JP2017179873A - Key position detection system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a key position detection system capable of accurately determining a key position.SOLUTION: An electronic key 2 acquires magnetic flux direction data Da and reception signal intensity data Dc at the time of receiving a radio wave transmitted from a vehicle 1 and key direction information Db as the electronic key 2's direction at the same time. The vehicle 1 acquires communication target direction information Dd as the vehicle 1's direction. A position determination unit 34 determines the electronic key 2's position on the basis of the magnetic flux direction data Da, key direction information Db, reception signal intensity data Dc, and communication target direction information Dd.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a key position detection system that detects the position of an electronic key.

  2. Description of the Related Art Conventionally, as a kind of electronic key system for a vehicle, a key operation free system that performs ID verification (smart verification) with an electronic key triggered by communication from the vehicle is well known (see Patent Document 1, etc.). In this type of key operation free system, the vehicle is provided with an outside LF antenna and an inside LF antenna for smart communication, and when the electronic key responds to the radio wave transmitted from the outside LF antenna, the electronic key is placed outside the vehicle. When the electronic key responds to the radio wave transmitted from the in-vehicle LF antenna, it is recognized that the electronic key is in the vehicle. When smart verification is established outside the vehicle, locking / unlocking of the vehicle door is permitted or executed, and when smart verification is established inside the vehicle, start operation of the vehicle engine is permitted.

JP 2005-262915 A

However, the above-described electronic key system can only determine whether the electronic key is located outside the vehicle or inside the vehicle, and cannot determine the detailed key position.
The objective of this invention is providing the key position detection system which can determine a key position in detail.

  The key position detection system that solves the problem is transmitted from the communication target through an ID verification communication network in a configuration that detects the position of the electronic key when the electronic key performs ID verification communication with the communication target. Key direction information from a magnetic flux direction acquisition unit that acquires a magnetic flux direction of the radio wave when the radio key is received by the electronic key, and a key direction detection unit provided in the electronic key to detect the direction of the electronic key. Position determination for determining the position of the electronic key based on the key direction acquisition unit to be acquired, the magnetic flux direction acquired by the magnetic flux direction acquisition unit, and the direction of the electronic key obtained from the output of the key direction detection unit And a communication correctness determination unit that determines whether the ID collation communication is correct based on the determination result of the position determination unit.

  According to this configuration, when determining the position of the electronic key during communication for ID verification, the magnetic flux direction when the electronic key receives the radio wave transmitted from the communication target and the direction of the electronic key at that time. The key position is specified as a determination element. Therefore, for example, it is possible to determine the key position in more detail than when determining the position of the electronic key based on whether or not the electronic key has received radio waves.

  In the key position detection system, the key direction detection unit preferably includes a G sensor. This configuration is advantageous for accurately determining the key orientation by the G sensor.

  In the key position detection system, the key direction detection unit preferably includes a geomagnetic sensor. This configuration is advantageous for accurately determining the key direction by the geomagnetic sensor.

  The key position detection system includes a signal strength acquisition unit that acquires a received signal strength when a radio wave is received in a communication process between the electronic key and a communication target, and the position determination unit also determines the received signal strength. It is preferable to determine the position of the electronic key. According to this configuration, since the received signal strength is added to the key position determination element, it is more advantageous to determine the key position more correctly.

  The key position detection system includes a communication target direction acquisition unit that acquires communication target direction information from a communication target direction detection unit provided in the communication target to detect the direction of the communication target, and the position determination unit includes: It is preferable to determine the position of the electronic key in addition to the determination factor of the direction of the communication target obtained from the output of the communication target direction detection unit. According to this configuration, since the direction of the communication target is added to the key position determination element, it is further advantageous to determine the key position more correctly.

  In the key position detection system, the ID collation is a smart collation that collates an electronic key ID wirelessly with communication from the communication target, and a series of processes for determining the position of the electronic key includes the smart collation. It is preferable to be executed in the communication process of performing. According to this configuration, the key position determination can be performed in parallel with the smart communication, which is advantageous in efficiently performing the key position determination.

