JP4754439B2 - Electronic key system for vehicles - Google Patents

Description

  The present invention relates to an electronic key system for a vehicle, and more particularly to a technique for improving the reliability of auto-lock.

  In recent years, development of smart key (electronic key) systems has been promoted by many automobile manufacturers. In the case of a car equipped with a smart key system, not only is it difficult to duplicate like a mechanical key but high security is ensured, and a driver carrying a smart key can unlock the door lock simply by grasping the door handle. In addition, since the engine can be started with a start button or the like, the convenience is greatly improved. In general, many smart key systems have an auto-lock function that automatically locks each door and trunk lid when the driver gets off to prevent the driver from forgetting to lock the door.

When the door handle or start button is operated, the smart key system device body (vehicle-mounted device) transmits a request signal to the smart key, and an authentication ID signal (authentication ID signal) returned from the smart key and the ROM The door lock is unlocked and the engine is automatically started by collating with the registered ID data stored in. The auto-lock function is activated when there is no smart key in the car when the door is closed and there is a smart key outside the car (that is, when it can be estimated that the driver has left the car). All doors are locked when the response of the authentication ID signal from the smart key to the signal stops (see Patent Document 1).
JP 2003-74238 A

  In the smart key system described above, the auto-lock function may not work because the mutual communication area (area where the request signal reaches) is small. Usually, since the authentication ID signal from the smart key is a high-frequency RF (Radio Frequency) signal, its radio wave reach is relatively long (about 5 to 10 m). However, since the request signal from the in-vehicle device is a low frequency LF (Low Frequency) signal, its radio wave reach is set relatively short in consideration of the anti-theft property (for example, a radius of about 1 m from the transmitting antenna). And are not received by smart keys that are not within the intercommunication area. Therefore, if the driver who has left the vehicle walks away while pushing the door closed, or if the passenger closes the door after the driver leaves the car, the driver will leave the communication area before the door is completely closed. The smart key comes out (that is, it cannot be estimated that the driver has gone out of the vehicle), and the auto-lock function is not activated.

  The present invention has been made in view of such a background, and an object thereof is to provide a vehicular electronic key system in which the reliability of auto-locking is improved.

  The invention of claim 1 is an electronic key system having an auto-lock function that automatically locks a door under predetermined conditions when a passenger carrying an electronic key goes out of the vehicle, and is mounted on a vehicle. In addition to having a signal transmission capability at the first radio wave reach distance, an in-vehicle transmission means for transmitting a request signal to the inside of the vehicle, and being mounted on the vehicle, having a signal transmission capability at the second radio wave reach range A vehicle outside transmission means for transmitting a request signal to the outside of the vehicle, and a signal transmission capability at a third radio wave arrival distance longer than the first and second radio wave arrival distances, and when the request signal is received An electronic key for returning an authentication ID signal; vehicle-side receiving means mounted on the vehicle for receiving the authentication ID signal; open / closed state detecting means for detecting an open / closed state of the door; Intermittent transmission including door lock means for locking the door, and transmitting an intermittent ID signal to the electronic key at a predetermined transmission interval when the opening / closing state detecting means detects that the door is opened. A command is transmitted from the vehicle interior transmission means and vehicle exterior transmission means, and when the open / closed state detection means detects that the door is closed, the intermittent ID signal is transmitted to the electronic key. An intermittent stop command to be stopped is transmitted from the vehicle interior transmission means, and after the intermittent stop command is transmitted, the intermittent ID signal is received by the vehicle side reception means, and then the authentication ID signal is received by the vehicle side reception means. The door lock means is actuated to the door lock side when it is no longer being used.

  According to the present invention, even after the driver goes out of the vehicle and the door is closed, the intermittent ID signal transmitted from the electronic key is received by the receiving means even when the driver is relatively away from the vehicle. The automatic lock is activated when the request signal does not reach the electronic key. Therefore, even when the driver who goes out of the vehicle walks away while pushing the door closed, or when the passenger closes the door after the driver leaves the vehicle, each door is surely auto-locked.

Hereinafter, an embodiment of a smart key system according to the present invention will be described in detail with reference to the drawings.
FIG. 1 is a perspective view of a main part showing an automobile according to the embodiment, and FIG. 2 is a block diagram showing a schematic configuration of an auto-lock ECU according to the embodiment. FIG. 3 is a flowchart showing a procedure of auto-lock control according to the embodiment, and FIG. 4 is a time chart showing output timings of various signals according to the embodiment.

