KR20170118804A - Electronic key system for vehicles - Google Patents

Abstract

The electronic key system for a vehicle includes a vehicle-mounted device 110 and a portable device 200 that is associated with the vehicle-mounted device and carried to the user. The vehicle-mounted device includes a vehicle-mounted-device-side transmitting unit 113, a communication-mode changing unit, and a vehicle-mounted-device-side receiving unit 112. The portable device includes a communication method selection unit, a first frequency-use antenna 220, a reception processing unit, a portable-unit-side transmission unit, and a noise determination unit. When it is determined by the noise judging unit that there is noise, the communication mode selection unit selects a communication mode different from the currently employed communication mode, and the portable unit side transmission unit transmits a mode change instruction signal to the vehicle-mounted device. The communication mode changing unit changes the communication mode to the communication mode specified by the mode change instruction signal when the vehicle-mounted-unit-side receiver receives the mode change instruction signal.

Description

Electronic key system for vehicles

<Cross reference of related application>

The present application is based on Japanese Patent Application No. 2015-71640 filed on March 31, 2015, the disclosure of which is hereby incorporated by reference.

The present disclosure relates to an electronic key system for a vehicle in which a vehicle-mounted device mounted on a vehicle and a portable device carried by a user communicate with each other.

2. Description of the Related Art Conventionally, on the basis of a vehicle-mounted device mounted on a vehicle and a verification by wireless communication between a portable device carried by a user and a portable device associated with the vehicle, various controls Is known.

Generally, in this type of vehicle electronic key system, the vehicle-mounted device transmits a signal to the portable device using a radio wave of a predetermined frequency belonging to the LF (Low Frequency) band. When the mobile device receives a signal transmitted from the vehicle-mounted device, the mobile device carries a response signal corresponding to the received signal using a radio wave of a predetermined frequency belonging to the UHF (Ultra High Frequency) band.

For example, the vehicle-mounted device transmits a signal (called a polling signal) requesting a response to the portable device at a predetermined polling cycle when a vehicle (called a child vehicle) on which the vehicle-mounted device is parked is transmitted, It is determined whether or not the portable device exists in the wireless communication area of the vehicle-mounted device according to whether or not there is a response from the mobile communication device. Then, when the vehicle-mounted device receives the response to the polling signal, the vehicle-mounted device initiates the process relating to the mobile device and the verification by wireless communication.

However, in the portable device, the polling signal transmitted by a vehicle other than the own vehicle (referred to as another vehicle) may become noise that hinders communication with the subject vehicle. Here, the noise refers to a radio wave (so-called jamming wave) having a signal intensity that can not normally receive a signal from the vehicle, among the radio waves transmitted from an electronic device (other vehicle) other than the vehicle .

To such a problem, Patent Document 1 discloses a technique of avoiding mutual interference when the wireless communication area of the vehicle is overlapped with the wireless communication area of the other vehicle by making the polling period different for each vehicle.

JP 5218572 B2

However, the noise in the portable device is not only the signal transmitted from the other vehicle. For example, there is a fear that radio waves emitted from an actuator mounted on a vehicle, another vehicle, or another device may become noise. Even if the configuration of Patent Document 1 is applied, there is a possibility that the timing at which the other vehicle polls and the timing at which the vehicle is polled accidentally overlap.

When noise is present, as described above, the signal from the vehicle can not be normally received, which may deteriorate the convenience of the user.

It is an object of the present disclosure to provide a vehicle electronic key system capable of reducing the possibility that a mobile device can not receive a signal from a vehicle-mounted device due to noise.

An electronic key system for a vehicle according to an example of the present disclosure includes a vehicle-mounted device mounted on a vehicle and a portable device associated with the vehicle-mounted device and carried by a user of the vehicle. The vehicle-mounted device corresponds to a predetermined plurality of types of communication methods using radio waves in the first frequency band, and includes a vehicle-mounted-apparatus-side transmitting unit that transmits a signal corresponding to a predetermined communication method among the plurality of types of communication methods to the portable device, A communication method changing unit that changes a communication method used by a vehicle-mounted-apparatus-side transmitting unit to transmit a signal to a portable device among a plurality of types of communication methods supported by the on-board device transmitting unit; And a vehicle-mounted-apparatus-side receiver for receiving signals in a second frequency band. The portable device includes a communication mode selection unit for selecting a communication mode to be employed by the vehicle-mounted device from among a plurality of types of communication modes supported by the vehicle-mounted device-side transmission unit, a first frequency-side antenna for receiving a signal in the first frequency band, A reception processing section for receiving the signal received by the antenna for the first frequency band according to the communication method selected by the communication mode selection section; a portable-device-side transmission section for transmitting a signal for the vehicle- A noise determination unit for determining the presence or absence of noise at a first use frequency, which is a frequency used for signal transmission from at least the vehicle-mounted device to the mobile device, among the frequencies belonging to the first frequency band, based on the result of the reception process by the reception processing unit Respectively. When it is determined by the noise judging section that there is noise, the communication mode selection section selects a communication mode different from the communication mode currently employed as a communication mode to be adopted by the vehicle-mounted device side transmitting section, The communication mode selection unit transmits a mode change instruction signal instructing the on-board device to employ a newly selected communication mode. The communication method changing section changes the communication method used by the vehicle-mounted-device-side transmitting section for signal transmission to the portable device to the communication method designated by the method change instruction signal when the vehicle-mounted device-side receiving section receives the mode change instruction signal.

In the above-described configuration, when it is determined by the noise determination section that there is noise, the portable device is configured to transmit, to the vehicle-mounted device, a communication method used for signal transmission to the portable device by a predetermined communication method different from a communication method currently employed And transmits a method change instruction signal instructing to change. When the vehicle-mounted device receives the method change instruction signal, the vehicle-mounted device changes the communication method used to transmit the signal to the mobile device to the communication method indicated in the received method change instruction signal. That is, the vehicle-mounted device dynamically changes the communication method used for signal transmission to the portable device according to the presence or absence of noise, and transmits a signal to the portable device.

This can occur when a signal transmitted by the vehicle-mounted device according to a certain communication method is not normally received by the mobile device due to noise. However, in all the communication methods of a plurality of types that can employ the vehicle-mounted-device-side transmitting unit, the possibility that the mobile device can not normally receive a signal transmitted from the vehicle-mounted device due to noise is small.

According to the above vehicle electronic key system, since the communication system used for signal transmission to the portable device is dynamically changed according to the presence or absence of noise to transmit a signal to the portable device, the signal transmitted from the vehicle- Can be expected to be normally received in the portable device. Therefore, according to the above configuration, it is possible to reduce the possibility that the mobile device can not receive the signal from the vehicle-mounted device due to the noise.

