JP2012122222A - Electronic key system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic key system that surely performs locking when an electronic key is taken out of a cabin.SOLUTION: An electronic key system allows a vehicle door to be locked in a case where an electronic key 10 is determined to be taken out of a cabin, even when an in-cabin collating is established despite the electronic key being outside the cabin because a request signal transmitted in the cabin leaks out of the cabin. This can inhibit a situation where locking is not performed even though a lock switch 32 is operated by a user holding the electronic key 10, and can improve the convenience.

Description

  The present invention relates to an electronic key system.

  2. Description of the Related Art In recent years, vehicles are equipped with an electronic key system that permits locking and unlocking of vehicle doors and engine starting based on wireless communication between the vehicle and the electronic key. In the electronic key system, the vehicle transmits a request signal for requesting a response of the electronic key inside and outside the vehicle interior. When the electronic key receives the request signal, it sends a response signal including its own ID code to the vehicle. The vehicle collates the ID code included in the response signal with the ID code stored in advance in the vehicle. The vehicle enters a locking / unlocking permission state when collation of the ID code contained in the response signal from the electronic key existing outside the vehicle compartment (verification outside the vehicle compartment) is established. In this state, when the user operates a lock switch provided on the door handle outside the vehicle door, the locking / unlocking state of the vehicle door is switched.

  Further, the vehicle enters an engine start permission state when collation of the ID code included in the response signal from the electronic key existing in the passenger compartment (vehicle compartment verification) is established. In this state, when an engine switch provided near the driver's seat is pushed, the engine is started.

  In the electronic key system, the engine can be started in a state where the electronic key is placed on a passenger seat, a dashboard, or the like. Therefore, it is conceivable that the user gets off the vehicle with the electronic key left in the passenger compartment and tries to lock the vehicle door through the operation of the lock switch. In such a case, a configuration for preventing so-called in-locking in which an electronic key is confined in a vehicle interior by locking a vehicle door is known. For example, in Patent Document 1, when a lock switch is operated, a request signal is transmitted to the vehicle interior, and it is determined whether vehicle interior verification is established based on a response signal from an electronic key in the vehicle interior. If it is determined that the vehicle interior verification is established, the vehicle door is not locked because the electronic key is left behind in the vehicle interior. Thereby, an interlock can be prevented.

JP 2005-194799 A

  By the way, the signal intensity and the like are set so that the request signal is transmitted according to the size of the passenger compartment. However, the request signal is an electromagnetic wave propagating in the air. Although this electromagnetic wave hardly leaks out of the passenger compartment through the iron material constituting the vehicle door, it may leak out of the passenger compartment through a window made of a glass material that also constitutes the vehicle door. In this case, the user receives a request signal that the electronic key has leaked out of the vehicle, even though the user operates the lock switch from outside the passenger compartment while carrying the electronic key. Therefore, there is a possibility that the vehicle door verification cannot be performed and the vehicle door cannot be locked even though the electronic key exists outside the vehicle compartment.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an electronic key system that can reliably perform locking when the electronic key is taken out of the passenger compartment.

In the following, means for achieving the above object and its operational effects will be described.
In the first aspect of the present invention, when the electronic key receives a request signal transmitted through an antenna provided in the vehicle, the electronic key transmits a response signal, and the in-vehicle device recognizes that locking has been attempted from outside the vehicle compartment. Determining whether or not the electronic key is present in the passenger compartment based on the presence or absence of the response signal to the request signal transmitted via the antenna, and determining that the electronic key is present in the passenger compartment. In the electronic key system for restricting the locking of the signal, a signal strength detection circuit for detecting a signal strength of the response signal or the request signal transmitted / received between the in-vehicle device and the electronic key, and detected by the signal strength detection circuit Whether the electronic key was taken out of the passenger compartment based on a change in signal strength of the response signal or the request signal from when the vehicle was boarded to when locking was attempted A determination unit that determines whether the electronic key has been taken out of the vehicle through the determination unit even when it is determined that the electronic key exists in the vehicle interior. The gist of the electronic key is to lock the vehicle door on the assumption that the electronic key has received the request signal from the antenna outside the passenger compartment.

