JP2016056587A - Electronic key system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic key system capable of preventing a key from being confined in a car even if the key is unable to receive a signal from an in-car antenna.SOLUTION: A vehicle-side matching ECU transmits a request signal from an out-car antenna (S11) when a lock switch is operated. A key placed in the car determines whether the key is in the car or carried out according to a history of acceleration and RSSI of the received request signal (S22) after transmitting a response signal when the request signal is received as the request signal leaks into the car. The key transmits a signal for prevention against confinement in the car (signal for prevention) (S23) when determining that the key is in the car. Further, the key transmits the signal for prevention with lower output than usual a predetermined time later without reference to whether the key is in the car or carried out. The matching ECU unlocks the doors (S14) and outputs an alarm buzzer (S15) when receiving the signal for prevention.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an electronic key system that locks and unlocks a door of a vehicle based on bidirectional communication between an in-vehicle device mounted on the vehicle and an electronic key possessed by a user of the vehicle.

  2. Description of the Related Art Conventionally, an electronic key system (so-called smart entry system) that locks and unlocks a door of a vehicle based on bidirectional communication between an in-vehicle device mounted on the vehicle and an electronic key possessed by a vehicle user is known. . In this type of electronic key system, when the lock switch provided on the outside of the door is operated, it is confirmed whether there is an electronic key around the door outside the vehicle by the outside antenna provided on the door. To do. When the confirmation is made, the door is locked. On the other hand, the signal transmitted from the vehicle exterior antenna may leak into the vehicle, and the electronic key may respond to the signal from the vehicle exterior antenna even though the electronic key is placed in the vehicle. Therefore, when the lock switch is operated, it is also confirmed whether the electronic key is placed in the car by the car interior antenna. If the electronic key remains in the car, the door is unlocked. The electronic key is prevented from being locked in the car.

  By the way, if the signal from the in-vehicle antenna is not leaked outside the vehicle, there is a possibility that an area (gap) in the inside of the vehicle where the signal from the in-vehicle antenna does not reach may be formed. The area may be, for example, a door pocket, a dashboard, a foot of each seat, or the like. If there is an electronic key in an area where the signal does not reach, or if the electronic key cannot receive the signal from the car antenna due to interference from surrounding noise, the door will be locked while the electronic key is kept inside the car. There is a problem.

  Therefore, in order to solve this problem, when a predetermined operation is detected after the door is locked, the detection area of the in-vehicle antenna is increased by increasing the output of the in-vehicle antenna or increasing the number of in-vehicle antennas to be used. There is a proposal of a technique for enlarging (see Patent Document 1). According to the technique of this patent document 1, since generation | occurrence | production of the area where the signal of an in-vehicle antenna does not reach can be suppressed, it is supposed that the electronic key can be effectively prevented from being closed.

JP 2009-263901 A

  However, in the technique of Patent Document 1, in order to unlock the door when the electronic key is left behind in the vehicle, the user has to perform a predetermined operation, and there is a problem that an operation burden is imposed on the user. Further, if the detection area of the in-vehicle antenna is expanded, the signal from the in-vehicle antenna may leak out of the vehicle. If the signal from the in-vehicle antenna leaks outside the vehicle, it may be erroneously determined that the electronic key is inside the vehicle even though the electronic key is outside the vehicle.

  The present invention has been made in view of the above-described problem, and in a vehicle door locking situation, the signal of the in-vehicle antenna can be prevented from leaking outside the vehicle, and the electronic key is in an area where the in-vehicle antenna signal does not reach To provide an electronic key system that can prevent the electronic key from being locked in the vehicle without imposing a burden on the user even if the electronic key cannot receive the signal from the vehicle antenna due to interference caused by noise or surrounding noise. Let it be an issue.

In order to solve the above problems, an electronic key system of the present invention includes an outside antenna that transmits a request signal to the periphery of the door outside the vehicle based on a predetermined operation instructing locking of the door of the vehicle,
An in-vehicle antenna that transmits a request signal into the vehicle based on the predetermined operation,
Vehicle-side receiving means for receiving a response signal transmitted in response to the request signal;
The vehicle-side receiving means locks the door based on receiving the response signal for vehicle exterior that is the response signal responding to the request signal transmitted by the vehicle exterior antenna. An in-vehicle device mounted on the vehicle, comprising door lock control means for unlocking the door based on receiving an in-vehicle response signal that is the response signal in response to the transmitted request signal;
Key side receiving means for receiving the request signal when entering the transmission area of the request signal;
An electronic key possessed by a user of the vehicle provided with response means for transmitting the response signal to the periphery based on the key side receiving means receiving the request signal,
When the electronic key receives the request signal from the vehicle exterior antenna, the electronic key includes a transmission unit that transmits a prevention signal that is a signal for preventing the key from being closed after the vehicle exterior response signal is transmitted.
The vehicle side receiving means also receives the prevention signal,
The door lock control means unlocks the door when the vehicle side receiving means receives the prevention signal even when the vehicle response signal is not received.

