Control system of a device in the vehicle

Abstract

In a vehicle control system, a vehicle-mounted unit (100) installed in a vehicle controls a device in the vehicle based on the result of a check performed by a portable device (200). This check is carried out through two-way communication, in which the portable device (200) returns a response signal in reply to a request signal sent by the vehicle-mounted unit (100). An ECU (110) of the vehicle-mounted unit (100) checks whether it is a scheduled check time (t) and, if so, performs an external check (S10 to S11). In this case, the ECU (110) establishes a communication frequency that has a higher priority than a communication frequency to be set for the portable device (2).

Description

TECHNICAL FIELD

[0001] The present invention relates to a control system of a device in a vehicle. BACKGROUND TECHNOLOGY

[0002] As an exemplary conventional in-vehicle device control system, an in-vehicle electronic key system (verification system) is disclosed in the following Patent Document 1. In this in-vehicle electronic key system, a control device mounted in a vehicle performs verification of a portable device worn by a user of the control device through two-way radio communication, and controls the in-vehicle device based on the verification result. This in-vehicle electronic key system includes a smart security control device mounted in a vehicle and a portable device worn by a user of the control device. The smart security control device transmits a setting request signal that sets a response frequency to the portable device.If no radio signal is received within a predetermined allowable time after transmission of the setting request signal, the intelligent safety control device transmits a setting request signal by changing the response frequency to another frequency. The portable device selects the response frequency specified by the setting request signal and transmits a reception response signal of the selected response frequency to the intelligent safety control device. This prevents the response signal from being received due to interference with the response signal. By making radio communication less susceptible to the influence of factors such as interference that interfere with radio communication, a control object can operate normally.

[0003] However, in the case of transmitting the request signal requesting the transmission of the response signal from the vehicle to the portable device at a fixed time interval, the request signal must be transmitted a plurality of times within the fixed time interval to establish a plurality of response frequencies. In order to make radio communication less susceptible to the influence of factors such as interference that interfere with radio communication, the number and frequency of communication operations may increase, resulting in increased power consumption. The vehicle is often at rest when the request signal is periodically transmitted from the vehicle to the portable device. As power consumption increases in this situation, more and more battery power is consumed. PRIOR ART DOCUMENTS PATENT DOCUMENTS Patent document 1: JP 2008- 190 173 A Patent document 2: DE 10 2008 007 223 A1 Patent document 3: JP 2006- 188 139 A Patent document 4: US 2008 / 0 186 131 A1 SUMMARY OF THE INVENTION

[0004] The present invention addresses the foregoing problems, and an object thereof is to provide a control system of an in-vehicle device capable of suppressing power consumption while making radio communication less susceptible to influence of factors such as interference.

[0005] A control system of an in-vehicle device according to a first aspect of the present invention includes a portable device and an on-vehicle unit. The on-vehicle unit is mounted in a vehicle to perform a check operation of the portable device based on two-way communication in which the portable device returns a response signal in response to a request signal sent from the on-vehicle unit, to control an in-vehicle device based on a check result of the check operation, and to switch a communication frequency for the two-way communication when the check result indicates unsuccessful check, thereby performing the check operation again. The portable device receives a request signal sent from the on-vehicle unit in the two-way communication with the in-vehicle device.The portable device includes a portable device communication section for returning the response signal including an ID code at a communication frequency set by the vehicle-mounted unit. The vehicle-mounted unit includes a frequency setting section for setting the communication frequency to be set for the portable device among a plurality of communication frequencies having respective rankings set in accordance with a possibility of successful verification.The vehicle-side unit includes a vehicle-side communication section for performing two-way communication with the portable device by transmitting the request signal containing the frequency information indicating the communication frequency set by the frequency setting section to the portable device and receiving the response signal from the portable device. The vehicle-side unit includes a verification section for performing the verification operation based on the ID code included in the response signal received from the portable device by the vehicle-side communication section.The frequency setting section sets a communication frequency having a higher priority than the communication frequency to be set for the portable device at each check time when performing the check operation at a regular interval.

[0006] Since a communication frequency with a higher priority is thus set as the communication frequency to be specified for the portable device at each verification time, it is only necessary to transmit the request signal containing the frequency information indicating such a communication frequency once. Since a communication frequency of the higher priority is specified for the portable device, communication is made less susceptible to the influence of factors such as radio interference. Since a request signal containing the frequency information indicating the specified frequency is transmitted at each verification time, the number of communication operations is reduced.

[0007] A control system of an in-vehicle device according to a second aspect of the invention includes a portable device and an on-vehicle unit. The on-vehicle unit is mounted in a vehicle to perform a check operation of the portable device based on two-way communication in which the portable device returns a response signal in response to a request signal sent from the on-vehicle unit, to control an in-vehicle device based on a check result of the check operation, and to switch a communication frequency for the two-way communication when the check result indicates unsuccessful check, thereby performing the check operation again. The portable device receives the request signal sent from the on-vehicle unit in the two-way communication with the on-vehicle unit.The portable device includes a portable device communication section for returning the response signal including an ID code at a communication frequency set by the vehicle-mounted unit. The vehicle-mounted unit includes a frequency setting section for setting the communication frequency to be set for the portable device among a plurality of communication frequencies having respective rankings set in accordance with a possibility of successful verification.The vehicle-side unit includes a vehicle-side communication section for performing two-way communication with the portable device by transmitting the request signal containing the frequency information indicating the communication frequency set by the frequency setting section to the portable device and receiving the response signal from the portable device. The vehicle-side unit includes a verification section for performing the verification operation based on the ID code included in the response signal received from the portable device by the vehicle-side communication section.The frequency setting section sets a communication frequency that has a higher priority than the communication frequency to be set for the portable device at each check time when performing the check operation at a regular interval until the check operation by the check section becomes unsuccessful. The frequency setting section sets a plurality of communication frequencies by switching the communication frequency to be set for the portable device when the check operation by the check section becomes unsuccessful despite reception of a radio wave from the portable device by the vehicle-side communication section.