  Although it is desirable that the request signal be transmitted only to a preset area, for example, the passenger compartment, the request signal may actually leak outside the passenger compartment. In this state, when locking is attempted from outside the passenger compartment by the user, the electronic key carried by the user transmits a response signal in response to a request signal from the antenna. For this reason, although the electronic key actually exists outside the passenger compartment, there is a possibility that the electronic key is determined to exist inside the passenger compartment and locking is restricted.

  According to the above configuration, even when it is erroneously determined that the electronic key exists in the vehicle interior as described above, when it is determined that the electronic key has been taken out of the vehicle interior through the determination unit, the vehicle door Locking is performed. Thereby, when the electronic key is taken out of the passenger compartment, the locking can be surely performed.

  According to a second aspect of the present invention, in the electronic key system according to the first aspect, the in-vehicle device transmits a request signal to a communication area formed according to a shape of a vehicle interior through the antenna, and the determination is made. Determining that the electronic key is present in an outer peripheral area, which is an outer peripheral portion in the communication area, based on the signal strength of the response signal or the request signal when locking is detected through the signal strength detection circuit. Then, the gist is to determine whether or not the electronic key has been taken out of the passenger compartment.

  According to this configuration, when it is determined that the electronic key exists in the outer peripheral area, it is determined whether the electronic key has been taken out of the passenger compartment. Here, there is a high possibility that the outer peripheral area of the communication area is formed outside the passenger compartment. As a result, it is possible to determine whether or not the electronic key has been taken out of the passenger compartment only when there is a high possibility that the electronic key exists outside the passenger compartment.

  According to a third aspect of the present invention, in the electronic key system according to the first or second aspect, the determination unit is configured to use the response signal or the request when the vehicle is boarded and when locking is attempted through the signal strength detection circuit. The gist of the present invention is to recognize the signal strength of the signals and to determine that the electronic key has been taken out of the passenger compartment when the difference between the recognized signal strengths exceeds a threshold value.

  According to this configuration, it is determined whether or not the electronic key has been taken out of the passenger compartment based only on the signal strength of the response signal or the request signal at both the timing of boarding and when locking is attempted. This makes it easier to determine whether the electronic key has been taken out of the passenger compartment.

The invention according to claim 4 is the electronic key system according to claim 1 or 2,
The determination unit stores a change pattern of the signal strength of the response signal or the request signal from when the vehicle is boarded to when locking is attempted, and whether or not the electronic key is taken out of the passenger compartment based on the change pattern. The gist is to judge.

  According to this configuration, it is determined whether or not the electronic key has been taken out of the passenger compartment based on the change pattern of the signal intensity of the response signal or the request signal from when the user boarded to when the locking was attempted. Therefore, it is possible to determine whether or not the electronic key has been taken out of the passenger compartment by comprehensively considering the movement of the electronic key from the time of getting on to when the locking is attempted.

  According to the present invention, in the electronic key system, locking can be reliably executed when the electronic key is taken out of the passenger compartment.

The block diagram of an electronic key system. The top view of the vehicle which showed the communication area. The time chart which shows the timing of a vehicle interior collation, RSSI, etc. The graph which shows the relationship between the distance between an electronic key and an in-vehicle transmission part, and RSSI. The flowchart which shows the operation processing procedure of a vehicle-mounted control part.

Hereinafter, an electronic key system according to the present invention will be described with reference to FIGS.
As shown in FIG. 1, the electronic key system 1 includes an electronic key 10 possessed by a user and an in-vehicle device 20 provided in the vehicle 2. In the electronic key system 1, mutual communication is automatically performed between the electronic key 10 and the in-vehicle device 20, and the door lock / unlock and the engine are performed on the condition that the mutual communication is established outside and inside the vehicle. Is allowed to start. Hereinafter, the configuration of the electronic key 10 and the in-vehicle device 20 will be described.

<Electronic key 10>
The electronic key 10 includes an electronic key control unit 11, an LF reception unit 12, and a UHF transmission unit 13.

  The electronic key control unit 11 is configured by a computer unit and includes a nonvolatile memory 11a. An ID code unique to the electronic key 10 is stored in the memory 11a.

