JP2019127724A - On-vehicle device, existence detection method, and computer program - Google Patents

Abstract

An on-vehicle apparatus capable of appropriately detecting the presence of a transmission source of a response signal in the vicinity of a transmission source of a request signal, a presence detection method, and a computer program.
An on-vehicle apparatus repeatedly transmits a second request signal requesting transmission of a second response signal to a wireless terminal by radio, and receives a second response signal from the wireless terminal. The on-vehicle apparatus determines whether the reception intensity of the second response signal is increasing with time based on the reception intensities of the plurality of second response signals received from the wireless terminal.
[Selection] Figure 10

Description

  The present invention relates to an in-vehicle apparatus, a presence detection method, and a computer program.

  Communication systems in which an in-vehicle device and a wireless terminal, so-called electronic key, communicate with each other wirelessly have become widespread. In this communication system, the on-vehicle apparatus wirelessly transmits a request signal requesting transmission of a response signal to the wireless terminal. The wireless terminal wirelessly transmits the response signal to the in-vehicle device when the request signal is received. When the on-vehicle apparatus receives the response signal, the on-vehicle apparatus detects the presence of the wireless terminal in the vicinity of the on-vehicle apparatus.

  For example, when the push button provided on the doorknob of the vehicle in which the door is locked is pressed, when the presence of the wireless terminal in the vicinity of the in-vehicle device is detected, the in-vehicle device unlocks the door of the vehicle. Output unlock data to instruct. Thus, the door of the vehicle is unlocked. Usually, when the owner of the wireless terminal is away from the vehicle, that is, the vicinity of the on-vehicle apparatus, the request signal does not reach the wireless terminal, so the presence of the wireless terminal in the vicinity of the on-vehicle apparatus is not detected. Therefore, when the holder of the wireless terminal is away from the vicinity of the in-vehicle apparatus, the door of the vehicle is not unlocked even if a third party different from the holder of the wireless terminal presses the push button on the door knob.

  However, even when the owner of the wireless terminal is away from the vicinity of the in-vehicle device, a third party uses a technique called relay attack to cause the in-vehicle device to detect the presence of the wireless terminal in the vicinity of the in-vehicle device. It is possible. In relay attack, for example, two relays that relay signals are used. One relay is disposed in the vicinity of the on-vehicle apparatus, and the other relay is disposed in the vicinity of the wireless terminal.

  When one repeater receives a request signal from the in-vehicle device, it generates a relay signal and wirelessly transmits the generated relay signal to the other repeater. The relay signal includes data similar to the data included in the request signal received by the on-vehicle apparatus, and the frequency band of the relay signal is different from the frequency band of the request signal. The other relay, upon receiving the relay signal, generates a request signal based on the data included in the received relay signal, and wirelessly transmits the generated request signal to the wireless terminal. As described above, when the wireless terminal receives the request signal, the wireless terminal transmits a response signal to the on-vehicle apparatus. If this response signal arrives at the on-vehicle apparatus, the on-vehicle apparatus may erroneously detect the presence of the wireless terminal in the vicinity of the on-vehicle apparatus.

  Therefore, Patent Document 1 discloses a communication system that prevents the presence of a wireless terminal in the vicinity of an in-vehicle device from being erroneously detected. In the communication system described in Patent Document 1, the strength of the response signal transmitted by the wireless terminal is weak, and the propagation distance of the response signal is short. When a relay attack is used, it is assumed that the distance from the wireless terminal to the in-vehicle device is long. For this reason, the response signal transmitted by the wireless terminal does not reach the in-vehicle device. As a result, the presence of the wireless terminal in the in-vehicle apparatus is not erroneously detected.

JP 2017-101496 A

  However, in the communication system described in Patent Document 1, when two repeaters that relay a request signal and relay a response signal in the same manner as the request signal are used, the response signal reaches the in-vehicle device. Therefore, the presence of the wireless terminal in the on-vehicle apparatus may be erroneously detected.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an in-vehicle device and presence detection capable of appropriately detecting the presence of a response signal transmission source in the vicinity of a request signal transmission source. A method and computer program are provided.

  An on-vehicle apparatus according to an aspect of the present invention includes a transmitter configured to wirelessly repeatedly transmit a request signal requesting transmission of a response signal, a receiver configured to wirelessly receive the response signal, and a response signal received by the receiver. And a rise determination unit that determines whether or not the reception intensity of the response signal has increased over time based on a plurality of reception intensities detected by the detection unit.

