JP2012144149A - Electronic key system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve security performance, in an electronic key system.SOLUTION: When determining that a vehicle door is unlocked by mechanical collation via a mechanical key 18 or the vehicle door is illegally unlocked, a mode is transferred to a precaution mode. In this mode, an engine is started only when electric collation in an immobilizer system is established. Here, in the immobilizer system, there is no risk of performing illegal communication of using a repeater differently from a key operation free system. Thus, the security performance as the whole electronic key system can be improved.

Description

  The present invention relates to an electronic key system.

  The conventional electronic key system can lock and unlock the vehicle door, start the engine, and the like when electrical verification is established through wireless communication between the electronic key and the vehicle. Specifically, the electronic key transmits a wireless signal including a unique ID code to the vehicle. The vehicle performs electrical verification through verification of an ID code included in the received wireless signal and an ID code stored in advance in the vehicle.

  In addition to the electronic key system described above, the vehicle is configured to be able to switch the locking / unlocking state of the vehicle door when mechanical verification is established between the key pattern of the mechanical key and the key cylinder of the vehicle door. A mechanical key system (see, for example, Patent Document 1).

JP 2009-293247 A

  Here, the mechanical verification in the mechanical key system has fewer key patterns than the electrical verification in the electronic key system. It is also conceivable that the mechanical key is forged or the key cylinder is picked. Thus, mechanical verification is less secure than electrical verification. However, even when the vehicle door is unlocked through either mechanical verification or electrical verification, the verification required for starting the engine is the same. Therefore, the security level as a vehicle differs depending on the verification method.

  The present invention has been made in view of these circumstances, and an object thereof is to provide an electronic key system with improved security.

Hereinafter, means for achieving the above-described object and its operation and effects will be described.
According to a first aspect of the present invention, there is provided an electronic key mounted on a vehicle having a mechanical key system for performing mechanical verification through a key pattern of a mechanical key and permitting unlocking of a vehicle door when the verification is established. In the system, when the electronic key receives a request signal transmitted from the in-vehicle device to the inside / outside of the vehicle, the electronic key transmits a response signal including an ID code, and the in-vehicle device performs electrical verification of the ID code included in the received response signal. When the electrical verification is established, a key operation free system that permits unlocking the vehicle door or starting the engine and the electronic key receive the drive signal locally transmitted from the in-vehicle device, The transponder response signal including the ID code is transmitted to the vehicle-mounted device, and the in-vehicle device is included in the received transponder response signal. And an immobilizer system that permits starting of the engine when the electrical verification is established, and the in-vehicle device has the vehicle door unlocked by the mechanical verification. Alternatively, when it is determined that the vehicle door has been unlocked illegally, the gist is to shift to a warning mode and permit engine start only when electrical verification in the immobilizer system is established.

  According to this configuration, when it is determined by mechanical verification that the vehicle door has been unlocked or the vehicle door has been illegally unlocked, the mode is shifted to a warning mode. Here, the case where the vehicle door is unlocked illegally may be, for example, a case where the vehicle door is opened or a case where a pseudo unlock request command signal is transmitted to the in-vehicle device. In such a case, no verification is performed when the vehicle door is unlocked, and the vehicle security is low. In addition, mechanical verification has fewer key patterns than electrical verification. For this reason, when the vehicle door is unlocked through the mechanical key, the security is lower than when the key operation free system is used. Thus, when it is difficult to ensure security, the mode is shifted to a warning mode. In this mode, the engine is started only when electrical verification in the immobilizer system is established. In other words, engine start through a key operation free system or a mechanical key is restricted.

  Here, in the key operation-free system, by interposing a repeater between the on-vehicle device and the electronic key, wireless communication is performed between the electronic key and the on-vehicle device even though the electronic key is located far from the vehicle. It is feared that the vehicle door may be unlocked or the engine may be started illegally. On the other hand, in the immobilizer system, there is no risk of unauthorized communication using the repeater. This is because the drive signal and the transponder response signal are signals transmitted locally.

  Considering the above points, if it is difficult to ensure security when unlocking the vehicle door, electrical verification in a highly secure immobilizer system is required when starting the engine. Thereby, the security property as the whole electronic key system can be improved.

