JP5026897B2 - Vehicle electronic key system - Google Patents

Description

  The present invention relates to an electronic key system that executes various controls of a vehicle through wireless communication between the vehicle and an electronic key.

  When the user holding the portable device (electronic key) approaches the vehicle door, the vehicle door is automatically unlocked, and when the user enters the vehicle interior, the engine is allowed to start. Electronic key systems are well known. Conventionally, as such an electronic key system, for example, a system described in Patent Document 1 is known. FIG. 5 shows an outline of an electronic key system that is generally employed in the past, including the system described in Patent Document 1.

As shown in FIG. 5, in this electronic key system, for example, a request signal is transmitted from the outdoor transmitter 11 provided in the vehicle door to the communicable area A set around the vehicle door, and in the vehicle interior. A request signal is transmitted from the provided indoor transmission device 13 to the communicable area B set in the passenger compartment. In this electronic key system, the request signal transmitted from the outdoor transmitter 11 and the indoor transmitter 13 is received, and a response signal including information such as an identification code (ID code) is received with respect to the received request signal. A user possesses the portable device 20 to transmit. That is, when the user who has the portable device 20 enters the communicable area A or the communicable area B, a response signal is transmitted from the portable device 20. In this system, the response signal transmitted from the portable device 20 is received by the receiving device 12 provided in the vehicle interior and transmitted to the vehicle-side control device 14 that executes various controls on the vehicle. The controller 14 collates the ID code of the portable device 20 included in the received response signal with the ID code stored in the memory in the controller 14 in advance, and through this collation, for example, a vehicle door The vehicle is controlled such as unlocking the door lock mechanism 15 provided in the vehicle or allowing the engine to start. According to such an electronic key system, various operations of the vehicle are automatically performed without direct manual operation by the user, so that convenience related to the operation of the vehicle is greatly improved. .
JP 2001-31333 A

  By the way, in such an electronic key system, as described above, various signals such as the request signal and the response signal are transmitted between the transmitter / receiver provided in the portable device 20 and the transmission devices 11 and 13 or the reception device 12 of the vehicle. Sent and received via wireless communication. For this reason, for example, in an environment where there is noise received by the receiving device 12 around the receiving device 12 of the vehicle, the influence of the noise received together with the response signal transmitted from the portable device 20 cannot be ignored. The information included in the response signal may not be properly recognized on the vehicle side. In such a case, when the vehicle control device 14 determines that the ID code included in the response signal received on the vehicle side does not match the ID code stored in the memory in the control device 14. In addition, the unlocking operation by the door lock mechanism 15 is not performed, and the functions required for the electronic key system may be hindered.

  The present invention has been made in view of such circumstances, and an object of the present invention is to appropriately transmit and receive radio signals between the vehicle and the electronic key even in an environment susceptible to noise. To provide an electronic key system.

In order to solve the above-described problem, the invention according to claim 1 is set based on a portable electronic key including a first communication device that transmits a predetermined wireless signal, and a frequency and a signal level of the wireless signal. Vehicle control through transmission / reception of the radio signal on the condition that the electronic key is in a communicable area with the vehicle with a vehicle including a second communication device that receives the radio signal in the received reception band In the electronic key system for a vehicle in which the various processes are executed, the first communication device and the second communication device can change the transmission / reception frequency of the radio signal transmitted / received between them to a plurality of frequencies, respectively. and at the second communication device, and the electronic key during the stop of the vehicle is mixed radio wave is detected in the the reception band in a situation not in the communicable area is the detection When the radio wave signal level is predetermined noise judgment level above which might affect radio signal transmitted from said first communication apparatus, said radio wave signal level is below the predetermined noise judgment level and sets changing the receiving frequency until, when that subsequent to the electronic key in front Symbol communications coverage area is determined, and transmits the information of the received frequency that the change to the first communication device, wherein The gist of the first communication device is to change the setting of the transmission frequency of the radio signal to the frequency specified by the information when the reception frequency information is received.