  According to the present invention, it is utilized that a signal from an antenna outside the vehicle leaks into the vehicle rather than a small amount. In other words, if the electronic key is left in the vehicle during a predetermined operation for instructing locking of the door, and the electronic key receives a signal from the outside antenna (a signal leaked into the vehicle), after sending the response signal Then, a signal for preventing the key from being closed (a signal for prevention) is transmitted. When receiving the prevention signal, the in-vehicle device unlocks the door even when there is no response of the electronic key by the in-vehicle antenna (no in-vehicle response signal is received). Thereby, even if the electronic key cannot receive the signal of the vehicle interior antenna, the electronic key can be prevented from being closed in the vehicle. In addition, since no user operation is required to prevent the electronic key from being closed in the vehicle, it is possible to prevent the electronic key from being closed without imposing a burden on the user. Furthermore, since it is not necessary to expand the detection area of the in-vehicle antenna, it is possible to prevent the signal from the in-vehicle antenna from leaking outside the vehicle.

It is a block diagram of an electronic key system. It is a figure explaining the installation position etc. of a transmission antenna. It is the sequence diagram which showed the mode of communication between collation ECU (vehicle) and an electronic key after lock switch operation. FIG. 4 is a flowchart according to the first embodiment as details of the process of S22 of FIG. FIG. 6 is a flowchart according to a second embodiment as details of the process of S22 of FIG. FIG. 9 is a flowchart according to a third embodiment as details of the process of S22 of FIG. It is the figure which illustrated the log | history of the acceleration when a key is taken out from the inside of a vehicle.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of the electronic key system of this embodiment. The electronic key system 1 of FIG. 1 includes an in-vehicle device 2 mounted on a vehicle 10 (see FIG. 2) and an electronic key 7 (hereinafter simply referred to as a key) possessed by a user of the vehicle 10. The electronic key system 1 is a system that locks and unlocks the door of the vehicle 10 based on wireless communication between the in-vehicle device 2 and the key 7. The electronic key system 1 includes a smart entry system that locks and unlocks the door based on bidirectional communication between the in-vehicle device 2 and the key 7, and a door based on one-way communication from the key 7 to the in-vehicle device 2. The wireless key system (RKE: Remote Keyless Entry) that locks and unlocks the system can be used. First, the configuration of the in-vehicle device 2 in the electronic key system 1 will be described.

  The in-vehicle device 2 includes a transmission antenna 4, a reception antenna 5, a door lock mechanism 61, a lock switch 62, a touch sensor 63, an alarm device 64, and a verification ECU 3 connected thereto. The transmission antenna 4 transmits a request signal for requesting a reply to the peripheral area of the transmission antenna 4. The transmission antenna 4 transmits the request signal as a radio wave having an LF band frequency (for example, 134 kHz).

  FIG. 2 is a diagram for explaining the installation position of the transmission antenna 4 and the like, and shows a plan view of the vehicle 10. As shown in FIG. 2, the transmission antenna 4 is installed at a plurality of locations of the vehicle 10. Specifically, the transmission antenna 4 is provided in the vicinity of the vehicle interior antennas 41 to 44 installed in the doors 101 to 104 of the vehicle 10, the vehicle interior antenna 45 installed in the vicinity of the front seat in the vehicle, and the vehicle rear seat. And an in-car rear antenna 46 installed.

  The vehicle exterior antenna 41 installed on the driver's seat door 101 is an antenna that transmits a request signal to the peripheral area 401 of the driver's seat door 101 outside the vehicle. The vehicle exterior antenna 42 installed on the passenger seat door 102 is an antenna that transmits a request signal to a peripheral area (not shown) of the passenger seat door 102 outside the vehicle. The vehicle exterior antenna 43 installed on the right rear seat door 103 is an antenna that transmits a request signal to the peripheral area 403 of the right rear seat door 103 outside the vehicle. The vehicle exterior antenna 44 installed in the left rear seat door 104 is an antenna that transmits a request signal to a peripheral area (not shown) of the left rear seat door 104 outside the vehicle. The in-vehicle front antenna 45 is an antenna that transmits a request signal to the front seat area 405 in the vehicle. The vehicle interior rear antenna 46 is an antenna that transmits a request to the vehicle rear seat area 406.