  When the LF receiver 12 receives a request signal that is a radio signal in the LF (Low Frequency) band transmitted from the in-vehicle device 20 through the receiving antenna 12a, the LF receiver 12 demodulates the request signal into a pulse signal and performs electronic key control on the request signal. To the unit 11. When the electronic key control unit 11 recognizes the demodulated request signal, the electronic key control unit 11 generates a response signal including the ID code stored in the memory 11 a and outputs it to the UHF transmission unit 13. The UHF transmitter 13 modulates the response signal and transmits it as a radio signal in the UHF (Ultra High Frequency) band via its own transmission antenna 13a.

  The LF receiver 12 includes an RSSI detection circuit 16. The RSSI detection circuit 16 detects the received signal strength RSSI (Receive Signal Strength Indication) of the request signal and outputs the detection result to the electronic key control unit 11. The electronic key control unit 11 generates an RSSI information signal including the detection result (RSSI of the request signal) of the RSSI detection circuit 16 and outputs it to the UHF transmission unit 13. The UHF transmitter 13 modulates the RSSI information signal and transmits it as a UHF band radio signal via its own transmission antenna 13a. In this example, the RSSI information signal is transmitted every time a request signal is received.

<In-vehicle device>
As shown in FIG. 1, the in-vehicle device 20 includes an in-vehicle control unit 21, an in-vehicle transmission unit 22, an in-vehicle transmission unit 23, and an in-vehicle reception unit 24. In addition, a lock switch 32, an engine switch 33, a door lock device 34, an engine device 35, a vehicle speed sensor 36, a courtesy switch 37, and a door handle sensor 38 are electrically connected to the in-vehicle control unit 21. Has been.

As shown in FIG. 2, the in-vehicle transmission unit 23 is installed in the center of the passenger compartment. Similarly, the in-vehicle receiver 24 is provided in the center of the passenger compartment.
The outside transmission unit 22 is built in the outside door handle 4 of each vehicle door, as shown in the enlarged right side of FIG. The door handle sensor 38 is provided on the surface of the outside door handle 4. The door handle sensor 38 detects contact of the user with the outside door handle 4 and outputs the detection result to the in-vehicle control unit 21.

  The door lock device 34 automatically locks and unlocks the vehicle door when the vehicle door is closed. The courtesy switch 37 detects the open / closed state of the vehicle door and outputs the detection result to the in-vehicle control unit 21.

  As shown in FIG. 1, the vehicle-mounted control unit 21 is configured by a computer unit and includes a nonvolatile memory 21a. In this memory 21a, the same ID code as the ID code stored in the memory 11a of the electronic key 10 is stored.

  The vehicle speed sensor 36 detects the speed of the vehicle and outputs the detection result to the in-vehicle control unit 21. The in-vehicle control unit 21 generates a request signal for every fixed period in a period from when the vehicle speed becomes equal to or less than a certain speed until the lock switch 32 is operated by the user who gets off the vehicle, and transmits the request signal to the in-vehicle transmission unit 23. Output to.

  When a request signal is input from the in-vehicle control unit 21, the in-vehicle transmission unit 23 modulates the request signal and transmits it to the vehicle interior as an LF band radio signal via its own in-vehicle transmission antenna 23a. As shown in FIG. 2, the request signal is transmitted to the in-vehicle communication area 31 having a shape corresponding to the size of the vehicle interior centered on the in-vehicle transmission unit 23. Here, since the request signal may leak out of the passenger compartment as described in the background art, it is difficult to completely form the in-vehicle communication area 31 according to the shape of the passenger compartment. For this reason, a part of the outer peripheral area 31a which is the outer peripheral part of the in-vehicle communication area 31 protrudes outside the passenger compartment.

  When a request signal is input from the in-vehicle control unit 21, the vehicle exterior transmission unit 22 modulates the request signal and transmits it to the outside of the vehicle compartment as an LF band radio signal via its vehicle exterior transmission antenna 22a. As shown in FIG. 2, the request signal is transmitted to a semicircular vehicle exterior communication area 30 whose bottom centered on the vehicle exterior transmission unit 22 is along the vehicle side.

A response signal and an RSSI information signal are transmitted from the electronic key 10 in response to request signals transmitted to both communication areas 30 and 31.
The in-vehicle receiving unit 24 receives the RSSI information signal from the electronic key 10 via the receiving antenna 24a. Then, the in-vehicle receiver 24 demodulates the RSSI information signal into a pulse signal and outputs it to the in-vehicle controller 21.

