JP2008202228A - Electronic key system, and in-vehicle device for electronic key system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic key system capable of automatically changing a channel at the occurrence of a communication failure and moreover improving responses up to the establishment of authentication. <P>SOLUTION: An in-vehicle device notifies a portable unit of a response channel when transmitting a response request to the portable unit. At that time, when the portable unit is estimated to be in a cabin (S107: in the cabin), an LF band channel is notified first (S110, S115), and when the portable unit is estimated to be outside of the cabin (S107: outside of the cabin), an RF band channel is notified first (S112, S115). Receiving of a response from the portable unit is tried on the notified response channel (S120), and when receiving fails (S125: No), a change to another channel is made (S140), and transmission of a response request (S115) and receiving of a response (S120) are retried. If receiving of the response is successful in this communication (S125: Yes), predetermined functional operation is carried out (S130). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electronic key system and an in-vehicle device for the electronic key system.

  2. Description of the Related Art Conventionally, in the field of automobile related technology, an electronic key system including an in-vehicle device mounted on a vehicle and a portable device possessed by a vehicle user has been put into practical use. This type of electronic key system can control door locking / unlocking and engine starting without the need to operate with mechanical keys, if authentication by wireless communication is established between the in-vehicle device and the portable device. It is a mechanism that can be executed.

  By the way, in this kind of electronic key system, when the channel used by the in-vehicle device and the portable device is fixed to a single channel, normal communication can be performed if an interference wave with the same frequency as that channel arrives. It causes problems such as disappearance.

In order to deal with such a problem, Japanese Patent Application Laid-Open No. 2004-228561 has already proposed a technique for performing communication by switching a plurality of channels having different frequencies. In the case of the technique described in Patent Document 1, a user can change a channel used at the time of communication by operating a switch and switching a plurality of channels to one of them.
Japanese Patent Laid-Open No. 4-315681

  However, in the technique described in Patent Document 1, the channel is not changed by the switch operation unless the user notices a communication failure caused by the jamming radio wave. Therefore, even in a situation where communication failure occurs with considerable frequency, if communication is occasionally successful, some users may not be aware of the occurrence of communication failure and may not change the channel. In addition, if the user arbitrarily changes the channel, there is a possibility that the channel is likely to be adversely affected by jamming radio waves.

Further, instead of manual setting as described above, it is possible to detect the occurrence of communication failure due to jamming radio waves and automatically change to another channel.
However, when a plurality of channels can be used, if the frequency band used for each channel is greatly different, the susceptibility to interference and the size of the communication area may vary depending on the channel.

  For this reason, simply changing the channel used for communication may cause a change to a channel that is susceptible to interference first, and in this case, the automatic change to a channel that is less susceptible to interference is complete. Takes a long time and causes a problem that the response until the authentication is established becomes worse.

  In addition, there is a possibility of changing to a channel whose communication area is only the vicinity of the vehicle even though the portable device does not exist in the vicinity of the vehicle. It takes time to complete the automatic change, which causes a problem that the response until the authentication is established is deteriorated.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide an electronic key that can automatically change a channel when a communication failure occurs and can improve the response until the authentication is established. A system and an in-vehicle device for such an electronic key system are provided.

Hereinafter, the configuration employed in the present invention will be described.
2. The electronic key system according to claim 1, wherein when the portable device is estimated to be in the vehicle interior, the in-vehicle device first tries to communicate on the LF channel while the portable device is estimated to be outside the vehicle compartment. If so, communication on the RF channel is first attempted.

  In general, various noise sources (for example, spark plugs, various motors, alternators, etc.) exist in a vehicle. Therefore, when such a noise source is in operation, there is a possibility that communication on the RF channel may be disturbed, but the LF channel is less susceptible to interference than the RF channel.

  Therefore, when the portable device is in the passenger compartment, the first attempt to communicate on the LF channel is less likely to be disturbed than the first attempt to communicate on the RF channel, and authentication is established. The response until is good.

  On the other hand, it is not easy for the LF channel to widen the communication area. Therefore, when the portable device is located away from the vehicle, there is a possibility that communication on the LF channel cannot be performed, but the communication area of the RF channel can be easily widened compared to the LF channel.

  Therefore, when the portable device is outside the passenger compartment, if the communication on the RF channel is first attempted, the possibility that the portable device exists in the communication area is greater than that on the first attempt to communicate on the LF channel. And the response until the authentication is established becomes good.