  According to the present invention, the key position can be determined in detail.

The block diagram of the key position detection system of one Embodiment. The schematic diagram of the electromagnetic wave transmitted from the electromagnetic wave transmitter of a vehicle. Schematic diagram when electronic key radio waves are transmitted from the electronic key. The schematic diagram of the magnetic flux direction provided to an electronic key in each position of an electronic key. (A), (b) is a schematic diagram of the magnetic flux direction provided to an electronic key in each direction of a vehicle.

Hereinafter, an embodiment of a key position detection system will be described with reference to FIGS.
As shown in FIG. 1, the vehicle 1 includes an electronic key system 3 that performs ID verification wirelessly with the electronic key 2. An electronic key ID is written and stored in the electronic key 2 as an ID unique to the key. The electronic key system 3 of this example is a key operation free system that implements ID collation with the electronic key 2 through narrow area communication triggered by communication from the vehicle 1. Generally, ID collation performed in a key operation free system is called “smart collation”, and the communication is called “smart communication”.

  The vehicle 1 includes a collation ECU (Electronic Control Unit) 4 that performs ID collation (smart collation), a body ECU 5 that manages the power supply and drive of in-vehicle electrical components, and an engine ECU 6 that controls the engine 7. These ECUs are electrically connected through a communication line 8 in the vehicle. The communication line 8 is composed of, for example, a CAN (Controller Area Network) or a LIN (Local Interconnect Network). In the verification ECU 4, the electronic key ID of the electronic key 2 registered in the vehicle 1 is written and stored in a memory (not shown). The vehicle 1 includes a radio wave transmitter 10 that transmits radio waves in the vehicle 1 and a radio wave receiver 11 that receives radio waves in the vehicle 1. The radio wave transmitter 10 transmits an LF (Low Frequency) band radio wave, for example. The radio wave receiver 11 receives, for example, UHF (Ultra High Frequency) radio waves. Thus, the electronic key system 3 of this example is LF-UHF bidirectional communication. The body ECU 5 switches the locking / unlocking of the vehicle door by controlling the operation of the door lock mechanism 12 provided on the vehicle door.

  The electronic key 2 includes a key control unit 15 that controls the operation of the electronic key 2, a receiving unit 16 that enables radio wave reception by the electronic key 2, and a transmission unit 17 that enables radio wave transmission by the electronic key 2. . In the key control unit 15, an electronic key ID is written and stored in a memory (not shown) as an ID unique to the key. The receiving unit 16 receives, for example, LF radio waves. The transmission unit 17 transmits, for example, UHF radio waves.

  When the electronic key 2 enters the communication area of the wake signal Swk periodically transmitted by the radio wave of the LF band from the radio wave transmitter 10, and the electronic key 2 receives the wake signal Swk, the electronic key 2 is activated, and as a response An ACK signal Sack is transmitted to the vehicle 1 by UHF. When the vehicle 1 receives the ACK signal Sack from the electronic key 2 after transmission of the wake signal Swk and communication (smart communication) is established between them, smart verification (smart verification) by bidirectional communication of LF-UHF starts. Is done. The smart verification includes vehicle code verification for authenticating a unique vehicle code of the vehicle 1, challenge response authentication using an encryption key (authentication key), and electronic key ID verification for authenticating an electronic key ID. The verification ECU 4 checks whether or not all of these verifications and authentications are established with the electronic key 2.

  When communication (smart communication) is established with the electronic key 2 located outside the vehicle, the verification ECU 4 performs smart verification (outdoor smart verification) and confirms that the verification is established. Permit or execute the locking and unlocking. Further, when communication (smart communication) is established with the electronic key 2 located in the vehicle, the verification ECU 4 executes smart verification (indoor smart verification) in the same manner as when outdoors, and confirms that the verification is established. If confirmed, the vehicle power supply transition operation (for example, engine start operation) is permitted.

