JP2018115463A - Electronic key system, electronic control device and receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic key system, an electronic control device and a receiver which are capable of improving security performance.SOLUTION: If a signal level Lof a response request signal Sreceived by a receiver 24 does not exceed a threshold value L, a communication area inside and outside a vehicle compartment is determined not to be illegally expanded. In this case, if an identification code IDincluded in a response signal Sis correct, an on-vehicle device such as a door lock device is allowed to operate. On the other hand, if the signal level Lof the response request signal Sreceived by the receiver 24 exceeds the threshold value L, the communication area inside and outside the vehicle compartment is determined to be illegally expanded. In this case, even if the identification code IDincluded in the response signal Sis correct, the on-vehicle device such as the door lock device is not allowed to operate.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an electronic key system, an electronic control device, and a receiver.

  2. Description of the Related Art Conventionally, as described in Patent Document 1, for example, an electronic key system that controls a vehicle through wireless communication between a portable device carried by a user and the vehicle is known. In this system, an ECU (electronic control unit) of a vehicle forms a communication area around each door by transmitting a response request through a transmission antenna provided on each door of the vehicle. When the ECU receives a response from the portable device in response to the response request, the ECU collates the ID code included in the response with the ID code stored in the ECU, and the operation of the door handle is detected in a state where the collation is established. When unlocked, the door is unlocked.

JP 2006-45908 A

  In recent years, theft of vehicles has been diversified. For example, there is a technique for expanding a communication area by intercepting a response request in a communication area formed around a vehicle and amplifying the intercepted response request using a repeater. According to this technique, a situation occurs in which the portable device exists outside the original communication area but exists within the expanded communication area. At this time, the portable device responds to a response request from the vehicle even though it is outside the original communication area. For this reason, there is a possibility that the door is unlocked illegally.

  An object of the present invention is to provide an electronic key system, an electronic control device, and a receiver that can improve crime prevention.

  An electronic key system that can achieve the above object includes a transmitter that wirelessly transmits a response request signal to and from a vehicle interior, a portable device that wirelessly transmits a response signal in response to the response request signal, and the response signal A receiver, and an electronic control unit that permits operation of the in-vehicle device based on a response signal received through the receiver. The receiver detects a signal level of a first reception circuit that receives the response signal, a second reception circuit that receives the response request signal, and a response request signal received through the second reception circuit. And a determination circuit for determining whether a signal level detected through the detection circuit exceeds a threshold value set to a value larger than a signal level normally assumed as the signal level. doing. When the electronic control unit determines that the response signal received through the first receiving circuit is valid, and the determination circuit determines that the signal level does not exceed the threshold value The operation of the in-vehicle device is permitted.

  When the signal level detected through the detection circuit exceeds the threshold value, the response request signal may be illegally amplified by a repeater or the like. In this regard, according to the above configuration, even when it is determined that the response signal received through the first receiving circuit is valid, the determination circuit determines that the signal level exceeds the threshold value. When the operation is performed, the operation of the in-vehicle device is not permitted. For this reason, crime prevention property improves.

  In the electronic key system, the determination circuit may wire-transmit the determination result of the signal level detected through the detection circuit to the electronic control device. The electronic control unit can recognize whether or not the signal level exceeds the threshold based on the determination result acquired through the determination circuit.

  In the electronic key system, the response signal may include an identification code unique to the portable device, and the electronic control device may determine validity of the response signal based on the identification code. When the determination circuit determines that the signal level does not exceed the threshold value, the first receiving circuit preferably transmits the identification code to the electronic control device by wire.

  According to this configuration, when the determination circuit determines that the signal level exceeds the threshold value, the identification code unique to the portable device is not wired to the electronic control device. Since the electronic control device does not determine the validity of the response signal based on the identification code, the operation of the in-vehicle device is not permitted.

  In the electronic key system, the electronic control device wirelessly transmits the response request signal including a vehicle code unique to the host vehicle through the transmitter, and transmits the vehicle code to the receiver by wire. Also good. In this case, the receiver has a vehicle code determination circuit that determines whether or not a vehicle code included in the response request signal matches a vehicle code acquired through the electronic control device, and the determination circuit includes: When the vehicle code determination circuit determines that the vehicle code included in the response request signal matches the vehicle code acquired through the electronic control device, the signal level determination process is preferably performed.

  It is also conceivable that the receiver receives a response request signal wirelessly transmitted from a transmitter of another vehicle. In this regard, according to the above configuration, the response request signal received by the receiver is automatically transmitted through the determination process of whether or not the vehicle code included in the response request signal matches the vehicle code acquired through the electronic control unit. It is possible to identify whether the wireless transmission is performed through a transmitter of the vehicle or the wireless transmission of a transmission device of another vehicle. For this reason, it can suppress that operation | movement of a vehicle equipment is accidentally permitted based on the response request signal transmitted by radio | wireless through the transmitter of the other vehicle.

  In the above electronic key system, when a plurality of transmitters are provided in a vehicle, the electronic control unit switches the transmitters that wirelessly transmit the response request signal in a predetermined order, and the response request Each time a signal is wirelessly transmitted, a transmitter number unique to the transmitter that wirelessly transmits the response request signal may be wired to the receiver. In this case, the determination circuit stores the threshold value set corresponding to each of the plurality of transmitters, and sets the threshold value corresponding to the transmitter number acquired through the electronic control unit. It is preferable to use the signal level determination process.

  According to this configuration, threshold values corresponding to a plurality of transmitters are used in the signal level determination process. For this reason, even when a plurality of transmitters are provided in the vehicle, the signal level of the response request signal wirelessly transmitted through these transmitters can be appropriately determined.

  An electronic control device capable of achieving the above object wirelessly transmits a response request signal to and from the interior of a vehicle through a transmitter, and receives a response signal wirelessly transmitted from a portable device in response to the response request signal through a receiver. Thus, it is assumed that the operation of the in-vehicle device is permitted based on the received response signal. The electronic control device includes a detection circuit that detects a signal level of a response request signal received through the receiver, and a signal level detected through the detection circuit is larger than a signal level normally assumed as the signal level. A determination circuit for determining whether or not a set threshold value is exceeded, and when it is determined that the response signal is valid, and the determination circuit determines that the signal level does not exceed the threshold value And a control circuit that permits the operation of the in-vehicle device.

  According to this configuration, even when it is determined that the response request signal received through the receiver is valid, when the determination circuit determines that the signal level exceeds the threshold value, the in-vehicle device Operation is not allowed. For this reason, crime prevention property improves.