  In other words, depending on whether the portable device is estimated to be in the passenger compartment or out of the passenger compartment, the channel to be tried first is changed to either the LF channel or the RF channel. The response until the authentication is established can be improved as compared with the case of trying from the LF channel or the case of always trying from the RF channel first.

  By the way, in this type of electronic key system, the in-vehicle device normally requests a response from the portable device by limiting the communication area to the interior of the vehicle, or responds to the portable device by expanding the communication area to the outside of the vehicle. Therefore, it can be determined whether the portable device is in the vehicle interior or the vehicle exterior depending on whether or not there is a response to the request.

  Therefore, as in the electronic key system according to claim 2, if it can be determined that the portable device is in the vehicle compartment at the time of the previous communication, if the mobile device is estimated to be in the vehicle compartment at the time of the next communication, In this case, it can be accurately estimated that the portable device is in the passenger compartment.

  Further, as in the electronic key system according to claim 3, when it can be determined that the portable device is outside the vehicle compartment at the time of the previous communication, if it is estimated that the portable device is outside the vehicle compartment at the next communication, In this case, it can be accurately estimated that the portable device is outside the passenger compartment.

  Further, as in the electronic key system according to claim 4, when the time elapsed from the previous communication exceeds a predetermined time, it is determined that the portable device is in the vehicle compartment at the previous communication. Regardless of whether or not, the portable device may be estimated to be outside the passenger compartment at the next communication.

  In this case, even if communication is not performed for a while after the last communication on the LF channel, in this case, communication on the RF channel having a wider communication area is first tried. The possibility of communication on the first attempt can be increased.

  Further, when the engine switch is turned off as in the electronic key system according to claim 5, the next communication is performed regardless of whether or not it is determined that the portable device is in the passenger compartment at the time of the previous communication. Sometimes it may be estimated that the portable device is outside the passenger compartment.

  In this way, even if the portable device is taken out of the passenger compartment after the engine switch is turned off and before the next communication is performed, in this case, communication on the RF channel having a wider communication area is first performed. Therefore, it is possible to increase the possibility of communication in the first attempt.

  Further, when the vehicle door is opened as in the electronic key system according to claim 6, the next communication is performed regardless of whether or not the portable device is determined to be in the passenger compartment at the time of the previous communication. Sometimes it may be estimated that the portable device is outside the passenger compartment.

  In this case, even if the portable device is taken out of the passenger compartment after the door of the vehicle is opened and before the next communication is performed, in that case, communication on the RF channel having a wider communication area is first performed. Therefore, it is possible to increase the possibility of communication in the first attempt.

  Further, as in the electronic key system according to claim 7, when the door of the vehicle is unlocked, regardless of whether or not it is determined that the portable device is in the vehicle interior during the previous communication, It may be estimated that the portable device is outside the passenger compartment at the next communication.

  In this way, even if the portable device is taken out of the passenger compartment before the next communication is performed after the vehicle door is unlocked, in that case, the RF channel with a wider communication area is used. Since communication is tried first, it is possible to increase the possibility of communication in the first attempt.

  According to the on-vehicle device for the electronic key system described in claim 8, the electronic key system described in claim 1 can be configured by combining with the portable device corresponding to the on-vehicle device.

Next, an embodiment of the present invention will be described with an example.
The electronic key system described below is a function (so-called smart function) that performs control such as door unlocking when a specific portable device possessed by a regular user of the vehicle enters a wireless communication area around the vehicle. It is equipped with. In the present embodiment, this electronic key system also has a function (so-called remote keyless entry function) for executing control such as door locking / unlocking in response to a button operation on the portable device.

FIG. 1 is a block diagram showing the configuration of the electronic key system. This electronic key system includes an in-vehicle device 1 mounted on a vehicle and a portable device 2.
Among these, the in-vehicle device 1 includes a control unit 10, an LF transmission unit 11, an LF reception unit 12, an RF reception unit 13, an engine switch 15, a door switch 16, and the like.

The control unit 10 is a microcomputer that controls the operation of the entire vehicle-mounted device 1 side.
The LF transmission unit 11 is a means for transmitting a radio signal to the portable device 2. The radio signal transmitted from the LF transmission unit 11 is limited to the vicinity of the door outside the vehicle compartment, the interior of the vehicle interior, the trunk, the vicinity of the trunk outside the vehicle interior, It reaches only within the designated communication area.

  The LF receiver 12 is means for receiving an LF band radio signal transmitted from the portable device 2. The RF receiver 13 is means for receiving an RF band radio signal transmitted from the portable device 2. The RF receiving unit 13 can communicate by switching any of the three channels RF1 to RF3 having different frequencies, and the control unit 10 controls which channel is switched to.