  The request signal transmission area (transmission distance) of each of the outside antennas 41 to 44 is set, for example, in a range of about 1 m to 2 m from each of the outside antennas 41 to 44. However, the request signals transmitted from the respective antennas 41 to 44 are leaking into the vehicle (see FIG. 2). FIG. 2 shows a state in which the transmission areas 401 and 403 of the outside antennas 41 and 43 extend into the vehicle.

  On the other hand, the transmission areas 405 and 406 of the vehicle interior antennas 45 and 46 are set so as not to leak outside the vehicle as much as possible. Therefore, as shown in FIG. 2, there may be an area 11 (a door pocket, a dashboard, a foot of each seat, etc.) in which the request signal from the in-vehicle antennas 45 and 46 does not reach.

  The receiving antenna 5 is an antenna that receives a signal of an RF band radio wave (for example, a radio wave of 300 to 400 MHz) transmitted from the key 7. The receiving antenna 5 may be installed at one place, or may be installed at a plurality of places in order to easily receive a signal from the key 7.

  The door lock mechanism 61, the lock switch 62, and the touch sensor 63 are provided for each of the doors 101 to 104. The door lock mechanism 61 has a motor, and the doors 101 to 104 are locked and unlocked by the operation of the motor. The lock switch 62 is provided, for example, in the vicinity of a door handle provided on the outer side of each of the doors 101 to 104, and an operation unit (for example, a push switch) for instructing the in-vehicle device 2 to lock (lock) the doors 101 to 104. It is. When the lock switch 62 is operated by the user, a signal indicating that the lock switch 62 has been operated is input to the verification ECU 3.

  The touch sensor 63 is a sensor that is provided, for example, on the door handle of each of the doors 101 to 104 and detects a user's touch (contact) on the door handle. For example, a capacitance sensor is used as the touch sensor 63. A detection signal from the touch sensor 63 is input to the verification ECU 3. The alarm device 64 is a device that outputs a buzzer sound toward the outside of the vehicle.

  The verification ECU 3 is an ECU (electronic control unit) that executes various processes related to the smart entry system and the wireless key system. Specifically, the verification ECU 3 includes a transmission data creation unit 32, an LF modulation unit 33, an RF demodulation unit 34, a reception data analysis unit 35, and a control unit 31. The transmission data creation unit 32 is a part that creates data (baseband data) before modulation of the request signal based on a command from the control unit 31. The LF modulation unit 33 is a part that receives the data created by the transmission data creation unit 32 and modulates the data (digital data) to analog data of the LF band frequency. The data modulated by the LF modulation unit 33 is transmitted from the transmission antenna 4 as the LF radio wave of the request signal.

  The RF demodulator 34 is a part that receives RF band radio waves (RF signals) received from the key 7 and received by the receiving antenna 5 and demodulates the RF signals into original digital data. The received data analyzing unit 35 is digital data (received data) demodulated by the RF demodulating unit 34 according to a predetermined format (RF signal format in the smart entry system or RF signal format in the wireless key system). This is the part that analyzes whether or not there is. When the reception data analysis unit 35 analyzes that the reception data is data conforming to a predetermined format, the reception data is sent to the control unit 31. On the other hand, when it is analyzed that the received data is not data conforming to a predetermined format, the received data is not sent to the control unit 31 as noise. In this case, no signal is received from the key 7. The receiving antenna 5, the RF demodulator 34, and the received data analyzer 35 correspond to the vehicle side receiving means in the present invention.

  The control unit 31 includes a CPU, a ROM, a RAM, and the like, and is a part that executes various processes related to the smart entry system and the wireless key system. Specifically, for example, when the vehicle 10 is in a parked state, the control unit 31 periodically performs an external antenna 41 to 44 in order to confirm whether or not an occupant approaches the vehicle 10 as a process related to the smart entry system. To send a request signal. Thereafter, when the receiving antenna 5 receives the response signal transmitted by the key 7 in response to the request signal, the control unit 31 includes the response signal (received data sent from the received data analyzing unit 35). The obtained ID code and the master ID code are collated. When the collation is successful, the control unit 31 sets the touch sensor 63 to the standby state, and then controls the door lock mechanism 61 when the touch sensor 63 detects that the door handle is touched. The door (the door with the touch of the door handle among the doors 101 to 104) is unlocked.

  Further, as a process related to the smart entry system, for example, when the lock switch 62 is operated in a state where the door is closed, the control unit 31 executes a process for locking the door (control at the time of locking). Details of the lock control will be described later.

  Further, as a process related to the wireless key system, when the control unit 31 receives an RF signal instructing locking or unlocking from the key 7, the control unit 31 adds the RF signal (received data sent from the reception data analysis unit 35) to the RF signal. The ID code included is checked against the master ID code. And when this collation succeeds, the control part 31 controls the door lock mechanism 61, and locks or unlocks a door (all the doors 101-104).