  The receiver that can achieve the above object is transmitted wirelessly from a portable device in response to a response request signal wirelessly transmitted from the vehicle-mounted electronic control device to the vehicle interior and exterior through the transmitter, and the electronic control device operates the vehicle-mounted device. It is assumed that a response signal including an identification code unique to the portable device whose validity is determined in order to permit permission is received. The receiver detects a signal level of the response request signal received through the second reception circuit, a first reception circuit that receives the response signal, a second reception circuit that receives the response request signal, and the second reception circuit. And a determination circuit for determining whether a signal level detected through the detection circuit exceeds a threshold value set to a value larger than a signal level normally assumed as the signal level. ing. When the determination circuit determines that the signal level does not exceed the threshold value, the first reception circuit transmits the identification code included in the response signal to the electronic control device.

  According to this configuration, even when it is determined that the response signal received through the first receiving circuit is valid, when the determination circuit determines that the signal level exceeds the threshold value, Device operation is not allowed. For this reason, crime prevention property improves.

  According to the electronic key system, the electronic control device, and the receiver of the present invention, it is possible to improve crime prevention.

1 is a block diagram showing a first embodiment of an electronic key system. The top view of the vehicle which shows arrangement | positioning and a communication area | region of an antenna when the vehicle by which the electronic key system of 1st Embodiment is mounted is seen from the top. The table which prescribes | regulates the relationship between the antenna used for the authentication process of an electronic key, an antenna number, and a threshold value in the electronic key system of 1st Embodiment. The sequence chart which shows the authentication process of an electronic key in the electronic key system of 1st Embodiment. The sequence chart which shows the authentication process of an electronic key in 2nd Embodiment of an electronic key system. The block diagram which shows the structure of a vehicle in 3rd Embodiment of an electronic key system. The sequence chart which shows the authentication process of an electronic key in 3rd Embodiment of an electronic key system. The front view of the window glass which shows the installation state of the glass antenna used in 4th Embodiment of an electronic key system.

<First Embodiment>
Hereinafter, a first embodiment of an electronic key system for a vehicle will be described.
As shown in FIG. 1, the electronic key system 10 includes an in-vehicle device 12 mounted on a vehicle 11 and a portable device 13 possessed by a user. A door lock device 14 and an engine start device 15 are connected to the in-vehicle device 12. The door lock device 14 performs locking and unlocking of the door, respectively. The engine starter 15 controls starting and stopping of the engine, respectively. Wireless communication is performed between the in-vehicle device 12 and the portable device 13. The in-vehicle device 12 authenticates the portable device 13 through exchange of a wireless signal with the portable device 13.

<Configuration of in-vehicle device>
As shown in FIG. 1, the in-vehicle device 12 includes an ECU (electronic control unit) 21, an outside LF transmitter 22, an in-vehicle LF transmitter 23, and a receiver 24.

  The ECU 21 is connected to the door lock device 14 and the engine start device 15. The ECU 21 is connected to an outside LF transmitter 22, an in-vehicle LF transmitter 23, and a receiver 24. The LF transmitter 22 outside the vehicle is provided at each door of the vehicle 11. The in-vehicle LF transmitter 23 and the receiver 24 are provided in the vehicle interior.

The vehicle exterior LF transmitter 22 and the vehicle interior LF transmitter 23 transmit a response request signal S _rq as a radio signal in the LF (Low Frequency) band based on a command from the ECU 21. The response request signal S _rq is a command signal for requesting a response from the portable device 13. By transmitting this response request signal Srq outside the vehicle compartment or inside the vehicle compartment at a predetermined control cycle, a communication area with the portable device 13 is formed outside the vehicle compartment or inside the vehicle compartment.

The receiver 24 receives a radio signal in the UHF (Ultra High Frequency) band. Here, the radio signal in the UHF band refers to a response signal S _rp transmitted from the portable device 13 in response to the response request signal S _rq transmitted from the vehicle 11. The response signal S _rp includes an identification code ID _k unique to the portable device 13.

When the ECU 21 receives the response signal S _rp from the portable device 13 through the receiver 24, the identification code ID _k of the portable device 13 included in the response signal S _rp and the identification code stored in its own storage device 21a. The validity of the portable device 13 is determined by collating with ID _k . Here, the validity of the portable device 13 means that the portable device 13 is properly registered as a communication partner of the ECU 21. The ECU 21 permits the operation of the door lock device 14 or the engine start device 15 when the validity of the portable device 13 is confirmed. The ECU 21 does not permit the operation of the door lock device 14 or the engine start device 15 when the validity of the portable device 13 cannot be confirmed.

When the vehicle 11 is in a parked state (vehicle power off, all doors closed, door locking), the ECU 21 transmits a response request signal S _rq through the outside LF transmitter 22 at a predetermined period. When the ECU 21 receives the response signal S _rp from the portable device 13 through the receiver 24, the identification code ID _k of the portable device 13 included in the response signal S _rp and the identification code stored in its own storage device 21a. ID _k is verified (external vehicle verification). When verification of these identification codes ID _k and ID _k is established, the ECU 21 unlocks all the doors through the door lock device 14 when a touch on the door handle is detected through a touch sensor provided on the door handle.

After unlocking the door, the ECU 21 stops the transmission of the response request signal _Srq through the outside LF transmitter 22 when the opening / closing of the door (the user's boarding) is detected through the door courtesy switch, and this time the in-vehicle LF transmission. A response request signal S _rq is transmitted to the passenger compartment through the machine 23. When the ECU 21 receives the response signal S _rp from the portable device 13 through the receiver 24, the identification code ID _k of the portable device 13 included in the response signal S _rp and the identification code stored in its own storage device 21a. ID _k is collated (in-vehicle collation). The ECU 21 permits the start of the engine when the verification of these identification codes ID _k and ID _k is established. The ECU 21 starts the engine through the engine starting device 15 when an operation of the engine switch is detected in a state where the brake pedal is depressed. Further, the ECU 21 stops the engine through the engine starting device 15 when the operation of the engine switch is detected in the idling state and the range position of the select lever is held at the parking position (P range).

The ECU 21 also transmits a response request signal S _rq through the outside LF transmitter 22 when detecting an operation of a lock switch provided on the door handle in the parking state (vehicle power off, all doors closed, door unlocked). . When the ECU 21 receives the response signal S _rp from the portable device 13 through the receiver 24, the ECU 21 stores the identification code ID _k of the portable device 13 included in the received response signal S _rp and its own storage device 21a. The identification code ID _k is checked. The ECU 21 locks all the doors through the door lock device 14 when the verification of the identification codes ID _k and ID _k is established.