The environment in which the vehicle is parked varies, and if the environment changes, the radio wave environment around the vehicle also changes accordingly. In other words, because the noise environment naturally changes depending on the parking location of the vehicle, just because a wireless signal can be appropriately transmitted and received between the vehicle and the electronic key in a certain parking location, the same applies to other parking locations. It is not always possible to properly transmit and receive radio signals. In this regard, as in the system, when the vehicle is parked and before the electronic key enters the communicable area of the vehicle, it is detected that radio waves are mixed into the reception band of the radio signal, and When the detected signal level of the radio wave is equal to or higher than a predetermined noise determination level that may affect the radio wave transmitted from the first communication device, the radio wave received by the second communication device by setting change receiving frequency until the signal level is below a predetermined noise judgment level, and preset changing the receiving frequency of the second communication device in a manner the influence of noise is accurately eliminated our Kukoto it can. And then, at the time the that the electronic key is in the communicable area of the vehicle is determined, the information of the reception frequency and the changes transmitted from the second communication apparatus to the first communication device, designated by the information By transmitting and receiving radio signals at the frequency that is used, even when the parking location of the vehicle changes variously, the entry of the electronic key into the communicable area is determined as soon as it is determined. The wireless signal transmission / reception between the first and second communication devices, that is, between the vehicle and the electronic key, is appropriately started. Thus, according to the system, even in an environment that is easily affected by noise, for example, the necessary radio signal is appropriately transmitted without going through negotiations between the vehicle and the electronic key. In addition, transmission / reception can be performed quickly.

Further, the setting changes in received frequency, it intends repeated line based on the comparison of the radio wave signal level and the noise judgment levels the received subsequent radio signals between the vehicle and the electronic key The reliability of transmission / reception of data is greatly improved.

According to a second aspect of the present invention, in the electronic key system for a vehicle according to the first aspect, the second communication device transmits the reception frequency to the first communication device through a setting change of a transmission / reception frequency of the radio signal. later by sending the information, the period in which the electronic key is determined to be in the front Symbol communications coverage area is directed to subject matter to stop the transmission of the information for the first communication device.

  When such a process for changing the frequency of the radio signal is executed, the radio signal can be appropriately transmitted and received between the vehicle and the electronic key, but these vehicles And in the electronic key, in addition to the processing related to the electronic key system, the processing for changing the frequency of the radio signal is executed. Therefore, the processing for changing the frequency of the radio signal is executed. There is concern about a decline in responsiveness as an electronic key system. In this regard, as in the system, during the period when the electronic key is determined to be in the area where communication with the vehicle is possible, transmission of frequency information to the first communication device is intentionally stopped, If the frequency is maintained as it is, it is possible to avoid such a decrease in responsiveness as the electronic key system.

  According to the present invention, even in an environment that is susceptible to noise, for example, the required radio signal can be appropriately and quickly transmitted without negotiating between the vehicle and the electronic key. You can send and receive.

  Hereinafter, an embodiment of an electronic key system for a vehicle according to the present invention will be described with reference to FIGS. The basic configuration of the electronic key system to which this embodiment is applied is the same as that of the electronic key system illustrated in FIG. FIG. 1 is a block diagram showing the system configuration of such an electronic key system. First, the configuration and operation of this electronic key system will be described more specifically with reference to FIG.

  As shown in FIG. 1, in this electronic key system, various communication controls by wireless communication are executed between a vehicle-side device 100 mounted on the vehicle side and a portable device 200 carried by the driver. . That is, the vehicle-side device 100 has a transmission circuit 110 for transmitting the above-described request signal to the portable device 200 and a receiving circuit 120 for receiving the above-described response signal transmitted from the portable device 200. Is provided. Then, the transmission control of the request signal by the transmission circuit 110 and the processing of the response signal received through the reception circuit 120 are performed collectively through the vehicle-side control unit 130 provided in the vehicle-side device 100. Incidentally, the vehicle-side control unit 130 is also a part that controls the control target 140 such as the door lock mechanism and the engine starter described above. On the other hand, the portable device 200 has a receiving circuit 210 for receiving the request signal transmitted from the vehicle side device 100, and transmits the response signal to the vehicle side device 100 based on reception of the request signal. A transmission circuit 220 is provided. And the generation of the response signal based on the request signal received through the reception circuit 210 and the transmission control of the generated response signal through the transmission circuit 220 are also provided in the portable device 200. 230 is performed collectively. Note that the portable device 200 is provided with an operation button 240 that is pressed by the driver based on an intention to lock / unlock the vehicle door, for example. When the button is pressed, a signal including information on the identification code (ID code) of the portable device 200 is generated, and the generated signal is transmitted from the transmission circuit 220.