  In addition, collation ECU3 (control part 31) transfers to the intermittent operation mode which repeats a sleep and starting alternately, when the vehicle 10 is parked. Then, at the time of startup in the intermittent operation mode, a request signal is transmitted and a response signal is received in the smart entry system. In addition, in order to ensure that the verification ECU 3 receives the RF signal in the wireless key system at the time of startup in the intermittent operation mode, the data configuration (format) of the RF signal is a data configuration in which a plurality of identical data (frames) are connected. It has become. And when collation ECU3 receives RF signal of a wireless key system at the time of starting, the reception will be completed and a starting state will be maintained until a door is locked or unlocked.

  Next, the configuration of the key 7 will be described. As shown in FIG. 1, the key 7 includes a reception antenna 72, an LF demodulation unit 73, a reception data analysis unit 74, a transmission data creation unit 75, an RF modulation unit 76, a transmission antenna 77, an RSSI measurement unit 78, a lock switch 79, An unlock switch 80, an acceleration sensor 81, and a control unit 71 are provided. The receiving antenna 72 is an antenna that receives a request signal (LF radio wave) transmitted from the in-vehicle device 2. The LF demodulator 73 is a part that receives the reception data received by the reception antenna 72 and demodulates the reception data (analog data) into the original digital data. The reception data analysis unit 74 receives the reception data (digital data) demodulated by the LF demodulation unit 73 and analyzes whether or not the reception data is data according to a predetermined format (request signal format). It is a part to do. When the reception data analysis unit 74 analyzes that the reception data is data conforming to a predetermined format, the reception data is sent to the control unit 71. On the other hand, when it is analyzed that the received data is not data conforming to a predetermined format, the received data is not sent to the control unit 71 as noise. In this case, no request signal is received from the in-vehicle device 2. The reception antenna 72, the LF demodulation unit 73, and the reception data analysis unit 74 correspond to the key side reception unit in the present invention.

  The transmission data creation unit 75 is a part that creates a response signal in response to a request signal or data (baseband data) before modulation of a signal in the wireless key system based on a command from the control unit 71. As described above, the data structure (format) of the signal in the wireless key system is a data structure in which a plurality of identical data (frames) are connected. That is, the transmission data creation unit 75 creates baseband data having different data configurations between the smart entry system and the wireless key system.

  The RF modulation unit 76 is a part that receives the data created by the transmission data creation unit 75 and modulates the data into analog data of an RF band frequency. The data modulated by the RF modulation unit 76 is transmitted from the transmission antenna 77 as an RF radio wave of a response signal or a wireless key system signal. The transmission data creation unit 75, the RF modulation unit 76, and the transmission antenna 77 correspond to response means in the present invention.

  The RSSI measuring unit 78 is connected to the receiving antenna 72 and is arranged in parallel with the LF demodulating unit 73 and the receiving data analyzing unit 74, and calculates the electric field strength (RSSI: Received Signal Strength Indicator) of the signal received by the receiving antenna 72. This is the part to be measured. The RSSI measured by the RSSI measuring unit 78 is input to the control unit 71. The RSSI measuring unit 78 corresponds to the measuring means in the present invention.

  The lock switch 79 is a switch (operation unit) that is provided so as to be exposed from the casing of the key 7 and that instructs to lock the doors 101 to 104. The unlock switch 80 is provided so as to be exposed from the casing of the key 7 and is a switch (operation unit) that instructs unlocking (unlocking) of the doors 101 to 104. These switches 79 and 80 are, for example, push switches. The acceleration sensor 81 is a sensor that detects acceleration with respect to the key 7.

  The control unit 71 includes a CPU, a ROM, a RAM, and the like, and is a part that executes various processes related to the smart entry system and the wireless key system. Specifically, as a process related to the smart entry system, for example, when a request signal from the in-vehicle device 2 is received by the reception antenna 72, the creation data creation unit 75 creates a response signal in response to the request signal, After this is modulated by the RF modulation section 76, it is transmitted from the transmission antenna 77 as an RF radio wave. At this time, the control unit 71 includes, in the response signal, encryption data (ID code) for authenticating whether or not the key 7 is a regular key on the in-vehicle device 2 side.

  Further, as a process related to the wireless key system, the control unit 71 generates a signal instructing locking or unlocking of the door to the transmission data generating unit 75 when the lock switch 79 or the unlock switch 80 is operated by the user. After this is modulated by the RF modulator 76, it is transmitted from the transmitting antenna 77 as an RF radio wave. At this time, the control unit 71 includes, in the signal to be transmitted, data for instructing locking or data for instructing unlocking, and encryption data (ID for authenticating whether or not the key 7 is a regular key on the in-vehicle device 2 side) Code).