<Configuration of portable device>
As shown in FIG. 1, the portable device 13 includes a microcomputer 31, an LF reception circuit 32, and a UHF transmission circuit 33. The storage device 31 a of the microcomputer 31 stores an identification code ID _k unique to the portable device 13 and a vehicle code ID _v unique to the vehicle 11 associated as a communication target of the portable device 13. The LF reception circuit 32 and the UHF transmission circuit 33 are connected to the microcomputer 31. The LF receiving circuit 32 receives an LF band radio signal. The UHF transmission circuit 33 transmits a UHF band radio signal based on a command from the microcomputer 31. The microcomputer 31, when receiving the response request signal _{S rq} through the LF reception circuit 32, generates a response signal _{S rp,} the response signal _{S rp} this generated, transmits through the UHF transmission circuit 33. The response signal S _rp includes a vehicle code ID _v unique to the vehicle 11 corresponding to the portable device 13 in addition to the identification code ID _k unique to the portable device 13.

<About LF transmitter arrangement, receiver arrangement and communication area>
As shown in FIG. 2, the LF transmitter 22 outside the vehicle is provided at five locations of the vehicle 11 including a driver seat door, a passenger seat door, a rear right seat door, a rear left seat door, and a trunk door. Here, five outside LF transmitters 22 are divided into an outside LF transmitter 22a provided at the driver's seat door, an outside LF transmitter 22b provided at the passenger seat door, an outside LF transmitter 22c provided at the rear right seat door, and the rear portion. A distinction is made between an out-of-vehicle LF transmitter 22d provided at the left seat door and an out-of-vehicle LF transmitter 22e provided at the trunk door. By transmitting response request signals S _rq from these outside LF transmitters 22a to 22e, outside communication areas A1, A2, A3, A4 and A5 indicated by broken lines in FIG. 2 are formed around each door. .

Moreover, the in-vehicle LF transmitter 23 is provided at two locations, a front portion and a rear portion, in the vehicle interior. Here, the two in-vehicle LF transmitters 23 are distinguished as an in-vehicle LF transmitter 23a provided at the front of the vehicle interior and an in-vehicle LF transmitter 23b provided at the rear of the vehicle interior. By transmitting response request signals S _rq from these in-vehicle LF transmitters 23a and 23b, in-vehicle communication areas A6 and A7 indicated by broken lines in FIG. 2 are formed in the front and rear portions of the vehicle interior. The receiver 24 is provided at a position on the right side in the rear part of the passenger compartment, for example.

ECU21, when performing exterior verification, rather than to transmit a response request signal _{S rq} simultaneously from five exterior LF transmitter 22 a to 22 e, by transmitting a response request signal _{S rq} in a defined order, each Out-of-vehicle communication areas A1 to A5 are sequentially formed around the door. In addition, when performing in-vehicle collation, the ECU 21 alternately generates response request signals S _rq from the two in-vehicle LF transmitters 23a and 23b, thereby alternately forming in-vehicle communication areas A6 and A7 in the vehicle interior.

  Incidentally, these external communication areas A1 to A5 and in-vehicle communication areas A6 and A7 are areas where a response from the portable device 13 is expected. The communication areas A1 to A5 outside the vehicle are the working distance of the portable device 13 required according to the product specifications of the electronic key system (with the vehicle 11 from which the portable device 13 can receive a radio signal transmitted from the vehicle 11). Distance).

<Unauthorized communication>
Here, in the electronic key system 10 in which mutual wireless communication is performed between the in-vehicle device 12 and the portable device 13, there is a concern about the following.

As shown in FIG. 2, it is conceivable that a third party installs a repeater 51 having an amplification function in an out-of-vehicle communication area A5 formed around a trunk door, for example. At this time, the response request signal S _rq transmitted from the outside LF transmitter 22e is amplified by the repeater 51, so that the outside communication area A5 is illegally expanded. Therefore, even if the portable device 13 exists outside the original outside-vehicle communication area A5, a situation exists in which the portable device 13 exists within the communication area _Adis that has been illegally expanded. The portable device 13 receives the response request signal S _rq amplified by the repeater 51 even though it exists outside the original outside-vehicle communication area A5, and the response signal for the amplified response request signal S _rq Send _Srp . For this reason, there exists a possibility that the door of the vehicle 11 may be unlocked illegally. In addition, when repeater 51 is installed in other in-vehicle communication areas A1 to A4 and in-vehicle communication areas A6 and A7, the same is concerned.

Therefore, in this example, the signal level of the response request signal S _rq is determined in the receiver 24 in order to suppress unauthorized operation of on-vehicle equipment such as the door lock device 14. The following configuration is adopted as the ECU 21 and the receiver 24.

<Detailed configuration of ECU>
The storage device 21a of the ECU21 is, the identification code ID _k, vehicle code ID _v and transmitter number _{S n} are stored. The identification code ID _k is identification information unique to the portable device 13 associated as a communication partner of the vehicle 11. The vehicle code ID _v is identification information unique to the vehicle 11. Further, transmitter number _{S n} is, LF transmitter (22 a to 22 e, 23a, 23b) to a unique identifier. The transmitter number S _n is used to specify the LF transmitter that has transmitted the response request signal S _rq . The ECU 21 generates an LF transmitter (22a to 22e, 23a, 23b) that transmits the vehicle code ID _v and the response request signal S _rq each time the response request signal S _rq is generated (each time the response request signal S _rq is transmitted). wired transmitting the transmitter number S _n to the receiver 24.

<Detailed configuration of receiver>
The receiver 24 is provided at a position that is considered to exist within the expanded communication area, even when any one of the plurality of communication areas (A1 to A7) is expanded by the repeater 51. . For example, it is assumed that the vehicle 11 is parked in an outdoor parking lot and the portable device 13 is present indoors. Under this circumstance, when the communication area is illegally expanded to include the indoor portable device 13, the receiver 24 is provided at any location in the vehicle interior, regardless of which communication area is expanded. At any time, the receiver 24 is considered to be located within a communications area that has been illegally expanded. Under this circumstance, the receiver 24 may not exist in the original communication area (A1 to A7).

The configuration of the receiver 24 is as follows.
As shown in FIG. 1, the receiver 24 includes a UHF reception circuit 41, an LF reception circuit 42, a signal level detection circuit 43, a vehicle code determination circuit 44, and a signal level determination circuit 45. The UHF reception circuit 41, the vehicle code determination circuit 44, and the signal level determination circuit 45 are connected to the ECU 21. A signal level detection circuit 43 and a vehicle code determination circuit 44 are connected in parallel between the signal level determination circuit 45 and the LF reception circuit 42.