  According to a second aspect of the present invention, in the electronic key system according to the first aspect, a control request signal including an ID code is transmitted from the electronic key based on an operation of a switch provided in the electronic key. A wireless key system that locks and unlocks a vehicle door when verification of an ID code included in the received control request signal is established, and the in-vehicle device includes an ID included in the received control request signal in the alert mode; The gist of the invention is to release the warning mode when the code verification is established and to allow the engine to be started when the ID code electrical verification is established in the immobilizer system or the key operation free system.

  In the wireless key system, there is no risk of unauthorized communication using a repeater. This is because the control request signal is transmitted in response to a switch operation by the user in the system, and the signal cannot be transmitted from the electronic key without the user's intention through the request signal as in the key operation free system. It is.

  According to the above configuration, when the verification of the ID code included in the received control request signal is established, the alert mode is canceled because there is no possibility of unauthorized communication using the repeater. In this case, the vehicle-mounted device starts the engine when the ID code electrical verification is established in the immobilizer system or the key operation free system. Thereby, even when the vehicle door is unlocked through a mechanical key, for example, the engine can be started using the key operation free system. Therefore, convenience can be improved.

  According to a third aspect of the present invention, in the electronic key system according to the first or second aspect, a determination unit that determines whether there is a risk of unauthorized communication using a repeater when the vehicle door is unlocked. The in-vehicle device has the gist of shifting to the alert mode when it is determined through the determination unit that there is a possibility of unauthorized communication using the repeater.

  According to this configuration, when there is a possibility that the vehicle door is unlocked using the repeater, the start of the engine using the key operation free system is restricted by shifting to the warning mode. Thereby, starting of the engine using a repeater is suppressed.

  According to the present invention, security can be improved in an electronic key system.

The block diagram of the electronic key system in 1st and 2nd embodiment. The flowchart which shows the process sequence of the vehicle-mounted control part in 1st and 2nd embodiment.

(First embodiment)
A first embodiment embodied in an electronic key system according to the present invention will be described below with reference to FIGS. A vehicle is equipped with a key operation free system, a wireless key system, and an immobilizer system as electronic key systems.

<Electronic key>
First, the structure regarding the key operation free system in the electronic key 10 is demonstrated.
The electronic key 10 includes an electronic key control unit 11 configured by a computer unit, an LF receiving unit 12 that receives a radio signal in the LF (low frequency) band, and a UHF that transmits a radio signal in the UHF (Ultra High Frequency) band. And a transmission unit 13.

  The LF receiver 12 receives a request signal that is an LF-band radio signal transmitted from the in-vehicle device 20 via the receiving antenna 12a. Then, the LF receiver 12 demodulates this request signal into a pulse signal and outputs it to the electronic key controller 11.

  The electronic key control unit 11 includes a nonvolatile memory 11a, and an ID code unique to the electronic key 10 is stored in the memory 11a. When the electronic key control unit 11 recognizes the request signal from the LF reception unit 12, the electronic key control unit 11 outputs a response signal including the ID code stored in the memory 11a to the UHF transmission unit 13. The UHF transmitter 13 modulates the response signal and transmits it as a UHF band radio signal via the transmission antenna 13a.

Next, the structure regarding the immobilizer system in the electronic key 10 will be described.
The electronic key 10 includes a transponder 14. The transponder 14 is composed of a coil, an IC chip, and the like, and when a driving radio wave transmitted locally in the vicinity of the engine switch of the vehicle is received, an induced power is generated in its own coil. Based on this power, the transponder 14 transmits a transponder response signal including its own ID code. Since the transponder 14 induces electric power based on the driving radio wave, the transponder response signal can be transmitted even when the battery of the electronic key 10 is exhausted.

  Next, a configuration related to the wireless key system in the electronic key 10 will be described. In the wireless key system, the electronic key control unit 11 and the UHF transmission unit 13 are shared with the key operation free system.

The electronic key 10 includes an unlocking switch 16 and a locking switch 17.
The unlocking switch 16 and the locking switch 17 are operably disposed on the surface of the electronic key 10 and, when operated, output an operation signal indicating that to the electronic key control unit 11.