  As shown in FIG. 2, the electronic key system 3 includes a key position detection function (key position detection system 21) that enables the position of the electronic key 2 to be detected in detail. The key position detection system 21 of this example includes a magnetic flux direction Bh detected by the electronic key 2 at the time of communication, the direction of the electronic key 2 obtained from the output of the key direction detection unit 22 provided on the electronic key 2, and at the time of communication. The received signal strength indicator (RSSI) of the obtained radio wave and the direction of the communication target 23 obtained from the output of the communication target direction detection unit 24 provided in the communication target 23 (this example is the vehicle 1, the same applies hereinafter). Based on this, the position of the electronic key 2 is determined.

  The key position detection system 21 acquires a magnetic flux direction Bh of a radio wave when the electronic key 2 receives a radio wave transmitted from a communication target 23 (vehicle 1 in this example) through an ID verification communication network (smart communication network). A magnetic flux direction acquisition unit 27 is provided. The magnetic flux direction acquisition unit 27 is provided in the key control unit 15. The magnetic flux direction acquisition unit 27 preferably acquires information on the magnetic flux direction Bh in a communication process in which smart verification is performed. In this example, the antenna of the receiving unit 16 of the electronic key 2 receives an X-axis antenna that receives radio wave components in the X-axis direction, a Y-axis antenna that receives radio wave components in the Y-axis direction, and receives radio wave components in the Z-axis direction. The Z-axis antenna is a three-axis antenna, and the three-axis component of the radio wave is acquired as the magnetic flux direction data Da as the magnetic flux direction Bh.

  The key position detection system 21 includes a key direction acquisition unit 28 that acquires key direction information Db from a key direction detection unit 22 provided in the electronic key 2. The key direction acquisition unit 28 is provided in the key control unit 15. The key direction acquisition unit 28 is preferably executed at the same timing as the detection of the magnetic flux direction Bh, for example. The key direction detection unit 22 preferably includes, for example, both a G sensor (acceleration sensor) that detects acceleration generated in the electronic key 2 and a geomagnetic sensor that detects the orientation of the electronic key 2.

  The key position detection system 21 includes a signal strength acquisition unit 29 that acquires a received signal strength (RSSI) when a radio wave is received in the communication process between the electronic key 2 and the communication target 23. The signal strength acquisition unit 29 is provided in the key control unit 15. The signal strength acquisition unit 29 acquires the received signal strength (received signal strength data Dc) when the receiving unit 16 receives the LF band radio wave transmitted from the vehicle 1.

  The key position detection system 21 uses the magnetic flux direction data Da obtained by the magnetic flux direction acquisition unit 27, the key direction information Db obtained by the key direction acquisition unit 28, and the received signal strength data Dc obtained by the signal strength acquisition unit 29. The information notification unit 30 that wirelessly notifies the communication target 23 (the vehicle 1 in this example) from the electronic key 2 is provided. The information notification unit 30 is provided in the key control unit 15. The information notification unit 30 UHF transmits a data group including the magnetic flux direction data Da, the key direction information Db, and the received signal strength data Dc to the vehicle 1 as the electronic key information Sk.

  The key position detection system 21 includes a communication target direction acquisition unit 33 that acquires communication target direction information Dd from a communication target direction detection unit 24 provided in the communication target 23. The communication target direction acquisition unit 33 is provided in the verification ECU 4. The communication target direction acquisition unit 33 preferably acquires the communication target direction information Dd at the timing of receiving the electronic key information Sk from the electronic key 2, for example. The communication target direction detection unit 24 is preferably a geomagnetic sensor that detects the orientation of the vehicle 1, for example.

  The key position detection system 21 includes a position determination unit 34 that determines the position of the electronic key 2 based on the electronic key information Sk received from the electronic key 2. The position determination unit 34 is provided in the verification ECU 4. The position determination unit 34 of this example includes the magnetic flux direction Bh acquired by the magnetic flux direction acquisition unit 27, the direction of the electronic key 2 obtained from the output of the key direction detection unit 22, and the reception signal acquired by the signal strength acquisition unit 29. The position of the electronic key 2 is determined based on the strength and the direction of the communication target 23 obtained from the output of the communication target direction detection unit 24. The key position obtained in this example is the position of the electronic key 2 with respect to the vehicle 1, and is not limited to the key position outside the vehicle, and the key position inside the vehicle may be specified.