The UHF receiving circuit 41 has an antenna 41a. The UHF receiving circuit 41 receives a UHF band radio signal via the antenna 41a. Here, it is assumed that the UHF receiving circuit 41 receives the response signal S _rp wirelessly transmitted from the portable device 13. The UHF receiving circuit 41 wire-transmits the identification code ID _k of the portable device 13 included in the response signal S _rp to the ECU 21.

The LF receiving circuit 42 has an antenna 42a. The LF receiving circuit 42 receives an LF band radio signal via the antenna 42a. Here, the LF receiving circuit 42 receives the response request signal S _rq wirelessly transmitted from the outside LF transmitters 22a to 22e and the in-vehicle LF transmitters 23a and 23b.

Signal level detection circuit 43 detects the signal level L _v of the radio signals in the LF band received through the LF reception circuit 42. Here, the signal level _Lv refers to, for example, the voltage (peak-to-peak value) of an analog signal received and processed by the LF receiving circuit 42.

The vehicle code determination circuit 44 determines whether or not the response request signal S _rq received through the LF reception circuit 42 is transmitted from the vehicle 11 (own vehicle) on which the vehicle code determination circuit 44 is mounted. The vehicle code determination circuit 44 takes in the vehicle code ID _v included in the response request signal S _rq received through the LF reception circuit 42. The vehicle code determination circuit 44 determines whether the vehicle code ID _v included in the response request signal S _rq matches the vehicle code ID _v acquired through the ECU 21. When the two vehicle codes ID _v and ID _v match, the vehicle code determination circuit 44 generates a determination result indicating that the response request signal S _rq received through the LF reception circuit 42 is transmitted from the _host vehicle. To do. When the two vehicle codes ID _v and ID _v do not match, the vehicle code determination circuit 44 does not transmit the response request signal S _rq received through the LF reception circuit 42 from the own vehicle, but from other vehicles. A determination result indicating that the data has been processed is generated.

The signal level determination circuit 45 takes in the signal level L _v detected by the signal level detection circuit 43 and the determination result generated by the vehicle code determination circuit 44. Signal level determination circuit 45, when the current response request signal S _rq by the vehicle code determination circuit 44 is determined that those originating from the vehicle, the signal level L _v detected by the signal level detection circuit 43 Based on this, it is determined whether the outside communication areas A1 to A5 or the inside communication areas A6 and A7 are illegally expanded.

The signal level determination circuit 45 stores a table TD. Signal level determining circuit 45 determines by using the table TD, the signal level L _v of the received response request signal S _rq is normal or abnormal through the LF reception circuit 42.

As shown in FIG. 3, the table TD defines LF transmitter (22 a to 22 e, 23a, 23b) the relationship between the transmitter number _{S n} and the threshold _{L th} of. The threshold value L _th is a response when a normal communication area (A1 to A5, A6, A7) is formed by the response request signal S _rq transmitted from each LF transmitter (22a to 22e, 23a, 23b). request when signal S _rq is received by the LF receiver circuit 42 is set based on the normal signal level L _v detected by the signal level detection circuit 43. Threshold L _th is set slightly larger than the normal signal level L _v.

Transmitter number S _n of exterior LF transmitter 22a provided in the driver's door is a "01", the threshold value L _th1 is associated with this transmitter number "01". The transmitter number S _n of exterior LF transmitter 22b provided on the front passenger's seat door is "02", the threshold value L _th2 is associated with this transmitter number "02". The transmitter number S _n of exterior LF transmitter 22c provided in the rear right seat door is "03", the threshold value L _th3 is associated with this transmitter number "03". The transmitter number S _n of exterior LF transmitter 22d provided on the rear left seat door is "04", the threshold value L _th4 is associated with this transmitter number "04". Transmitter number S _n of the vehicle exterior LF transmitter 22e provided in the trunk door is a "05", the threshold L _th5 is associated with in the transmitter number "05". The transmitter number S _n of interior LF transmitter 23a provided in front of the passenger compartment is "06", the threshold value L _th6 is associated with this transmitter number "06". The transmitter number S _n of interior LF transmitter 23b provided in the rear of the passenger compartment is "07", the threshold value L _th7 is associated with this transmitter number "07".

Signal level determining circuit 45 takes in the signal level L _v detected through a signal level detection circuit 43. Signal level determining circuit 45 includes a signal level _{L v} detected by the signal level detection circuit 43, LF transmitter that sent the current response request signal _{S rq} acquired through ECU21 (22a~22e, 23a, 23b) to determining the corresponding through comparison with the threshold L _th, whether the signal level L _v is normal or abnormal. Signal level determining circuit 45 wired transmits the determination result _{R L} of the signal level _{L v} to ECU 21.

Signal level determination circuit 45, when the value of the signal level L _v is less than or equal to a threshold L _th, that the signal level L _v of this response request signal S _rq received through the LF reception circuit 42 is normal determination To do. Here, normal means that the response request signal S _rq is not amplified by the repeater 51. When the signal level _{L v} is determined that is normal, the response request signal _{S rq} of this time, by the communication area (A1 to A5, A6, A7) are illegally expanded, it is received by the LF receiver circuit 42 Not a thing.

Signal level determination circuit 45, when the value of the signal level L _v exceeds the threshold L _th, determines that the signal level L _v of this response request signal S _rq received through the LF reception circuit 42 is abnormal . Here, the abnormality means that the response request signal S _rq is amplified by the repeater 51. When the signal level _{L v} is determined that an abnormal response request signal _{S rq} of this time, by the communication area (A1 to A5, A6, A7) are illegally expanded, it is received in the LF reception circuit 42 It is a thing.

<Operation of electronic key system>
Next, the operation of the electronic key system will be described. Here, the case where the vehicle 11 is in a parked state and the user gets on is taken as an example.

As shown in the sequence chart of FIG. 4, the ECU 21 switches the five external LF transmitters 22a to 22e in a predetermined order, and transmits a response request signal S _rq through the switched external LF transmitters 22a to 22e ( Step S101). Thus, vehicle exterior communication areas A1 to A5 are sequentially formed around each door. Then, ECU 21 of the vehicle code ID _v, and the response request signal _{S rq} LF transmitters that transmits (22 a to 22 e, 23a, 23b) transmitter number to the wired transmitting the _{S n} to the receiver 24 in (step S102).

When the portable device 13 enters any of the outside communication areas A1 to A5, the portable device 13 receives the response request signal S _rq (step S201).
Next, the portable device 13 determines whether or not the vehicle code ID _v included in the response request signal S _rq matches the vehicle code ID _v stored in its own storage device 31a (step S202).