  In the presence detection method according to an aspect of the present invention, a request signal requesting transmission of a response signal is repeatedly transmitted by radio, and the reception intensity of the response signal is received based on a plurality of reception intensities of the plurality of response signals. And determining whether or not is rising with time.

  A computer program according to an aspect of the present invention is characterized by repeatedly instructing a computer to transmit a request signal requesting transmission of a response signal by radio, and based on a plurality of reception strengths of a plurality of the response signals. Determining whether the reception strength of the response signal has increased with time.

  Note that the present invention can be realized not only as an in-vehicle device having such a characteristic processing unit, but also as a presence detection method using such characteristic processing as a step, or executing such step in a computer. It can be realized as a computer program for Further, the present invention can be realized as a semiconductor integrated circuit that realizes part or all of the in-vehicle device, or as a communication system including the in-vehicle device.

  According to the above aspect, it is possible to appropriately detect the presence of the transmission source of the response signal in the vicinity of the transmission source of the request signal.

FIG. 1 is a block diagram showing a main configuration of a communication system in Embodiment 1. It is a block diagram which shows the principal part structure of a radio | wireless terminal. It is a flowchart which shows the procedure of a 1st transmission process. It is a flowchart which shows the procedure of a 2nd transmission process. It is a block diagram which shows the principal part structure of a vehicle-mounted apparatus. It is a flow chart which shows the procedure of separation detection processing. It is a flowchart which shows the procedure of a writing process. It is a flowchart which shows the procedure of a 1st door process. It is a flowchart which shows the procedure of 2nd door processing. It is a sequence diagram which shows the operation example of a communication system. 7 is a flowchart illustrating a procedure of separation detection processing in the second embodiment. It is a sequence diagram which shows the operation example of a communication system. 15 is a flowchart illustrating a procedure of first transmission processing in the third embodiment. It is a flow chart which shows the procedure of separation detection processing. It is a sequence diagram which shows the operation example of a communication system.

Description of the embodiment of the present invention
First, embodiments of the present invention will be listed and described. At least a part of the embodiments described below may be arbitrarily combined.

(1) An in-vehicle device according to an aspect of the present invention includes: a transmission unit that repeatedly transmits a request signal for requesting transmission of a response signal; a reception unit that wirelessly receives the response signal; and the reception unit that receives the response signal. A detection unit that detects the reception intensity of the response signal, and an increase determination unit that determines whether or not the reception intensity of the response signal increases over time based on a plurality of reception intensities detected by the detection unit; Equipped with

(2) The vehicle-mounted device according to one aspect of the present invention instructs the unlocking of the vehicle door when the increase determination unit determines that the reception strength of the response signal increases with time. An output unit for outputting unlocking data is provided.

(3) The in-vehicle device according to an aspect of the present invention provides a plurality of receptions detected by the detection unit when the increase determination unit determines that the reception intensity of the response signal increases with time. The signal processing apparatus further includes a strength determination unit that determines whether the latest reception strength in strength is equal to or more than a threshold, and the output determination unit determines that the latest reception strength is equal to or more than the threshold. In the case, the unlocking data is output.

(4) The on-vehicle apparatus according to an aspect of the present invention wirelessly repeatedly transmits a second request signal requesting transmission of a second response signal wirelessly, and wirelessly transmits the second response signal. And the second response signal is transmitted when the reception strength of the second request signal is less than a second threshold, and the transmission unit is configured to receive the second response signal. When the receiving unit receives the second response signal, it repeatedly starts transmitting the request signal.

(5) The on-vehicle apparatus according to an aspect of the present invention includes a second strength determination unit that determines whether the reception strength detected by the detection unit is less than a third threshold, and the increase determination unit The determination is made after the second intensity determining unit determines that the received intensity is less than the third threshold.

(6) The on-vehicle apparatus according to one aspect of the present invention repeatedly receives a third request signal requesting transmission of a third response signal by radio, and a third transmission unit, and receives the third request signal. The third receiving unit wirelessly receives a third response signal including intensity data indicating the intensity, and the reception intensity indicated by the intensity data included in the third response signal received by the third receiving unit is the fourth A third strength determining unit that determines whether or not the received data is less than the fourth threshold value, and the transmitting unit is configured such that the received strength indicated by the strength data is less than the fourth threshold value by the third strength determining unit. If it is determined that there is, the repetitive transmission of the request signal is started.