  Further, as one of the processes related to the smart entry system, the control unit 71 locks the door in a state where the key 7 is confined in the vehicle in the door locking scene (when the lock switch 62 of the vehicle 10 is operated). A process (control at the time of locking) is executed to prevent this. Details of the lock control will be described later.

  The control unit 71 also includes a memory 711 such as a flash memory that stores various data. The memory 711 stores the history of acceleration detected by the acceleration sensor 81 (change in acceleration with time). Note that the memory 711 corresponds to a storage unit in the present invention. The control unit 71 has a function of adjusting the output of the transmission antenna 77. The control unit 71 adjusts the output of the transmission antenna 77 so that the transmission distance of the signal transmitted from the transmission antenna 77 is, for example, 10 m to 100 m.

  Next, details of the process (control at the time of locking) executed by the verification ECU 3 (control unit 31) and the key 7 (control unit 71) in the locking scene of the vehicle door will be described. FIG. 3 is a sequence showing what signals are transmitted / received between the vehicle 10 (matching ECU 3) and the key 7 in the lock-time control, and what processing each of the matching ECU 3 and key 7 executes. FIG. FIG. 3 shows a sequence diagram when the lock switch 62 is operated with the key 7 placed in the vehicle. Note that FIG. 3 shows that the time has passed toward the lower side of FIG.

  When the lock switch 62 is operated by the user when the vehicle 10 is parked, the verification ECU 3 (the control unit 31) requests from the outside antenna provided on the door where the lock switch 62 is operated among the outside antennas 41 to 44. A signal is transmitted (S11). In addition, you may transmit a request signal from all the vehicle-mounted antennas 41-44. In addition, the verification ECU 3 sends a request signal transmitted in S11 and a request signal transmitted in another scene (for example, a scene where a user approaching the vehicle to get into the vehicle at the time of parking) to the key 7 side. The contents of the request signal transmitted in each scene are made different so that they can be distinguished. That is, the request signal transmitted in S11 includes data indicating that it is a door locking signal.

  When the key 7 exists in the transmission area of the request signal transmitted in S11, the key 7 receives the request signal. The request signal received by the reception antenna 72 is input to the control unit 71 via the LF demodulation unit 73 and the reception data analysis unit 74, and is also input to the RSSI measurement unit 78 (see FIG. 1). The RSSI measurement unit 78 measures the RSSI of the input request signal and inputs the measured RSSI to the control unit 71. The control unit 71 stores the RSSI in the memory 711.

  When the request signal transmitted in S11 leaks into the vehicle and the key 7 receives the request signal, the key 7 (control unit 71) transmits a response signal in response to the request signal (S21). . Note that the key 7 also transmits a response signal when a request signal is received outside the vehicle. The response signal transmitted in S21 is received by the verification ECU 3. When the key 7 does not exist in the transmission area of the request signal transmitted in S11, the verification ECU 3 operates the lock switch 62 without the key 7 on the condition that there is no response from the key 7. Do not lock the door (leave it unlocked).

  Next, in order to confirm whether or not the key 7 is placed in the vehicle, the verification ECU 3 transmits a request signal from the vehicle antennas 45 and 46 (S12). At this time, when the key 7 is placed in the area 11 (see FIG. 2) where the request signal does not reach or when noise exists, the key 7 cannot receive the request signal. In this case, the verification ECU 3 determines that the key 7 has been taken out of the vehicle, and locks all the doors 101 to 104 (S13).

  Note that when the key 7 receives the request signal transmitted in S12, the key 7 transmits a response signal in response to the request signal. In this case, the verification ECU 3 determines that the key 7 is placed in the vehicle and stops the locking of the doors 101 to 104 in order to prevent the key 7 from being closed. Further, the verification ECU 3 causes the alarm device 64 (see FIG. 1) to output an alarm buzzer. The control unit 31 corresponds to the door lock control means in the present invention.

  On the other hand, the key 7 determines from the content of the request signal received in S11 that the scene is a scene where the door is to be locked. Then, after transmitting the response signal in S21, the key 7 waits for a request signal from the in-vehicle antennas 45 and 46. If the request signal does not come, a signal for preventing the key 7 from being closed in the vehicle ( It is determined whether or not a prevention signal is transmitted (S22). 4 to 6 are flowcharts showing details of the determination in S22, FIG. 4 is a flowchart of the first embodiment, FIG. 5 is a flowchart of the second embodiment, and FIG. 6 is a flowchart of the third embodiment. It is. In S22, any one of the processes of FIGS. 4 to 6 is executed. Note that the key 7 does not execute the processes of FIGS. 4 to 6 when a request signal is received in a scene other than the door locking scene. First, Example 1 of FIG. 4 will be described.