When the two vehicle codes ID _v and ID _v do not match (NO in step S202), the portable device 13 ends the process. When the two vehicle codes ID _v and ID _v do not match, the response request signal S _rq received by the portable device 13 is not transmitted from the vehicle 11 corresponding to itself, but transmitted from another vehicle. .

When the two vehicle codes ID _v and ID _v match (YES in step S202), the portable device 13 transmits a response signal S _rp (step S203) and ends the process. When the two vehicle codes ID _v and ID _v match, the response request signal S _rq received by the portable device 13 is transmitted from the vehicle 11 corresponding to itself.

The receiver 24 determines whether or not the response request signal S _rq transmitted from the LF transmitters 22a to 22e outside the host vehicle is received (step S301). This is because the receiver 24 may not be able to receive the response request signal S _rq in a normal case where the communication areas (A1 to A7) inside and outside the vehicle compartment are not expanded illegally.

If the receiver 24, it is determined that it has received the response request signal _{S rq} (YES at step S301), when the vehicle code ID _v and transmitter number _{S n} is received is wired transmitted from ECU 21 (step S302) Then, it is determined whether or not the vehicle code ID _v included in the response request signal S _rq matches the vehicle code ID _v acquired through the ECU 21 (step S303).

When the two vehicle codes ID _v and ID _v do not match (NO in step S303), the receiver 24 ends the process. When the two vehicle codes ID _v and ID _v match (YES in step S303), the receiver 24 moves the process to step S304.

At step S304, the receiver 24, the signal level _{L v} of the response demand signal _{S rq} received is determined whether it exceeds the threshold _{L th} (step S304). Here the receiver 24 refers to the table TD, using the threshold _{L th} associated with transmitter number _{S n} which is obtained through ECU 21.

The receiver 24 determines when (NO in step S304), the signal level _{L v} is indicating the normal operating signal level _{L v} is determined that the threshold value is not exceeded _{L th} (step S305). The receiver 24, when the signal level _{L v} is determined that the threshold value is exceeded _{L th} (YES at step S304), the signal level _{L v} is determined that an abnormality (step S306). Thereafter, the receiver 24 wire-transmits the determination result _RL in step S304 to the ECU 21 (step S307).

Next, when the response signal S _rp is received (step S308), the receiver 24 wire-transmits the identification code ID _k unique to the portable device 13 included in the response signal S _rp to the ECU 21 (step S309). The process is terminated.

ECU21, after the vehicle code ID _v and transmitter number _{S n} wirelessly transmitted in the step S102, when the judgment result _{R L} of the signal level _{L v} by the receiver 24 is received (step S103), the signal by the receiver 24 the determination result of the level _{L v} is determined whether _{R L} are those showing a normal (step S104).

ECU21, when the determination result _{R L} of the signal level _{L v} is determined that does not indicate a normal (at step S104 NO), the process ends. At this time, operation of in-vehicle devices such as the door lock device 14 is not permitted.

ECU21, when the determination result _{R L} of the signal level _{L v} is determined that shows the normal (YES at step S104), and when the identification code ID _k from the receiver 24 is received (step S105), this determines the identification code ID _k received, whether the identification code ID _k stored in the storage device 21a match (step S106).

When the two identification codes ID _k and ID _k do not match (NO in step S106), the ECU 21 ends the process. At this time, operation of in-vehicle devices such as the door lock device 14 is not permitted. When the two identification codes ID _k and ID _k match (YES in step S106), the ECU 21 permits the operation of the in-vehicle device such as the door lock device 14 (step S107) and ends the process.

Even when it is determined in step S301 that the response request signal S _rq has not been received (NO in step S301), the receiver 24 transmits the vehicle code ID _v wired from the ECU 21 and the transmission. receiving a machine number _{S n} (step S401). When the response signal S _rp is received (step S402), the receiver 24 determines whether the vehicle code ID _v included in the response signal S _rp matches the vehicle code ID _v acquired through the ECU 21. (Step S403). When the two vehicle codes ID _v and ID _v do not match (NO in step S403), the receiver 24 ends the process. Further, when the two vehicle codes ID _v and ID _v match (YES in step S403), the receiver 24 shifts the process to step S309.

  Thus, a series of operations of the electronic key system is completed. Each process shown in the sequence chart of FIG. 4 is basically performed also when the portable device 13 is authenticated in the vehicle interior.

<Effect of the first embodiment>
Therefore, according to the first embodiment, the following effects can be obtained.
(1) signal level _{L v} of the response request signal _{S rq} received by the receiver 24, when the threshold value is not exceeded _{L th,} the vehicle interior outside of the communication area (A1 to A7) are being illegally expanded It is determined that there is not. In this case, when the identification code ID _k included in the response signal S _rp is correct, the operation of the in-vehicle device such as the door lock device 14 is permitted. In contrast, the signal level _{L v} of the response request signal _{S rq} received by the receiver 24, when the threshold value is exceeded _{L th,} the vehicle interior outside of the communication area (A1 to A7) are illegally expanded It is determined that it is. In this case, even when the identification code ID _k included in the response signal S _rp is correct, the operation of the in-vehicle device such as the door lock device 14 is not permitted. For this reason, the crime prevention property of the vehicle can be improved.

(2) ECU 21 on the basis of the determination result _{R L} of the signal level _{L v} which is obtained through the receiver 24 (signal level judging circuit 45) recognizes that the signal level _{L v} does not exceed the threshold value _{L th} be able to.

(3) When the vehicle code ID _v included in the response request signal S _rq received by the receiver 24 matches the vehicle code ID _v acquired through the ECU 21, the signal level L _v of the response request signal S _rq The comparison process with the threshold value L _th is executed. In contrast, the vehicle code ID _v included in the response request signal _{S rq} received by the receiver 24, when the vehicle code ID _v do not match acquired through ECU 21, the signal level of the response request signal _{S rq L v} And the threshold value L _th are not executed. Therefore, on the basis of the response request signal S _rq transmitted from another vehicle, it is determined erroneously correctness of the signal level L _v is avoided. Therefore, it can be determined more accurately that the communication areas (A1 to A7) inside and outside the vehicle are illegally expanded.

(4) ECU 21, a plurality of LF transmitter (22 a to 22 e, 22f, 22 g) with switches in the order defined and the response request signal _{S rq} every time the response request signal _{S rq} is wirelessly transmitted wireless transmission wired transmission to the receiver 24 a unique transmitter number S _n to the LF transmitter. Signal level determining circuit 45 of the receiver 24 performs determination processing of the signal level _{L v} using the threshold _L th, corresponding to the transmitter number _{S n} from ECU21 _(L th1 _{~L th7).} In the determination processing of the signal level L _v, by the threshold L _th corresponding to the plurality of LF transmitter is used, in the case where a plurality of LF transmitter is provided in the vehicle 11, the radio through these LF transmitter signal level L _v of the response request signal S _rq transmitted can be appropriately determined.