These and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description when read in conjunction with the accompanying drawings. In the accompanying drawings,
1 is a block diagram showing an example of a schematic configuration of an electronic key system for a vehicle,
2 is a block diagram showing an example of a schematic configuration of the vehicle-side control unit,
3 is a block diagram showing an example of the schematic configuration of the portable device side control unit,
4 is a flowchart for explaining the portable-device-side processing,
5 is a block diagram showing a schematic configuration of a vehicle-side control section and a portable-device-side control section according to the second embodiment,
Fig. 6 is a block diagram showing a schematic configuration of a vehicle-side control section and a portable-device-side control section according to the third embodiment,
7 is a diagram showing an example of the configuration of a method change instruction signal,
8 is a diagram showing an example of the configuration of a method change instruction signal.

(First Embodiment)

Hereinafter, a first embodiment of the present disclosure will be described with reference to the drawings. 1 is a diagram showing an example of a schematic configuration of an electronic key system 1 for a vehicle according to the present embodiment. As shown in Fig. 1, an electronic key system 1 for a vehicle includes a vehicle mounting system 100 mounted on a vehicle and a portable device 200 carried by the user. The portable device 200 is associated with the in-vehicle system 100 and has a function as a unique key for the vehicle. For convenience sake, hereinafter, a vehicle on which the vehicle-mounted system 100 mounted on the portable device 200 is mounted is referred to as a vehicle.

The in-vehicle system 100 and the portable device 200 each have a function for realizing a well-known smart entry system by performing wireless communication using radio waves in a predetermined frequency band.

Specifically, the vehicle-mounted system 100 transmits a signal in a predetermined first frequency band toward a predetermined range (called a wireless communication area) in the vehicle interior and the surroundings of the vehicle, Of the first frequency band. The portable device 200 also has a function of receiving a signal in the first frequency band transmitted from the in-vehicle system 100 and conveying a signal in a predetermined second frequency band to the in-vehicle system 100.

Here, as an example, the first frequency band refers to a frequency from 20 kHz to 200 kHz, and the second frequency band refers to a frequency from 300 MHz to 400 MHz. Of course, the range indicated by the first frequency band and the second frequency band may be appropriately designed.

In this embodiment, as an example, a frequency of 22 kHz is used in the first frequency band for transmitting signals from the vehicle-mounted system 100 to the mobile device 200. [ This makes it possible to increase the intensity of the radio wave to be output, as compared with the case of using a radio wave having a frequency higher than 30 kHz for transmission of signals from the vehicle-mounted system 100 to the mobile device 200. This effect is derived from the Radio Law in Japan, and is not limited to other countries.

When the portable device 200 is present in the wireless communication area, the in-vehicle system 100 carries out a verification process by wireless communication with the portable device 200, and based on the verification, And executes various controls for executing engine starting, engine starting, and the like. Thus, the user carrying the portable device 200 can realize the correcting / unlocking of the door and the start / stop of the engine without operating the portable device 200 as a key. The wireless communication area formed by the in-vehicle system 100 may be suitably designed. For example, the wireless communication area other than the vehicle room is within a range of several meters from the vehicle.

The portable device 200 also has a switch operated by the user. By transmitting a signal corresponding to the switch operated by the user to the vehicle-mounted system 100, control such as correcting / unlocking of the vehicle door is executed Called remote keyless entry function. Thus, the portable device 200 functions as a key of the vehicle. Hereinafter, the respective parts constituting the electronic key system 1 for vehicles will be described in more detail.

[Configuration of Vehicle Mounting System 100]

1, the vehicle mounting system 100 includes a control ECU 110, a vehicle-side receiving antenna 120, a vehicle-side transmitting antenna 130, a touch sensor 140, a start button 150, And an ECU (160). The verification ECU 110 is an ECU (Electronic Control Unit) that executes various processes for realizing the above-described smart entry system. Each of the control ECU 110, the vehicle-side receiving antenna 120, the vehicle-side transmitting antenna 130, the touch sensor 140, the start button 150, and the body ECU 160 is connected to a LAN Area Network). The control ECU 110 further includes a vehicle-side control unit 111, a receiving unit 112, and a transmission control unit 113, which are more detailed components. And the control ECU 110 corresponds to the vehicle-mounted device of the present disclosure.

The vehicle-side receiving antenna 120 receives the radio wave of the second frequency band, converts it into an electric signal, and outputs it to the receiving unit 112. At least one of the vehicle-side receiving antennas 120 may be provided at a position which is properly designed in the vehicle.

The vehicle-side transmission antenna 130 converts the signal input from the transmission control unit 113 into a radio wave of the first frequency band and radiates it into the space. The vehicle-side transmission antenna 130 is installed at a plurality of locations in the vehicle. For example, the vehicle-side transmitting antenna 130 is installed near the door handle installed on each door of the vehicle, near the door handle of the trunk door, and at any position in the vehicle. An area (referred to as a reach area) where radio waves transmitted from each of the vehicle-side transmission antennas 130 arrive is determined to form a desired radio communication area.

The touch sensor 140 is mounted on each door handle of the vehicle and detects that the user is touching the door handle. The detection results of the respective touch sensors 140 are sequentially output to the control ECU 110 (specifically, the vehicle-side control unit 111).

The start button 150 is a push switch for the user to start the engine. When the push button 150 is pressed by the user, the start button 150 outputs a control signal indicating the fact to the vehicle-side control unit 111.

The body ECU 160 is an ECU that controls various actuators (not shown) mounted on the vehicle. For example, based on an instruction from the comparison ECU 110, the body ECU 160 outputs a drive signal for controlling the time constant of the door installed in the vehicle to the door lock motor installed in each vehicle door, We do the time fixing. The receiving unit 112 demodulates the signal input from the vehicle-side receiving antenna 120 and provides the demodulated signal to the vehicle-side control unit 111. This receiving unit 112 corresponds to a vehicle-mounted-apparatus-side receiving unit of the present disclosure.

The transmission control section 113 generates a signal (referred to as a transmission signal) obtained by modulating the baseband signal input from the vehicle-side control section 111 into a carrier signal. Then, the generated transmission signal is output to the vehicle-side transmission antenna 130 and is radiated as a radio wave.

The transmission control section 113 corresponds to a plurality of types of modulation schemes and modulates the baseband signals according to the modulation scheme indicated by the vehicle-side control section 111 among the plurality of types of modulation schemes, and generates transmission signals . This transmission control section 113 corresponds to the vehicle-mounted-apparatus-side transmission section of the present disclosure. As an example, the transmission control section 113 corresponds to three modulation schemes of PSK (Phase Shift Keying), ASK (Amplitude Shift Keying), and FSK (Frequency Shift Keying).