[0008] A communication frequency having a higher priority is set as the communication frequency to be set for the portable device at each check time as long as a radio wave is received by the portable device and the check operation is successful. It is only necessary to transmit the request signal including the frequency information indicating the communication frequency once. On the other hand, a plurality of communication frequencies are set by switching the communication frequency to be set for the portable device at each check time when the check operation is unsuccessful despite reception of a radio wave from the portable device. The request signal including the frequency information indicating the specified communication frequency is thus transmitted a plurality of times at each check time.

[0009] Since a communication frequency of a higher priority is thus set as long as the verification operation fails while the radio wave is being received by the portable device, the communication is made less susceptible to the influence of factors such as interference radio waves. Since a request signal including the frequency information indicating the set communication frequency is transmitted to the portable device at each verification time, the number of communication operations is reduced. On the other hand, since the plurality of communication frequencies are set when the verification fails while the radio wave is being received by the portable device, the communication is made less susceptible to the influence of factors such as interference radio waves.Since the request signal including the frequency information indicating the plurality of specified frequencies is transmitted at each verification time, the possibility of successful verification increases. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram showing a control system of an in-vehicle device according to an embodiment of the present invention. Fig. 2 is a flowchart showing a processing operation of the control system of an in-vehicle device according to the embodiment of the present invention. Fig. 3 is a timing chart showing a transmission timing of a request signal transmitted in the control system of an in-vehicle device according to the embodiment of the present invention. Fig. 4 is a flowchart showing a processing operation of a control system of an in-vehicle device according to a first modified embodiment of the present invention. Fig. 5 is a timing chart showing a transmission timing of a request signal transmitted in the control system of an in-vehicle device according to the first modified embodiment of the present invention. Fig. 6 is a flowchart showing determination processing of an NG of a changeover check executed in a control system of an in-vehicle device according to a second modified embodiment of the present invention. Fig. 7 is a flowchart showing determination processing of an NG of a changeover check executed in a control system of an in-vehicle device according to a third modified embodiment of the present invention. Fig. 8 is a flowchart showing determination processing of an NG of a changeover check executed in a control system of an in-vehicle device according to a fourth modified embodiment of the present invention. Fig. 9 is a flowchart showing a processing operation of a control system of an in-vehicle device according to a fifth modified embodiment of the present invention. Fig. 10 is a timing chart showing a transmission timing of a request signal transmitted in the control system of an in-vehicle device according to a fifth modified embodiment of the present invention. Fig. 11 is a timing chart showing a transmission timing of a request signal transmitted in a control system of an in-vehicle device according to a sixth modified embodiment of the present invention. Fig. 12 is a timing chart showing a transmission timing of a request signal transmitted in a control system of an in-vehicle device according to a seventh modified embodiment of the present invention. Fig. 13 is a timing chart showing a transmission timing of a request signal transmitted in a control system of an in-vehicle device according to an eighth modified embodiment of the present invention. Fig. 14 is a timing chart showing a transmission timing of a request signal transmitted in a control system of an in-vehicle device according to a ninth modified embodiment of the present invention. PREFERRED EMBODIMENT OF THE INVENTION

[0010] Embodiments of the present invention are described below with reference to the drawings.

[0011] As in Fig. As shown in Figure 1, an in-vehicle device control system according to an embodiment of the present invention includes an in-vehicle unit 100 and a portable device 200. The in-vehicle device control system performs a check of the portable device 200 through two-way communication (radio communication), in which the portable device 200 sends a response signal to a request signal sent from the in-vehicle unit 100 mounted in a vehicle. The in-vehicle device control system controls an in-vehicle device (e.g., a door lock device, an engine start device) based on a check result of the check operation.The control system of a device in the vehicle performs the check again by changing a communication frequency of the two-way communication in the event that the check result indicates an unsuccessful check.

[0012] The on-vehicle unit 100 is mounted in the vehicle. The on-vehicle unit 100 is provided to control functions of the on-vehicle unit 100 and includes an ECU (electronic control unit) 110 equipped with a CPU 111, a memory 112, and the like. In the on-vehicle unit 100, the ECU 110 is connected to a transmitter 120 (a vehicle-side communication section), a receiver 130 (a vehicle-side communication section), a door lock sensor (a detection section), a door lock controller 150, and an engine controller 160. The transmitter 120 is for transmitting a request signal (containing frequency information) to a predetermined detection area outside the vehicle. The receiver 130 is a tuner for receiving a response signal radio-transmitted from the portable device 200.The door lock controller 150 is used to control and drive a door lock motor that locks and unlocks a vehicle door. The engine controller 160 is used to control the starting of an engine mounted in the vehicle. The door lock sensor 140 may be a switch or a touch sensor provided on or near an exterior handle of the vehicle door.