(5) In the normal case where the communication areas (A1 to A7) inside and outside the vehicle are not expanded illegally, the receiver 24 may not be able to receive the response request signal _Srq . At this time, the vehicle code ID _v included in the response signal S _rp from the portable device 13 matches the vehicle code ID _v acquired through the ECU 21, and the identification code ID _k included in the response signal S _rp is correct. At some point, the operation of in-vehicle devices such as the door lock device 14 is permitted. Even in a normal case, in-vehicle devices such as the door lock device 14 can be operated while ensuring crime prevention.

<Second Embodiment>
Next, a second embodiment of the electronic key system will be described. This example basically has the same configuration as that of the first embodiment shown in FIGS. Therefore, the same members and configurations as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

As indicated by the two-dot chain line in FIG. 1, UHF receiving circuit 41 takes in the determination result R _L of the signal level L _v by the signal level judging circuit 45. UHF receiving circuit 41, when the signal level _{L v} is a determination result _{R L} shown that is normal to the wired transmitting an identification code ID _k of the portable device 13 included in the response signal _{S rp} received the ECU 21. UHF receiving circuit 41, if the determination result indicating that the signal level _{L v} is abnormal is _{R L,} does not transmit an identification code ID _k of the portable device 13 included in the response signal _{S rp} received the ECU 21.

Next, the operation of the electronic key system will be described.
As shown in the sequence chart of FIG. 5, the ECU 21 transmits a response request signal S _rq through the five out-of-vehicle LF transmitters 22a to 22e (step S101). Further, ECU 21, the vehicle code ID _v, and the response request signal _{S rq} LF transmitters that transmits (22 a to 22 e, 23a, 23b) transmitter number to the wired transmitting the _{S n} to the receiver 24 in (step S102).

When the response request signal S _rq from the vehicle 11 is received (step S201), the portable device 13 receives the vehicle code ID _v included in the response request signal S _rq and the vehicle code stored in its own storage device 31a. When ID _v matches (YES in step S202), a response signal _Srp is transmitted (step S203), and the process is terminated.

The receiver 24 determines whether or not the response request signal S _rq from the vehicle 11 has been received (step S301). The receiver 24 is, when it is determined that received the response request signal _{S rq} (YES at step S301), the vehicle code ID _v is wired transmitted from ECU 21, and receives a transmitter number _{S n} (step S302). The receiver 24 includes a vehicle code ID _v contained in the response request signal _{S rq,} when the vehicle code ID _v do not match to be obtained through ECU 21 (NO in step S303), and ends the process. When the vehicle code ID _v included in the response request signal S _rq matches the vehicle code ID _v acquired through the ECU 21 (YES in step S303), the receiver 24 receives the response signal S _rp from the portable device 13. wait.

When the response signal S _rp is received from the portable device 13 (step S311), the receiver 24 refers to the table TD, and the signal level L _{v of} the received response request signal S _rq is set to the threshold value L _th . It is determined whether or not it exceeds (step S312). The receiver 24, when the signal level _{L v} is determined that the threshold value is exceeded _{L th} (YES at step S312), the process ends. The receiver 24, when the signal level _{L v} is determined that the threshold value is not exceeded _{L th} (NO at step S312), the portable unit 13 included in the response signal _{S rp} a unique identification code ID _k ECU 21 Is wired (step S313), and the process is terminated.

ECU21, when the identification code ID _k from the receiver 24 is received (step S 111), the identification code ID _k is the received, whether the identification code ID _k stored in the storage device 21a matches Determination is made (step S112). When the two identification codes ID _k and ID _k do not match (NO in step S112), the ECU 21 ends the process. When the two identification codes ID _k and ID _k match (YES in step S112), the ECU 21 permits the operation of the in-vehicle device such as the door lock device 14 (step S113) and ends the process.

Even when it is determined in step S301 that the response request signal S _rq has not been received (NO in step S301), the receiver 24 transmits the vehicle code ID _v wired from the ECU 21 and the transmission. receiving a machine number _{S n} (step S401). When the response signal S _rp is received (step S402), the receiver 24 determines whether the vehicle code ID _v included in the response signal S _rp matches the vehicle code ID _v acquired through the ECU 21. (Step S403). When the two vehicle codes ID _v and ID _v do not match (NO in step S403), the receiver 24 ends the process. Further, when the two vehicle codes ID _v and ID _v match (YES in step S403), the receiver 24 shifts the process to step S313.

<Effects of Second Embodiment>
Therefore, according to the second embodiment, the following effects can be obtained.
(1) Even when the response signal S _rp is received by the receiver 24, there is a possibility that the communication areas (A 1 to A 7) inside and outside the vehicle are unjustly expanded (signal of the response request signal S _rq level when _{the L v} exceeds the threshold _{L th),} the receiver 24 is not transmitted to the ECU21 a unique identification code ID _k on the portable device 13 included in the response signal _{S rp.} Since the ECU 21 does not receive the identification code ID _k , the operation of the in-vehicle device is not permitted. For this reason, the crime prevention property of the vehicle can be improved.

(2) the receiver 24 determines the signal level _{L v} of the response request signal _{S rq,} whether the determination result based on the _{R L,} and transmits an identification code ID _k included in the response signal _{S rp} relative ECU21 Decide. Therefore, unlike the first embodiment, ECU 21 does not need to check the determination result _{R L} of the signal level _{L v.} The processing load on the ECU 21 is reduced by the amount that the determination result confirmation process is unnecessary. In addition, the number of communications between the ECU 21 and the receiver 24 can be reduced.

(3) when the receiver 24 does not receive a response request signal _{S rq,} identification and vehicle code ID _v from the vehicle code ID _v and ECU21 included in the response signal _{S rp} match and contained in the response signal _{S rp} When the code ID _k is correct, the operation of the in-vehicle device is permitted. Even when the response request signal S _rq is not received by the receiver 24, the in-vehicle device can be operated while ensuring the crime prevention.

<Third Embodiment>
Next, a third embodiment of the electronic key system will be described. This example is different from the first embodiment in that the ECU 21 has a part of the function of the receiver 24. Therefore, the same members and configurations as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

As shown in FIG. 6, the receiver 24 includes a UHF receiving circuit 41 and an LF receiving circuit 42. The ECU 21 has a signal level detection circuit 43, a vehicle code determination circuit 44, and a signal level determination circuit 45. These circuits (43, 44, 45) basically have the same functions as those in the first embodiment. However, the signal level detecting circuit 43 temporarily stores the signal level L _v of the response request signal S _rq detected.