More specifically, it is assumed that BPSK (Binary-PSK) is employed as the PSK and CPFSK (Continuous Pahse FSK) is employed as the FSK. Of course, other phase shift keying schemes such as Quadrature Phase Shift Keying (QPSK) may be employed as the PSK. The transmission control section 113 corresponds to a plurality of kinds of PSKs such as BPSK and QPSK as other forms, and uses a modulation scheme adopted among a plurality of types of PSKs in accordance with an instruction from the vehicle-side control section 111 . Also, the transmission control section 113 may correspond to another modulation method, for example, 16QAM (Quadrature Amplitude Modulation).

It is to be noted that the configuration corresponding to the plurality of types of modulation schemes herein means that any of the plurality of types of modulation schemes can be implemented. The function of performing the modulation processing and the function of switching the modulation method to be employed may be implemented in hardware or in software. Here, it is assumed that it is implemented in software as an example.

The vehicle-side control unit 111 is mainly composed of a microcomputer including a CPU, a ROM, a flash memory, a RAM, and an I / O, and executes various programs by executing a control program stored in the ROM. For example, the vehicle-side control unit 111 executes processing on the vehicle-mounted system 100 side for realizing the smart entry system.

This vehicle-side control section 111 is a functional block implemented by executing the above-described program, and includes a communication processing section F1, a vehicle information obtaining section F2, a verification processing section F3, and a modulation mode changing section F4A as shown in Fig. 2 . In addition, some or all of the functions of the vehicle-side control unit 111 may be implemented by hardware using one or more ICs.

The communication processing unit F1 acquires data received by the receiving unit 112 via the vehicle-side receiving antenna 120. [ The communication processing unit F1 generates (or acquires) a baseband signal to be transmitted from the vehicle-side transmission antenna 130, and outputs it to the transmission control unit 113. [

The vehicle information obtaining section F2 obtains various information (vehicle information) indicating the state of the vehicle from sensors or ECUs mounted on the vehicle such as the touch sensor 140, the start button 150, and the body ECU 160 . The vehicle information includes, for example, whether or not the user touches the door handle, whether the start button 150 is depressed, whether the door is open or closed, and whether the door is in the open / closed state.

Whether or not the user is in contact with the door handle can be obtained from the touch sensor 140. Whether or not the start button 150 is depressed can be determined from the signal output from the start button 150. [ In addition, the opening and closing state of the door, the corrective / unbalanced state of each door, and the like are obtained from the body ECU 160. [ The vehicle information also includes a shift position detected by a shift position sensor (not shown), a detection result of a brake sensor that detects whether or not the brake pedal is depressed, and the like.

The verification processing unit F3 implements a well-known smart entry function by performing a series of processes (referred to as verification-related processing) for performing verification by wireless communication with the portable device 200. [ Since the procedure of the verification related processing is known, a detailed description thereof will be omitted here.

The outline is as follows. When the vehicle is parked, the verification processing section F3 cooperates with the communication processing section F1 to transmit the polling signal from the vehicle-side transmitting antenna 130 at a predetermined polling period (for example, 200 milliseconds). This polling signal is a signal for requesting a response to the portable device 200 and for determining whether or not the portable device 200 exists in the wireless communication area by the verification processing part F3.

Then, the verification processing section F3 starts verification processing when the portable device 200 is present in the wireless communication area and a predetermined condition for performing the verification processing is satisfied. For example, when the control unit F3 detects that the portable device 200 enters the wireless communication area of the vehicle-mounted system 100 while the vehicle is parked, or when the start button 150 is pushed A verification process is performed.

Whether or not the mobile device 200 has entered the wireless communication area can be determined based on the presence or absence of a response from the mobile device 200 to the polling signal transmitted periodically. That is, when the response signal from the portable device 200 is received while the state in which the response signal from the portable device 200 to the wake signal is not received continues, the portable device 200 It is determined that the wireless communication area has entered the wireless communication area.

In the verification processing, a verification request signal requesting the portable device 200 to transmit an ID code generated from an ID (portable device ID) unique to the portable device 200 is transmitted in cooperation with the communication processor F1. Thereafter, when the communication processing unit F1 acquires the response signal transmitted from the mobile device 200 as a response corresponding to the verification request signal, the ID code contained in the response signal is analyzed, It is determined whether the portable device 200 is a regular portable device 200 or not.

Then, when the verification of the portable device 200 is successful, various processes (preparatory processing of the door and preparation of the engine start) according to the situation of the vehicle at that time are performed.

The modulation scheme changing section F4A outputs a control signal (referred to as a modulation scheme control signal) designating a modulation scheme to the transmission control section 113. [ Thus, the vehicle-side control unit 111 can transmit, from the vehicle-side transmission antenna 130, a signal modulated by an arbitrary modulation method among a plurality of types of modulation systems supported by the transmission control unit 113. [ This modulation method changing section F4A corresponds to an example of the communication mode changing section of the present disclosure.

The modulation scheme changing unit F4A outputs the modulation scheme control signal when the receiving unit 112 receives a scheme change instruction signal to be described later transmitted from the mobile device 200. [ The modulation scheme changing unit F4A outputs a modulation scheme control signal for instructing switching to the modulation scheme indicated by the received scheme change instruction signal do.

Here, as an example, the modulation method changing section F4A, after once outputting the modulation method control signal, does not need to change the modulation method, that is, when the new method change instruction signal is not received, A control signal is not output. In this case, the transmission control section 113 continuously adopts the modulation scheme based on the modulation scheme control signal last input. Of course, as another form, the modulation mode designation command signal may be output in a sequential manner.

Immediately after the start of the comparison ECU 110, the modulation scheme changing unit F4A outputs a modulation scheme control signal for instructing modulation to a predetermined modulation scheme (referred to as a default modulation scheme) to the transmission control unit 113 do. The default modulation scheme may be suitably designed and is referred to herein as PSK (more specifically, BPSK).

[Configuration of Portable Device 200]

Next, the configuration of the portable device 200 will be described. 1, the portable device 200 includes a portable device-side control unit 210, a portable device-side receiving antenna 220, and a portable device-side transmission antenna 230. The portable device- The portable unit side control unit 210 is connected to the portable unit side reception antenna 220 and the portable unit side transmission antenna 230 in a communicable manner.

The portable-unit-side receiving antenna 220 receives radio waves in the first frequency band, converts the received electric waves into electric signals, and outputs the electric signals to the portable-unit-side control unit 210. The portable-unit-side transmitting antenna 230 converts a signal input from the portable-unit-side control unit 210 into a radio wave of a second frequency band and radiates it into a space. This portable-unit-side receiving antenna 220 corresponds to the antenna for the first frequency in the present disclosure.