  When receiving an operation signal indicating that the unlocking switch 16 has been operated, the electronic key control unit 11 generates an unlocking request signal including an ID code for requesting the vehicle 2 to unlock the door, Is output to the UHF transmitter 13. The UHF transmission unit 13 modulates the unlock request signal input from the electronic key control unit 11 and transmits it as a UHF band radio signal via the transmission antenna 13a. Even when the electronic key control unit 11 receives an operation signal indicating that the locking switch 17 has been operated, the UHF transmission unit 13 sends a locking request signal including an ID code requesting locking of the door, as described above. Via wireless transmission.

The vehicle 2 is equipped with a mechanical key system.
Specifically, a mechanical key 18 is accommodated in the main body of the electronic key 10. For example, when the battery of the electronic key 10 runs out, the user takes out the mechanical key 18 and inserts the mechanical key 18 into a key cylinder (not shown) provided on the vehicle door. In this state, the mechanical key 18 is rotated. Thereby, the locking / unlocking state of the vehicle door is switched.

<In-vehicle device>
Next, the configuration related to the key operation free system in the in-vehicle device 20 will be mainly described.
As shown in FIG. 1, the in-vehicle device 20 includes an in-vehicle control unit 21 configured by a computer unit, an out-of-vehicle transmission unit 22 that transmits an LF band radio signal to the outside of the vehicle, and an LF band radio signal in the vehicle. And a vehicle-mounted receiving unit 24 for receiving a UHF band radio signal transmitted from inside and outside the vehicle.

  In addition, a door handle sensor 32, an engine switch 33, a door lock device 34, an engine device 35, and a lock switch 36 are electrically connected to the in-vehicle control unit 21.

  The door handle sensor 32 is provided on a door handle (not shown) on the outside of the vehicle and detects whether or not the user touches the door handle. The door handle sensor 32 outputs the detection result to the in-vehicle control unit 21.

  The lock switch 36 is also provided on the door handle and is pushed when the vehicle door is locked and unlocked. Then, the lock switch 36 outputs an operation signal indicating that it has been operated to the in-vehicle control unit 21.

  The engine switch 33 is provided in the vicinity of the driver's seat and is pushed when the engine is started. Then, the engine switch 33 outputs an operation signal indicating that it has been operated to the in-vehicle control unit 21.

  The in-vehicle control unit 21 includes a nonvolatile memory 21a, and the same ID code as the ID code of the electronic key 10 is stored in the memory 21a. The in-vehicle control unit 21 generates a request signal at regular intervals and transmits it to the outside transmission unit 22 or the inside transmission unit 23.

  The outside transmission unit 22 is provided, for example, inside a door handle outside the vehicle. When a request signal is input from the in-vehicle control unit 21, the vehicle outside transmission unit 22 modulates the request signal and transmits it to the outside of the vehicle as an LF band radio signal via the vehicle outside transmission antenna 22a.

  The in-vehicle transmission unit 23 is provided in the vehicle, and when a request signal is input from the in-vehicle control unit 21, the request signal is modulated and transmitted to the inside of the vehicle via the in-vehicle transmission antenna 23a.

  When receiving the response signal transmitted from the electronic key 10 via the receiving antenna 24 a, the in-vehicle receiving unit 24 demodulates this signal into a pulse signal and outputs it to the in-vehicle control unit 21.

  The in-vehicle control unit 21 collates the ID code included in the response signal with the ID code stored in the memory 21a. The in-vehicle control unit 21 determines whether the vehicle exterior verification or the vehicle interior verification is performed based on whether the response signal transmitted from the electronic key 10 is a response to the request signal transmitted from the vehicle exterior transmission unit 22 or the vehicle interior transmission unit 23. It is determined which has been established. Verification outside the vehicle refers to verification of the ID code with the electronic key 10 existing outside the vehicle via the transmission unit 22 outside the vehicle. In-vehicle collation refers to collating an ID code with the electronic key 10 existing in the vehicle via the in-vehicle transmission unit 23.

  The vehicle-mounted control unit 21 enters the vehicle door unlocking permitted state when the vehicle exterior verification is established in the locked state of the vehicle door. In this unlocking permitted state, the vehicle-mounted control unit 21 unlocks the vehicle door via the door lock device 34 when it recognizes through the door handle sensor 32 that the user has touched the door handle (not shown). In addition, the vehicle-mounted control unit 21 locks the vehicle door via the door lock device 34 when recognizing that the lock switch 36 has been operated in the unlocked state of the vehicle door.