(7) The on-vehicle apparatus according to an aspect of the present invention repeatedly wirelessly transmits a request signal requesting transmission of a response signal, and, based on a plurality of reception strengths of a plurality of the response signals, Determining whether the reception intensity has increased over time.

(8) A computer program according to an aspect of the present invention is based on the step of repeatedly instructing the computer to transmit a request signal requesting transmission of a response signal wirelessly, and based on a plurality of reception strengths of a plurality of the response signals. And determining whether or not the reception intensity of the response signal increases with time.

  In the in-vehicle device, the presence detection method, and the computer program according to the above aspect, the reception intensity of the response signal is changed over time based on the reception intensity of the plurality of response signals received by repeatedly transmitting the request signal. Determine if it is rising. When the request signal is received and the transmission source of the response signal approaches the transmission source of the request signal, the reception strength of the response signal increases with time. Therefore, the presence of the transmission source of the response signal in the vicinity of the transmission source of the request signal is appropriately detected by determining whether the reception strength of the response signal is increasing with time.

  In the in-vehicle device according to the above aspect, when it is determined that the reception strength of the response signal is increasing with time, for example, when an unlocking instruction for the door of the vehicle is received, unlocking data is received. Output. Thus, the door of the vehicle is unlocked.

  In the in-vehicle device according to the above aspect, it is determined whether or not the latest reception strength among the plurality of reception strengths used in the determination regarding the increase in the reception strength of the response signal is equal to or greater than a threshold value. If the latest reception strength is equal to or higher than the threshold, that is, if the latest reception strength is strong, it is certain that the transmission source of the response signal is in the vicinity of the transmission source of the request signal.

  In the in-vehicle device according to the above aspect, when the second response signal is received, it is determined that the transmission source of the second response signal has moved away from the vicinity of the own device, and the response signal is repeatedly transmitted. It is determined whether the reception strength of the signal is increasing with time.

  In the on-vehicle apparatus according to the above aspect, after the reception strength of the response signal becomes less than the third threshold, that is, after the transmission source of the response signal is separated once from the vicinity of the own apparatus, It is determined whether the reception intensity is increasing with time.

  In the on-vehicle apparatus according to the above aspect, when the reception strength of the third request signal is less than the fourth threshold, the transmission source of the third response signal is considered to be separated from the vicinity of the own apparatus. Repeated transmission of the signal is started, and it is determined whether the reception strength of the response signal is increasing with time.

Details of the Embodiment of the Present Invention
A specific example of a communication system according to an embodiment of the present invention will be described below with reference to the drawings. The present invention is not limited to these exemplifications, but is shown by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

(Embodiment 1)
FIG. 1 is a block diagram showing the main configuration of the communication system 1 in the first embodiment. The communication system 1 includes an on-vehicle device 10, a plurality of doors 11, 11, ..., and a wireless terminal 20. The in-vehicle device 10 and the plurality of doors 11, 11,... Are mounted on the vehicle 100.

  The in-vehicle device 10 wirelessly transmits to the wireless terminal 20 a first request signal that requests transmission of the first response signal and a second request signal that requests transmission of the second response signal. Each of the first request signal and the second request signal includes transmission source identification data for identifying a transmission source. The in-vehicle apparatus 10 transmits, to the wireless terminal 20, a first request signal and a second request signal including vehicle identification data specific to the in-vehicle apparatus 10 as transmission source identification data.

  Each of the first request signal and the second request signal is a signal generated by modulating the amplitude or frequency of a sinusoidal carrier wave, for example. The frequency bands of the first request signal and the second request signal are included in the range of 30 kHz to 300 kHz, for example. The first request signal includes data indicating that it is the first request signal. The second request signal also includes data indicating that it is the second request signal. The wireless terminal 20 identifies the received signal based on the data included in the received signal.

  When the wireless terminal 20 receives the first request signal whose transmission source identification data is vehicle identification data, the wireless terminal 20 wirelessly transmits the first response signal to the in-vehicle device 10. The wireless terminal 20 wirelessly transmits the second response signal to the in-vehicle apparatus 10 when the second request signal in which the transmission source identification data is the vehicle identification data is received. Each of the first response signal and the second response signal also includes transmission source identification data. The wireless terminal 20 transmits the first response signal and the second response signal including the terminal identification data specific to the wireless terminal 20 as the transmission source identification data to the on-vehicle apparatus 10.