  The engine switch 15 is a switch operated by the user when starting the engine. When the operation of the engine switch 15 is detected by a signal from the engine switch 15, the control unit 10 determines that the engine is started. Determine whether it is in a permitted state. If the engine start is permitted, an engine start signal is transmitted from the control unit 10 to the engine control system.

  The door switch 16 is a switch provided on a door handle that is operated by a user when the door is opened. When the operation of the door handle by the user is detected by a signal from the door switch 16, the control unit 10. Determines whether door unlocking is permitted. When the door unlocking is permitted, an unlock signal is transmitted from the control unit 10 to the door lock control system.

The portable device 2 includes a control unit 21, an LF reception unit 22, a transmission unit 23, an operation unit 24, and the like.
The control unit 21 is a microcomputer that controls the operation of the entire portable device 2 side. The LF receiver 22 is a means for receiving a radio signal transmitted from the in-vehicle device 1.

  The transmission unit 23 is means for transmitting a radio signal to the in-vehicle device 1. The transmission unit 23 includes a transmission frequency selection unit 23A, and in response to a command from the control unit 21, the frequency of the LF band is set so that the channel used for transmission is the same channel as the vehicle-mounted device 1 side. Is switched to any one of the channel LF using the RF and the channels RF1 to RF3 using the frequency of the RF band.

  The operation unit 24 includes a switch serving as a trigger for using the remote keyless entry function. When a predetermined operation is performed on the operation unit 24, door locking / unlocking control is performed on the in-vehicle device 1 side. It is structured.

[Processes executed by in-vehicle devices and portable devices]
Next, processing executed by the in-vehicle device 1 and the portable device 2 when using the smart function will be described. 2 is a flowchart of processing executed by the in-vehicle device 1, FIG. 3 is a response channel setting table, and FIG. 4 is a flowchart of processing executed by the portable device.

  When the in-vehicle device 1 starts the process shown in FIG. 2, the in-vehicle device 1 determines whether or not a predetermined communication condition is satisfied (S105). If the predetermined communication condition is not satisfied (S105: NO), the process of S105 is repeated. On the other hand, if the predetermined communication condition is satisfied (S105: YES), the process proceeds to S107.

  In the process of S105, as a specific example when a predetermined communication condition is satisfied, for example, a condition that an operation on a door switch is performed or an engine switch operation is performed can be cited. However, these conditions themselves are not particularly limited. For example, an affirmative determination may be made in the process of S105 when a condition that the communication timing to be performed periodically is reached in addition to the timing at which the user performs some operation as described above.

  When the process proceeds to S107, the in-vehicle device 1 determines whether the portable device 2 is estimated to be in the vehicle interior or the vehicle interior (S107). In the case of the present embodiment, it is estimated that the portable device 2 is in the vehicle interior in the process of S107 when it can be determined that the portable device 2 is in the vehicle interior during the previous communication, and during the previous communication. This is a case where the time elapsed from the time does not exceed a predetermined time.

  In addition, in the process of S107, it is estimated that the portable device 2 is outside the vehicle compartment. (1) When it can be determined that the portable device 2 is outside the vehicle compartment during the previous communication, (2) When communication with the machine 2 is not established, (3) When the time elapsed since the previous communication exceeds a predetermined time, at least one of these (1) to (3) This is the case.

  However, the condition for determining whether the portable device 2 is estimated to be in the vehicle interior or the vehicle exterior may further consider other conditions. Specific examples include (A) when the engine switch is turned off, (B) when the vehicle door is opened, (C) when the vehicle door is unlocked, If at least one of (C) is applicable, the user may have gone out of the vehicle. In this case, it was determined that the portable device 2 was in the passenger compartment during the previous communication. It may be estimated that the portable device 2 is outside the vehicle compartment at the next communication, regardless of whether or not.

  When it is estimated that the portable device 2 is in the passenger compartment by the estimation method as described above (S107: passenger compartment), an initial value “00” is set in the variable AA (S110). When it is estimated that the portable device 2 is outside the vehicle compartment (S107: outside the vehicle compartment), an initial value “01” is set to the variable AA (S112). The value set in the variable AA is used when selecting a response channel from the response channel setting table (see FIG. 3) in the processing described later.

  Subsequently, the in-vehicle device 1 transmits data to the portable device 2 by LF (S115). The reason why signal transmission using LF band radio waves is performed in S115 is mainly to limit the detection area of the portable device 2 to the periphery of the vehicle.