  The key position detection system 21 includes a communication correctness determination unit 35 that determines whether communication of ID verification (smart verification) is correct based on the determination result of the position determination unit 34. The communication correctness determination unit 35 is provided in the verification ECU 4. A series of processing for determining the position of the electronic key 2 (acquisition of magnetic flux direction Bh, acquisition of key direction, acquisition of RSSI, acquisition of communication target direction, position determination) is preferably executed in the process of performing smart verification. .

Next, the operation and effect of the key position detection system 21 will be described with reference to FIGS.
As shown in FIG. 2, when the electronic key 2 receives a radio wave (LF radio wave Slf) transmitted from the radio wave transmitter 10 (vehicle 1) in the communication process of smart verification, the magnetic flux direction acquisition unit 27 is connected to the triaxial antenna. The magnetic flux direction Bh (magnetic field direction) in the three-axis direction of the received LF radio wave Slf is acquired based on the output from the receiving unit 16. Specifically, information on the magnetic flux direction Bh (magnetic flux direction data Da) of the LF radio wave Slf is acquired by a combination of the X-axis component, the Y-axis component, and the Z-axis component of the LF radio wave Slf received by the 3-axis antenna. The LF radio wave Slf may be an electric wave transmitted from the vehicle 1 such as a challenge code used in challenge response authentication or a vehicle ID that is a unique ID of the vehicle 1 in addition to the wake signal Swk.

  2 shows an example in which the radio wave transmitters 10 are arranged on the left and right sides of the vehicle body (the driver's seat side and the passenger seat side) and the communication areas for the LF radio waves Slf are formed on both the left and right sides. The number and arrangement position of 10 are not limited to the patterns of the embodiments. In addition, an LF band communication area is formed in the vehicle 1 (inside the vehicle) by the radio wave transmitter 10, but this is omitted in the figure.

  The key direction acquisition unit 28 acquires the output of the key direction detection unit 22 when the electronic key 2 receives the LF radio wave Slf. That is, the key direction information Db necessary for determining the direction (tilt) of the electronic key 2 is acquired from the key direction detection unit 22.

  Further, when the electronic key 2 receives the LF radio wave Slf, the signal intensity acquisition unit 29 measures the received signal intensity (RSSI) of the received LF radio wave Slf based on the output from the reception unit 16. Specifically, the received signal strength of the X-axis antenna, the received signal strength of the Y-axis antenna, and the received signal strength of the Z-axis antenna are combined, and the combined value is used as received signal strength data Dc of the LF radio wave Slf. get.

  As shown in FIG. 3, when the magnetic key direction data Da, the key direction information Db, and the received signal strength data Dc can be obtained in the electronic key 2, the information notifying unit 30 uses these information groups as the electronic key information Sk. Send to. In this example, the information notification unit 30 transmits the electronic key information Sk to the vehicle 1 by UHF radio waves. The electronic key information Sk includes magnetic flux direction data Da, key direction information Db, and received signal strength data Dc. The verification ECU 4 (vehicle 1) receives the electronic key information Sk transmitted UHF from the electronic key 2 by the radio wave receiver 11.

  The communication target direction acquisition unit 33 acquires the output of the communication target direction detection unit 24 when the vehicle 1 receives the electronic key information Sk. That is, the communication target direction information Dd necessary for determining the direction of the vehicle 1 is acquired from the communication target direction detection unit 24.

  The position determination unit 34 determines the position of the electronic key 2 based on the magnetic flux direction data Da, the key direction information Db, the received signal strength data Dc, and the communication target direction information Dd. In the case of this example, the memory of the verification ECU 4 stores the correspondence between the combination of “magnetic flux direction data Da, key direction information Db, received signal strength data Dc, communication target direction information Dd” and the position of the electronic key 2 with respect to the vehicle 1. Determination data (mapping data) Dk is written and stored in advance as information whose relationship is defined by actual measurement. Then, the position determination unit 34 compares the parameter group “magnetic flux direction data Da, key direction information Db, received signal strength data Dc, communication target direction information Dd” acquired at the time of key position determination with the determination data Dk in the memory ( Mapping), the position of the electronic key 2 is specified.