The portable unit side control unit 210 is mainly composed of a microcomputer including a CPU, a ROM, a flash memory, a RAM, and an I / O, and executes various processes by executing a control program stored in the ROM. For example, the portable device side control unit 210 executes the process of the portable device for realizing the smart entry system. In addition to the above program, the ROM stores a portable ID that is an ID unique to the portable device 200. [

The vehicle-side control unit 111 is a functional block realized by executing the above-described program, and includes a reception processing unit G1, a modulation method selection unit G2A, and a transmission processing unit G3 as shown in Fig. In addition, some or all of the functions of the portable device side control unit 210 may be implemented by hardware using one or more ICs.

The reception processing section G1 converts the reception signal received by the portable-unit-side reception antenna 220 into a digital signal, performs demodulation processing (including decoding), and acquires data transmitted by the vehicle- The reception processing section G1 is configured to be able to perform demodulation processing corresponding to each of a plurality of kinds of modulation methods that the transmission control section 113 can employ. Specifically, the reception processing section G1 in the present embodiment has a configuration capable of demodulating processing corresponding to each of the three modulation methods PSK, ASK, and FSK. The reception processing section G1 performs demodulation processing corresponding to the modulation method selected by the modulation method selection section G2A, which will be described later, in the demodulation processing corresponding to each of the plurality of types of modulation methods. In the initial state, the reception processing section G1 performs demodulation processing corresponding to the default modulation method.

The reception processing section G1 includes a noise determination section G11 for determining whether or not noise of a frequency (referred to as a first use frequency) used for transmission of a signal from the vehicle-mounted system 100 to the mobile device 200 exists Respectively. Note that the noise here refers to a signal transmitted from the vehicle-mounted system 100 to the portable device 200 (hereinafter, referred to as &quot; (Demodulation) can not normally be received (demodulated). That is, a state in which noise exists indicates a state in which the portable device 200 is under the radio wave disturbance at the first use frequency.

The case where the portable device 200 is subjected to radio wave interference is, for example, a case where the timing at which the other vehicle transmits the polling signal and the timing at which the vehicle transmits the polling signal are accidentally overlapped. Particularly, in the case of using a radio wave of a frequency of 30 kHz or less for transmitting a signal from the in-vehicle system 100 to the portable device 200 as in the present embodiment, the frequency conventionally used (for example, The output can be made larger than that in the case of using radio waves of 140 kHz. As a result, the wireless communication area can be largely formed.

When the wireless communication area is formed to be larger, the range in which the service can be provided to the user is expanded or the kinds of services to be provided to the user can be diversified. As a result, the convenience of the user can be improved. On the other hand, however, the polling signal of the other vehicle is likely to become noise. In other words, a mode of using radio waves of a frequency of 30 kHz or less is popularized for the transmission of signals from the vehicle-mounted system 100 to the mobile device 200, and also for other vehicles as well as the vehicle itself. When a radio wave of 30 kHz or less is used for the transmission of the signal, the polling signal of the other vehicle becomes noise, and the portable device 200 is easily disturbed by radio waves.

A method for judging whether or not noise is present may be a known method. For example, when a CRC (Cyclic Redundancy Check) method, a parity check, or the like is performed on data obtained by digitizing a reception signal received by the portable-unit-side reception antenna 220 and an error is detected in the reception data It is determined that noise exists.

It is also possible to analyze data obtained by digitizing a received signal whose received signal strength is equal to or greater than a predetermined threshold value and judge that there is noise when a command or a code composed of a predetermined bit string can not be detected. That is, when the data obtained by digitizing the received signal does not conform to the format used in the communication between the in-vehicle system 100 and the mobile device 200, it is determined that noise exists.

Further, it may be determined that there is noise when a signal in which the received signal strength is equal to or greater than a predetermined threshold value is continuously received for a predetermined time or more. When it is determined that noise is present, the noise determination unit G11 notifies the modulation method selection unit G2A of the fact.

In addition, when receiving normal data transmitted from the vehicle-mounted system 100, the reception processing section G1 provides the data to the transmission processing section G3. Normal data refers to data that can not be uncorrected, such as data corruption, and can recognize a predetermined command or code.

The modulation scheme selection unit G2A is currently employed as the modulation scheme to be adopted by the transmission system (such as the transmission control unit 113) of the vehicle-mounted system 100 when it is determined that noise is present by the noise determination unit G11 And selects a predetermined modulation scheme different from the modulation scheme. Then, it transmits a method change instruction signal for instructing transmission of the modulated signal by the selected modulation method to the transmission processing section G3. Further, it instructs the reception processing section G1 to perform demodulation in a manner corresponding to the selected modulation method.

More specifically, the modulation method selection section G2A instructs the transmission control section 113 of the in-vehicle system 100 to employ a modulation scheme different from the currently adopted modulation scheme among the three modulation schemes supported by the transmission control section 113 . For example, if the currently adopted modulation scheme is PSK, then a scheme change instruction signal instructing to change to FSK is transmitted. When the currently adopted modulation scheme is FSK, a method change instruction signal instructing to change to ASK is transmitted.

The modulation scheme to be changed may be determined in accordance with a rule designed in advance. For example, the modulation method selection unit G2A may turn a predetermined number of times each time it is determined that the noise is present by the noise determination unit G11 from the default modulation method (PSK in this case). If it is determined that there is noise in a state other than the default modulation system, such as PSK? FSK? PSK? ASK? PSK, the system may be returned to the default modulation system once. This modulation method selecting section G2A corresponds to an example of the communication mode selecting section of the present disclosure.

The transmission processing section G3 generates a signal to be transmitted to the vehicle-mounted system 100, outputs it to the portable-unit-side transmission antenna 230, and transmits it as a radio wave in the second frequency band. This transmission processing section G3 corresponds to the portable unit side transmission section of the present disclosure. Signals to be transmitted to the vehicle-mounted system 100 include, in addition to the above-described mode change instruction signal, a response signal to data received and demodulated by the reception processing section G1. For example, when the reception processing unit G1 receives the verification request signal, it generates an ID code from the portable device ID according to a predetermined rule, and transmits a signal including the ID code. That is, when receiving the signal transmitted from the vehicle-mounted system 100, the transmission processing unit G3 performs a process corresponding to the command included in the received signal, and returns the response signal.

(Portable-side processing)

Next, the process performed by the portable device 200 (referred to as a portable device side process) will be described using the flowchart shown in Fig. The flow chart shown in Fig. 4 may be started when, for example, a signal whose received signal strength is equal to or higher than a predetermined threshold value is received.

In general, the portable device 200 is an operation mode in which a normal mode capable of performing a response process to a received signal transmitted from the in-vehicle system 100 and a function capable of being executed in comparison with the normal mode are defined, And a sleep mode which is a mode for suppressing power. The flowchart shown in Fig. 4 may be started when transitioning from the sleep mode to the normal mode. The transition from the sleep mode to the normal mode is a case where a switch (not shown) provided in the mobile device 200 is operated by the user in addition to the case where the polling signal is received.