  In the electronic key system configured as described above, it is assumed that a request signal is issued from the transmission circuit 110 to a communicable area set around the vehicle door or a communicable area set in the vehicle interior. When the portable device 200 possessed by the driver enters the communicable area, signal exchange between the vehicle-side device 100 and the portable device 200 is executed in the following manner. That is, in this system, the request signal transmitted from the transmission circuit 110 is received by the reception circuit 210, and the request signal is transmitted to the portable device side control unit 230. When the request signal is transmitted in this manner, the portable device-side control unit 230 generates a response signal including an identification code (ID code) stored in the built-in memory and transmits the response signal to the transmission circuit 220. This response signal is transmitted to the vehicle side device 100. When the response signal is transmitted in this manner, the reception circuit 120 receives the response signal and transmits the received response signal to the vehicle-side control unit 130. As a result, the vehicle-side control unit 130 collates the ID code included in the transmitted response signal with the ID code stored in the memory built in the control unit 130 as described above. On the basis of the determination that the ID codes match, the vehicle door is unlocked through the door lock mechanism, which is the control target 140, or the vehicle engine is started through the engine starting device.

  By the way, in such a system that transmits and receives signals through wireless communication, for example, when the vehicle is parked and there is noise that can be received by the reception circuit 120 at the parking place of the vehicle, the transmission circuit 220 described above. The influence of noise received together with the response signal transmitted from cannot be ignored. That is, as described above, information included in the response signal cannot be properly recognized by the vehicle-side device 100, and functions required for the electronic key system may be hindered. In addition, there are various environments in which vehicles are parked. If these environments change, the radio wave environment around the vehicles also changes accordingly. That is, because the noise environment naturally changes depending on the parking location of the vehicle, it is possible to appropriately transmit and receive radio signals between the vehicle-side device 100 and the portable device 200 at a certain parking location. Similarly, it is not always possible to appropriately transmit and receive radio signals at other parking locations.

  Therefore, in the electronic key system according to the present embodiment, as shown in FIG. 1, the reception frequency of the reception circuit 120 is set to the frequency Freq. 1-Freq. N can be set to any frequency (where 1 to N are natural numbers within a predetermined range). In addition to this, the transmission frequency of the transmission circuit 220 is also transmitted to the frequency Freq. 1-Freq. N can be set to any frequency. That is, when the portable device side control unit 230 and the transmission circuit 220 are the first communication device, and the vehicle side control unit 130 and the reception circuit 120 are the second communication device, the first communication device and the second communication device. The transmission / reception frequencies of radio signals transmitted / received between the two can be set and changed to N types of frequencies. Note that these frequencies Freq. 1-Freq. The value of N is stored in frequency registers 131 and 231 incorporated in the control units 130 and 230, respectively. Furthermore, in this system, when the vehicle is stopped, the wireless radio wave to the reception band of the reception circuit 120 set based on the frequency and the signal level of the wireless signal, even though the portable device 200 does not exist in the communicable area. When mixing is detected, it is determined based on the signal level of the mixed radio wave whether or not the radio wave is harmful noise that affects a radio signal exchanged with the portable device 200. If it is determined through this determination that the mixed radio wave is harmful noise that affects the radio signal, the reception frequency of the reception circuit 120 is changed in advance, and the portable device 200 is placed in a communicable area. When entering, the mobile device 200 is notified of information on the changed frequency.