The ECU 21 has a control circuit 46. The control circuit 46 controls the operation of the outside LF transmitter 22 and the operation of the in-vehicle LF transmitter 23, respectively. Further, the control circuit 46 acquires the identification code ID _k included in the response signal S _rp through the receiver 24. The control circuit 46 determines whether or not the identification code ID _k acquired through the receiver 24 matches the identification code ID _k stored in its own storage device 21a. Further, the control circuit 46, the determination result of the signal level _{L v} by the signal level judging circuit 45 _{R L} also captures.

The control circuit 46 includes an identification code ID _k is obtained through the receiver 24, when the identification code ID _k stored in the storage device 21a matches, and judgment result of the signal level L _v by the signal level judging circuit 45 R when the signal level L _v based on _L is determined that the threshold value is not exceeded L _th, enables operation of the door lock device 14 or the engine starting device 15.

Next, the operation of the electronic key system will be described.
As shown in the flowchart of FIG. 7, the ECU 21 transmits a response request signal S _rq through the five vehicle exterior LF transmitters 22a to 22e (step S101).

When the response request signal S _rq from the vehicle 11 is received (step S201), the portable device 13 receives the vehicle code ID _v included in the response request signal S _rq and the vehicle code stored in its own storage device 31a. When ID _v matches (YES in step S202), a response signal _Srp is transmitted (step S203), and the process is terminated.

The receiver 24 determines whether or not the response request signal S _rq from the vehicle 11 has been received (step S301). When the response request signal S _rq from the vehicle 11 is received (YES in step S301), the receiver 24 wire-transmits the vehicle code ID _v included in the response request signal S _rq to the ECU 21 (step S321). Thereafter, the receiver 24 waits for a response signal S _rp from the portable device 13. When the response signal S _rp is received from the portable device 13 (Step S322), the receiver 24 wire-transmits the identification code ID _k unique to the portable device 13 included in the response signal S _rp to the ECU 21. (Step S323), the process ends.

When the ECU 21 transmits the response request signal S _rq and then receives the vehicle code ID _v from the receiver 24 (step S121), the ECU 21 stores the received vehicle code ID _v and its own storage device 21a. It is determined whether or not the vehicle code ID _v matches (step S122).

When the two vehicle codes ID _v and ID _v do not match (NO in step S122), the ECU 21 ends the process. When the two vehicle codes ID _v and ID _v match (YES in step S122), the ECU 21 waits for the identification code ID _k from the receiver 24.

Or ECU21, when the identification code ID _k from the receiver 24 is received (step S123), the identification code ID _k is the received, the identification code ID _k stored in its own storage device 21a matches It is determined whether or not (step S124).

When the two identification codes ID _k and ID _k do not match (NO in step S124), the ECU 21 ends the process. When the two identification codes ID _k and ID _k match (YES in step S124), the ECU 21 determines that the signal level L _v of the response request signal S _rq detected by the signal level detection circuit 43 exceeds the threshold value L _th . It is determined whether or not (step S125).

ECU21, when the signal level _{L v} is determined that the threshold value is exceeded _{L th} (YES at step S125), the process ends. ECU21, when the signal level _{L v} is determined that the threshold value is not exceeded _{L th} (NO at step S125), and it permits the operation of the in-vehicle equipment such as a door lock device 14 (step S126), the process ends To do.

Note that when the response request signal S _rq is not received in the previous step S301 (NO in step S301), the receiver 24 waits for the response signal S _rp from the portable device 13. When the response signal S _rp is received from the portable device 13 (Step S501), the receiver 24 shifts the processing to Step S323.

Incidentally, the processing order of step S124 and step S125 may be reversed.
<Effect of the third embodiment>
Therefore, according to the third embodiment, the following effects can be obtained.

(1) ECU 21, the signal level _{L v} of the response request signal _{S rq} received through the receiver 24 has a Do of decision function if it is less than the threshold value _{L th.} Even if the identification code ID _k included in the response signal S _rp acquired through the receiver 24 is correct, the ECU 21 does not permit the operation of the in-vehicle device when the signal level L _v exceeds the threshold value L _th. . For this reason, the crime prevention property of the vehicle 11 can be improved.

(2) For example unlike the case to have a determining function of the signal level _{L v} in the receiver 24, ECU 21 does not need to send the vehicle code ID _v, and the transmitter number _{S n} to receiver 24. Further, ECU 21 is not necessary to obtain a determination result of the signal level _{L v} through the receiver 24. For this reason, the frequency | count of communication between ECU21 and the receiver 24 can be reduced more.

(3) In the normal case where the communication area inside and outside the vehicle is not expanded illegally, when the receiver 24 does not receive the response request signal S _rq , the receiver 24 is included in the response signal S _rp from the portable device 13. The identification code ID _k is wired to the ECU 21. The identification code ID _k stored in the storage device 21a of the identification code ID _k and ECU21 from the receiver 24 match and when the signal level _{L v} does not exceed the threshold value _{L th,} the operation of the in-vehicle equipment Is allowed. Therefore, even in a normal case, the in-vehicle device can be operated while ensuring crime prevention.

<Other embodiments>
The first to third embodiments may be modified as follows.
In the first to third embodiments, for example, a bar antenna is employed as the antenna 42a that receives a radio signal in the LF band. The bar antenna is formed by winding an electric wire (coil) around a core made of a magnetic material such as ferrite. Further, a so-called glass antenna may be employed as the antenna 42a instead of the bar antenna.

As shown in FIG. 8, a linear antenna 62 is provided on the outer surface of the window glass 61 of the vehicle 11. The antenna 62 is connected to the receiver 24 (more precisely, the LF receiving circuit 42). In this way, compared to the case where an antenna for receiving a radio signal in the LF band is provided in the vehicle interior, it is less affected by metal such as the vehicle body, and the radio signal in the LF band from the outside of the vehicle 11 (here, , It becomes easier to receive the response request signal S _rq ).

In the third embodiment, as shown in the flowchart of FIG. 7, when the receiver 24 receives the response signal S _rp from the portable device 13 (step S322 and step S501), the response signal S _rp The included identification code ID _k is wired to the ECU 21 (step S323). However, each process of step S323, step S123, and step S124 may be read as follows.

That is, the receiver 24, regardless of whether it has received a response request signal _{S rq,} when receiving the response signal _{S rp} (step S322 and step S501), the identification code ID _k and vehicle contained in the response signal _{S rp} The code ID _v is wired and transmitted to the ECU 21 (step S323).