[0013] The transmitter 120, the door lock sensor 140, the door lock controller 150, the door lock motor, and the like are provided for each vehicle door. Although not shown, the vehicle-mounted unit 100 may further include, for each vehicle door, a lock state detection sensor for detecting a lock / unlock state of a vehicle door and a door open detection sensor for detecting an open door.

[0014] The memory 112 of the ECU 110 stores an ID code, frequency information (e.g., frequencies A and B), and the like. The ID code is for use in verification. The frequency information specifies a plurality of communication frequencies available for radio communication from the portable device 200. The plurality of communication frequencies (frequency information) are assigned to respective ranks in order of the possibility of verification success and are stored in the memory 112 with the respective assigned ranks.

[0015] The ranking among the communication frequencies can be determined based on the communication frequency at which the previous check was successfully performed, the communication frequency at which the checks were successfully performed more frequently, or the communication frequency at which the checks were unsuccessfully performed less frequently. To determine the ranking as described above, it is preferable to store in the memory 112 the communication frequency at the previous successful check, the number of past successful checks for each communication frequency, and the number of past unsuccessful checks for each communication frequency.

[0016] The CPU 111 of the ECU 110 outputs a control signal to command the transmitter 120 to transmit a request signal based on a signal from the door lock sensor 140. The CPU 110 (as a verification section) further performs verification of an ID code included in the response signal from the portable device 200 and a pre-registered code based on a signal from the receiver 130, and outputs control signals to the door lock controller 150 and the engine controller 160.

[0017] The CPU 111 (as the frequency determination section) of the ECU 110 determines the communication frequency to be set for the portable device 200 from among the plurality of communication frequencies stored in the memory 112. For example, when the communication frequency to be set for the portable device 200 is changed due to an unsuccessful check or the check is periodically performed (polled), the CPU 111 (as the frequency determination section) determines a communication frequency of a higher rank than the communication frequency to be set for the portable device at each check time. The processing operation of the ECU 110 (specifically, the CPU 111) will be described in detail later.

[0018] The transmitter 120 transmits predetermined data through FM modulation or AM modulation of a radio wave, which is a carrier wave of an LF (low frequency) band (for example, approximately 134 kHz). The receiver 130 is configured to be capable of receiving a radio wave in a predetermined range, such as a UHF (ultra high frequency) band. The receiver 130 has a tuning function for receiving a radio wave of a predetermined frequency with high receiver sensitivity. The receiver 130 receives the response signal by tuning the reception frequency to the communication frequency transmitted from the portable device 200 when the portable device 200 outputs the response signal at the specified communication frequency in the door lock control described later.

[0019] The portable device 200 includes a microcomputer (not shown), a receiver section (portable device communication section) 210, and a transmitter section (portable device communication section) 220. The microcomputer controls functions of the portable device 200. The receiver section 210 communicates with the vehicle-mounted unit 100 and receives the request signal transmitted from the transmitter 7 through a receiver antenna, so that data including the request signal is input to the microcomputer. The transmitter section 220 transmits (returns) the response signal including the data output from the microcomputer through a transmitter antenna. The portable device 200 stores an ID code that identifies the portable device itself.

[0020] The transmitter section 220 selects the specified communication frequency from among the plurality of communication frequencies for transmitting the response signal, and transmits the predetermined data by FM modulation or AM modulation of the radio wave having the carrier wave of the selected communication frequency. When the portable device 200 receives the frequency information indicating the specified communication frequency transmitted from the in-vehicle unit 100, the portable device 200 transmits the response signal to the in-vehicle unit 100 at the communication frequency corresponding to the frequency information. As the communication frequency selectable by the transmitter section 220, radio waves within a range of a UHF band (for example, 300 to 400 MHz) are set. The plurality of frequency information (for example, a frequency Fl to a frequency Fn) is set within this range.

[0021] In the control system of an in-vehicle device, the radio wave in the UHF band that the portable device 200 uses for transmission is more susceptible to noise (interference noise) generated by communication cables, large-scale displays, and the like than the radio wave in the LF band used by the vehicle-mounted unit 100. Thus, interference (i.e., communication abnormality) is likely to occur.

[0022] However, it is possible to reduce an influence of factors such as interference noise that interferes with radio communication by changing the frequency set for the portable device 200 in a case of unsuccessful verification.

[0023] In the case of periodically transmitting (polling) the request signal from the vehicle to the portable device 200 to request transmission of the response signal, it is possible to reduce the adverse influence of factors such as interference radio waves that interfere with radio communication by setting a plurality of communication frequencies. However, in the case of transmitting (polling) the request signal at a fixed interval, the request signal must be periodically transmitted a plurality of times. As a result, in order to make radio communication less susceptible to adverse factors such as interference radio waves and the like, the number and time of communication operations will increase, and therefore, power consumption will also increase. The request signal is periodically transmitted from the vehicle to the portable device in a state that the vehicle is parked and at rest in most cases.If the power consumption increases in such a state, a battery will become empty.

[0024] According to the embodiment, when the request signal is periodically transmitted, power consumption is suppressed by reducing the influence of factors such as interference radio waves that interfere with communications. The processing operation of the control system of an in-vehicle device is described next with reference to Fig. 2 and Fig. 3 described. In Fig. 3, (a), (b) and (c) show respective cases where frequency A has the highest rank, frequency B has the highest rank, and frequency C has the highest rank.

[0025] At a step S10 in Fig. 2, the CPU 111 first checks whether this is a regular time t. This is to check whether this is a verification time, that is, whether it is the time to send the request signal to the portable device 200. If it is determined that this is the regular time, step S11 is executed. If it is determined that this is not the regular time, step S10 is repeated.