  Next, referring to FIG. 2, a method for determining whether or not this is harmful noise affecting the radio signal when the radio wave mixed into the reception band of the reception circuit 120 is detected is described. A specific method will be described. FIG. 2 is a graph showing an example of the relationship between the frequency of radio waves around the vehicle received by the receiving circuit 120 and its signal level.

  As shown in FIG. 2, the vehicle-side control unit 130 sets two types of determination levels with respect to the received radio wave signal level, that is, a code determination level D1 and a signal level smaller than the code determination level. The corresponding noise determination level D2 is set, and the following determination is performed according to the signal level of the received radio wave.

  (A) When the signal level of the received radio wave is a signal level that is equal to or higher than the code determination level D1, the received radio wave is a signal having a level that is large enough to recognize the code contents. Therefore, the match / mismatch is determined through a comparison between the recognized code and the code stored in the vehicle-side control unit 130. Then, the control unit 130 determines that the signal determined to be coincident is a normal radio signal transmitted from the transmission circuit 220, and affects the radio signal if the signal is determined to be inconsistent. It is determined that the noise is harmful. A signal having a signal level equal to or higher than the code determination level D1 includes both a radio signal transmitted from the transmission circuit 220 and a radio wave having a high signal level. It is determined whether or not is noise.

  (B) If the signal level of the received radio wave is less than the code determination level D1 and greater than or equal to the noise determination level D2, the received radio wave may affect the radio signal. Judged as harmful noise.

  (C) When the signal level of the received radio wave is less than the noise determination level D2, it is assumed that the received radio wave is noise but has a low possibility of affecting the radio signal, and is harmless. Judged as noise or no noise.

And the vehicle side control part 130 changes the receiving frequency of the receiving circuit 120 with the following aspect as needed based on the result of determination by these (a)-(c).
For example, now, the reception frequency of the reception circuit 120 is the frequency Freq. 1, a radio wave having a frequency band and a signal level as shown by a solid line in FIG. 2 around the reception circuit 120, that is, a frequency Freq. It is assumed that a radio wave having a signal level equal to or higher than the code determination level D1 is generated. At this time, based on the determination in (a), the vehicle-side control unit 130 first confirms the code content of the received radio wave through the verification. If this code does not match the code stored by itself, it is determined that this radio wave is harmful noise, and the table of the frequency register 131 is stored in the frequency Freq. Shift so that 2 is preferred. As a result, the reception frequency of the reception circuit 120 becomes the frequency Freq. 1 to the frequency Freq. Is changed to 2.

  Next, the reception frequency of the reception circuit 120 is set to the frequency Freq. 2 that the signal level of the radio signal received by the receiving circuit 120 is less than the code determination level D1 and equal to or higher than the noise determination level D2, as seen in the example of FIG. To do. At this time, on the basis of the determination in (b) above, the vehicle-side control unit 130 assumes that the received radio wave is also harmful noise, and similarly sets the frequency register 131 table in the form shown in FIG. Freq. Shift so that 3 has priority. As a result, the reception frequency of the reception circuit 120 becomes the frequency Freq. 2 to the frequency Freq. It is further changed to 3.

  Thus, the reception frequency of the reception circuit 120 is changed to the frequency Freq. As a result of changing to 3, the signal level of the radio wave received by the receiving circuit 120 becomes less than the noise determination level D2 as seen in the example of FIG. Then, based on the determination in (c) above, the vehicle-side control unit 130 determines that the received radio wave is harmless noise and has the same frequency Freq. 3 is determined to be a frequency that is not easily affected by noise, that is, a communicable frequency. That is, the frequency register 131 is set to the frequency Freq. 3 is maintained in the priority state. Then, after that, when the portable device 200 enters the communicable area, the vehicle-side control unit 130 sets the frequency communicable with the portable device 200 to the frequency Freq. 3 is transmitted. Accordingly, in the portable device 200, based on the reception of the frequency information, the frequency Freq. Specified by the information among the frequencies set in the frequency register 231 is received. 3 is changed as the transmission frequency of the transmission circuit 220.