First, in step S101, the reception processing section G1 converts the reception signal received by the portable-device-side reception antenna 220 into a digital signal, performs demodulation processing, and moves to step S102. In step S102, the reception processing section G1 determines whether or not the received data is normal data transmitted from the vehicle-mounted system 100. [ As described above, normal data refers to data that can not be uncorrected (that is, a bit error) or the like and does not cause a predetermined command or code to be recognized.

The case of receiving data other than normal data refers to a case where noise is received or a signal transmitted from the vehicle-mounted system 100 where data corruption occurs partially due to the influence of noise is received. In any case, when the received data is not normal data, it means that noise exists. Therefore, this step S102 corresponds to the processing in which the noise determination section G11 determines the presence or absence of noise.

If it is determined in S102 that the received data is normal data, S102 is YES and the process proceeds to S103. On the other hand, if it is determined in S102 that the received data is not normal data, S102 returns to "NO"

In S103, the transmission processing section G3 generates and transmits a response signal corresponding to the received data. When the processing in S103 is completed, this flow ends.

In S104, the noise determining section G11 determines that noise is present and moves to S105. In step S105, the modulation method selection unit G2A selects a predetermined modulation method that is different from the currently adopted modulation method as a modulation method to be adopted by the transmission system of the vehicle-mounted system 100, and moves to step S106.

In step S107, the transmission processing section G3 generates and transmits a method change instruction signal for instructing the modulation method selecting section G2A to transmit the signal by the modulation method selected by the modulation method selecting section G2A. Further, the reception processing section G1 changes the setting so that demodulation is performed in a manner corresponding to the modulation method selected by the modulation method selecting section G2A. When the processing in S107 is completed, this flow ends.

According to the above configuration, when determining that noise is present by the noise determination section G11, the portable device 200 transmits a mode change instruction signal to instruct the vehicle mounting system 100 to change the modulation mode. When the in-vehicle system 100 receives the method change instruction signal, the in-vehicle system 100 changes the communication form to transmit the signal to the mobile device 200 using the modulation method in accordance with the method change instruction signal. That is, according to the above configuration, the vehicle-mounted system 100 dynamically changes the modulation method according to the presence or absence of noise, and transmits a signal to the mobile device 200. [

Even if the timing of transmitting the polling signal of the other vehicle and the timing of transmitting the polling signal of the other vehicle overlap each other, the signal from the vehicle can be normally demodulated if the modulation scheme is different.

Therefore, according to the above configuration, it is possible to reduce the possibility that the mobile device 200 can not receive a signal from the vehicle-mounted system 100 due to noise.

Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and the following embodiments are also included in the technical scope of the present disclosure, and various modifications .

(Second Embodiment)

Next, a second embodiment of the present disclosure will be described with reference to the drawings. In the following description, members having the same functions as those of the members of the first embodiment described above are denoted by the same reference numerals, and a description thereof will be omitted. In addition, when only a part of the configuration is mentioned, the first embodiment described earlier can be applied to other parts.

The vehicle electronic key system 1 according to the second embodiment includes the vehicle mounting system 100 and the portable device 200 as in the first embodiment described above. The outline configuration of the in-vehicle system 100 and the portable device 200 is also the same as that of the first embodiment described above. The main difference between the first embodiment and the second embodiment is a coping method in a case where noise of the first use frequency exists. Specifically, in the first embodiment described above, the influence of noise is suppressed by changing the modulation method. However, in the present embodiment, the influence of noise is suppressed by changing the first use frequency. Hereinafter, the portion related to this difference will be described in detail.

The transmission control section 113 in the second embodiment corresponds to a plurality of predetermined types of frequencies out of the frequencies belonging to the first frequency band and selects the frequency indicated by the vehicle side control section 111 from among the plural types of frequencies And generates a transmission signal at the carrier frequency (i.e., the first used frequency). Here, as an example, it is assumed that the transmission control section 113 corresponds to three different frequencies of 22 kHz, 25 kHz, and 28 kHz. In addition, the configuration that corresponds to three different frequencies here means a configuration in which any one of three different frequencies can be adopted as the carrier frequency. That is, the transmission control section 113 is configured to dynamically change the frequency to be employed as the first use frequency out of a plurality of predetermined types of frequencies.

Of course, the number of frequencies corresponding to the transmission control section 113 and the specific frequency values are not limited to the above examples. The transmission control section 113 may correspond to two or four or more frequencies. Incidentally, as an example, all three frequencies are set to 30 kHz or less, but the present invention is not limited to this. It may correspond to a frequency of 100 kHz or more. For example, the transmission control section 113 may correspond to three frequencies of 125 kHz, 130 kHz, and 134 kHz. Further, it may correspond to three frequencies of 23 kHz, 29 kHz, 125 kHz, and 134 kHz.

The function of switching the adopted frequency as the carrier frequency (i.e., the first used frequency) and the function of generating the transmission signal of the employed frequency may be realized by hardware or by software. Here, as an example, it is assumed that hardware resources for generating transmission signals are controlled by software and used for a plurality of frequencies.

In addition, the vehicle-side control section 111 in the second embodiment includes a frequency changing section F4B as a functional block as shown in Fig. The frequency changing section F4B outputs to the transmission control section 113 a control signal (referred to as a frequency control signal) designating a frequency to be employed as the first use frequency. Thus, the vehicle-side control unit 111 can transmit, from the vehicle-side transmission antenna 130, a transmission signal in which data is placed on a carrier wave of an arbitrary frequency out of a plurality of predetermined types (here, three frequencies). This frequency changing section F4B corresponds to an example of the communication mode changing section of the present disclosure.

The case where the frequency changing section F4B outputs the frequency control signal is a case where the receiving section 112 receives the mode change instruction signal transmitted from the mobile device 200 as in the first embodiment described above. However, the mode change instruction signal in the second embodiment indicates not the modulation scheme to be adopted by the transmission control section 113 but the frequency that the transmission control section 113 should employ as the first use frequency. The frequency changing section F4B outputs a frequency control signal instructing to employ the frequency indicated by the received mode change instruction signal as the first use frequency.

Further, immediately after the start of the comparison ECU 110, the frequency changing section F4B outputs to the transmission control section 113 a frequency control signal instructing to employ a predetermined frequency (referred to as a default frequency) as the first use frequency . The default frequency has to be designed properly and is set to 22 kHz here.

The portable device side control unit 210 in the second embodiment includes a reception processing unit G1, a frequency selection unit G2B, and a transmission processing unit G3.

The reception processing section G1 converts the signal of the first use frequency received by the portable-unit-side reception antenna 220 into a digital signal and performs demodulation processing (including decoding) to convert the data transmitted by the vehicle- . The reception processing section G1 corresponds to each of a plurality of types of frequencies that can be employed by the transmission control section 113. Of the plurality of types of frequencies, the frequency selection section G2B, which will be described later, Demodulation processing is performed for the signal of As an initial state, the reception processing section G1 performs demodulation processing on the signal of the default frequency.