  As shown in FIG. 3, the in-vehicle controller 21 receives the RSSI information signal received during the period from when the vehicle speed sensor 36 recognizes that the vehicle speed has become equal to or less than a certain speed until the lock switch 32 is operated by the user who gets off the vehicle. The RSSI of the request signal included in is stored in its own memory 21a. And the vehicle-mounted control part 21 judges whether the electronic key 10 exists in a vehicle interior based on each said RSSI. This determination method will be described in detail later.

  The in-vehicle receiving unit 24 receives a response signal from the electronic key 10 via the receiving antenna 24a. Then, the in-vehicle receiver 24 demodulates the response signal into a pulse signal and outputs it to the in-vehicle controller 21.

  When the vehicle-mounted control unit 21 recognizes the response signal from the vehicle-mounted receiving unit 24, the vehicle-mounted control unit 21 collates the ID code included therein with the ID code stored in the memory 21a. Here, the in-vehicle control unit 21 determines whether the electronic key 10 is in the vehicle interior or the vehicle interior based on whether the response signal is in response to the request signal transmitted to the vehicle communication area 30 or the vehicle communication area 31. Can recognize if it exists. Collation of the ID code for the response signal from the electronic key 10 existing in the vehicle interior is called vehicle interior verification, and verification of the ID code for the response signal from the electronic key 10 existing outside the vehicle interior is called outdoor verification.

  When the in-vehicle control unit 21 determines that the vehicle interior verification has been established in the engine stop state, the engine start permission state is entered. In this state, the vehicle-mounted control unit 21 starts the engine through the engine device 35 when recognizing that the engine switch 33 is pushed.

  Moreover, the vehicle-mounted control part 21 performs vehicle interior collation and vehicle interior collation in order, when it recognizes that the lock switch 32 was operated after a user got off. Here, when the vehicle-mounted control unit 21 recognizes that the vehicle door is closed after being opened through the courtesy switch 37, it determines that the user has got off the vehicle. The in-vehicle controller 21 locks the vehicle door on the assumption that the electronic key 10 exists outside the vehicle interior when the vehicle interior verification is not established and the vehicle interior verification is established as a result of performing both the above verifications. Further, as a result of performing both the above verifications, when the vehicle interior verification is established and the vehicle exterior verification is not established, the in-vehicle control unit 21 does not lock the vehicle door because the electronic key 10 exists in the vehicle interior. Thereby, so-called in-lock is prevented. Further, as a result of performing both of the above verifications, the in-vehicle control unit 21 determines whether or not the electronic key 10 exists in the outer peripheral area 31a when the above both verifications are established.

  Hereinafter, a method for determining whether or not the electronic key 10 exists in the outer peripheral area 31a will be described. As shown in FIG. 4, the RSSI of the request signal received by the electronic key 10 decreases as the distance between the in-vehicle transmission unit 23 and the electronic key 10 increases. When the electronic key 10 receives a request signal with an RSSI equal to or higher than the first threshold Th1, the electronic key 10 recognizes the signal normally and transmits a response signal. Accordingly, the size of the in-vehicle communication area 31 is set by the first threshold Th1. The second threshold Th2 is set based on the RSSI of the request signal received by the electronic key 10 at the position closest to the in-vehicle transmitter 23 in the outer peripheral area 31a. That is, when the electronic key 10 exists in the outer peripheral area 31a, the RSSI of the request signal received by the electronic key 10 is in the range of the first threshold Th1 or more and less than the second threshold Th2. For this reason, when the RSSI of the request signal based on the RSSI information signal is in the range of the first threshold value Th1 or more and less than the second threshold value Th2, the in-vehicle control unit 21 has the electronic key 10 in the outer peripheral area. It is judged that it exists in 31a.

  And when the vehicle-mounted control part 21 judges that the electronic key 10 exists in the outer periphery area 31a, it will judge whether the electronic key 10 was taken out from the vehicle interior based on each RSSI memorize | stored in the memory 21a. To do.