  Moreover, the vehicle-mounted control part 21 will be in an engine starting permission state, when vehicle collation is materialized. When the in-vehicle control unit 21 recognizes that the engine switch 33 is operated in the engine start permission state, the in-vehicle control unit 21 starts the engine through the engine device 35.

  Next, the structure regarding the immobilizer system in the vehicle-mounted apparatus 20 is demonstrated. In the immobilizer system, the in-vehicle control unit 21 and the like are shared with the key operation free system.

  The in-vehicle device 20 includes an immobilizer communication device 25. The immobilizer communication device 25 is built in the engine switch 33. The vehicle-mounted control unit 21 outputs a command signal to the immobilizer communication device 25, for example, when the brake pedal is depressed while the engine is stopped. The immobilizer communication device 25 transmits a driving radio wave based on a command signal from the in-vehicle control unit 21. This driving radio wave is locally transmitted in the vicinity of the engine switch 33. When the electronic key 10 is held over the engine switch 33, the transponder 14 of the electronic key 10 is activated by receiving the driving radio wave. Then, the transponder 14 transmits a transponder response signal including the ID code. When receiving the transponder response signal, the immobilizer communication device 25 demodulates this signal into a pulse signal and outputs it to the in-vehicle control unit 21. The in-vehicle controller 21 collates the ID code included in the transponder response signal with the ID code stored in the memory 21a (transponder collation). The vehicle-mounted control unit 21 enters an engine start permission state when this transponder verification is established. The in-vehicle controller 21 starts the engine through the engine device 35 when recognizing that the engine switch 33 is operated in the engine start permission state.

  Next, the structure regarding the wireless key system in the vehicle-mounted apparatus 20 is demonstrated. In the wireless key system, the in-vehicle controller 21 and the in-vehicle receiver 24 are shared with the key operation free system.

  The in-vehicle receiver 24 demodulates the unlock request signal or the lock request signal received through its own receiving antenna 24 a and outputs it to the in-vehicle controller 21. When the in-vehicle controller 21 recognizes the unlock request signal from the in-vehicle receiver 24, the in-vehicle controller 21 collates the ID code included in the unlock request signal with the ID code stored in the memory 21a (wireless verification). The in-vehicle control unit 21 unlocks the vehicle door when determining that the wireless verification is established. Moreover, the vehicle-mounted control part 21 locks a vehicle door, when it is judged that the wireless collation about the locking request signal was materialized.

In-vehicle and external verification, transponder verification, and wireless verification are all electrical verifications.
In each of the above electronic key systems, the key operation free system is highly convenient because the user does not need to perform key operations. However, in the system, there is a concern about unauthorized communication using a repeater that establishes out-of-vehicle and in-vehicle verification even though the electronic key 10 is far from the vehicle. Specifically, the repeater receives the request signal at its first transmission / reception unit. The signal is transmitted from the second transmission / reception unit through a cable. A request signal from the second transmission / reception unit is transmitted to the electronic key 10 possessed by the user away from the vehicle. Receiving this, the electronic key 10 transmits a response signal to the in-vehicle device 20 via the repeater or directly. As a result, the vehicle exterior verification may be established in the vehicle and the vehicle door may be unlocked. There is a possibility that in-vehicle verification is performed in the same manner.

  Unauthorized communication using the repeater is not likely to be performed in the wireless key system. In this system, when the unlock request signal or the lock request signal is transmitted with the operation of the unlock switch 16 or the lock switch 17 as a trigger, the user's intention is transmitted through the request signal as in the key operation free system. This is because no signal can be transmitted from the electronic key 10.

  In addition, unauthorized communication using a repeater is not likely to be performed in the immobilizer system. This is because the driving radio wave and the transponder response signal are transmitted locally and cannot be relayed.

  The in-vehicle control unit 21 normally enters an engine start permission state when in-vehicle verification or transponder verification is established, and starts the engine when it is determined that the engine switch 33 is operated in this state.