The reception processing section G1 includes a noise determination section G11 similar to that of the first embodiment described above. The noise determination section G11 determines whether or not noise of a frequency selected as the first use frequency exists by at least the frequency selection section G2B. The method for determining the presence or absence of noise is as described above.

The frequency selection unit G2B is a frequency selection unit G2B that selects a frequency at which the transmission system of the vehicle-mounted system 100 is to be used as the first use frequency to be employed by the vehicle-mounted system 100 Selects a predetermined frequency that is different from the currently adopted frequency among the plurality of types of frequencies that can be employed as the first use frequency. Then, it transmits a method change instruction signal to instruct the transmission processing section G3 to transmit a transmission signal having the selected frequency as the first use frequency. Further, it instructs the reception processing section G1 to demodulate the reception signal of the selected frequency component.

The frequency to be changed may be determined according to a pre-designed rule. For example, when the currently adopted frequency is 22 kHz, the frequency selecting section G2B transmits a method change instruction signal instructing to change to the first use frequency to 25 kHz. When the currently adopted frequency is 25 kHz, a method change instruction signal instructing to change to 28 kHz is transmitted. That is, the frequency selecting unit G2B may be turned by one cycle from the default frequency in a predetermined order every time it is determined by the noise determining unit G11 that noise exists.

If it is determined that there is noise in a state where a frequency other than the default frequency is selected as the first use frequency, such as 22 kHz? 25 kHz? 22 kHz? 28 kHz? 22 kHz, The frequency may be once returned to the default frequency. This frequency selection section G2B corresponds to an example of the communication mode selection section of the present disclosure.

The transmission processing unit G3 generates and transmits to the vehicle-mounted transmission antenna 230 a signal to be transmitted to the vehicle-mounted system 100, such as a method change instruction signal or a response signal, as in the first embodiment .

In the above-described configuration, when it is determined by the noise determination unit G11 that there is noise at a frequency currently employed as the first use frequency, the portable device 200 changes the method for changing the first use frequency to another frequency And sends an instruction signal to the vehicle-mounted system 100. When the vehicle-mounted system 100 receives the mode change instruction signal, the in-vehicle system 100 changes the communication mode so as to generate a transmission signal in which the frequency corresponding to the mode change instruction signal is set to the first use frequency and transmit the transmission signal to the mobile device 200 . That is, according to the above configuration, the vehicle-mounted system 100 dynamically changes the first use frequency according to the presence or absence of noise, and transmits a signal to the portable device 200. [

Even if the timing at which the other vehicle transmits the polling signal overlaps the timing at which the own vehicle transmits the polling signal, if the frequency employed as the first frequency is different, the signal from the vehicle is normally demodulated and received can do.

That is, according to the above configuration, even when the timing of transmitting the polling signal is overlapped with that of the other vehicle, there is a possibility that the polling signal from the other vehicle can not normally receive the signal from the vehicle. Can be reduced.

The noise in the portable device 200 is not only a signal transmitted from another vehicle. When the radio waves emitted from various devices coincide with the first use frequency and the signal strength thereof is equal to or higher than a predetermined level, a signal from the vehicle-mounted system 100 is received by the radio waves (i.e., noise) It may become impossible to normally receive data. For example, radio waves emitted from an actuator or an electronic control device mounted on a vehicle or another vehicle, another machine, or the like may become noise.

Further, in a situation where noise from the actuator or the electronic control unit normally occurs as such, even if the polling period is any value, the portable device 200 can not normally receive signals from the vehicle-mounted system 100 .

However, even if there is noise at a certain frequency, there is a relatively small possibility that noise exists at all frequencies of plural kinds of frequencies supported by the transmission control section 113. [

Here, according to the configuration of the present embodiment, when it is determined that there is noise by the noise determining unit G11 in a situation where a certain frequency is set to the first use frequency, the first use frequency is dynamically changed and operated. Therefore, even when a radio wave having a predetermined signal strength at a predetermined frequency is issued from various devices, it is possible to reduce the possibility that a signal from the vehicle-mounted system 100 can not be received by the radio wave .

That is, according to the above configuration, it is possible to reduce the possibility that the mobile device 200 can not receive a signal from the vehicle-mounted system 100 due to noise.

(Third Embodiment)

Next, a third embodiment of the present disclosure will be described with reference to the drawings. In the following description, members having the same functions as those of the members of the first and second embodiments described above are denoted by the same reference numerals, and a description thereof will be omitted. In addition, when only a part of the configuration is mentioned, the first and second embodiments described above can be applied to other parts.

The electronic key system 1 for a vehicle according to the third embodiment is an electronic key system for a vehicle which is a combination of the first embodiment and the second embodiment described above. That is, the vehicle-mounted system 100 reduces the influence of noise by changing the modulation scheme, changing the first use frequency, and a combination thereof when noise of the first use frequency exists. That is, the vehicle electronic key system 1 according to the third embodiment attempts to reduce the influence of noise by changing the communication system from the vehicle-mounted system 100 to the mobile device 200. [ Specifically, it is as follows.

The transmission control section 113 in the third embodiment corresponds to a plurality of types of modulation schemes and modulates the baseband signals in accordance with the modulation scheme indicated by the vehicle-side control section 111 from among the plurality of types of modulation schemes . Further, the transmission control section 113 corresponds to a plurality of predetermined types of frequencies among the frequencies belonging to the first frequency band, and of the plurality of types of frequencies, the frequency instructed from the vehicle-side control section 111 is referred to as a carrier frequency 1 used frequency).

For example, as in the first embodiment, the transmission control section 113 corresponds to three types of modulation schemes of PSK, FSK, and ASK, and corresponds to three different frequencies of 22 kHz, 25 kHz, and 28 kHz .

As shown in Fig. 6, the vehicle-side control unit 111 in the third embodiment includes a communication mode changing unit F4 including both a modulation mode changing unit F4A and a frequency changing unit F4B. The operation of the modulation method changing section F4A and the frequency changing section F4B is as described above. Therefore, the communication mode changing section F4 plays a role of changing the carrier frequency and the modulation method (that is, the communication method) of the signal to be transmitted from the transmission control section 113 on the basis of the mode change instruction signal transmitted from the mobile device 200 I am responsible.

It should be noted that the modulation scheme to be adopted by the transmission control section 113 and the frequency to be adopted by the transmission control section 113 may be indicated in the mode change instruction signal in the present embodiment. For example, as shown in Fig. 7, the changing method change instruction signal includes an ID code for recognizing the transmitting side portable device 200 on the receiving side (the control ECU 110), a frequency specifying command, It may be configured to include a designated command. The frequency assignment command is a bit string indicating the frequency to be adopted by the transmission control section 113 and the modulation mode designation command is a bit string indicating the modulation scheme to be adopted by the transmission control section 113. [

Also, the method change instruction signal does not necessarily include both the frequency assignment command and the modulation method designation command, and even if the configuration change command signal does not include a command related to an element (frequency or modulation method) do.