  In FIG. 4, the example figure of the magnetic flux direction Bh provided to the electronic key 2 of each position is shown. As shown in the figure, the magnetic key direction 2h is different between the electronic key 2a located at the point Pa and the electronic key 2b located at the point Pb, so that these key positions can be distinguished. In this way, the position determination unit 34 specifies the position of the electronic key 2. Then, the verification ECU 4 confirms that a series of verifications and authentications are established, and if it is confirmed that the electronic key 2 is present within the prescribed area outside the vehicle (position sufficiently close to the vehicle 1), the smart verification outside the vehicle is established. Process as. Thereby, the locking / unlocking of the vehicle door by the body ECU 5 is permitted or executed.

  By the way, in the electronic key 2c and the electronic key 2a located in the point Pc, both the magnetic flux direction Bh and the key direction are the same. At this time, if the key position determination elements are only the magnetic flux direction Bh and the key direction, the positions of the electronic keys 2a and 2c cannot be distinguished even though the positions are different. However, in this example, since the received signal strength data Dc is added to the key position determination element, it is possible to distinguish the electronic keys 2a and 2c having different positions.

  5A and 5B show examples of the magnetic flux direction Bh applied to the electronic key 2 when the direction of the vehicle 1 is changed. As shown in the figure, for example, when the key position is determined only by the magnetic flux direction Bh in the electronic key 2, the electronic key 2d when the vehicle 1 faces the front (state of FIG. 5A) and the vehicle 1 are oblique. If the magnetic key direction 2h is applied in the same direction in the electronic key 2e (the state shown in FIG. 5B) when facing the vehicle, the electronic key 2 is in a different position with respect to the vehicle 1. Nevertheless, they cannot be distinguished. Therefore, in the case of this example, since the vehicle orientation information Dd is also used as a determination element, the electronic keys 2d and 2e can be distinguished. Therefore, it becomes more advantageous to determine the key position more correctly.

  In the case of this example, when determining the position of the electronic key 2 during ID verification (smart verification) communication, the electronic key 2 has received the radio wave (LF radio wave Slf) transmitted from the vehicle 1 that is the communication target 23. The key position is specified using the current magnetic flux direction Bh and the direction of the electronic key 2 at that time as determination factors. Therefore, for example, the key position can be determined in more detail than in the case where the position of the electronic key 2 is determined based on whether or not the electronic key 2 has received radio waves. In particular, in the case of this example, as the key position determination element, the received signal strength when the electronic key 2 receives the LF radio wave Slf of the vehicle 1 and the direction of the vehicle 1 are further added, so that the key position is determined more correctly. This is even more advantageous.

The key direction detection unit 22 of this example includes a G sensor. Therefore, it is advantageous to accurately determine the key direction by the G sensor.
Moreover, the key direction detection part 22 of this example contains a geomagnetic sensor. Therefore, it is advantageous to accurately determine the key direction by the geomagnetic sensor. In particular, if the key direction detection unit 22 is composed of both the G sensor and the geomagnetic sensor, it is more advantageous to accurately detect the key direction.

  A series of processing for determining the position of the electronic key 2 is executed in a communication process in which smart matching is performed. Therefore, it is possible to perform key position determination in parallel with smart communication, which is advantageous for efficient key position determination.

Note that the embodiment is not limited to the configuration described so far, and may be modified as follows.
When the position of the electronic key 2 is not known in the vehicle, the position of the electronic key 2 may be specified using the key position detection system 21 of this example. In this case, when the position of the electronic key 2 can be specified, the key position can be notified to the user by displaying the key position on the screen of the car navigation system in the vehicle.

  -If the key position detection system 21 of this example is used, it can be discriminate | determined in which seat in the vehicle the holder of the electronic key 2 is. For example, when a person who has the electronic key 2 of another vehicle is in the vehicle, this history can be left in the vehicle 1.