  Further, the data transmitted in the process of S115 is data for notifying the portable device 2 that a response is requested, and information for designating a response channel is carried at the time of this data transmission. Notify machine 2 More specifically, the in-vehicle device 1 refers to the response channel setting table (see FIG. 3), and selects the channel associated with the value stored in the variable AA as the response channel. Then, the mobile device 2 is notified of information indicating the response channel.

  When the initial value “00” is set in the variable AA, the LF band channel (LF) is first selected as the response channel. On the other hand, when the initial value “01” is set to the variable AA, the RF band channel (RF1) is first selected as the response channel.

  Now, as shown in FIG. 4, the portable device 2 notified of the information indicating the response channel first changes the channel used in the transmission unit 23 to the frequency commanded by the in-vehicle device 1 (S305). Since the frequency commanded from the in-vehicle device 1 is included in the data transmitted by the process of S115, the frequency used by the transmission unit 23 is changed in the process of S305 based on the data.

  And the response from the transmission part 23 to the vehicle-mounted apparatus 1 is transmitted (S310), and the process by the side of the portable device 2 is complete | finished. In the process of S310, a response signal including a unique ID for identifying that the portable device 2 corresponds to a vehicle is transmitted.

  When the processing as described above is executed on the portable device 2 side, the in-vehicle device 1 side receives a response from the portable device 2 through the response channel (S120). What is received by the process of S120 is a response transmitted from the portable device 2 side by the process of S310.

  However, in the process of S120, the response from the portable device 2 may be received normally or may not be received depending on the surrounding environment. For example, an interference wave having the same frequency as the response may arrive. In a difficult environment, the response may not be received normally. In addition, unexpected data may be received.

  Therefore, when the process of S120 is completed, the ID included in the received response is collated with the control ID stored on the in-vehicle device 2 side to determine whether or not they match by the process of S125. (S125).

  Here, if the ID collation results match (S125: YES), it is considered that the response transmitted from the predetermined portable device 2 has been normally received. In this case, in this case, a predetermined function operation (for example, a door) Unlocking, starting the engine, etc.) are executed (S130), and the processing shown in FIG.

  On the other hand, if the ID collation results do not match in the processing of S125 (S125: NO), there is a possibility that the response could not be received normally due to the influence of the jamming radio wave. Try.

  Specifically, first, 1 is added to the variable AA (S140). As a result, the channel selected from the response channel setting table (see FIG. 3) is updated to the next channel. In the process of S140, the value of the variable AA changes in the order of “00” → “01” → “10” → “11”, and when 1 is further added, the value returns to “00”.

  Therefore, if the stored value of the variable AA updated in the process of S140 is different from the initial value (the value set in S110 or S112), communication by all response channels is still being attempted. (S145: NO). In this case, since the value of the variable AA has been updated to a value corresponding to a channel different from the already tried channel, the process returns to S115 in this case.

  In the loop processing that returns from S115 to S115 through S120, S125, S140, and S145 as described above, the ID collation matches (S125: YES), or even if all channels are tried, the ID collation does not match (S145: Repeat until YES).

  On the other hand, if the ID collation results match in the processing of S125 during the loop processing (S125: YES), it is considered that the response transmitted from the predetermined portable device 2 has been successfully received. Therefore, in this case, a predetermined function operation (for example, release of the door lock, engine start, etc.) is executed (S130). If the ID verification does not match even after trying all channels (S145: YES), the processing shown in FIG. 2 is terminated.

[Effect of the embodiment]
As described above, according to the electronic key system, the channel can be automatically changed without the user having to manually set the channel by operating the switch.

  Moreover, according to the electronic key system, when it is estimated that the portable device 2 is in the vehicle interior, the in-vehicle device 1 first tries to communicate on the LF channel, while the portable device 2 is outside the vehicle compartment. First, communication on the RF channel is tried.

  Therefore, when the portable device 2 is present in the passenger compartment that is easily affected by noise sources existing in the vehicle, the communication until the authentication is established can be obtained by first trying communication on the LF channel that is not easily disturbed. Can be improved. In addition, when the portable device 2 is located outside the passenger compartment where the distance from the in-vehicle device 1 is far, it is possible to improve the response until the authentication is established by first trying communication on the RF channel having a wide communication area. Can do. Therefore, it is possible to improve the response until the authentication is established, compared with the case where the first attempt is made from the LF channel and the case where the first attempt is always made from the RF channel.

[Modifications, etc.]
As mentioned above, although embodiment of this invention was described, this invention is not limited to said specific one Embodiment, In addition, it can implement with a various form.