  The vehicle-mounted control unit 21 shifts to a warning mode when a device other than the key operation free system and the wireless key system is used when the vehicle door is unlocked. When a key operation free system or a wireless key system is used, specifically, when the vehicle door is unlocked through the mechanical key 18, when the vehicle door is physically opened, and when the door lock device 34 is used. In some cases, a pseudo unlock request command signal is transmitted to unlock the vehicle door. When the vehicle-mounted control unit 21 shifts to the warning mode, the vehicle-mounted control unit 21 permits the engine to be started only when the transponder verification is established. That is, the engine start is restricted through establishment of in-vehicle verification in the key operation free system.

  Moreover, the vehicle-mounted control part 21 will cancel | release warning mode, if the user who has the electronic key 10 exists in the circumference | surroundings of a vehicle, if wireless collation is materialized by receiving a locking request signal or an unlocking request signal in warning mode.

  In other words, when the vehicle door is unlocked or the wireless verification is not performed, for example, when the vehicle door is unlocked through the mechanical key 18, the transponder verification is performed when the engine is started by shifting to the warning mode. Request.

  Here, the mechanical key 18 performs mechanical verification with the key cylinder of the vehicle door through the key groove (key pattern). However, this mechanical verification has a low security because it has fewer key patterns than the electrical verification in each electronic key system. Therefore, when the vehicle door is unlocked without performing electrical verification, the engine can be started with an electronic key system with higher security, specifically, an immobilizer system. Thereby, the security property as an electronic key system can be improved.

  Moreover, the warning mode is canceled by operating the unlocking switch 16 or the locking switch 17. For this reason, even if it is a case where outside verification or wireless verification is not performed at the time of unlocking a vehicle door, an engine can be started using a key operation free system normally used. Thereby, the convenience can be improved.

Next, the processing procedure of the in-vehicle control unit 21 will be described with reference to the flowchart of FIG. This flowchart is executed at a predetermined cycle.
First, when the unlocking of the vehicle door is executed (S101), it is determined whether or not the unlocking has been performed through the establishment of outside vehicle verification or wireless verification (S102). When it is determined that the unlocking of the vehicle door has been performed through the establishment of external verification or wireless verification (YES in S102), engine startup using the key operation free system and the immobilizer system is permitted as usual. Specifically, it is determined whether in-vehicle collation is established (S103). When it is determined that in-vehicle verification is established (YES in S103), when it is recognized that the engine switch 33 has been operated (S105), the engine is started (S106). Thereby, the process of the vehicle-mounted control part 21 is complete | finished. For example, when it is determined that the in-vehicle verification is not established due to the battery running out of the electronic key 10 (NO in S103), it is determined whether or not the transponder verification is established (S104). If it is determined that the transponder verification is established (YES in S104) and it is recognized that the engine switch 33 has been operated (S105), the engine is started (S106). Thereby, the process of the vehicle-mounted control part 21 is complete | finished. If it is determined that the transponder verification is not established (NO in S104), the processing of the in-vehicle control unit 21 ends without starting the engine.

  On the other hand, when it is determined that the unlocking of the vehicle door has not been performed through the establishment of the external verification or the wireless verification (NO in S102), the process shifts to a warning mode (S107). Then, it is determined whether or not transponder verification is established (S108). If it is determined that the transponder verification is established (YES in S108), and it is recognized that the engine switch 33 is operated (S105), the engine is started (S106). Thereby, the process of the vehicle-mounted control part 21 is complete | finished. If it is determined that transponder verification is not established (NO in S108), it is determined whether wireless verification is established (S109). If it is determined that the wireless verification is not established (NO in S109), the process proceeds to step S108 again. When it is determined that wireless verification is established (YES in S109), in other words, when the unlocking switch 16 or the locking switch 17 is operated, the warning mode is canceled (S110). Then, by shifting the processing to step S103, the engine can be started using the key operation free system.

As described above, according to the embodiment described above, the following effects can be obtained.
(1) When it is determined that the vehicle door is unlocked by mechanical verification through the mechanical key 18 or the vehicle door is illegally unlocked, the mode is shifted to a warning mode. In this mode, the engine is started only when electrical verification in the immobilizer system is established. Here, in the immobilizer system, unlike the key operation free system, there is no possibility of unauthorized communication using the repeater. Thereby, the security property as the whole electronic key system can be improved.

