の信号を得ることになるが、タイヤ空気圧の判定は、その中の特定の１つを採用すればよいし、平均値をとってもよい。 The various threshold values, setting values, parameters, determination values, and the like described in each embodiment can be changed as appropriate.
-In 3rd Embodiment, the vehicle tuner 14 will obtain the same signal many times from the same valve 52 at the time of tire position specification, but if the specific one of them is adopted for judgment of tire air pressure, You may take an average value.

・第３実施形態において、タイヤ空気圧監視システム５０のコントロールユニットは、照合ＥＣＵ９が兼ねることに限定されず、専用のＥＣＵを設けてもよい。
・第１〜第３実施形態において、キー操作フリーシステム３及びタイヤ空気圧監視システム５０は、車体側の通信インフラが共用されることに限定されず、各システムで機能が独立していてもよい。また、本例の技術思想は、車両１に搭載されることに限らず、他の機器や装置に採用可能である。 -In 3rd Embodiment, the control unit of the tire pressure monitoring system 50 is not limited to what collation ECU9 serves, and you may provide dedicated ECU.
In the first to third embodiments, the key operation free system 3 and the tire pressure monitoring system 50 are not limited to sharing the communication infrastructure on the vehicle body side, and the functions may be independent in each system. In addition, the technical idea of this example is not limited to being mounted on the vehicle 1 but can be applied to other devices and apparatuses.

次に、上記実施形態及び別例から把握できる技術的思想について、それらの効果とともに以下に追記する。
（イ）請求項１〜５のいずれかにおいて、前記位置判定手段は、係数乗算後の前記強度差とその判定閾値とを比較することにより、前記通信端末の位置を判定する。この構成によれば、係数乗算後の強度差と判定閾値とを比較するという簡素な処理によって、電子キーの位置を判定することが可能となる。 Next, technical ideas that can be grasped from the above-described embodiment and other examples will be described below together with their effects.
(A) In any one of claims 1 to 5, the position determination means determines the position of the communication terminal by comparing the intensity difference after coefficient multiplication with a determination threshold value. According to this configuration, the position of the electronic key can be determined by a simple process of comparing the strength difference after the coefficient multiplication and the determination threshold.

（ロ）請求項１〜５、前記技術的思想（イ）のいずれかにおいて、前記位置判定手段は、第１受信強度及び前記第２受信強度の両方前記係数を乗算し、係数乗算を経た後の前記第１受信強度及び前記第２受信強度により前記強度差を算出する。   (B) In any one of claims 1 to 5 and the technical idea (a), the position determination means multiplies both the first reception strength and the second reception strength by the coefficients, and passes through the coefficient multiplication. The strength difference is calculated from the first received strength and the second received strength.

（ハ）請求項１〜５、前記技術的思想（イ），（ロ）のいずれかにおいて、前記位置判定手段は、前記通信端末が前記通信マスタの室外及び室内のどちらに位置するのかを判定する。この構成によれば、通信端末が通信マスタの室内及び室外のどちらに位置するのかを、より正確に判定することが可能となる。   (C) In any one of claims 1 to 5 and technical ideas (a) and (b), the position determination means determines whether the communication terminal is located outside or indoors of the communication master. To do. According to this configuration, it is possible to more accurately determine whether the communication terminal is located inside or outside the communication master.

（二）請求項１〜５、前記技術的思想（イ）〜（ハ）のいずれかにおいて、前記位置判定手段は、２つの前記受信強度の前記強度差を、正負を持つ値で算出し、当該強度差を基に前記通信端末の位置を判定する。この構成によれば、通信端末が一アンテナ及び他アンテナのどちら側に位置するのかまで見ることが可能となるので、より精度よく通信端末の位置を判定することが可能となる。   (2) In any one of claims 1 to 5 and the technical thoughts (a) to (c), the position determination means calculates the intensity difference between two received strengths as a value having a positive and negative value, The position of the communication terminal is determined based on the intensity difference. According to this configuration, since it is possible to see which side of the communication terminal is located on one antenna or the other antenna, the position of the communication terminal can be determined with higher accuracy.