  For example, in the above-described embodiment, an example has been shown in which one LF band channel and three RF band channels are used as response channels, and communication is performed by sequentially switching these four channels. Is not limited to the above example. Specifically, two or more LF band channels may be prepared, or one, two, or four or more RF band channels may be prepared.

The schematic block diagram of the electronic key system demonstrated as embodiment of this invention. The flowchart of the process which a vehicle-mounted apparatus performs at the time of smart function utilization. Response channel setting table. The flowchart of the process which a portable device performs at the time of smart function utilization.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... In-vehicle apparatus, 2 ... Portable machine, 10 ... Control part, 11 ... LF transmission part, 12 ... LF reception part, 13 ... RF reception part, 15 ... Engine Switch, 16 ... door switch, 21 ... control unit, 22 ... LF reception unit, 23 ... transmission unit, 23A ... transmission frequency selection unit, 24 ... operation unit.

Claims (8)

In order to cause the in-vehicle device to perform various controls by performing wireless communication between the in-vehicle device and a portable device carried by a user, and performing wireless communication between the in-vehicle device and the portable device. An electronic key system that performs the necessary authentication,
When the in-vehicle device requests a response from the portable device, the portable device in response to the response request is configured to return a response to the in-vehicle device,
The channel used when transmitting the response is selected from a plurality of channels including at least one LF channel using an LF band frequency and at least one RF channel using an RF band frequency. Which channel is to be used is selected on the in-vehicle device side, and information indicating the selected channel is transmitted from the in-vehicle device to the portable device when the response request is transmitted. Thus, the vehicle-mounted device and the portable device can execute transmission and reception of the response using the same channel,
In addition, the in-vehicle device estimates whether the portable device is in the vehicle interior or the vehicle interior based on a predetermined condition, and when it is estimated that the mobile device is in the vehicle interior, first the LF channel is set. If it is estimated that the vehicle is outside the passenger compartment, the RF channel is selected first, and the transmission of the response request and the reception of the response are attempted. As a result of the attempt, reception of the response fails. In such a case, it is configured to re-select a channel other than the channel selected at the time of reception failure from the plurality of channels and retry transmission of the response request and reception of the response. And electronic key system. The said in-vehicle device presumes that said portable machine is in a vehicle room at the time of next communication, when it can be judged that said portable machine is in a vehicle room at the time of previous communication. Electronic key system. The in-vehicle device estimates that the portable device is outside the vehicle compartment during the next communication when it can be determined that the portable device is outside the vehicle compartment during the previous communication. The electronic key system according to 2. If the time elapsed since the previous communication exceeds a predetermined time, the in-vehicle device, whether or not it is determined that the portable device is in the vehicle interior during the previous communication, the next time The electronic key system according to any one of claims 1 to 3, wherein the portable device is estimated to be outside a passenger compartment during communication. When the engine switch is turned off, the in-vehicle device has the portable device outside the vehicle compartment at the next communication regardless of whether or not it is determined that the portable device is in the vehicle cabin at the previous communication. The electronic key system according to claim 1, wherein the electronic key system is estimated as follows. When the vehicle door is opened, the in-vehicle device has the portable device outside the vehicle compartment at the next communication regardless of whether or not it is determined that the portable device is in the vehicle cabin at the previous communication. The electronic key system according to claim 1, wherein the electronic key system is estimated. When the vehicle door is unlocked, the in-vehicle device is connected to the vehicle at the next communication regardless of whether the portable device is determined to be in the passenger compartment at the time of the previous communication. The electronic key system according to claim 1, wherein the electronic key system is estimated to be outside. An in-vehicle device capable of configuring the electronic key system according to claim 1,
The channel used when transmitting the response from the portable device is any one of a plurality of channels including at least one LF channel using an LF band frequency and at least one RF channel using an RF band frequency. The same channel as the portable device can be selected by selecting which channel to use and transmitting information indicating the selected channel to the portable device when transmitting the response request. The response can be received using
In addition, based on a predetermined condition, it is estimated whether the portable device is in the vehicle interior or the vehicle interior, and when it is estimated that the portable device is in the vehicle interior, the LF channel is selected first, When it is estimated that the user is outside the room, first, the RF channel is selected and transmission of the response request and reception of the response are attempted. If the response fails as a result of the attempt, An electronic key system configured to re-select a channel other than the channel selected at the time of reception failure from the plurality of channels, and retry transmission of the response request and reception of the response. In-vehicle device.

Images