  Each of the first response signal and the second response signal is a signal generated by modulating the amplitude or frequency of a sinusoidal carrier wave, for example. The frequency bands of the first response signal and the second response signal are included in the range of 30 MHz to 300 MHz, for example. The first response signal includes data indicating that it is a first response signal. The second response signal also includes data indicating that it is the second response signal. The in-vehicle device 10 identifies the received signal based on data included in the received signal.

  As described above, the in-vehicle device 10 communicates with the wireless terminal 20 by wireless. The on-vehicle apparatus 10 detects the presence of the wireless terminal 20 in the vicinity of the vehicle 100, that is, the on-vehicle apparatus 10 based on the communication status with the wireless terminal 20. The user instructs, for example, locking or unlocking the plurality of doors 11, 11,... By pressing a push button provided on the door knob of the door 11. When the push button is pressed in a state where the plurality of doors 11, 11, ... are unlocked, the on-vehicle device 10 indicates that the locking instruction of the plurality of doors 11, 11, ... has been received. Lock reception data is input. When the push button is pressed in a state where the plurality of doors 11, 11, ... are locked, it is indicated to the vehicle-mounted device 10 that the unlocking instruction of the plurality of doors 11, 11, ... has been received. Unlocking acceptance data is input.

  The on-vehicle apparatus 10 detects the presence of the wireless terminal 20 in the vicinity of the on-vehicle apparatus 10, and when lock reception data is input, the on-vehicle apparatus 10 instructs the lock data to instruct locking of the plurality of doors 11, 11,. , And output to a device (not shown) in the vehicle 100. Thereby, the plurality of doors 11, 11, ... are locked.

The on-vehicle device 10 instructs the unlocking of the plurality of doors 11, 11,... When the unlocking reception data is input in a state where the presence of the wireless terminal 20 in the vicinity of the on-vehicle device 10 is detected. The lock data is output to a device (not shown) in the vehicle 100. Thereby, the plurality of doors 11, 11, ... are unlocked.
When the on-vehicle apparatus 10 does not detect the presence of the wireless terminal 20 in the vicinity of the on-vehicle apparatus 10, the on-vehicle apparatus 10 does not output the unlocking data or the locking data.

  FIG. 2 is a block diagram showing the main configuration of the wireless terminal 20. As shown in FIG. The wireless terminal 20 includes a terminal receiving unit 30, an intensity detecting unit 31, a terminal transmitting unit 32, a microcomputer (hereinafter referred to as a microcomputer) 33, a receiving antenna Rw, and a transmitting antenna Tw. The microcomputer 33 has input units 40 and 41, an output unit 42, a storage unit 43, and a control unit 44.

  The receiving antenna Rw is connected to the terminal receiving unit 30 and the intensity detecting unit 31. The terminal reception unit 30 and the strength detection unit 31 are further connected to input units 40 and 41 of the microcomputer 33. The transmission antenna Tw is connected to the terminal transmission unit 32. The terminal transmission unit 32 is further connected to the output unit 42 of the microcomputer 33. In the microcomputer 33, input units 40 and 41, an output unit 42, a storage unit 43 and a control unit 44 are connected to the internal bus 45.

  The terminal receiving unit 30 receives the first request signal and the second request signal from the in-vehicle device 10 via the receiving antenna Rw. When receiving the first request signal, the terminal reception unit 30 outputs, to the input unit 40, first request data that is data included in the received first request signal. The first request data includes transmission source identification data. The first request data of the first request signal transmitted by the in-vehicle device 10 includes vehicle identification data as transmission source identification data.

  When receiving the second request signal, the terminal reception unit 30 outputs second request data, which is data included in the received second request signal, to the input unit 40. The second request data also includes transmission source identification data. The second request data of the second request signal transmitted by the in-vehicle device 10 also includes vehicle identification data as transmission source identification data.

  When data is input from the terminal receiving unit 30 to the input unit 40, the input unit 40 notifies the control unit 44 to that effect. The control unit 44 acquires data input to the input unit 40 from the input unit 40. Therefore, the first request data and the second request data are acquired by the control unit 44 from the input unit 40.

  The intensity detection unit 31 detects the reception intensity of the signal received by the terminal reception unit 30 via the reception antenna Rw. Therefore, the intensity detection unit 31 detects the reception intensity of the first request signal. When detecting the reception strength, the strength detection unit 31 outputs terminal strength data indicating the detected reception strength to the input unit 41. The control unit 44 acquires the terminal strength data input to the input unit 41 from the input unit 41.