[0026] In step S11, the CPU 111 performs an external check. In this step, the CPU 111 (as the frequency determining section) determines a high-ranking communication frequency as the communication frequency set for the portable device 200. The request signal including the frequency information is transmitted to the portable device 200 using the transmitter 120 (as the vehicle-mounted communication section). The frequency information indicates the determined communication frequency. The portable device 200 (as the communication section of a portable device) transmits the response signal on the communication frequency set by the vehicle-mounted unit 100 when the response signal is transmitted in response to the received request signal.

[0027] The CPU 111 sets the communication frequency to be set to frequency A when the rank of frequency A is the highest. As shown in (a) of Fig. 3, the request signal having the frequency information indicating the frequency A is transmitted. The CPU 111 sets the communication frequency to be determined to the frequency B when the rank of the frequency B is the highest. As shown in (b) of Fig. 3, the request signal having the frequency information indicating the frequency B is transmitted. The CPU 111 sets the communication frequency to be determined to the frequency C when the rank of the frequency C is the highest. As shown in (c) of Fig. 3, the request signal having the frequency information indicating the frequency C is thus transmitted.

[0028] In step S12, the CPU 111 (as the checking section) checks whether the external verification is OK. That is, it checks whether the ID code included in the received response signal and the ID code stored in the memory 112 satisfy a predetermined correspondence relationship (e.g., a match: OK of verification) or not (NG of verification). If the verification determination by the CPU 111 is OK (YES, i.e., a successful verification), step S13 is executed. If the verification determination is NG (NO, i.e., a failed verification), step S10 is repeated.

[0029] The NG of a check indicates that the check was unsuccessful. This determination is made when no response signal was received within a fixed period of time after the request signal was transmitted, or when the ID code included in the received response signal and the ID code stored in the memory 112 of the ECU 110 do not have the predetermined correspondence relationship (e.g., a match). The OK of a check indicates that the check was successful. This determination is made when the response signal was received within the fixed period of time after the request signal was transmitted, and the ID code included in the response signal and the ID code stored in the memory 112 of the ECU 110 have the predetermined correspondence relationship (e.g., a match).

[0030] In step S13, the CPU 111 checks whether the door lock sensor 140 is outputting a sensor detection. That is, it checks whether a user has operated or influenced the door lock sensor 140 to input a command to unlock the vehicle door. If the sensor detection is present (i.e., the door lock sensor 140 was operated by the user), step S14 is executed. If the sensor detection is not present (i.e., the door lock sensor 140 was not operated by the user), step S10 is repeated.

[0031] At step S14, the CPU 111 outputs a control signal commanding unlocking of the vehicle door to the door lock controller 150 so that the vehicle door is unlocked.

[0032] Thus, the CPU 111 periodically transmits the request signal containing frequency information indicating only a communication frequency with the highest rank (at a regular time interval t). Since a higher-rank communication frequency is set for the portable device 200, communication is made less susceptible to the influence of factors such as radio waves. Since a request signal containing frequency information indicating the set frequency is transmitted at each check time, the number of communication operations is reduced. <Erstes modifiziertes Ausführungsbeispiel>

[0033] The verification may fail in some places or in some time zones even if a communication frequency to be set for the portable device 200 is set to the frequency having a high rank, as illustrated in the embodiment. As a first modified embodiment, as shown in Fig. 4 and Fig. 5, it is possible to change the communication frequency set for the portable device 200 when the verification is unsuccessful.

[0034] The processing operation of the control system of an in-vehicle device is explained with reference to a flowchart shown in Fig. 4 is shown.

[0035] In step S20, the CPU 111 checks whether this is the regular time t. This is to check whether this is the verification time, that is, whether it is the time to send the request signal to the portable device 200. If it is determined that this is the regular time, step S21 is executed. If it is determined that this is not the regular time, step S20 is repeated.

[0036] In step S21, the CPU 111 performs the external verification. In this step, the CPU 111 (as the frequency determination section) determines a high-ranking communication frequency as the communication frequency set for the portable device 200 until the verification performed by receiving the radio wave from the portable device 200 becomes NG. Although described later, the communication frequency set for the portable device 200 is set to other communication frequencies after the verification performed by receiving the radio wave from the portable device 200 becomes NG.

[0037] The request signal including the frequency information is transmitted to the portable device 200 using the transmitter 120 (as the vehicle-side communication section). The frequency information indicates the specific communication frequency. The device 200 (as the communication section of a portable device) transmits the response signal at the communication frequency specified by the vehicle-side unit 100 when the response signal is transmitted in response to the received request signal.

[0038] The CPU 111 sets the communication frequency to be set to frequency A when the rank of frequency A is the highest. The request signal having the frequency information indicative of frequency A is thus transmitted. The communication frequency to be set is set to frequency B when the rank of frequency B is the highest. The request signal having the frequency information indicative of frequency B is thus transmitted. Similarly, the communication frequency to be set is set to frequency C when the rank of frequency C is the highest. The request signal having the frequency information indicative of frequency C is thus transmitted.

[0039] In step S22, the CPU 111 (as a checking section) checks whether the external check is OK. That is, it checks whether the ID code included in the received response signal and the ID code stored in the memory 112 satisfy the predetermined correspondence relationship (e.g., a match). If the check determination by the CPU 111 is OK, step S23 is executed. If the check determination is NG, step S25 is executed.