  FIG. 4 is a flowchart showing the processing procedure of the reception frequency switching process executed by the vehicle-side control unit 130 for the process of changing the transmission / reception frequency of the transmission circuit 220 and the reception circuit 120. Based on FIG. 4, the specific procedure of the process is summarized. Note that the processing shown in FIG. 4 is actually repeatedly executed with a predetermined calculation cycle.

  As shown in FIG. 4, in this reception frequency switching process, it is first determined whether or not the vehicle is stopped (step S100). With regard to the determination processing in step S100, for example, it is determined that the vehicle is stopped based on the fact that the ignition switch of the vehicle is in an OFF state. If it is determined that the vehicle is stopped (step S100: YES), then the portable device 200 is set in the communicable area set around the vehicle door or in the vehicle interior. It is determined whether or not the communication area exists (step S101). By the way, in this electronic key system, detection of presence / absence of the portable device 200, such as whether the portable device 200 is in each of the above-described communicable areas or not, through execution of various controls by the system. Are performed sequentially. For this reason, in the determination process of step S101, it is determined whether or not the portable device 200 grasped by the electronic key system exists in the communicable area. When it is determined that the portable device 200 does not exist within the communicable area (step S101: NO), it is determined whether or not the radio wave is received by the receiving circuit 120 (step S101: NO). Step S102). If it is determined through the determination process in step S102 that a radio wave is received (step S102: YES), the radio wave being received is harmful noise that affects the radio signal. It is determined whether or not (step S103). Specifically, in the determination process in step S103, it is determined whether the radio wave being received is harmful noise based on the determinations (a) to (c) described above. When it is determined that the radio wave being received is harmful noise (step S103: YES), the process of changing the reception frequency of the reception circuit 120 described above is executed (step S104). It is determined whether harmful noise still exists in the reception band of the reception circuit 120 (step S105). Then, while it is determined that harmful noise exists in the reception band of the reception circuit 120 (step S105: YES), the process of changing the reception frequency of the reception circuit 120 in step S104 is repeatedly performed. As described above, it is expected that the signal level of the noise received by the receiving circuit 120 is gradually reduced. When the signal level of the noise received by the receiving circuit 120 becomes less than the noise determination level D2, that is, when the radio wave being received has reached a level where it can be determined as harmless noise, step S105 is performed. Through this determination process, it is determined that there is no harmful noise within the reception band of the reception circuit 120 (step S105: NO). Then, in the subsequent step S106, the same process as in step S101, that is, the portable device 200 is located in a communicable area set around the vehicle door or in a communicable area set in the vehicle interior. It is determined whether or not. Then, while it is determined that the portable device 200 is not located within the communicable area (step S106: NO), the reception frequency switching process is in a standby state, and the portable device 200 has entered the communicable area. Is determined (step S106: YES), the information on the changed reception frequency, that is, the information on the communicable frequency is transmitted to the portable device 200 (step S107).

  As a result of such processing in the vehicle-side control unit 130, the portable device 200 receives the information on the communicable frequency from the vehicle-side device 100 as soon as the portable device 200 enters the communicable area. The transmission frequency of the transmission circuit 220 is changed to the frequency specified by the information through the side control unit 230. For this reason, the subsequent transmission / reception of the radio signal between the transmission circuit 220 and the reception circuit 120 is appropriately and promptly executed. For example, information necessary for performing unlock control or the like is also prompt. Will be transmitted to.

  In the reception frequency switching process shown in FIG. 4, when it is determined that the code included in the received radio wave matches the code stored in the vehicle-side control unit 130 through the determination process in step S103, As a so-called type of fail process, the reception frequency is not changed. Specifically, it is determined through the determination process in step S103 that the radio wave being received is not harmful noise (step S103: NO), and the reception frequency switching process is temporarily terminated. Thus, even when the electronic key system determines that there is no portable device 200 in the communicable area even though the portable device 200 exists in the communicable area for some reason (step S101). : NO), the transmission / reception frequencies of the transmission circuit 220 and the reception circuit 120 are maintained as they are, and radio signals are appropriately transmitted / received.