  The output unit 42 outputs the first response data to be included in the first response signal and the second response data to be included in the second response signal to the terminal transmission unit 32 according to the instruction of the control unit 44. The first response data includes terminal identification data and data indicating that it is a first response signal. The second response data includes terminal identification data and data indicating that it is a second response signal.

  When the first response data is input, the terminal transmission unit 32 wirelessly transmits the first response signal including the input first response data to the in-vehicle device 10 via the transmission antenna Tw. Similarly, when the second response signal is input, the terminal transmission unit 32 wirelessly transmits the second response signal including the input second response data to the in-vehicle apparatus 10 via the transmission antenna Tw.

  The terminal transmission unit 32 transmits the first response signal each time the first response data is input. Here, the strength of the first response signal at the time of transmission is constant. Similarly, the terminal transmission unit 32 transmits a second response signal each time the second response data is input. Here, the strength of the second response signal at the time of transmission is constant.

  The storage unit 43 is a non-volatile memory. The storage unit 43 stores vehicle identification data and terminal identification data. Further, the storage unit 43 stores a computer program P3.

  The control unit 44 includes one or more CPUs (Central Processing Units). One or more CPUs included in the control unit 44 execute a computer program P3 to execute a first transmission process for transmitting a first response signal, and a second transmission process for transmitting a second response signal. Run. The computer program P3 is used to cause one or more CPUs of the control unit 44 to execute the first transmission process and the second transmission process.

  The computer program P3 may be stored in the storage medium E3 so that it can be read by one or a plurality of CPUs included in the control unit 44. In this case, the computer program P3 read from the storage medium E3 by a reading device (not shown) is written in the storage unit 43. The storage medium E3 is an optical disk, a flexible disk, a magnetic disk, a magnetic optical disk, a semiconductor memory, or the like. The optical disc is a CD (Compact Disc) -ROM (Read Only Memory), a DVD (Digital Versatile Disc) -ROM, a BD (Blu-ray (registered trademark) Disc), or the like. The magnetic disk is, for example, a hard disk. Alternatively, the computer program P3 may be downloaded from an external device (not shown) connected to a communication network (not shown), and the downloaded computer program P3 may be written in the storage unit 43.

  FIG. 3 is a flowchart showing the procedure of the first transmission process. Every time the first request data including the vehicle identification data is input from the terminal receiving unit 30 to the input unit 40, the control unit 44, that is, the terminal receiving unit 30 receives the first request signal including the vehicle identification data. Each time reception is performed, the first transmission process is performed.

  First, the control unit 44 acquires terminal strength data indicating the reception strength of the first request signal related to the execution of the first transmission process from the input unit 41 (step S1), and the first request indicated by the acquired terminal strength data It is determined whether the reception strength of the signal is less than the terminal threshold (step S2). The terminal threshold is a fixed value and is preset.

When the control unit 44 determines that the reception intensity of the first request signal is less than the terminal threshold (S2: YES), the control unit 44 reads terminal identification data from the storage unit 43 (step S3). Next, the control unit 44 instructs the output unit 42 to output the first response data including the terminal identification data read in step S3 (step S4). Thereby, the output unit 42 outputs the first response data to the terminal transmission unit 32, and the terminal transmission unit 32 wirelessly transmits the first response signal including the first response data to the on-vehicle device 10 via the transmission antenna Tw. Send by Therefore, instructing the output unit 42 to output the first response data corresponds to instructing the terminal transmission unit 32 to transmit the first response signal by radio.
The first request signal, the first response signal, and the terminal threshold respectively correspond to a second request signal, a second response signal, and a second threshold.

  When it is determined that the reception intensity of the first request signal is equal to or higher than the terminal threshold (S2: NO), or after executing Step S4, the control unit 44 ends the first transmission process.

  As described above, in the wireless terminal 20, when the terminal reception unit 30 receives the first request signal via the reception antenna Rw, the reception strength of the first request signal detected by the strength detection unit 31 is greater than or equal to the terminal threshold value. At one time, the terminal transmission unit 32 wirelessly transmits the first response signal via the transmission antenna Tw. In the same case, when the reception strength of the first request signal detected by the strength detection unit 31 is less than the terminal threshold, the terminal transmission unit 32 does not transmit the first response signal.

  FIG. 4 is a flowchart showing the procedure of the second transmission process. Every time the second request data including the vehicle identification data is input from the terminal receiving unit 30 to the input unit 40, the control unit 44 receives the second request signal including the vehicle identification data as the terminal receiving unit. Every time 30 receives, the second transmission process is executed.