  -If the key position detection system 21 of this example is used, since a user's motion outside a vehicle can be grasped | ascertained, it becomes possible to estimate a user's action. Thereby, for example, when the user who possesses the electronic key 2 approaches the vehicle 1, the vehicle door is automatically unlocked, or conversely, when the user who possesses the electronic key 2 leaves the vehicle 1, Can be locked automatically.

The key position determination is not limited to being performed on the vehicle 1 side, but may be performed on the electronic key 2 side.
The key position determination is not limited to the method of comparing the acquired data and the mapping data, and can be changed to various methods such as specifying the key position by calculating the data itself.

The receiving unit 16 is not limited to a triaxial antenna, and may be, for example, a uniaxial or biaxial antenna.
The key position determination may be performed at a timing different from the ID verification communication. For example, key position determination may be performed in advance before performing ID collation, or key position determination may be performed separately after performing ID collation.

-The frequency of the radio wave used in the electronic key system 3 may be changed to a frequency other than LF and UHF.
The communication of the electronic key system 3 can use various standards such as Bluetooth (registered trademark).

The electronic key system 3 is not limited to a smart communication system, and may be any system that executes ID collation communication triggered by communication from the communication target 23.
-ID collation is not limited to smart collation, What is necessary is just the authentication which confirms the right or wrong of the electronic key 2. FIG.

The electronic key 2 may be changed to another terminal such as a high function mobile phone.
The communication target 23 is not limited to the vehicle 1 and may be a partner that can communicate with the electronic key 2.
The key position determination may be performed using only the magnetic flux direction Bh and the key direction as determination elements. That is, if only the magnetic flux direction Bh and the key direction are used as the determination elements, the presence and combination of other determination elements can be set as appropriate.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle which is an example of communication object, 2 ... Electronic key, 3 ... Electronic key system, 21 ... Key position detection system, 22 ... Key direction detection part, 23 ... Communication object, 24 ... Communication object direction detection part, 27 ... Magnetic flux direction acquisition unit, 28 ... Key direction acquisition unit, 29 ... Signal strength acquisition unit, 30 ... Information notification unit, 33 ... Communication target direction acquisition unit, 34 ... Position determination unit, 35 ... Communication correctness determination unit, Bh ... Magnetic flux direction , Da: magnetic flux direction data, Db: key direction information, Dc: received signal strength data, Dd: communication target direction information.

Claims (6)

In the key position detection system that detects the position of the electronic key when the electronic key communicates with the communication target for ID verification,
A magnetic flux direction acquisition unit that acquires a magnetic flux direction of the radio wave when the electronic key receives a radio wave transmitted from the communication target through an ID verification communication network;
A key direction acquisition unit for acquiring key direction information from a key direction detection unit provided in the electronic key to detect the direction of the electronic key;
A position determination unit that determines the position of the electronic key based on the magnetic flux direction acquired by the magnetic flux direction acquisition unit and the direction of the electronic key obtained from the output of the key direction detection unit;
A key position detection system comprising: a communication correctness determination unit that determines whether the ID verification communication is correct based on a determination result of the position determination unit. The key position detection system according to claim 1, wherein the key direction detection unit includes a G sensor. The key position detection system according to claim 1, wherein the key direction detection unit includes a geomagnetic sensor. A signal strength acquisition unit that acquires a received signal strength when a radio wave is received in a communication process between the electronic key and a communication target;
The key position detection system according to any one of claims 1 to 3, wherein the position determination unit determines a position of the electronic key in addition to an element of determination of the received signal strength. A communication target direction acquisition unit that acquires communication target direction information from a communication target direction detection unit provided in the communication target in order to detect the direction of the communication target;
The said position determination part determines the position of the said electronic key in addition to the element of the determination of the direction of the said communication object calculated | required from the output of the said communication object direction detection part. Key position detection system. The ID collation is a smart collation that collates electronic key IDs wirelessly triggered by communication from the communication target,
The key position detection system according to any one of claims 1 to 5, wherein a series of processes for determining the position of the electronic key is executed in a communication process in which the smart matching is performed.

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