  Further, in the present embodiment, as is clear from the reception frequency switching process, after the information on the communicable frequency is once transmitted to the portable device 200 as the process of step S107, the vehicle is stopped. However, the transmission / reception frequencies of the transmission circuit 220 and the reception circuit 120 are maintained as they are during the period in which the portable device 200 is determined to be in the communicable area (step S101: YES). That is, during this period, the processing related to steps S102 to S107 is not performed intentionally, and the same transmission / reception frequency is maintained as it is so as to avoid a decrease in responsiveness as an electronic key system associated with executing the reception frequency switching processing. I have to.

As described above, according to the electronic key system for a vehicle according to the present embodiment, the following effects can be obtained.
(1) The transmission / reception frequency of a radio signal transmitted / received between the transmission circuit 220 and the reception circuit 120 can be set and changed to N types of frequencies. In addition, when noise is detected in the reception band of the reception circuit 120 while the vehicle is stopped, the reception frequency of the reception circuit 120 is changed in a manner that reduces the influence of the noise. Then, when it is detected that the portable device 200 has entered a communication area with the vehicle-side device 100, the information on the changed reception frequency is transmitted to the portable device 200, and the transmission circuit 220 of the portable device 200 transmits. The frequency was changed to the frequency specified by the same information. As a result, radio signals can be appropriately transmitted and received between the vehicle-side device 100 and the portable device 200, and the vehicle door is unlocked when the portable device 200 enters the communicable area. It becomes possible to quickly transmit and receive information necessary for executing the locking control and the like.

  (2) When the reception frequency of the reception circuit 120 is changed, mixing of radio waves into the reception band of the reception circuit 120 is detected, and the signal level of the detected radio waves is equal to or higher than the noise determination level D2. Based on the judgment of. As a result, the setting of the reception frequency is changed between the transmission circuit 220 and the reception circuit 120 in such a manner that the influence of noise mixed in the reception band of the reception circuit 120 is accurately eliminated.

  (3) In reducing the influence of noise, the reception frequency is repeatedly changed until the signal level of the radio wave received by the receiving circuit 120 becomes less than the noise determination level D2. Thereby, the reliability concerning transmission / reception of a radio signal between the vehicle-side device 100 and the portable device 200 is greatly enhanced.

  (4) When it is determined that the signal level of the radio wave received by the receiving circuit 120 is equal to or higher than the code determination level D1, the code included in the radio wave and the memory in the vehicle-side control unit 130 The match / mismatch is determined through collation with a stored code, and radio waves determined to be mismatch are regarded as noise. As a result, it is possible to avoid erroneous determination of the radio signal transmitted from the transmission circuit 220 as noise.

  (5) Such code verification is performed only when the signal level of the radio wave received by the receiving circuit 120 exceeds the code determination level D1. As a result, the code verification processing for radio waves having a signal level that is less than the code determination level D1, that is, radio waves that are highly likely to be noise, is omitted, and as a result, code verification is executed. The processing load of the accompanying vehicle-side control unit 130 can be reduced.

  (6) After once transmitting the information on the communicable frequency to the portable device 200, even if the vehicle is stopped, the portable device 200 is portable for a period during which it is determined that the portable device 200 is in the communicable area. The transmission of the same information to the machine 200 is stopped. As a result, it is possible to avoid a decrease in responsiveness as an electronic key system associated with executing the reception frequency switching process.

In addition, the said embodiment can also be implemented with the following forms which changed this suitably.
In the above embodiment, in order to reduce the influence of noise, the reception frequency is repeatedly changed until the signal level of the radio signal received by the receiving circuit 120 becomes less than the noise determination level D2. Instead, for example, the frequency Freq. 1-Freq. The signal level of the received radio wave may be measured for all N, and the frequency with the lowest signal level may be selected as the reception frequency of the reception circuit 120.
(Appendix)
Next, a technical idea that can be grasped from the above embodiment and its modifications will be additionally described.