First, the control unit 44 reads terminal identification data from the storage unit 43 (step S11), and instructs the output unit 42 to output second response data including the read terminal identification data (step S12). Thereby, the output unit 42 outputs the second response data to the terminal transmission unit 32, and the terminal transmission unit 32 wirelessly transmits the second response signal to the on-vehicle device 10 via the transmission antenna Tw. Therefore, instructing the output unit 42 to output the second response data corresponds to instructing the terminal transmission unit 32 to wirelessly transmit the second response signal.
After executing step S12, the control unit 44 ends the second transmission process.

  As described above, in the wireless terminal 20, the terminal transmitter 32 transmits the second response signal wirelessly every time the terminal receiver 30 receives the second request signal.

  FIG. 5 is a block diagram showing the main configuration of the on-vehicle apparatus 10. As shown in FIG. The on-vehicle apparatus 10 includes a vehicle transmission unit 50, a vehicle reception unit 51, an intensity detection unit 52, a microcomputer 53, a reception antenna Rc, and a transmission antenna Tc. The microcomputer 53 includes output units 60 and 61, input units 62, 63 and 64, a first timer 65, a second timer 66, a clock unit 67, a storage unit 68, and a control unit 69.

  The transmission antenna Tc is connected to the vehicle transmission unit 50. The vehicle transmission unit 50 is connected to the output unit 60 of the microcomputer 53. The reception antenna Rc is connected to the vehicle reception unit 51 and the strength detection unit 52. The vehicle reception unit 51 and the strength detection unit 52 are further connected to input units 62 and 63 of the microcomputer 53. In the microcomputer 53, the output units 60 and 61, the input units 62, 63 and 64, the first timer 65, the second timer 66, the clock unit 67, the storage unit 68 and the control unit 69 are connected to the internal bus 70.

  The output unit 60 outputs the first request data for requesting transmission of the first response signal and the second request data for requesting transmission of the second response signal to the vehicle transmitting unit 50 in accordance with the instruction of the control unit 69.

  When the first request data is input, the vehicle transmission unit 50 wirelessly transmits the first request signal including the input first request data to the wireless terminal 20 via the transmission antenna Tc. The first request data includes vehicle identification data and data indicating that the signal is a first request signal. Similarly, when the second request data is input, the vehicle transmission unit 50 wirelessly transmits a second request signal including the input second request data to the wireless terminal 20 via the transmission antenna Tc. The second request data includes vehicle identification data and data indicating that it is the second request signal.

  The vehicle transmission unit 50 transmits the first request signal each time the first request data is input. Here, the strength of the first request signal at the time of transmission is constant. Similarly, the vehicle transmission unit 50 transmits a second request signal each time the second request data is input. Here, the strength of the second request signal at the time of transmission is constant.

The vehicle reception unit 51 wirelessly receives the first response signal and the second response signal from the wireless terminal 20 via the reception antenna Rc. The vehicle receiver 51 functions as a receiver and a second receiver.
When receiving the first response signal, the vehicle reception unit 51 outputs, to the input unit 40, first response data included in the received first response signal. The first response data includes transmission source identification data. As described above, the first response data of the first response signal transmitted by the wireless terminal 20 includes terminal identification data as transmission source identification data.

  When the vehicle reception unit 51 receives the second response signal, the vehicle reception unit 51 outputs the second response data included in the received second response signal to the input unit 40. The second response data includes transmission source identification data. As described above, the second response data of the second response signal transmitted by the wireless terminal 20 includes terminal identification data as transmission source identification data.

  When data is input from the vehicle receiving unit 51 to the input unit 62, the input unit 62 notifies the control unit 69 to that effect. The control unit 69 acquires the data input to the input unit 62 from the input unit 62. Therefore, the first response data and the second response data are acquired by the control unit 69 from the input unit 62.

  The intensity detection unit 52 detects the reception intensity of the signal received by the vehicle reception unit 51 via the reception antenna Rc. Therefore, the strength detection unit 52 detects the reception strength of the second response signal received by the vehicle reception unit 51. When detecting the reception intensity, the intensity detection unit 52 outputs vehicle intensity data indicating the detected reception intensity to the input unit 63. The control unit 69 acquires the vehicle strength data input to the input unit 63 from the input unit 63.