  Specifically, as described above, the RSSI detected in the in-vehicle communication area 31 decreases as the electronic key 10 moves away from the in-vehicle transmission unit 23. Therefore, the RSSI when the electronic key 10 is taken out of the passenger compartment and the lock switch 32 is operated is stored in the memory 21a (when the vehicle speed is equal to or lower than a certain speed). Less than the RSSI. A third threshold Th3 is set based on the difference between these RSSIs. When the value Δr obtained by subtracting the minimum RSSI from the maximum RSSI among the RSSIs stored in the memory 21a is equal to or greater than the third threshold Th3, the in-vehicle controller 21 moves the electronic key 10 from the vehicle interior to the vehicle interior. Judging that the vehicle has been taken out, the vehicle door is locked. At this time, the electronic key 10 is assumed to be present in the outer peripheral area 31a outside the passenger compartment, as indicated by the position P1 in the upper right circle in FIG. In the example shown in FIG. 3, the maximum RSSI is when the vehicle speed is equal to or lower than a certain speed, and the minimum RSSI is when the lock switch 32 is operated.

  On the other hand, when the value Δr obtained by subtracting the minimum RSSI from the maximum RSSI among the RSSIs stored in the memory 21a is less than the third threshold Th3, the in-vehicle control unit 21 moves the electronic key 10 from the vehicle interior to the vehicle. Do not lock the vehicle door as it is not taken out of the room. At this time, it is assumed that the electronic key 10 exists in the outer peripheral area 31a in the vehicle interior, as indicated by a position P2 in FIG.

  When the vehicle door is in a locked state, a request signal is transmitted to the outside communication area 30 at regular intervals. At this time, when the in-vehicle control unit 21 determines that the verification outside the vehicle compartment has been established by the electronic key 10 entering the vehicle outside communication area 30, the vehicle-mounted control unit 21 enters a locking / unlocking permission state. In this state, when the vehicle-mounted control unit 21 recognizes that the door handle 4 has been touched through the door handle sensor 38, the vehicle door is unlocked via the door lock device 34.

  According to the above configuration, even when the electronic key 10 exists in the outer peripheral area 31a outside the passenger compartment and the vehicle interior verification is established, it is determined that the electronic key 10 has been taken out of the passenger compartment and is normally locked. Executed.

  Next, a processing procedure related to locking of the vehicle door executed by the in-vehicle control unit 21 will be described with reference to the flowchart of FIG. This flowchart is started when the vehicle travels beyond a certain speed.

  First, it is waited for the vehicle speed to become a certain speed or less (NO in S101). Then, when the vehicle speed is equal to or lower than a certain speed (YES in S101), vehicle interior verification is performed (S102). At this time, the RSSI of the request signal is stored in the memory 21a based on the RSSI information signal from the electronic key 10 (S103). Next, the operation of the lock switch 32 after the opening / closing of the vehicle door is awaited (NO in S104). Until the lock switch 32 is operated after the vehicle door is opened and closed, the vehicle interior verification (S102) and the RSSI storage (S103) are repeated. When the operation of the lock switch 32 after the opening / closing of the vehicle door is recognized (YES in S104), it is determined whether or not the vehicle interior verification is established (S105). If it is determined that the vehicle interior verification is not established (NO in S105), and then it is determined that the vehicle exterior verification is established (YES in S106), it is determined that the electronic key 10 exists outside the vehicle compartment (S107). . In this case, the vehicle door is locked through the door lock device 34 (S108). If it is determined that the vehicle interior and vehicle interior verification is not established (NO in S105 and S106), the electronic key 10 does not exist outside the vehicle interior and the flowchart is ended without performing locking.

  On the other hand, when it is determined that the vehicle interior verification is established (YES in S105), the RSSI of the request signal is stored in the memory 21a based on the RSSI information signal from the electronic key 10 (S109). Then, it is determined whether or not vehicle interior verification is established (S110). When it is determined that the vehicle exterior verification is not established (NO in S110), it is determined that the electronic key 10 exists in the vehicle interior (S111). In this case, assuming that the electronic key 10 is misplaced in the passenger compartment, the flowchart is terminated without locking.

  If it is determined that the vehicle exterior verification is established (YES in S110), it is determined whether or not the electronic key 10 is present in the outer peripheral area 31a (S112). When it is determined that the electronic key 10 does not exist in the outer peripheral area 31a (NO in S112), it is determined that the electronic key 10 exists in the vehicle interior (S111). In this case, assuming that the electronic key 10 is misplaced in the passenger compartment, the flowchart is terminated without locking.