(2) When the verification of the ID code included in the received lock request signal or unlock request signal is established, the in-vehicle device 20 cancels the warning mode because there is no possibility of unauthorized communication using the repeater. In this case, the in-vehicle device 20 also starts the engine when electrical verification in the key operation free system is established. Thereby, for example, even when the vehicle door is unlocked through the mechanical key 18, the engine can be started using the key operation free system. Therefore, convenience can be improved.
(Second Embodiment)
Hereinafter, a second embodiment of the present invention will be described. The electronic key system of this embodiment is different from the first embodiment in that it is determined whether or not there is a possibility of unauthorized communication using a repeater in a key operation free system. Hereinafter, a description will be given focusing on differences from the first embodiment.

  As indicated by a broken line in FIG. 1, the LF receiver 12 includes an RSSI detection circuit 19. On the other hand, the in-vehicle control unit 21 continuously transmits two request signals having signal strengths different from each other by a certain value or more via the outside transmission unit 22. The RSSI detection circuit 19 detects the RSSI of the two request signals and outputs the detection result to the electronic key control unit 11. The electronic key control unit 11 includes the detection result in the response signal and transmits the response signal through the UHF transmission unit 13.

  The in-vehicle control unit 21 recognizes RSSIs of two request signals that are detection results of the RSSI detection circuit 19 included in the response signal received through the in-vehicle reception unit 24. The in-vehicle control unit 21 determines that there is no possibility of unauthorized communication using the repeater when the difference between the RSSIs of both request signals is a certain value or more. Moreover, the vehicle-mounted control part 21 judges that there exists a possibility of the unauthorized communication using a repeater, when the difference of RSSI of both request signals is less than a fixed value. Here, even if the repeater receives two request signals having different signal strengths via the first transmission / reception unit, the signal strengths of the two request signals transmitted from the second transmission / reception unit are the same. For this reason, when a repeater exists between the in-vehicle device 20 and the electronic key 10, the difference in RSSI between both request signals is less than a certain value. This makes it possible to make the above determination.

A processing procedure of the in-vehicle control unit 21 in the present embodiment will be described.
As shown by a broken line in FIG. 2, when it is determined that the unlocking of the vehicle door has been performed through the establishment of the external verification or wireless verification (YES in S102), there is a possibility of unauthorized communication using a repeater. Is determined (S201). When it is determined that there is a possibility of unauthorized communication using a repeater in the outside verification (YES in S201), the mode is shifted to a warning mode (S107). Thereafter, processing is performed in the same manner as in the first embodiment. Further, when it is determined that there is no possibility of unauthorized communication using the repeater (NO in S201), it is determined whether in-vehicle collation is established (S103). Thereafter, processing is performed in the same manner as in the first embodiment.

As described above, according to the embodiment described above, the following effects can be obtained in addition to the effects (1) and (2) of the first embodiment.
(3) When there is a possibility that the vehicle door has been unlocked using the repeater, the engine is shifted to the warning mode and the engine start using the key operation free system is restricted. Therefore, it is possible to prevent the engine from being continuously started with the unlocking of the vehicle door using the repeater.

In addition, the said embodiment can be implemented with the following forms which changed this suitably.
In the above embodiment, the engine could not be started through the wireless key system. However, the electronic key 10 may be provided with an engine start switch. In this case, when the switch is operated, the electronic key 10 transmits a radio signal for requesting engine start including the ID code. The in-vehicle device 20 starts the engine when collation between the ID code included in the received wireless signal and the ID code stored in its own memory 21a is established. The engine can be started through the operation of the engine start switch even in the alert mode. This is because in the wireless key system as described above, there is no fear of unauthorized communication using a repeater.

  In both the above-described embodiments, when the mode is shifted to the alert mode, the user may be notified of this through, for example, an indicator or voice. Thereby, the user can recognize that the mode has changed to the alert mode and can perform transponder verification or wireless verification.

  In both the above embodiments, when it is determined that the in-vehicle verification is established (S103) or when it is determined that the transponder verification is established (S104), the engine is started by operating the engine switch 33 (S105). (S106). However, the engine may be started through the mechanical key 18. In this case, the mechanical key 18 is inserted into a key cylinder provided in the steering column. In this state, the mechanical key 18 is rotated. This starts the engine. Starting of the engine through the mechanical key 18 is restricted in the warning mode.