１…車両、２…通信端末を構成する電子キー、３…無線システム及び電子キーシステムを構成するキー操作フリーシステム、９…通信マスタとしての照合ＥＣＵ、１１…一アンテナ及び他アンテナを構成する運転席アンテナ、１３…一アンテナ及び他アンテナを構成する助手席アンテナ、１８…位置判定装置、２０…受信強度算出手段を構成する磁界強度算出部、２１…受信強度算出手段を構成する磁界強度通知部、２２…受信強度算出手段を構成する磁界強度取得部、２３…位置判定手段を構成する係数乗算部、２４…位置判定手段を構成する位置判定部、４２…一アンテナ及び他アンテナを構成するラッゲージドアアンテナ、５０…無線システムを構成するタイヤ空気圧監視システム、５１（５１ａ〜５１ｄ）…タイヤ、５２…通信端末及びタイヤ通信機を構成するバルブ、５３…一アンテナ及び他アンテナを構成するリヤアンテナ、Ｈｄ…第１受信強度及び第２受信強度を構成する運転席側磁界強度、Ｈｐ…第１受信強度及び第２受信強度を構成する助手席側磁界強度、Ｈｒ…第１受信強度及び第２受信強度を構成するラッゲージドア側磁界強度、Ｈdp，Ｈdr，Ｈpr…強度差としての磁界強度差、α，β，γ…係数。   DESCRIPTION OF SYMBOLS 1 ... Vehicle, 2 ... Electronic key which comprises a communication terminal, 3 ... Key operation free system which comprises a wireless system and an electronic key system, 9 ... Verification ECU as a communication master, 11 ... Operation which comprises one antenna and another antenna Seat antenna, 13 ... Passenger seat antenna constituting one antenna and other antenna, 18 ... Position determination device, 20 ... Magnetic field intensity calculation unit constituting reception intensity calculation means, 21 ... Magnetic field intensity notification part constituting reception intensity calculation means , 22 ... Magnetic field intensity acquisition unit constituting reception intensity calculation means, 23 ... Coefficient multiplication part constituting position judgment means, 24 ... Position judgment part constituting position judgment means, 42 ... Luggage constituting one antenna and other antennas Door antenna, 50 ... tire pressure monitoring system constituting wireless system, 51 (51a-51d) ... tire, 52 ... communication terminal And a valve constituting the tire communicator, 53 ... a rear antenna constituting one antenna and another antenna, Hd ... a driver seat side magnetic field intensity constituting a first reception intensity and a second reception intensity, Hp ... a first reception intensity and a first antenna 2 Passenger side magnetic field strength constituting reception strength, Hr... First reception strength and second reception strength constituting luggage door side magnetic field strength, Hdp, Hdr, Hpr ... Magnetic field strength difference as strength difference, α, β, γ ... coefficient.

Claims (5)

通信マスタからの問い合せに通信端末が応答して、これらが双方向通信する無線システムに使用される通信端末位置判定装置において、
前記通信マスタの一アンテナ及び他アンテナから交互に電波が送信された際、前記一アンテナからの電波を前記通信端末が受信した際の第１受信強度と、前記他アンテナからの電波を前記通信端末が受信した際の第２受信強度とを算出する受信強度算出手段と、
２つの前記受信強度の少なくとも一方に、位置誤判定をキャンセルできる係数を乗算し、該乗算の後、２つの当該受信強度の差を算出し、この強度差を基に前記通信端末の位置を判定する位置判定手段と
を備えたことを特徴とする通信端末位置判定装置。 In the communication terminal position determination device used in the wireless system in which the communication terminal responds to the inquiry from the communication master and these communicate bidirectionally,
When radio waves are transmitted alternately from one antenna and another antenna of the communication master, a first reception intensity when the communication terminal receives radio waves from the one antenna, and radio waves from the other antennas are transmitted to the communication terminal. Receiving strength calculating means for calculating the second receiving strength at the time of receiving,
Multiply at least one of the two received strengths by a coefficient capable of canceling a position error determination, calculate the difference between the two received strengths after the multiplication, and determine the position of the communication terminal based on the strength difference A communication terminal position determining device. 前記通信マスタのアンテナは、少なくとも３つ以上設けられ、前記位置判定手段は、少なくとも３つ以上設けた前記アンテナにおいて、各々の２つずつを組みとして該組み同士の前記強度差を算出し、当該強度差から前記通信端末の位置を細分して判定する
ことを特徴とする請求項１に記載の通信端末位置判定装置。 At least three or more antennas of the communication master are provided, and the position determination unit calculates the intensity difference between the two sets of each of the two antennas provided as a set, and The communication terminal position determination apparatus according to claim 1, wherein the position of the communication terminal is subdivided and determined from an intensity difference. 前記通信端末は、電子キーであり、
前記無線システムは、前記通信マスタが前記電子キーとＩＤ照合する電子キーシステムであり、
前記位置判定手段は、前記電子キーの位置を判定する
ことを特徴とする請求項１又は２に記載の通信端末位置判定装置。 The communication terminal is an electronic key;
The wireless system is an electronic key system in which the communication master performs ID verification with the electronic key,
The communication terminal position determination apparatus according to claim 1, wherein the position determination unit determines a position of the electronic key. 前記通信端末は、車両の各タイヤに取り付けられたタイヤ通信機であり、
前記無線システムは、前記タイヤ通信機からタイヤ空気圧を無線により取得するタイヤ空気圧監視システムであり、
前記位置判定手段は、前記タイヤ通信機の位置を判定することにより、タイヤの位置を特定する
ことを特徴とする請求項１〜３のうちいずれか一項に記載の通信端末位置判定装置。 The communication terminal is a tire communication device attached to each tire of a vehicle,
The wireless system is a tire pressure monitoring system that wirelessly acquires tire pressure from the tire communication device,
The communication terminal position determination device according to any one of claims 1 to 3, wherein the position determination unit specifies a position of a tire by determining a position of the tire communication device. 前記通信端末としての電子キーとＩＤ照合する前記無線システムとしての電子キーシステムと、前記通信端末としてのタイヤ通信機から無線によりタイヤ空気圧を取得する前記無線システムとしてのタイヤ空気圧監視システムとは、１つの前記通信マスタを共用する
ことを特徴とする請求項１〜４のうちいずれか一項に記載の通信端末位置判定装置。 An electronic key system as the wireless system for ID verification with an electronic key as the communication terminal, and a tire pressure monitoring system as the wireless system for acquiring tire pressure wirelessly from a tire communication device as the communication terminal are: The said communication master is shared, The communication terminal position determination apparatus as described in any one of Claims 1-4 characterized by the above-mentioned.
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