  If it is determined that the electronic key 10 is present in the outer peripheral area 31a (YES in S112), it is determined whether the electronic key 10 has been taken out of the passenger compartment based on a plurality of RSSIs stored in the memory 21a (S113). ). When it is determined that the electronic key 10 has been taken out of the passenger compartment (YES in S113), the vehicle door is locked through the door lock device 34 even if the passenger compartment verification is established in step S105. (S108). This completes the flowchart.

  If it is determined that the electronic key 10 is not taken out of the passenger compartment (NO in S113), it is determined that the electronic key 10 is present in the passenger compartment (S111). In this case, the flowchart is ended without locking the vehicle door.

As described above, according to the embodiment described above, the following effects can be obtained.
(1) Even if there is an electronic key outside the vehicle interior and the vehicle interior verification is established (YES in S105), the request signal transmitted to the vehicle interior leaks out of the vehicle interior. Is determined to have been taken out of the passenger compartment (YES in S113), the vehicle door is locked. Thereby, although the user carries the electronic key 10 and operates the lock switch 32, the situation where locking is not performed can be suppressed and the convenience can be improved.

  (2) Only when it is determined that the electronic key 10 is present in the outer peripheral area 31a (YES in S112), a determination is made as to whether or not the electronic key 10 has been taken out of the passenger compartment (S113). Here, there is a high possibility that the outer peripheral area 31a, which is the outer peripheral portion of the in-vehicle communication area 31, protrudes outside the passenger compartment. Therefore, when it is determined that the electronic key 10 exists in the outer peripheral area 31a, the possibility that the electronic key 10 exists outside the passenger compartment is high. Only at this time, by determining whether or not the electronic key 10 has been taken out of the passenger compartment, the number of determinations can be reduced.

In addition, the said embodiment can be implemented with the following forms which changed this suitably.
In the above embodiment, when the lock switch 32 is operated after opening and closing of the vehicle door, the vehicle exterior verification is performed after the vehicle interior verification. However, the order of these collations may be reversed.

  In the above embodiment, vehicle interior verification is performed at regular intervals through transmission of a request signal during a period from when the vehicle speed becomes equal to or less than a certain speed to when the lock switch 32 is operated by the user who gets off the vehicle. It was broken. However, the timing of vehicle interior verification is not limited to this. For example, the vehicle interior verification may be performed only when the vehicle speed is equal to or lower than a certain speed and when the lock switch 32 is operated by the user who gets off the vehicle. Thereby, since the frequency | count of vehicle interior collation can be reduced, the process which concerns can be skipped.

  Further, the cycle in which the vehicle interior verification is performed may not be constant. For example, the cycle may be shortened only immediately after the ignition switch is turned off. Thereby, it becomes easy to detect the change of RSSI accompanying the user getting off after turning off the ignition switch.

  In the above embodiment, the RSSI of the request signal has been detected. However, the RSSI of the response signal is detected, and based on the detection result, it is determined whether the electronic key 10 exists in the outer peripheral area 31a (S112) and whether the electronic key 10 is taken out of the passenger compartment (S113). May be performed. In this case, the RSSI detection circuit 16 is provided in the in-vehicle receiving unit 24. Also in the RSSI of the response signal, the RSSI changes according to the distance between the in-vehicle receiving unit 24 and the electronic key 10 as in FIG. Therefore, the same effect as the above embodiment can be obtained. Further, the determinations in steps S112 and S113 may be made based on the RSSI of both the request signal and the response signal. In this case, the accuracy of determination is improved.