(A) In the electronic key system for a vehicle according to claim 1 or 2 , when the second communication device detects that radio waves are mixed into the reception band, the radio wave received by the second communication device. For a signal having a level that is recognizable and capable of recognizing the code included in the signal, the match / mismatch is determined by comparing the recognized code with the code stored in the second communication device. vehicles electronic key system for you, characterized in that the process be regarded to as a noise for determining the signal is further performed. The signal having a level that is large enough to recognize the code included in the radio wave received by the second communication device is a regular radio signal transmitted from the first communication device, or has a very high signal level. There is a possibility of high noise. For this reason, when the determination as to whether or not the radio wave received by the second communication device is noise is performed using the signal level as an evaluation criterion, a legitimate radio signal may be erroneously determined as noise. In this regard, as in the same configuration, for a signal having a level that is high enough to recognize a code included in the radio wave received by the second communication device, the recognized code and the second communication device By determining whether or not there is noise through verification with a stored code, it is possible to avoid the problem that the radio signal transmitted from the first communication device is erroneously determined as noise. become.

(B) In the electronic key system for a vehicle described in appendix (i), the code verification is a specific code determination in which a signal level of a radio wave received by the second communication device is higher than a level to be determined as noise. vehicles electronic key system you characterized by being performed only when the level or higher. Even though the signal included in the radio wave received by the second communication device can be recognized as a signal having a sufficiently high level, for example, a signal of a regular radio signal transmitted from the first communication device. If the signal level is lower than the preset signal level, there is a high possibility of noise. Therefore, according to the same configuration, the processing for code verification for a radio wave having a signal level that is less than the code determination level, that is, a radio wave that is likely to be noise, is omitted. It becomes possible to avoid a decrease in responsiveness as an electronic key system accompanying execution of collation.

The block diagram which shows the system configuration | structure about one Embodiment of the electronic key system of the vehicle concerning this invention. The graph which shows the example about the relationship between the receiving frequency by the receiving circuit of the vehicle side apparatus of the electronic key system of the embodiment, the frequency of the radio wave around the vehicle, and the signal level. The figure which shows typically the setting change aspect of the receiving frequency memorize | stored in the frequency register about the vehicle side control part of the electronic key system of the embodiment. The flowchart which shows the process sequence about the reception frequency switching process by the electronic key system of the embodiment. The top view which shows typically the outline | summary of the electronic key system generally employ | adopted conventionally.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Outdoor transmission device, 12 ... Reception device, 13 ... Indoor transmission device, 14 ... Vehicle side control device, 15 ... Door lock mechanism, 20,200 ... Portable machine, 100 ... Vehicle side device, 110, 220 ... Transmission circuit, DESCRIPTION OF SYMBOLS 120,210 ... Reception circuit, 130 ... Vehicle side control part, 131,132 ... Frequency register, 140 ... Control object, 230 ... Portable machine side control part, 240 ... Operation button.

Claims (2)

A portable electronic key having a first communication device for transmitting a predetermined wireless signal, and a second communication device for receiving the wireless signal in a reception band set based on the frequency and signal level of the wireless signal In the vehicle electronic key system in which various processes relating to vehicle control are executed through transmission and reception of the wireless signal on the condition that the electronic key is in a communicable area with the vehicle.
The first communication device and the second communication device can each be set and changed to a plurality of frequencies for transmission and reception frequencies of radio signals transmitted and received between them,
The second communication device detects that radio waves are mixed into the reception band in a situation where the electronic key is not in the communicable area while the vehicle is stopped, and the signal level of the detected radio waves Is equal to or higher than a predetermined noise determination level that may affect the radio signal transmitted from the first communication device, the reception frequency is set until the signal level of the radio wave becomes less than the predetermined noise determination level. as well as configuration changes, when that subsequent to the electronic key in front Symbol communications coverage area is determined, and transmits the information of the received frequency that the change to the first communication device,
When the information on the reception frequency is received, the first communication device changes the setting of the transmission frequency of the radio signal to a frequency specified by the information. The second communication device, the radio signal after sending the information of the reception frequency to the first communication device through the setting change of the transmission and reception frequencies of the electronic key that is before Symbol communications coverage area the determined specified period of a vehicle electronic key system according to claim 1 for stopping the transmission of the information for the first communication device.

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