[0040] The NG of a check indicates that the check was unsuccessful. This determination is made when no response signal was received within a fixed period of time after transmission of the request signal, or when the ID code included in the received response signal and the ID code stored in the memory 112 of the ECU 110 do not have the predetermined correspondence relationship (e.g., a match). The OK of a check indicates that the check was successful. This determination is made when the response signal was received within the fixed period of time after transmission of the request signal, and the ID code included in the received response signal and the ID code stored in the memory 112 of the ECU 110 have the predetermined correspondence relationship (e.g., a match).

[0041] When NG is determined in the external check at step S22, it is likely that no response signal has been received from the portable device 200, or that the ID code included in the received response signal and the ID code stored in the memory of the ECU 110 do not have the predetermined correspondence relationship (e.g., a match).

[0042] In the case where the external verification results in a determination of NG due to no reception of the response signal from the portable device 200, it is likely that the user wearing the portable device 200 is not present around the vehicle (within a predetermined detection range outside the vehicle). In the case where the external verification results in a determination of NG with reception of a radio wave from the portable device 200, it is likely that the response signal is disturbed by adverse factors such as interference radio waves. In such a case, it is desirable to change a transmission frequency at which the portable device 200 transmits the response signal. That is, it is desirable to change the communication frequency set for the portable device 200.The NG of a review thus includes a case where changing the communication frequency is required and another case where such changing of the communication frequency is not required.

[0043] Therefore, in step S25, it is checked whether the check NG indicates that the communication frequency has been changed (determination of a check NG of change). That is, it is checked whether the check NG results from no reception of a response signal or other causes while a response signal (some radio waves from the portable device 200) is being received. If it is determined that the check NG indicates that the communication frequency should be changed, step S26 is executed. If it is determined not to be so, step S20 is repeated.

[0044] The NG of check (the NG of check of change) indicating that the communication frequency should be changed corresponds to a case (an NG of check of a radio wave) where the ID code included in the signal received by the portable device 200 and the ID code stored in the memory 112 of the ECU 110 do not have the predetermined correspondence relationship (e.g., coincidence) even though a radio wave has been received by the portable device 200.The switching of the communication frequency should also be performed when no normal bit is found in the radio wave received by the portable device 200 (NG of a check of a bit), when the predetermined correspondence relationship (e.g., a match) is not satisfied (NG of a check of data) although the response signal is received, or when some of the response signals are not received (NG of a check of a command) in a case where the plurality of request signals are transmitted.

[0045] In step S26, the CPU 111 (the frequency setting section) changes the communication frequency set for the portable device 200 if the check result is the determination of a change check NG. In this first modified example, the CPU 111 (the frequency setting section) sets other high-ranking communication frequencies B and C as the communication frequency to be set for the portable device 200, in addition to the frequency A from among only the frequency A (highest in rank). Fig. 5, a plurality of request signals including frequency information indicating frequency A, frequency B, and frequency C are shown.

[0046] In step S23, the CPU 111 checks whether the door lock sensor 140 is outputting a sensor detection. That is, it checks whether the user has operated the door lock sensor 140 to input the command to unlock the vehicle door. If the sensor detection is present (i.e., the door lock sensor 140 has been operated by the user), step S24 is executed. If the sensor detection is not present (i.e., the door lock sensor 140 has not been operated by the user), step S20 is repeated.

[0047] At step S24, the CPU 111 outputs a control signal commanding unlocking of the vehicle door to the door lock controller 150 so that the vehicle door is unlocked.

[0048] The CPU 111 thus transmits (polls) the request signal including the frequency information indicating only one communication frequency having the highest rank at a regular time t (at a fixed interval) until the switching check result becomes NG. Therefore, it is necessary to transmit the request signal including the frequency information indicating such a communication frequency only once at each check time. If the check fails even though the radio wave is received by the portable device 200, the plurality of communication frequencies are set by switching the communication frequency to be fixed for the portable device 200 at the regular time t (at a fixed interval). The request signal including the frequency information indicating the communication frequency at each check time results.

[0049] Since a higher-ranking communication frequency is set for the portable device 200 as long as the verification does not fail while the radio wave is being received by the portable device 200, the communication is made less susceptible to the influence of factors such as interference radio waves. Since a request signal including frequency information indicating the set frequency is transmitted at each verification time, the number of communication operations is reduced. Since the majority of communication frequencies are set for the portable device 200 when the verification fails while the radio wave is being received by the portable device 200, the communication is made less susceptible to the influence of factors such as interference radio waves.Since the request signal including the frequency information indicating the plurality of specified frequencies is transmitted at each verification time, the possibility of successful verification increases.

[0050] Although the communication frequency is switched to a plurality of frequencies when switching the communication frequency in the first modified embodiment, the present invention is not limited to such an example. It is only required that the CPU 111 (frequency setting section) switches the communication frequency when the request signal is sent at the regular time t (polling at a fixed interval) if the verification fails even though the radio wave is received by the portable device 200.