Returning to Fig. 6, the configuration of the portable unit side control unit 210 in the present embodiment will be described next. As shown in FIG. 6, the portable device side control unit 210 in this embodiment includes a communication mode selection unit G2 including both a modulation mode selection unit G2A and a frequency selection unit G2B. The operation of the modulation scheme selection unit G2A and the frequency selection unit G2B is as described above. Therefore, the communication mode selection unit G2 plays a role of selecting a carrier frequency and a modulation mode to be adopted by the transmission control unit 113 when it is determined that the noise is present by the noise determination unit G11.

The rule for changing the modulation method and the frequency when it is determined by the noise determination section G11 that noise exists is appropriately designed. Here, as an example, first, in the state where the modulation method is fixed by PSK, the frequency is turned by one turn in the order of 22 kHz, 25 kHz, and 28 kHz. If communication is not successful or noise is determined to be present in any setting state, the frequency is turned once again in a state where the modulation method is fixed to FSK. If the communication is not successful or noise is determined to be present in any setting state, the frequency is rotated once again in a state where the modulation method is fixed to FSK. In addition, even if it is determined that noise exists, each setting state may be maintained until a predetermined time (for example, a polling period) elapses after the setting state is entered. This is because, even if it is determined that there is noise, a signal from the vehicle-mounted system 100 may be normally received.

In addition, the procedure for changing the communication method exemplified here is merely an example, and the rule for changing the modulation method and the frequency may be appropriately designed. For example, as will be described later, when it is possible to specify a frequency having a relatively small noise level among a plurality of types of frequencies, a process of turning a plurality of types of modulation schemes around the frequency may be preferentially performed.

The transmission processing section G3 generates and transmits a method change instruction signal for instructing transmission of the signal by the frequency and modulation method determined by the communication method selection section G2.

In the above configuration, when it is determined by the noise determination unit G11 that there is noise, the portable device 200 transmits a method change instruction signal to instruct the vehicle-mounted system 100 to change the communication method. Upon receiving the method change instruction signal, the vehicle-mounted system 100 changes the form when transmitting the signal to the mobile device 200 to the communication method indicated by the received method change instruction signal. That is, according to the above configuration, the vehicle-mounted system 100 dynamically changes the communication method when transmitting a signal to the portable device 200, and transmits a signal to the portable device 200 depending on the presence or absence of noise.

Therefore, according to the above configuration, it is possible to reduce the likelihood that the mobile device 200 will not be able to receive signals from the vehicle-mounted system 100 due to noise, as in the first and second embodiments described above .

(Modified Example 1)

The condition for the portable device 200 to transmit the mode change instruction signal may be a case where noise having a certain similarity with the pattern of the signal transmitted from the vehicle mounted system 100 is received. This is to prevent the portable device 200 from unnecessarily transmitting the method change instruction signal. Specifically, it is as follows.

It is sufficient that the mobile device 200 receives noise even in a scene separated from the subject vehicle. It is not necessary to receive the signal from the vehicle-mounted system 100 and transmit the method change instruction signal. On the other hand, when noise having a certain similarity with the pattern of the signal transmitted from the vehicle-mounted system 100 is received, it is suggested that the portable device 200 may exist near the vehicle. Therefore, when the noise exists and the noise has a certain similarity with the pattern of the signal transmitted from the vehicle-mounted system 100, by transmitting the method change instruction signal, it is unnecessary to transmit the method change instruction It is possible to suppress transmission of a signal.

This modification may be realized, for example, as follows. The signal transmitted from the vehicle-mounted system 100 may have a configuration in which a burst signal of a predetermined length (for example, several milliseconds) is provided at the head thereof. In such a configuration, the portable device 200 transmits the mode change instruction signal when it is determined that the received data is not normal data, in the case where the burst signal having the specified length or longer is received. According to such a configuration, transmission of the method change instruction signal can be suppressed when pulse noise is received.

In general, predefined preambles are arranged at the head of signals transmitted from the vehicle-mounted system 100. Since the preamble portion is relatively short with respect to the entire data, the possibility that the preamble portion is broken due to the influence of noise is relatively small. Incidentally, the case where non-normal data capable of recognizing the preamble is received means that there is a possibility that the signal transmitted from the vehicle-mounted system 100 in which data corruption partially occurs due to the influence of noise is received. That is, there is a high possibility that the portable device 200 is present near the vehicle. Therefore, in a situation where it is determined that the noise is present by the noise determination section G11, the mode change instruction signal may be transmitted when the non-normal data capable of recognizing the preamble is received.

(Modified example 2)

In the second and third embodiments, when the number of frequencies supported by the transmission control section 113 is three or more, the reception processing section G1 selects, from among a plurality of types of frequencies supported by the transmission control section 113, The strength of the noise at a frequency (referred to as unused frequency) not adopted as the first use frequency may be evaluated.

For example, the reception processing section G1 of the portable device 200 acquires the reception signal strength of the frequency component corresponding to the unused frequency from the reception signal received by the portable device-side reception antenna 220, And supplies the intensity to the frequency selecting section G2B as noise information indicating the intensity of the noise at the unused frequency. The frequency component of the unused frequency may be extracted from a received signal by a well-known filter circuit or the like.

When it is determined by the noise determination section G11 that there is noise at the first use frequency, the frequency selection section G2B employs a frequency having the smallest noise level among the plurality of unused frequencies as the frequency of the change destination.

According to this configuration, it is possible to select a frequency that is less influenced by noise as a frequency to be changed when noise is determined to exist by the noise determination unit G11. Therefore, according to the configuration of the second modified example, it is possible to further reduce the possibility that signals from the vehicle-mounted system 100 can not be received due to noise.

(Modification 3)

The method change instruction signal may include not only a command designating a communication method such as a frequency designation command or a modulation method designation command but also a command for instructing execution of predetermined control processing to the vehicle-mounted system 100. 8, the system change instruction signal may include a control command, which is a command for instructing execution of predetermined control processing, to the vehicle-mounted system 100. [ An object to be controlled by the control command is an electrical component connected to be able to communicate with the verification ECU 110 in a communicable manner.

The control processing to be performed on the vehicle-mounted system 100 by the control command is lighting of the welcome light, angle adjustment of the side mirror, and the like. For example, when the vehicle-mounted system 100 receives the method change instruction signal including the control command instructing to turn on the welcome illumination, the control ECU 110 controls the body ECU 160, And cooperates with an ECU or the like to light a predetermined lighting device. Further, the power supply ECU is an ECU that controls power supply to various electric components in the vehicle.