  When the processing of FIG. 4 is started, the key 7 (control unit 71) first reads the history of acceleration by the acceleration sensor 81 stored in its own memory 711 (S31). Next, in the acceleration history, it is determined whether or not there is a change in acceleration during a period from the present time to a predetermined time before (S32). Here, FIG. 7 illustrates an acceleration history (change in acceleration with time) when the key 7 is taken out of the vehicle.

  As shown in FIG. 7, when the key 7 is taken out of the vehicle, the acceleration of the key 7 increases as the user moves out of the vehicle. Thereafter, as the user stops in front of the door to close the door and operate the lock switch 62, the acceleration decreases to approximately zero. After locking the door, the acceleration increases again as the user leaves the vehicle. Therefore, in S32, for example, when the acceleration exceeds a predetermined threshold in a period that goes back a predetermined time with reference to the current time or the response time in S21, it is determined that there is a change in acceleration, and the acceleration is less than the threshold. In this case, it is determined that there is no change in acceleration.

  In S32, if there is a change in acceleration (S32: Yes), it is determined that the key 7 has been taken out of the vehicle (S34). On the other hand, when there is no change in acceleration (S32: No), it is determined that the key 7 is in the vehicle (S33). After S33 or S34, the process of the flowchart of FIG.

  Next, Example 2 of FIG. 5 will be described. When the processing of FIG. 5 is started, the key 7 first reads out the RSSI of the request signal stored in the memory 711 (S41). When the request signal from the antenna outside the vehicle leaks into the vehicle, the RSSI of the request signal is weaker than when received outside the vehicle. Therefore, next, in order to determine whether the request signal is received inside or outside the vehicle, it is determined whether the RSSI read in S41 is equal to or less than a predetermined threshold (S42). If the RSSI is equal to or less than the threshold (S42: Yes), it is determined that the key 7 is in the vehicle (S43). On the other hand, when the RSSI is larger than the threshold (S42: No), it is determined that the key 7 has been taken out of the vehicle (S44). After S43 or S44, the process of the flowchart of FIG. In addition, the control part 71 which performs the process of FIG. 4 or FIG. 5 is equivalent to the determination means in this invention.

  Next, Example 3 of FIG. 6 will be described. When the process of FIG. 6 is started, the key 7 first determines whether or not a predetermined time has elapsed since the response signal was transmitted in S21 (S51). This predetermined time corresponds to the threshold time in the present invention, and is a predetermined time as a time required for the user of the vehicle 10 to leave the vehicle 10 and then to leave the vehicle 10. It is determined as the time required to leave the vehicle 10 to a position that is equal to or greater than the transmission distance of the RF signal to be transmitted. However, if the predetermined time is too long, it becomes difficult for the user to notice that the key 7 remains in the vehicle, and the key 7 remains in the vehicle for a long time. Therefore, it is preferable that the predetermined time is less than 1 minute, for example.

  If the predetermined time has not yet elapsed after the response in S21 (S51: No), the process waits until the predetermined time elapses. When the predetermined time has elapsed (S51: Yes), it is determined to transmit the prevention signal (S52). Thereafter, the process of the flowchart of FIG. As described above, in the third embodiment, it is determined that the prevention signal is always transmitted on condition that a predetermined time has elapsed. In addition, the control part 71 which performs the process of FIG. 6 is corresponded to the transmission means in this invention.

  Returning to the description of FIG. 3, when the key 7 is determined to be in the vehicle in S33 of FIG. 4 or S43 of FIG. 5, or when it is determined to transmit the prevention signal in S52 of FIG. An RF radio wave as a prevention signal is transmitted from the transmission antenna 77 (S23). As the format of the prevention signal, for example, the format (frame) of the RF signal used in the wireless key system is used. However, data indicating that the signal is a prevention signal is included in the prevention signal so that the in-vehicle device 2 side can identify the prevention signal instead of the RF signal of the wireless key system.

  Further, when the prevention signal is transmitted through the processing of the third embodiment shown in FIG. 6, the transmission antenna 77 is transmitted more than when a normal RF signal (response signal RF signal, wireless key system RF signal) is transmitted. Decrease the output. That is, the transmission distance of the prevention signal is made shorter than usual. Specifically, when the prevention signal is transmitted from a position away from the vehicle, the transmission distance is a distance at which the in-vehicle device 2 cannot receive the prevention signal, and the prevention signal is transmitted from the inside of the vehicle. Is set to a distance that the in-vehicle device 2 can receive the prevention signal. For example, the output of the transmission antenna 77 is weakened so that the transmission distance is sufficient to cover the entire area of the vehicle (transmission distance of about several meters). Accordingly, when the key 7 is taken out of the vehicle, the in-vehicle device 2 can be prevented from receiving the prevention signal, and when the key 7 is in the vehicle, the in-vehicle device 2 can receive the prevention signal. Can do. When the output of the normal transmission antenna 77 is not so strong (when the normal RF signal transmission distance is not so long), the prevention signal transmission distance may not be changed from the normal time.