  In the above embodiment, the in-vehicle control unit 21 determines whether the electronic key 10 is present in the outer peripheral area 31a as a determination unit (S112), whether the electronic key 10 is taken out of the passenger compartment (S113), and the like. Had gone. However, these determinations may be made by the electronic key control unit 11 of the electronic key 10. In this case, the in-vehicle control unit 21 notifies the electronic key 10 through a wireless signal of the vehicle interior verification (S102, S105) and the presence / absence of the operation of the lock switch 32 after the door opening / closing (S104). When the electronic key control unit 11 recognizes that the vehicle interior verification has been established through the wireless signal, the electronic key control unit 11 stores the RSSI of the request signal in its own memory 11a. And while making determination of said step S112, S113, the determination result is included in a radio signal, and is transmitted to the vehicle-mounted apparatus 20. The in-vehicle device 20 determines whether the position of the electronic key 10 is inside or outside the vehicle interior (S112, S113) based on the determination result included in the wireless signal. Here, the radio signal including the determination result has a smaller information amount than the RSSI information signal. In addition, this wireless signal requires a smaller number of transmissions than an RSSI information signal transmitted each time a request signal is received. Therefore, according to this configuration, it is possible to reduce the processing burden related to the signal transmission of the electronic key 10.

  -In above-mentioned embodiment, the vehicle-mounted control part 21 is electronic based on the comparison with 3rd threshold value Th3, and the value (DELTA) r which deducted minimum RSSI from largest RSSI among RSSI memorize | stored in the memory 21a. It has been determined whether or not the key 10 has been taken out of the passenger compartment. However, the vehicle-mounted control unit 21 stores only the RSSI (first RSSI) when the vehicle speed is equal to or lower than a certain speed and the RSSI (second RSSI) when the lock switch 32 is operated in the memory 21a. May be. In this case, the in-vehicle control unit 21 determines that the electronic key 10 has been taken out of the vehicle interior from the vehicle interior when “first RSSI−second RSSI” becomes equal to or greater than the third threshold Th3. According to this configuration, only two RSSIs are stored, and the process of selecting the maximum and minimum RSSIs among a plurality of RSSIs can be omitted.

  Furthermore, the vehicle-mounted control unit 21 recognizes the RSSI change pattern from when the vehicle speed becomes equal to or less than a certain speed until the lock switch 32 is operated, and the electronic key 10 is moved from the vehicle interior to the vehicle based on the change pattern. It may be determined whether it has been taken out of the room. This change pattern is typically a graph showing the RSSI change in FIG. For example, the in-vehicle control unit 21 calculates an inclination for each sampling cycle in the change pattern through differentiation, and determines that the vehicle is taken out of the vehicle interior from the vehicle interior when the absolute value of the inclination is a certain value or more.

  Here, even when the movement amount of the electronic key 10 is large in a certain period from when the vehicle speed becomes equal to or less than a certain speed to when the lock switch 32 is operated, the electronic key 10 when the vehicle speed becomes equal to or less than the certain speed. Is close to the position of the electronic key 10 when the lock switch 32 is operated, the value Δr is less than the third threshold Th3. In this regard, by making a determination based on the change pattern, a comprehensive movement mode of the electronic key 10 in the certain period is taken into consideration.

  In the above embodiment, when the lock switch 32 is operated after opening and closing of the vehicle door (S104), the vehicle interior verification is performed assuming that locking is attempted (S105). However, the condition after the opening and closing of the vehicle door may be omitted. In addition, when the vehicle door is closed, the vehicle interior verification in step S105 may be executed on the assumption that locking is attempted thereafter.

  -Moreover, in the said embodiment, when the vehicle speed became below a fixed speed (it is YES at S101), vehicle interior collation was started (S102). However, during boarding, the vehicle speed is not limited to a certain speed or lower, but may be when the ignition switch is turned off or when the shift lever is set to the parking position.

  In the above embodiment, one in-vehicle transmission unit 23 is provided at the center of the passenger compartment, but the number and position thereof are not limited to this. When a plurality of in-vehicle transmission units 23 are provided, the RSSI of the request signal from each may be stored.

  -You may abbreviate | omit the vehicle interior collation of step S110, S106 in the said embodiment. In this case, if the vehicle interior verification is established (YES in S105), after the RSSI is stored (S109), it is determined whether or not the electronic key 10 exists in the outer peripheral area 31a (S112). If the vehicle interior verification is not established (NO in S105), it is determined that the electronic key 10 exists outside the vehicle interior (S107).

  In the above embodiment, it is determined whether or not the electronic key 10 exists in the outer peripheral area 31a (S112) and whether or not the electronic key 10 is taken out of the passenger compartment (S113). However, the determination in step S112 may be omitted. Even in this case, when it is determined through step S113 that the electronic key 10 has been taken out of the passenger compartment, locking is normally performed.