Locking reception data and unlocking reception data are input to the input unit 64. When the lock receiving data or the unlock receiving data is input, the input unit 64 notifies the control unit 69 of the input data.
The output unit 61 outputs the locking data and the unlocking data to a device (not shown) according to the instruction of the control unit 69. When the output unit 61 outputs the lock data, the plurality of doors 11, 11, ... are locked. When the output unit 61 outputs unlocking data, the plurality of doors 11, 11,... Are unlocked.

Each of the first timer 65 and the second timer 66 starts and ends clocking according to the instruction of the control unit 69. The control unit 69 reads from the first timer 65 the first clocking time counted by the first timer 65, and reads the second clocking time counted by the second timer 66 from the second timer 66.
Control unit 69 acquires date and time data indicating date and time from clock unit 67. The date and time indicated by the date and time data acquired by the control unit 69 is the date and time at the time of acquisition.

  The storage unit 68 is a non-volatile memory. The storage unit 68 stores vehicle identification data and terminal identification data. Further, the storage unit 68 stores the value of the flag. The value of the flag is set to zero or 1 by the control unit 69. Further, the storage unit 68 stores a computer program P5. When the value of the flag is zero, it means that the wireless terminal 20 is not separated from the vicinity of the in-vehicle apparatus 10 at least once after the presence of the wireless terminal 20 in the vicinity of the in-vehicle apparatus 10 is detected. When the value of the flag is 1, it means that the wireless terminal 20 is separated at least once from the vicinity of the in-vehicle apparatus 10 after the presence of the wireless terminal 20 in the vicinity of the in-vehicle apparatus 10 is detected.

  The control unit 69 has one or more CPUs. One or more CPUs of the control unit 69 execute the computer program P5 to execute the separation detection process, the writing process, the first door process, and the second door process. The separation detection process is a process of detecting that the wireless terminal 20 is separated from the vehicle 100, that is, the vicinity of the on-vehicle device 10. The writing process is a process of writing vehicle strength data in the storage unit 68 in association with date and time data. Each of the first door processing and the second door processing is processing for locking or unlocking the plurality of doors 11, 11,. The computer program P5 is used to cause one or more CPUs of the control unit 69 to execute the separation detection process, the writing process, the first door process, and the second door process.

  The computer program P5 may be stored in the storage medium E5 so as to be readable by one or a plurality of CPUs included in the control unit 69. In this case, the computer program P <b> 5 read from the storage medium E <b> 5 is written to the storage unit 68 by a reading device (not shown). The storage medium E5 is an optical disk, a flexible disk, a magnetic disk, a magnetic optical disk, a semiconductor memory, or the like. Alternatively, the computer program P5 may be downloaded from an external device (not shown) connected to a communication network (not shown), and the downloaded computer program P5 may be written in the storage unit 68.

  FIG. 6 is a flowchart showing the procedure of the separation detection process. When the vehicle 100 is parked and the value of the flag is zero, the control unit 69 periodically executes the separation detection process. When the vehicle 100 parks, the value of the flag is zero.

  First, the control unit 69 reads the vehicle identification data from the storage unit 68 (step S21), and instructs the output unit 60 to output the first request data including the read vehicle identification data (step S22). Thus, the output unit 60 outputs the first request data to the vehicle transmission unit 50, and the vehicle transmission unit 50 transmits the first request signal including the first request data input from the output unit 60 through the transmission antenna Tc. And transmit to the wireless terminal 20 by radio. Therefore, instructing the output unit 60 to output the first request data corresponds to instructing the vehicle transmission unit 50 to transmit the first request signal wirelessly.

  As described above, when the wireless terminal 20 receives the first request signal, the wireless terminal 20 transmits the first response signal to the on-vehicle apparatus 10 when the reception intensity of the first request signal is less than the terminal threshold. In the same case, the wireless terminal 20 does not transmit the first response signal to the in-vehicle apparatus 10 when the reception intensity of the first request signal is equal to or higher than the terminal threshold.

  Therefore, the fact that the vehicle reception unit 51 has received the first response signal is that the reception intensity of the first request signal received by the wireless terminal 20 is less than the terminal threshold value, that is, the wireless terminal 20 has moved away from the vicinity of the in-vehicle device 10. It means that That the vehicle reception unit 51 does not receive the first response signal means that the reception intensity of the first request signal received by the wireless terminal 20 is equal to or higher than the terminal threshold, that is, the wireless terminal 20 is separated from the vicinity of the on-vehicle device 10 Means not.