  Furthermore, when the key 7 is in the vehicle, the key 7 transmits the prevention signal (predetermined transmission), for example, every predetermined time to ensure that the in-vehicle device 2 receives the prevention signal. That is, the prevention signal is repeatedly transmitted a plurality of times (S23). As a result, it is possible to avoid a situation in which the in-vehicle device 2 cannot receive the prevention signal due to the influence of ambient noise. Note that when the prevention signal is periodically transmitted, the timing for terminating the periodic transmission may be, for example, a timing at which a predetermined time has elapsed since the prevention signal was first transmitted, or the prevention signal may be transmitted a predetermined number of times. It is good also as the timing which transmitted only. In addition, the control part 71 which performs the process of S23, the transmission data preparation part 75, the RF modulation part 76, and the transmission antenna 77 are equivalent to the transmission means in this invention.

  On the other hand, when receiving the prevention signal transmitted from the key 7, the verification ECU 3 determines that the key 7 is placed in the vehicle and controls the door lock mechanism 61 to control the doors (for example, all the The doors 101 to 104) are unlocked (S14). Further, the verification ECU 3 causes the alarm device 64 to output an alarm buzzer (for example, a continuous tone “Peep”) (S15). This makes it easy for the user to notice that the key 7 remains in the vehicle, and the user can open the door and take the key 7 out of the vehicle (the key 7 is closed in the vehicle). Can be prevented). In addition, collation ECU3 maintains the door locking performed by S13, when the signal for prevention is not received. In addition, the control part 31 and the alarm device 64 which perform the process of S15 are equivalent to the alarm means in this invention.

  As described above, according to the present embodiment, when the key receives the door locking request signal from the antenna outside the vehicle, the RF signal (for prevention) for preventing the key from being closed based on the determination of the key itself. Signal) is transmitted to the in-vehicle device side, so that even if there is a key in an area where the signal of the in-vehicle antenna does not reach, the key can be reliably prevented from being closed in the vehicle. Since the RF radio wave of the prevention signal has a longer transmission distance than the LF radio wave transmitted by the in-vehicle device, the in-vehicle device can reliably receive the prevention signal no matter where the key is placed in the vehicle.

  Further, since the key determines whether or not to transmit the prevention signal through any of the processes in FIGS. 4 to 6, the door is unlocked even though the key is taken out of the vehicle. It is possible to prevent the alarm buzzer from sounding.

  In addition, this invention is not limited to the said embodiment, A various change is possible to the limit which does not deviate from description of a claim. For example, in the above embodiment, the verification ECU can confirm the presence of the key with the antenna outside the vehicle (S11 and S21 in FIG. 3), and if the presence of the key cannot be confirmed with the antenna inside the vehicle (S12 in FIG. 3), Is locked (S13 in FIG. 3), and then the door is unlocked when a prevention signal is received (S14 in FIG. 3). Instead, the verification ECU can confirm the presence of the key with the antenna outside the vehicle, and even if the presence of the key cannot be confirmed with the antenna inside the vehicle, the verification ECU determines whether the prevention signal has been received or not. Leave unlocked. The verification ECU may employ a configuration in which the door is locked when the prevention signal is not received, and the locking is stopped when the prevention signal is received. That is, in the example of FIG. 3 (the key is in the vehicle), the process of S13 is omitted, and in S14, the door is unlocked, that is, the door lock mechanism is not controlled. Also by this, the same effect as the above embodiment can be obtained.

  In addition, when receiving the prevention signal from the key, the verification ECU (control unit) retransmits the request signal to the vehicle interior antenna, assuming that the key may be placed in the vehicle, and You may try to detect the key again. Thereafter, when the response ECU receives a response signal in response to the request signal retransmitted from the in-vehicle antenna, the verification ECU executes the processes of S14 and S15. As a result, the processing of S14 and S15 may be stopped. Thus, for example, when a prevention signal is erroneously transmitted from a key taken out of the vehicle (for example, in the processing of FIG. 5, the RSSI of the request signal received by the key outside the vehicle happens to be below the threshold due to the influence of noise or the like. If the prevention signal transmitted from outside the vehicle in the process of Fig. 6 happens to be received by the in-vehicle device, the door may be unlocked or the alarm buzzer will sound. Can be prevented. In this example, the control unit 31 that retransmits the request signal corresponds to the retransmission control means in the present invention.