  In the second embodiment, the in-vehicle control unit 21 determines whether there is a possibility of unauthorized communication using a repeater. However, the electronic key control unit 11 may make this determination. In this case, the electronic key control unit 11 transmits the determination result included in, for example, a response signal. The in-vehicle control unit 21 performs the determinations in steps S103 and S104 based on the determination result included in the response signal. Further, similarly to the request signal, two response signals may be transmitted continuously to change the signal strength of these signals. In this case, the RSSI detection circuit 19 is provided in the in-vehicle receiving unit 24.

  In addition to the request signal, a plurality of RSSI measurement signals having different signal strengths may be transmitted. Through the RSSI of these RSSI measurement signals, a determination is made as to whether or not there is a possibility of unauthorized communication using a repeater, as in the second embodiment.

  In the second embodiment, based on the RSSI of the two request signals, it is determined whether or not there is a possibility of unauthorized communication using a repeater. However, if this determination can be made, the method is not limited to the method of the second embodiment. For example, it may be determined whether there is a possibility of unauthorized communication using the repeater through a delay in the reception timing of the response signal caused by interposing the repeater.

  The determination as to whether or not there is a possibility of unauthorized communication using the repeater in the second embodiment (S201) may be made when in-vehicle verification is established in step S103. In this case, two request signals having signal strengths different from each other by a certain value or more are continuously transmitted to the vehicle interior via the in-vehicle transmission unit 23. Also in this configuration, when it is determined that there is a possibility of unauthorized communication using a repeater (YES in S201), the mode is shifted to a warning mode (S107).

  In both the above embodiments, the warning mode is canceled when the wireless verification is established. However, the alert mode may be canceled when not only wireless verification but biometric authentication such as fingerprint authentication is established, for example.

  The wireless key system in both the above embodiments may be omitted. In this case, steps S109 and S110 in FIG. 2 are omitted, and the engine can be started only when transponder verification is established in the alert mode (YES in S108).

  DESCRIPTION OF SYMBOLS 1 ... Electronic key system, 2 ... Vehicle, 10 ... Electronic key, 11 ... Electronic key control part, 14 ... Transponder, 18 ... Mechanical key, 20 ... In-vehicle apparatus, 21 ... In-vehicle control part (determination part), 25 ... Immobilizer communication Machine.

Claims (3)

In an electronic key system mounted on a vehicle having a mechanical key system that performs mechanical verification through a key pattern of mechanical keys and permits unlocking of the vehicle door when the verification is established,
When the electronic key receives a request signal transmitted from the in-vehicle device to the inside / outside of the vehicle, the electronic key transmits a response signal including an ID code, and the in-vehicle device performs electrical verification of the ID code included in the received response signal. A key operation free system that permits unlocking of the vehicle door or starting of the engine when electrical verification is established; and
When the electronic key receives a drive signal locally transmitted from the in-vehicle device, the electronic key also locally transmits a transponder response signal including an ID code, and the in-vehicle device transmits an ID code included in the received transponder response signal. An immobilizer system that performs electrical verification and permits engine start when the electrical verification is established,
When the vehicle door is unlocked by the mechanical verification or when it is determined that the vehicle door is illegally unlocked, the in-vehicle device shifts to a warning mode, and the electrical verification in the immobilizer system is performed. An electronic key system that allows the engine to start only when it is established. The electronic key system according to claim 1.
A control request signal including an ID code is transmitted from the electronic key based on an operation of a switch provided on the electronic key, and the vehicle-mounted device detects the vehicle door when the ID code included in the received control request signal is verified. Equipped with a wireless key system for locking and unlocking,
In the warning mode, the in-vehicle device cancels the warning mode when collation of the ID code included in the received control request signal is established, and the ID code electrical in the immobilizer system or the key operation free system is released. An electronic key system that allows the engine to start when verification is successful. The electronic key system according to claim 1 or 2,
A determination unit that determines whether there is a risk of unauthorized communication using a repeater when unlocking the vehicle door;
The on-vehicle device is an electronic key system that shifts to the alert mode when it is determined through the determination unit that there is a possibility of unauthorized communication using the repeater.

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