<< Configuration of Embodiment >>
As shown in FIG. 1, the vehicle V of the embodiment is a so-called two-door coupe type passenger car, and a driver's seat side door 1 has an outside LF antenna (handle antenna: vehicle outside transmission means) 2R and a door lock actuator (door lock). Means) 3R is built in. Further, the vehicle body 4 is provided with a door opening / closing sensor (opening / closing state detecting means) 5R in front of the door opening, and an RF receiving antenna (car interior transmitting means) 6 and a vehicle interior LF antenna (car interior transmitting means) on the instrument panel. 7 and are decorated. As shown in FIG. 2, an LF antenna 2L outside the vehicle, a door lock actuator 3L, and a door opening / closing sensor 5L are also installed on the door or door opening on the passenger seat side. Further, an auto-lock ECU 10 is installed in the front part of the passenger compartment, and exchanges signals with the above-described devices.

  The outside LF antennas 2R, 2L and the inside LF antenna 7 are connected to a smart key (electronic key) 9 possessed by the driver D with a relatively short radio wave distance (1 m in the present embodiment) and an LF signal such as a request signal. In the embodiment, 125 kHz) is transmitted. The RF receiving antenna 6 receives an RF signal (315 MHz in this embodiment) such as an authentication ID signal transmitted from the smart key 9 with a relatively long radio wave reach (10 m in this embodiment). The door lock actuators 3R and 3L lock and unlock a lock (not shown) in the driver side door 1 and the passenger side door. The door open / close sensors 5R and 5L are sensors that detect the open / closed state of the driver's seat side door 1 and the passenger's seat side door, and also serve as lighting sensors such as room lamps. Note that an LF antenna outside the vehicle, an RF receiving antenna, a trunk clock actuator, and the like are installed at the rear of the automobile V, but the description thereof will be omitted because the explanation is complicated.

<Auto-lock ECU>
As shown in FIG. 2, the auto-lock ECU 10 includes an input interface 11 to which the RF reception antenna 6 and door opening / closing sensors 5R and 5L are connected, and a door lock signal that generates a door lock signal based on the reception result of the RF reception antenna 6. A request signal at a predetermined transmission interval (1 second in the present embodiment), a generation unit 12, an intermittent command signal generation unit 13 that generates an intermittent transmission command and an intermittent stop command based on detection results of the door open / close sensors 5R and 5L. And an output interface 15 that outputs a door lock signal, an intermittent transmission command, and the like to the door lock actuators 3R and 3L, the vehicle exterior LF antennas 2R and 2L, and the vehicle interior LF antenna 7.

<< Operation of Embodiment >>
When the driver D gets on the vehicle V and a predetermined condition (engine stop, parking brake operation, etc.) is established, the auto-lock ECU 10 has a predetermined processing interval (for example, 10 ms) in the flowchart of FIG. Auto-lock control showing the procedure is repeated.

  When the auto-lock control is started, the auto-lock ECU 10 first determines in step S1 in FIG. 3 whether or not the driver side door 1 or the passenger side door is opened based on the input signals from the door opening / closing sensors 5R and 5L. If this determination is No, the automatic lock control is terminated without performing any processing.

  When the determination in step S1 is Yes when the driver D or a passenger gets off, the auto-lock ECU 10 transmits an intermittent transmission command via the outside LF antennas 2R and 2L and the inside LF antenna 7 in step S2. Thereby, as shown in FIG. 4, the smart key 9 inside and outside the vehicle transmits an intermittent ID signal at a predetermined transmission interval (1 second in the present embodiment). In the present embodiment, the intermittent ID signal from the smart key 9 is automatically stopped after a predetermined time (for example, about 1 minute) in order to prevent the internal battery from being consumed.

  Next, the auto-lock ECU 10 repeatedly determines whether or not both the driver's seat side door 1 and the passenger's seat side door are closed in step S3, and when this determination is Yes, the auto-lock ECU 10 passes through the in-vehicle LF antenna 7. Send intermittent stop command. As a result, as shown in FIG. 4, the intermittent ID signal is continuously transmitted from the smart key 9 existing outside the vehicle, but the intermittent ID signal is not transmitted from the smart key 9 existing inside the vehicle.

  Next, the auto-lock ECU 10 determines whether or not the intermittent ID signal is received via the RF receiving antenna 6 within a predetermined time (for example, within 2 seconds) in step S4. Since this determination is No when the driver D opens and closes the door without getting off, or when the passenger gets off, the auto-lock ECU 10 ends the auto-lock control without performing any processing.