[0051] That is, if the verification results in a determination of NG (unsuccessful) while the radio wave is being received by the portable device 200, the communication frequency set for the portable device 20 is switched. The request signal including the frequency information indicating the switched communication frequency is then transmitted once at the verification time. Thus, the possibility of a successful verification is increased by switching the communication frequency to be set for the portable device when the verification becomes unsuccessful despite reception of the radio wave by the portable device 200. After the communication frequency to be set for the portable device is switched, the request signal including the frequency information indicating only a communication frequency is transmitted.As a result, the number of communication processes is suppressed from increasing. <Zweites modifiziertes Ausführungsbeispiel>

[0052] Although the NG of checking a radio wave, the NG of checking a bit reception, the NG of checking a data reception, and the NG of checking a command are referred to as an example of the NG of checking a change in the first modified embodiment, the present invention is not limited to such an example.

[0053] A second modified embodiment is described with reference to Fig. 6 as another example of determination processing of an NG of checking a change (determination processing at step S25 in Fig. 4) described.

[0054] In step S30, the CPU 111 checks whether the radio wave of the portable device 200 has been received by the receiver 130 in an external verification NG state. If it is determined that the radio wave is present (has been received), step S32 is executed. If it is determined that no radio wave is present (has been received), step S31 is executed. In step S31, the CPU 111 resets a timer and ends this processing.

[0055] At step S32, the CPU 111 checks whether more than a fixed time has elapsed since reception of the radio wave from the portable device 200. If it is determined that the fixed time has elapsed, the switching check is determined as NG (step S33). If it is determined that the fixed time has not yet elapsed, this processing is terminated. That is, if the determination of reception of the radio wave continues for longer than the fixed time in an external check state of NG, the switching check is determined as NG (step S33). If it continues for no longer than the fixed time, this processing is terminated.

[0056] Thus, it is possible to determine the switching verification NG when the radio wave from the portable device 200 continues for longer than the fixed time in determining an external verification NG. That is, the switching verification NG can be determined when the switching verification NG (the provisional switching verification NG) continues with the reception of a radio wave from the portable device 200 for longer than the fixed time.

[0057] In the second modified embodiment, it is further possible to check under an NG of an external check whether the bit reception continues the fixed time, whether the data reception continues the fixed time, or whether the command reception continues the fixed time. <Drittes modifiziertes Ausführungsbeispiel>

[0058] In the first modified embodiment, the radio wave check NG, the bit reception check NG, the data reception check NG, and the command check NG are referred to as an example of the switching check NG. The present invention is not limited to such an example.

[0059] A third modified example is shown as another example of the determination processing of an NG of checking a change (determination processing at a step S25 in Fig. 4) with reference to Fig. 7 described.

[0060] In step S40, the CPU 111 checks whether the radio wave of the portable device 200 has been received by the receiver 130 in an external check NG state. If it is determined that the radio wave is present (has been received), step S42 is executed after counting up the provisional switch check NG. If it is determined that no radio wave is present (has been received), step S41 is executed. In step S41, the CPU 111 resets the number of times of the provisional switch check NG and ends this processing. The CPU 111 counts the number of times (the number of times of a provisional switch check NG) when the radio wave of the portable device 200 has been received in the external check NG state by the receiver 130 and stores it in the memory 112.

[0061] In step S42, the CPU 111 checks whether the radio wave of the portable device 200 has been received for more than a fixed number of times in an external verification NG state. That is, it checks whether the number of times of the provisional switching verification result has reached the fixed number of times. If it is determined that the fixed number of times has been achieved, the switching verification is determined as NG (step S43). If it is determined that the fixed number of times has not yet been achieved, this processing is terminated.

[0062] Thus, it is possible to determine a switching verification NG when the radio wave from the portable device 200 continues to be present a fixed number of times during the external verification NG determination. That is, a switching verification NG can be determined when a switching verification NG (a provisional switching verification NG) indicating reception of a radio wave from the portable device 200 continues a fixed number of times in the external verification NG state.

[0063] In the third modified embodiment, it is further possible to check, at the NG of an external check, whether the bit reception is continued the fixed number of times, whether the data reception is continued the fixed number of times, or whether the command reception is continued the fixed number of times. <Viertes Ausführungsbeispiel>

[0064] In the first modified embodiment, reference is made to a radio wave check NG, a bit reception check NG, a data reception check NG, and a command check NG as an example of a switching check NG. The present invention is not limited to such an example.

[0065] A fourth embodiment is described with reference to Fig. 8 as another example of the determination processing of an NG of checking a change (determination processing at step S25 in Fig. 4) described.

[0066] In step S50, the CPU 111 checks whether the radio wave of the portable device 200 has been received by the receiver 130 in an external check NG state. If it is determined that the radio wave is present (has been received), step S53 is executed after the provisional switch check NG is incremented. If it is determined that no radio wave is present (has been received), step S51 is executed.

[0067] The CPU 111 resets a timer in step S51 and resets the number of times a provisional changeover verification NG was performed in step S52. The CPU 111 terminates this processing after step S52. The CPU 111 counts the number of times (the number of times a provisional changeover verification NG was performed) and stores it in the memory 112 when the radio wave of the portable device 200 was received by the receiver 130 in the external verification NG state.

[0068] In step S53, the CPU 111 checks whether more than the fixed time has elapsed since receiving the radio wave from the portable device 200. If it is determined that the fixed time has elapsed, step S54 is executed. If it is determined that the fixed time has not yet elapsed, this processing is terminated.

[0069] At step S54, the CPU 111 checks whether the radio wave of the portable device 200 has been received more than the fixed number of times in the external verification NG state. That is, it is checked whether the number of times of a provisional switching verification NG has reached the fixed number of times. If it is determined that the fixed number of times has been achieved, this means that the fixed time has elapsed after reception of the radio wave by the portable device 200, and the number of times of reception of the radio wave by the portable device 200 has reached the fixed number of times. The switching verification is determined as a result to be NG (step S55). If it is determined that the fixed number of times has not yet been achieved, this processing is terminated.