When the vehicle-mounted system 100 receives the mode change instruction signal including a control command instructing the user to change the angle of the side mirror to a predetermined angle, the control ECU 110 controls the body ECU 160 And changes the angle of the side mirror to a predetermined angle by driving and controlling the motor for changing the angle of the side mirror.

If the comparison with the portable device 200 is not established even after a predetermined time (for example, one minute) has elapsed since the completion of the processing according to the control command included in the method change instruction signal You can restore the state. That is, the lighting apparatus that was turned on as the welcome illumination is turned off, or the angle of the side mirror is returned to the angle of the parking state.

The content of the control executed by the vehicle-mounted system 100 by the method change instruction signal is not limited to the above-described example. However, it is preferable that the content of the control is such that there is no security problem such as ON / OFF of illumination lighting.

The process (referred to as a welcome process) that is performed due to the approach of the user to the vehicle has been performed since the match between the conventional portable device 200 and the vehicle-mounted system 100 has been established. According to the configuration of the modified example 3, the welcome process can be performed in a state before the matching between the portable device 200 and the in-vehicle system 100 is established.

In addition, the process of the flowcharts or flowcharts described in the present application is made up of a plurality of steps (also referred to as sections), and each step is represented by, for example, S101. In addition, each step can be divided into a plurality of sub-steps, while a plurality of steps can be combined into one step.

Although the embodiment and the configuration of the vehicle electronic key system according to the present disclosure have been described above, the embodiments and configurations of the present disclosure are not limited to the above-described embodiments and configurations. The embodiments and configurations obtained by suitably combining the technical elements disclosed in the different embodiments and configurations are also included in the scope of the embodiments and configurations of the present disclosure.

Claims (6)

A vehicle electronic key system comprising a vehicle-mounted device (110) mounted on a vehicle, and a portable device (200) associated with the vehicle-mounted device and carried by a user of the vehicle,
The vehicle-
A vehicle-mounted-apparatus-side transmitting unit (113) that corresponds to a predetermined plurality of types of communication systems using radio waves in a first frequency band and transmits a signal corresponding to a predetermined communication system among the plurality of types of communication systems to the portable device,
A communication mode changing section (F4, F4A, F4B) for changing a communication mode used by the vehicle-mounted-device-side transmitting section to transmit a signal to the portable device out of a plurality of types of communication modes supported by the vehicle-
And a vehicle-mounted-apparatus-side receiving unit (112) for receiving a signal in a second frequency band used for signal transmission from the portable device to the vehicle-mounted device,
The portable device includes:
(G2, G2A, G2B) for selecting a communication method to be employed by the vehicle-mounted device out of a plurality of types of communication methods supported by the vehicle-mounted-
A first frequency antenna 220 for receiving the first frequency band signal,
A reception processing section (G1) for receiving and processing the signal received by the antenna for the first frequency according to the communication system selected by the communication mode selection section,
A portable-unit-side transmitter (G3) for transmitting a signal for the vehicle-mounted device as a radio wave in the second frequency band,
Based on a result of the reception processing by the reception processing section, determining whether or not there is noise at a first use frequency which is a frequency used for signal transmission from at least the vehicle-mounted device to the portable device among frequencies belonging to the first frequency band And a noise determination section G11,
When the noise determining section determines that the noise is present, the communication mode selection section selects a communication mode that is different from the communication mode currently employed as a communication mode to be adopted by the vehicle-mounted device side transmission section, The transmission transmitter transmits a mode change instruction signal instructing the vehicle-mounted device to employ the newly selected communication mode by the communication mode selector,
Wherein the communication mode changing section changes the communication mode used by the vehicle-mounted-device-side transmitting section to transmit signals to the portable device when the vehicle-mounted device-side receiving section receives the mode change instruction signal, In which the electronic key system is changed. The method according to claim 1,
Wherein the first frequency band includes a frequency of 30 kHz or less,
Wherein the first use frequency includes a frequency of 30 kHz or less. 3. The method according to claim 1 or 2,
The vehicle-mounted-apparatus-side transmitting section corresponds to a plurality of predetermined types of modulation schemes,
Wherein the communication mode changing section has a function of changing a modulation mode used for signal transmission to the portable device from a plurality of types of modulation modes supported by the vehicle-
Wherein the communication mode selection unit selects a modulation mode to be adopted by the vehicle-mounted device from a plurality of types of modulation modes that can be employed by the vehicle-mounted device-side transmission unit, based on the determination that the noise is present by the noise determination unit,
Wherein the portable-unit-side transmitting unit transmits, as the mode change instruction signal, a signal to the vehicle-mounted device instructing the communication mode selection unit to transmit a signal using the selected modulation scheme,
Wherein the communication mode change section changes the modulation mode used by the vehicle-mounted-device-side transmitting section to transmit the signal to the portable device when the vehicle-mounted device-side receiving section receives the mode change instruction signal, To the modulation scheme indicated by the modulation scheme. 4. The method according to any one of claims 1 to 3,
Wherein the vehicle-mounted-apparatus-side transmitting section is capable of dynamically changing a frequency adopted as the first use frequency out of a plurality of predetermined types of frequencies,
Wherein the communication mode changing unit has a function of changing a frequency used for signal transmission to the portable unit among a plurality of types of frequencies supported by the vehicle-
Wherein the communication mode selection section selects a frequency to be adopted by the vehicle-mounted-apparatus-side transmission section among a plurality of types of frequencies that can be employed by the vehicle-mounted device-side transmission section, based on the determination that the noise is present by the noise determination section,
The portable unit transmitter transmits to the vehicle-mounted device a signal instructing to transmit a signal using the frequency selected by the communication mode selection unit as the mode change instruction signal,
Wherein the communication mode changing section is configured to change the communication mode of the automobile electronic key system, which adopts the frequency indicated by the received mode change instruction signal as the first use frequency when the vehicle- . 5. The method of claim 4,
The vehicle-mounted-apparatus-side transmitting section corresponds to three or more predetermined frequencies,
Wherein the reception processing section sets the reception signal strength for each unused frequency which is a frequency not adopted as the first use frequency out of a plurality of types of frequencies supported by the vehicle-mounted-apparatus-side transmitting section as the intensity of the noise at the unused frequency As a noise level indicating &lt; RTI ID = 0.0 &gt;
Wherein the communication mode selection section selects, as a frequency to be adopted by the vehicle-mounted-apparatus-side transmission section, a frequency having the smallest noise level among a plurality of the unused frequencies when the noise determination section determines that the noise exists, Automotive electronic key system. 6. The method according to any one of claims 1 to 5,
Wherein the mode change instruction signal includes a control command for executing a predetermined operation on an electric component connected to be communicable with the vehicle-mounted device.

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