  If the driver D gets off at the time when both the driver seat side door 1 and the passenger seat side door are closed, the determination in step S5 is Yes, so the auto lock ECU 10 enters the auto lock standby state. In S6, transmission of a request signal is started with a predetermined transmission interval to the outside of the vehicle. Next, the auto-lock ECU 10 determines whether or not an authentication ID signal is input in step S7, and the driver D is near the driver's seat side door 1 (that is, the LF antenna 2R outside the vehicle). While No becomes No, the auto-lock ECU 10 repeatedly performs the determination in step S6.

  When the driver D walks away from the vehicle V and the request signal does not reach the smart key 9, the determination in step S7 is Yes, and the auto-lock ECU 10 outputs a door lock command signal to the door lock actuators 3R and 3L in step S8. To do. Thereby, the driver's seat side door 1 and the passenger's seat side door are locked, and unauthorized boarding by a third party is not performed.

  In the case of this embodiment, as shown in FIG. 1, when the driver D who goes out of the vehicle walks away while pushing the driver's seat side door 1 closed, or after the driver D leaves the vehicle V, the passenger is an assistant. When the seat side door is closed, the smart key 9 comes out from the radio wave arrival area of the LF signal (indicated by a two-dot chain circle in FIG. 1) before the door is completely closed.

  However, since the intermittent ID signal from the smart key 9 is an RF signal having a long radio wave reach, it is received by the RF receiving antenna 6 even when the driver D is relatively far from the vehicle V, and the determination in step S5 is performed. Yes (auto lock standby state). In this case, since the request signal does not reach the smart key 9, the authentication ID signal is not transmitted from the smart key 9, and the determination in step S 6 becomes “Yes” immediately. A lock command signal is output to the door lock actuators 3R and 3L.

  In the present embodiment, by adopting the above-described configuration, auto-locking when the driver gets off can be performed reliably and smoothly, and improvement in security performance can be realized.

  Although the description of the specific embodiment is finished as described above, the present invention is not limited to the above embodiment and can be widely modified. For example, in the above embodiment, the present invention is applied to a smart key system mounted on a two-door coupe car. However, the present invention may be applied to a smart key system mounted on a four-door sedan car or other types of electronic devices. It may be applied to a key system. In addition, the specific configuration of the vehicle, the specific control procedure, and the like can be changed as appropriate without departing from the scope of the present invention.

It is a principal part perspective view which shows the motor vehicle which concerns on embodiment. It is a block diagram showing a schematic structure of an auto lock ECU concerning an embodiment. It is a flowchart which shows the procedure of the auto-lock control which concerns on embodiment. It is a time chart which shows the output timing of the various signals which concern on embodiment.

Explanation of symbols

1 Driver's side door 2R, 2L Outside LF antenna (outside transmission means)
3R, 3L door lock actuator (door lock means)
5R, 5L Door open / close sensor (open / close state detection means)
6 RF receiving antenna (vehicle-side receiving means)
7 In-car LF antenna (inside car transmission means)
9 Smart key (electronic key)
10 Auto-lock ECU
D Driver V Car

Claims (1)

An electronic key system having an auto-lock function that automatically locks a door under a predetermined condition when a passenger carrying an electronic key goes out of the vehicle,
Vehicle inside transmission means mounted on the vehicle, having signal transmission capability at the first radio wave reach, and transmitting a request signal to the vehicle interior;
Vehicle exterior transmission means mounted on the vehicle and having a signal transmission capability at a second radio wave reach, and transmitting a request signal to the outside of the vehicle;
An electronic key having a signal transmission capability at a third radio wave arrival distance longer than the first and second radio wave arrival distances and returning an authentication ID signal when receiving the request signal;
Vehicle-side receiving means mounted on the vehicle for receiving the authentication ID signal;
Open / closed state detecting means for detecting the open / closed state of the door;
Door lock means for locking the door,
When the opening / closing state detection means detects that the door is opened, an intermittent transmission command for transmitting an intermittent ID signal to the electronic key at a predetermined transmission interval is transmitted to the vehicle interior transmission means and the vehicle exterior side. Send from the sending means,
When the opening / closing state detection means detects that the door is closed, the vehicle interior transmission means transmits an intermittent stop command for stopping the transmission of the intermittent ID signal to the electronic key,
After the intermittent ID signal is received by the vehicle side receiving means after the intermittent stop command is transmitted, the door lock means is operated to the door lock side when the authentication ID signal is no longer received by the vehicle side receiving means. An electronic key system for a vehicle.

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