[0070] Thus, it is possible to determine a switching verification NG when the radio wave reception from the portable device 200 continues the fixed number of times within the fixed time in the external verification NG state. That is, it is possible to determine the switching verification NG when the switching verification NG (a provisional switching verification NG) of radio wave reception from the portable device 200 continues the fixed number of times within the fixed time in the external verification NG state.

[0071] In the fourth modified embodiment, it is further possible to check under an NG of an external check whether the bit reception is continued the fixed number of times, whether the data reception is continued the fixed number of times, or whether the command reception is continued the fixed number of times. <Fünftes modifiziertes Ausführungsbeispiel>

[0072] A fifth modified embodiment directed to the switching timing for switching the communication frequency to be set for the portable device 200 as shown in the first modified embodiment to the fourth modified embodiment will be described with reference to Fig. 9 and Fig. 10 described.

[0073] Steps S60 to S66 are similar to steps S20 to S26 in Fig. 4, and therefore details of such steps are not described.

[0074] In step S67, the CPU 111 checks whether the changeover time is now or soon. If it is determined to be now, step S61 is executed. If it is determined to be soon, step S60 is executed.

[0075] When the switching time is determined to be soon, the CPU 111 (the frequency setting section) switches the communication frequency at which the request signal is sent at the next check time following an NG of checking a switch, as shown in Fig. 10 is shown.

[0076] Since the number of times the request signals are sent is suppressed from increasing, the power consumption is also suppressed from increasing. <Sechstes modifiziertes Ausführungsbeispiel>

[0077] As a sixth modified embodiment, it is possible to transmit the request signal at a transmission time that is Fig. 11, to the control system of a device in the vehicle.

[0078] As indicated by (a) in Fig. As shown in FIG. 11, the CPU 111 (frequency setting section) sets two high-ranking communication frequencies as the communication frequency set for the portable device at each verification time point (regular time point t) when switching the communication frequency. That is, since two high-ranking communication frequencies are set at each regular time point t (at a fixed interval), the request signal including frequency information indicating the communication frequency is transmitted twice at each verification time point. As a result, the verification is more likely to succeed.

[0079] As indicated by (b) in Fig. As shown in FIG. 11, the CPU 111 (the frequency setting section) can switch the communication frequency between two high-order communication frequencies when switching the communication frequency. That is, when switching the communication frequency to be set for the portable device 200, the communication frequency is switched to one of the two high-order communication frequencies, and the request signal including the frequency information indicating such a communication frequency is transmitted once at each verification time. As a result, the verification is more likely to be successful. <Siebtes Ausführungsbeispiel>

[0080] As a seventh modified embodiment, it is possible to transmit the request signal at a transmission time that is Fig. 12, to the control system of a device in the vehicle.

[0081] As indicated by (a) in Fig. As shown in Figure 12, the CPU 111 (the frequency setting section) sets one of the two communication frequencies (a frequency A in this embodiment) that has a higher priority as a main communication frequency. The main frequency is fixed, and the other communication frequency is switched.

[0082] Even with a communication frequency that will provide a more successful verification, the verification may fail depending on the timing of a communication (a verification). Thus, fixing the primary communication frequency and switching to the other communication frequency makes the verification more likely to be successful.

[0083] As indicated by (b) in Fig. 12, the CPU 111 (the frequency setting section) can set one of the communication frequencies (the frequency A in this embodiment) of a higher rank than the main communication frequency, and switch the communication frequency between the main frequency and the other communication frequency when switching the two communication frequencies of higher ranks.

[0084] By setting the main communication frequency once and changing the communication frequency twice, the verification is more likely to be successful. <Achtes modifiziertes Ausführungsbeispiel>

[0085] As an eighth modified embodiment, it is possible to transmit the request signal at a transmission time that is Fig. 13, to the control system of a device in the vehicle.

[0086] As in Fig. 13, the CPU 111 (the vehicle-side communication section) extends an interval (t') in which the request signal is sent to the portable device 200 after a lapse of a certain fixed time since the start of a check performed every regular time t (at a regular interval).

[0087] The verification time itself is thus reduced, and therefore the power consumption is reduced.

[0088] The CPU 111 may stop transmission of the request signal, by which the request signal is sent to the portable device 200, after a lapse of a certain fixed time from the extension of the interval (t'). <Neuntes modifiziertes Ausführungsbeispiel>

[0089] As a ninth modified embodiment, it is possible to transmit the request signal at a transmission timing which is Fig. 14, to the control system of a device in the vehicle.

[0090] As in Fig. 14, in changing the communication frequency set for the portable device 200, the CPU 111 (frequency setting section) reduces the number of a plurality of communication frequencies set to be set for the portable device 200 when the changeover check becomes NG.

[0091] The number of communication processes is thus reduced, and therefore power consumption is reduced.

[0092] The foregoing embodiment and its first to ninth modified embodiments may be selectively combined in implementing the invention.