  In the above embodiment, the example in which the present invention is applied to an electronic key system that can support both the smart entry system and the wireless key system has been described. However, the present invention is applied to an electronic key system that includes only the smart entry system. Also good.

1 Electronic key system 2 On-vehicle device 3 Verification ECU
31 Control unit of verification ECU 41-44 Antenna outside vehicle 45, 46 Antenna inside vehicle 7 Electronic key 71 Control unit of electronic key 10 Vehicle 101-104 Door

Claims (11)

An outside antenna (41 to 44) for transmitting a request signal to the periphery of the door outside the vehicle based on a predetermined operation instructing locking of the door (101 to 104) of the vehicle (10);
In-vehicle antennas (45, 46) for transmitting a request signal into the vehicle based on the predetermined operation,
Vehicle-side receiving means (5, 34, 35) for receiving a response signal transmitted in response to the request signal;
The vehicle-side receiving means locks the door based on receiving the response signal for vehicle exterior that is the response signal responding to the request signal transmitted by the vehicle exterior antenna. On-vehicle device mounted on the vehicle, comprising: door lock control means (31) for unlocking the door based on reception of an in-vehicle response signal that is the response signal in response to the transmitted request signal. 2) and
Key side receiving means (72, 73, 74) for receiving the request signal when entering the request signal transmission area;
An electronic key (7) possessed by a user of the vehicle, comprising response means (75, 76, 77) for transmitting the response signal to the periphery based on the fact that the key side receiving means has received the request signal In an electronic key system (1) comprising:
When the electronic key receives the request signal from the vehicle exterior antenna, the electronic key transmits a prevention signal that is a signal for preventing the key from being closed after transmitting the vehicle exterior response signal (S23, 71). 75, 76, 77)
The vehicle side receiving means also receives the prevention signal,
The door lock control means (S14) unlocks the door when the vehicle side receiving means receives the prevention signal even when the vehicle response signal is not received. And electronic key system.   The said in-vehicle apparatus is provided with the alarm means (S15, 64) which outputs an alarm toward the exterior based on the said vehicle side receiving means having received the said signal for prevention. Electronic key system.   When the vehicle exterior response signal is received, the door lock control means (S13, S14) locks the door before determining whether or not the prevention signal is received, and after the lock, the door lock control means (S13, S14) 3. The electronic key system according to claim 1, wherein the door is unlocked when a signal is received.   The door lock control means, in the case of receiving the response signal for outside the vehicle, keeps the door unlocked until it is determined whether or not the prevention signal has been received, and if the prevention signal is not received. 3. The electronic key system according to claim 1, wherein when the determination is made, the door is locked, and when it is determined that the prevention signal is received, the locking of the door is stopped. When the electronic key receives the request signal from the antenna outside the vehicle, the electronic key has determination means (S31 to S34, S41 to S44) for determining whether the electronic key is placed inside the vehicle or taken out of the vehicle. Prepared,
The transmission means transmits the prevention signal when the request signal is received from the antenna outside the vehicle and the determination means determines that the electronic key is placed in the vehicle, and the determination The electronic key system according to any one of claims 1 to 4, wherein when the means determines that the electronic key has been taken out of the vehicle, transmission of the prevention signal is stopped. The electronic key includes an acceleration sensor (81) that detects an acceleration with respect to the electronic key, and a storage unit (711) that stores a history of the acceleration detected by the acceleration sensor.
The determination means (S31 to S34) determines whether the electronic key is placed in the vehicle or taken out of the vehicle based on the history stored in the storage means. Electronic key system as described. The electronic key includes measuring means (78) for measuring the intensity of the request signal from the outside antenna received by the key side receiving means,
The determination means (S41 to S44) determines that the electronic key is placed in a vehicle when the intensity measured by the measurement means is less than or equal to a threshold, and when the intensity is greater than the threshold, the electronic key The electronic key system according to claim 5, wherein the electronic key system is determined to have been taken out of the vehicle.   The transmission means (S51, S52) transmits the prevention signal after a predetermined threshold time has elapsed as a time required for the user of the vehicle to leave the vehicle after transmission of the response signal for vehicle exterior. The electronic key system according to any one of claims 1 to 4, wherein:   9. The electronic key system according to claim 8, wherein the transmission unit makes a transmission distance of the prevention signal smaller than a transmission distance of the response signal.   The electronic key system according to claim 1, wherein the transmission unit transmits the prevention signal a plurality of times when the prevention signal is transmitted. The on-vehicle device comprises a retransmission control means (31) for retransmitting the request signal to the in-vehicle antenna when the prevention signal is received,
The door lock control means receives the prevention signal, and the vehicle side receiving means receives the response signal in response to the request signal retransmitted by the retransmission control means. The electronic key system according to claim 1, wherein the electronic key system is unlocked.

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