When the identification code ID _k and the vehicle code ID _v from the receiver 24 are received (step S123), the ECU 21 determines the validity of the identification code ID _k and the vehicle code ID _v from the receiver 24 (step S124). ). Specifically, the ECU 21 determines whether the identification code ID _k and the vehicle code ID _v from the receiver 24 match the identification code ID _k and the vehicle code ID _v stored in the storage device 21a. When it is determined that both identification code ID _k and vehicle code ID _v from receiver 24 are valid (YES in step S124), ECU 21 proceeds to step S125. Further, when it is determined that at least one of the identification code ID _k and the vehicle code ID _v from the receiver 24 is not valid (NO in step S124), the ECU 21 ends the process.

In this way, even if the receiver 24 does not receive the response request signal S _rq , the validity of the vehicle code ID _v , the identification code ID _k, and the signal level L _{v by} the ECU 21 is determined. Can secure crime prevention.

In the first to third embodiments, the vehicle code determination circuit 44 may be omitted depending on product specifications. In this case, each process related to the determination of the vehicle code is also omitted.
For example, in the first and second embodiments, the processes in step S303, step S401, and step S403 in FIGS. 4 and 5 are omitted. Then, when the response request signal S _rq is not received (NO in step S301), the receiver 24 receives the response signal S _rp from the portable device 13 (step S402), and the identification code included in the response signal S _rp ID _k is wired and transmitted to the ECU 21 (steps S309 and S313). Even in this case, the validity of the identification code ID _k is determined by the ECU 21 so that the crime prevention property can be ensured.

Further, in the third embodiment, the processes of step S301, step S321, step S121, step S122, and step S501 in FIG. 7 are omitted. In this case, when the response signal S _rp is received from the portable device 13 (step S322), the receiver 24 wire-transmits the identification code ID _k included in the response signal S _rp to the ECU 21 (step S323). ). Even in this case, by the validity of the validity and the signal level L _v of the identification code ID _k by ECU21 it is determined respectively, can be secured crime prevention.

  In the first to third embodiments, the numbers of the outside LF transmitter 22 and the inside LF transmitter 23 may be changed as appropriate. Depending on the product specifications of the vehicle 11, one outside LF transmitter 22 and one in-vehicle LF transmitter 23 may be provided.

  DESCRIPTION OF SYMBOLS 10 ... Electronic key system, 13 ... Portable machine, 14 ... Door lock device (vehicle equipment), 15 ... Engine starter (vehicle equipment), 21 ... Electronic control device, 22 ... Outside LF transmitter, 23 ... In-vehicle LF transmitter , 24 ... receiver, 41 ... UHF reception circuit (first reception circuit), 42 ... LF reception circuit (second reception circuit), 43 ... signal level detection circuit, 44 ... vehicle code determination circuit, 45 ... signal level Determination circuit, 46... Control circuit.

Claims (7)

A transmitter that wirelessly transmits a response request signal to and from a vehicle interior, a portable device that wirelessly transmits a response signal in response to the response request signal, a receiver that receives the response signal, and a receiver that receives the response signal An electronic control device that permits the operation of the in-vehicle device based on the response signal,
The receiver detects a signal level of a first reception circuit that receives the response signal, a second reception circuit that receives the response request signal, and a response request signal received through the second reception circuit. And a determination circuit for determining whether a signal level detected through the detection circuit exceeds a threshold value set to a value larger than a signal level normally assumed as the signal level. And
When the electronic control unit determines that the response signal received through the first receiving circuit is valid, and the determination circuit determines that the signal level does not exceed the threshold value An electronic key system that permits the operation of the in-vehicle device. The electronic key system according to claim 1.
The determination circuit wire-transmits a determination result of a signal level detected through the detection circuit to the electronic control device,
The electronic control device is an electronic key system that recognizes whether or not the signal level exceeds the threshold value based on the determination result acquired through the determination circuit. The electronic key system according to claim 1.
The response signal includes an identification code unique to the portable device, and the electronic control unit determines validity of the response signal based on the identification code,
An electronic key system in which the first receiving circuit wire-transmits the identification code to the electronic control unit when the determination circuit determines that the signal level does not exceed the threshold value. In the electronic key system according to any one of claims 1 to 3,
The electronic control unit wirelessly transmits the response request signal including a vehicle code unique to the host vehicle through the transmitter, and wire-transmits the vehicle code to the receiver.
The receiver includes a vehicle code determination circuit that determines whether a vehicle code included in the response request signal matches a vehicle code acquired through the electronic control device,
The determination circuit performs electronic signal level determination processing when the vehicle code determination circuit determines that the vehicle code included in the response request signal matches the vehicle code acquired through the electronic control unit. Key system. In the electronic key system according to any one of claims 1 to 4,
The vehicle is provided with a plurality of the transmitters,
The electronic control unit switches the transmitter that wirelessly transmits the response request signal in a predetermined order, and is unique to the transmitter that wirelessly transmits the response request signal every time the response request signal is wirelessly transmitted. Send the transmitter number to the receiver by wire,
The determination circuit stores the threshold value set corresponding to each of the plurality of transmitters, and uses the threshold value corresponding to the transmitter number acquired through the electronic control unit. An electronic key system for performing the signal level determination process. A response request signal is wirelessly transmitted to the vehicle interior and exterior through the transmitter, and a response signal wirelessly transmitted from the portable device in response to the response request signal is received through the receiver, and the vehicle is mounted based on the received response signal. In the electronic control device that permits the operation of the device,
A detection circuit for detecting a signal level of a response signal received through the receiver;
A determination circuit for determining whether a signal level detected through the detection circuit exceeds a threshold value set to a value larger than a signal level normally assumed as the signal level;
A control circuit that permits operation of the in-vehicle device when it is determined that the response signal is valid and when the determination circuit determines that the signal level does not exceed the threshold value. Electronic control device. In-vehicle electronic control device is wirelessly transmitted from the portable device in response to a response request signal wirelessly transmitted to the inside and outside of the vehicle through a transmitter, and the electronic control device determines its validity in order to permit the operation of the in-vehicle device. A receiver for receiving a response signal including an identification code unique to the portable device,
A first receiving circuit that receives the response signal; a second receiving circuit that receives the response request signal; and a detection circuit that detects a signal level of the response request signal received through the second receiving circuit; A determination circuit for determining whether or not a signal level detected through the detection circuit exceeds a threshold value set to a value larger than a signal level normally assumed as the signal level,
The first reception circuit is a receiver that transmits the identification code included in the response signal to the electronic control unit when the determination circuit determines that the signal level does not exceed the threshold value.

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