Claims

[1] Control system of a device in the vehicle, comprising: a portable device (200); and a vehicle-side unit (100) mounted in a vehicle for performing a check operation of the portable device based on two-way communication, in which the portable device returns a response signal in response to a request signal sent from the vehicle-side unit, for controlling a device in the vehicle based on a check result of the check operation, and for changing a communication frequency for the two-way communication when the check result indicates an unsuccessful check, to thereby perform the check operation again, wherein the portable device (200) receives the request signal sent from the vehicle-side unit during mutual communication with the device in the vehicle, the portable device (200) has a portable device communication section (210, 220) for returning the response signal having an ID code by using a communication frequency set by the vehicle-side unit, the vehicle-mounted unit (100) has a frequency setting section (111) for setting the communication frequency to be set for the portable device among a plurality of communication frequencies having respective rankings set in accordance with a possibility of successful verification, the vehicle-side unit (100) has a vehicle-side communication section (120, 130) for performing the two-way communication with the portable device by transmitting the request signal containing the frequency information indicating the communication frequency set by the frequency setting section to the portable device and receiving the response signal from the portable device, the vehicle-side unit (100) has a checking section (111) for performing the checking operation based on the ID code contained in the response signal received from the portable device through the vehicle-side communication section, the frequency setting section (111) sets a communication frequency having a higher priority than the communication frequency to be set for the portable device at each check time when performing the check operation at a regular interval until the check operation by the check section becomes unsuccessful, and the frequency setting section (111) sets a plurality of communication frequencies by changing the communication frequency to be set for the portable device when the checking operation by the checking section becomes unsuccessful despite reception of a radio wave from the portable device by the vehicle-side communication section, wherein the communication frequency is not changed when the response signal from the portable device (200) is not received in response to the request signal transmitted from the vehicle-side unit (100). [2] A control system of an in-vehicle device according to claim 1, wherein the frequency setting section (111) sets a ranking based on a frequency that has provided one of a successful check last time, a larger number of times of successful checks, or a smaller number of times of unsuccessful checks. [3] A control system of an in-vehicle device according to claim 1 or 2, wherein the checking section (111) determines that the checking operation is unsuccessful in response to an occurrence of at least one of predetermined conditions in which a normal bit is not received despite reception of the response signal, the response signal does not have a predetermined correspondence relationship relative to a pre-registered signal despite reception of the response signal, and the response signal is not received in response to one of the request signals. [4] A control system of a device in the vehicle according to claim 1 or 2, wherein the checking section (111) starts counting the time in response to an occurrence of at least one of predetermined conditions in which a normal bit is not received despite reception of the response signal, the response signal does not have a predetermined correspondence relationship relative to a pre-registered signal despite reception of the response signal, or the response signal is not received in response to one of the request signals; and the checking section (111) determines that the checking operation is unsuccessful when a counted time indicating a continuation of at least one of the predetermined states is less than a fixed time. [5] The in-vehicle device control system according to claim 4, wherein the checking section (111) resets a counted time when no radio wave is received from the portable device. [6] A control system of a device in the vehicle according to claim 1 or 2, wherein the checking section (111) counts a number of times of occurrence of at least one of predetermined states in which a normal bit is not received despite reception of the response signal, the response signal does not have a predetermined correspondence relationship relative to a pre-registered signal despite reception of the response signal, or the response signal is not received in response to one of the request signals; and the checking section (111) determines that the checking operation is unsuccessful when a counted number of times of occurrence of at least one of predetermined conditions reaches a fixed number of times. [7] The in-vehicle device control system according to claim 6, wherein the checking section (111) resets the counted number of times when no radio wave is received from the portable device. [8] A control system of an in-vehicle device according to claim 1 or 2, wherein the checking section (111) starts counting a time of continuation and a number of times of occurrence of at least one of predetermined conditions in which a normal bit is not received despite reception of the response signal, the response signal does not have a predetermined correspondence relationship relative to a pre-registered signal despite reception of the response signal, or the response signal is not received in response to one of the request signals; and the checking section (111) determines that the checking operation is unsuccessful when a counted number of times of occurrence of at least one of predetermined conditions reaches a fixed number of times within a fixed time. [9] A control system of an in-vehicle device according to claim 6, wherein the checking section (111) resets a counted time and the counted number of times when no radio wave is received from the portable device. [10] The in-vehicle device control system according to claim 1 or 2, wherein the frequency setting section (111), in changing the communication frequency to be set for the portable device, changes the communication frequency at a time when the on-vehicle communication section sends the request signal at a next check timing after the check section determines that the check operation is unsuccessful. [11] The in-vehicle device control system according to claim 1 or 2, wherein, when changing the communication frequency to be set for the portable device, the frequency setting section (111) sets two communication frequencies having higher ranks than the communication frequency to be set for the portable device at each check time. [12] A control system of an in-vehicle device according to claim 1 or 2, wherein the frequency setting section (111) sets one of two communication frequencies having a higher ranking than a main communication frequency, and switches the other of the two communication frequencies while maintaining the main communication frequency when switching the communication frequency to be set for the portable device. [13] The in-vehicle device control system according to claim 1 or 2, wherein the vehicle-side communication section (120, 130) extends an interval at which the request signal is transmitted to the portable device after a lapse of a fixed time since a start of the check operation performed at the regular interval. [14] A control system of an in-vehicle device according to claim 13, wherein the vehicle-side communication section (120, 130) stops transmitting the request signal after a lapse of another fixed time following an extension of the interval. [15] The in-vehicle device control system according to claim 1 or 2, wherein the frequency setting section (111), in changing the communication frequency set as the communication frequency, reduces a number of the plurality of communication frequencies set to be set for the portable device when the checking section determines that the checking operation is unsuccessful.

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