Next, the technical idea that can be grasped from the embodiment will be described together with the effects.
(A) In the electronic key system according to any one of claims 1 to 3, the electronic key system is provided outside the compartment of the vehicle door, and when operated in a state where the locking of the vehicle door is not regulated, It is provided with a lock switch that is locked, and the time when the lock is attempted is when the lock switch is operated, and the time when the vehicle is on is when the vehicle speed is a certain speed or less, The on-vehicle device is an electronic key system that transmits a request signal through the antenna when a vehicle speed becomes a certain speed or less and when the lock switch is operated.

  According to this configuration, the request signal is transmitted when the vehicle speed is equal to or lower than a certain speed and when the lock switch is operated. Thereby, the signal intensity | strength of the request signal or the response signal when boarding and locking is tried reliably can be recognized.

  (B) The electronic key system according to any one of claims 1 to 3 and (a), wherein the signal strength detection circuit is provided in the electronic key and detects the signal strength of the request signal. And the electronic key transmits the signal strength of the request signal detected through the signal strength detection circuit in a wireless signal, and the determination unit is provided in the in-vehicle device and the request included in the wireless signal. An electronic key system that determines whether or not the electronic key has been taken out of a passenger compartment based on a detection result of signal strength of a signal.

  According to this configuration, the determination unit is provided in the in-vehicle device. Thereby, compared with the case where the determination part is provided in an electronic key, an electronic key can be comprised more compactly. Here, the electronic key is particularly useful because it requires higher portability than the in-vehicle device.

  DESCRIPTION OF SYMBOLS 1 ... Electronic key system, 2 ... Vehicle, 10 ... Electronic key, 11 ... Electronic key control part, 16 ... RSSI detection circuit (signal strength detection circuit), 20 ... In-vehicle apparatus, 21 ... In-vehicle control part, 23 ... In-vehicle transmission part , 24 ... vehicle-mounted receiving unit, 32 ... lock switch, 33 ... engine switch, 34 ... door lock device, 35 ... engine device, 36 ... vehicle speed sensor, 37 ... courtesy switch, 38 ... door handle sensor.

Claims (4)

The electronic key transmits a response signal when a request signal transmitted through an antenna provided in the vehicle is received, and the in-vehicle device transmits the signal transmitted through the antenna when recognizing that locking is attempted from outside the vehicle compartment. In an electronic key system that determines whether or not the electronic key exists in a vehicle interior based on the presence or absence of the response signal with respect to a request signal, and restricts locking of a vehicle door when it is determined that the electronic key exists in the vehicle interior ,
A signal strength detection circuit for detecting a signal strength of the response signal or the request signal transmitted and received between the in-vehicle device and the electronic key;
Judgment to determine whether or not the electronic key has been taken out of the passenger compartment based on a change in signal strength of the response signal or the request signal from when the boarding is detected through the signal strength detection circuit to when locking is attempted. And comprising
Even when the in-vehicle device determines that the electronic key is present in the passenger compartment, the electronic key is located outside the passenger compartment when the electronic key is determined to be taken out of the passenger compartment through the determination unit. An electronic key system that locks the vehicle door on the assumption that the request signal is received from the vehicle. The electronic key system according to claim 1.
The in-vehicle device transmits a request signal to a communication area formed according to the shape of the passenger compartment through the antenna,
The determination unit is located in an outer peripheral area, which is an outer peripheral part in the communication area, based on the signal strength of the response signal or the request signal when locking is detected through the signal strength detection circuit. An electronic key system that determines whether the electronic key has been taken out of the passenger compartment when it is determined. The electronic key system according to claim 1 or 2,
The determination unit recognizes the signal strength of the response signal or the request signal when boarding and when locking is attempted through the signal strength detection circuit, and the difference between the recognized signal strengths is equal to or greater than a threshold value. An electronic key system for determining that the electronic key has been taken out of the passenger compartment. The electronic key system according to claim 1 or 2,
The determination unit stores a change pattern of the signal strength of the response signal or the request signal from when the vehicle is boarded to when locking is attempted, and whether or not the electronic key is taken out of the passenger compartment based on the change pattern. Electronic key system to determine whether.

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