  After executing step S22, the control unit 69 instructs the first timer 65 to start timing (step S23). Thereby, the first timer 65 starts clocking. Next, the control unit 69 determines whether first response data including terminal identification data is input to the input unit 62 (step S24). The fact that the first response data including the terminal identification data is input to the input unit 62 corresponds to that the vehicle reception unit 51 receives the first response signal including the terminal identification data. That the first response data including the terminal identification data is not input to the input unit 62 corresponds to the vehicle reception unit 51 not receiving the first response signal including the terminal identification data.

  When it is determined that the first response data is not input (S24: NO), the controller 69 determines whether or not the first time measured by the first timer 65 is equal to or longer than the reference time ( Step S25). The reference time is a fixed value and is set in advance. If the control unit 69 determines that the first clocked time is less than the reference time (S25: NO), the control unit 69 executes step S24, and the first response data is input to the input unit 62, or the first clocked time Wait until the time exceeds the reference time.

  When it is determined that the first measured time is equal to or longer than the reference time (S25: YES), the control unit 69 instructs the first timer 65 to end the measurement (step S26). As a result, the first timer 65 ends clocking. After executing step S26, the control unit 69 ends the separation detection process.

When it is determined that the first response data is input (S24: YES), the control unit 69 instructs the first timer 65 to finish counting (step S27). As a result, the first timer 65 ends clocking. Next, assuming that the wireless terminal 20 has left the vicinity of the in-vehicle apparatus 10, the control unit 69 sets the value of the flag to 1 (step S28), and ends the separation detection process.
When the control unit 69 executes step S28 and ends the separation detection process, periodic execution of the separation detection process is stopped until the value of the flag is set to zero again.

  As described above, in the in-vehicle device 10, when the value of the flag is zero, the control unit 69 periodically executes the separation detection process, and the vehicle transmission unit 50 repeatedly transmits the first request signal. When the vehicle reception unit 51 receives the first response signal, the control unit 69 sets the value of the flag to 1 on the assumption that the wireless terminal 20 is separated from the vicinity of the on-vehicle device 10, and periodically executes the separation detection process. Stop. The vehicle transmission unit 50 functions as a second transmission unit.

  FIG. 7 is a flowchart showing the procedure of the writing process. The control unit 69 periodically executes the writing process when the value of the flag is 1, that is, when the wireless terminal 20 is separated from the vicinity of the in-vehicle apparatus 10 once.

  First, the control unit 69 reads the vehicle identification data from the storage unit 68 (step S31), and instructs the output unit 60 to output the second request data including the read vehicle identification data (step S32). Thus, the output unit 60 outputs the second request data to the vehicle transmission unit 50, and the vehicle transmission unit 50 transmits the second request signal including the second request data input from the output unit 60 via the transmission antenna Tc. And transmit to the wireless terminal 20 by radio. Therefore, instructing the output unit 60 to output the second request data corresponds to instructing the vehicle transmission unit 50 to transmit the second request signal by radio.

  After executing Step S32, the control unit 69 instructs the first timer 65 to start timing (Step S33). Thereby, the first timer 65 starts clocking. Next, the control unit 69 determines whether second response data including terminal identification data is input to the input unit 62 (step S34). The fact that the second response data including the terminal identification data is input to the input unit 62 corresponds to the vehicle reception unit 51 receiving the second response signal including the terminal identification data. That the second response data including the terminal identification data is not input to the input unit 62 corresponds to the vehicle reception unit 51 not receiving the second response signal including the terminal identification data.

  When it is determined that the second response signal is not input (S34: NO), the control unit 69 determines whether or not the first clocked time counted by the first timer 65 is equal to or longer than the reference time (S34). Step S35). If the control unit 69 determines that the first clocked time is less than the reference time (S35: NO), the control unit 69 executes step S34, and the second response data is input to the input unit 62 or the first clocked time Wait until the time exceeds the reference time.

  When determining that the first clocked time is equal to or longer than the reference time (S35: YES), the control unit 69 instructs the first timer 65 to end the clocking (step S36). As a result, the first timer 65 ends clocking. After executing step S36, the control unit 69 ends the writing process.

  When it is determined that the second response data has been input (S34: YES), the control unit 69 instructs the first timer 65 to end timing (step S37). As a result, the first timer 65 ends clocking. Next, the control unit 69 acquires, from the input unit 62, vehicle intensity data indicating the reception intensity of the second response signal corresponding to the second response data input to the input unit 62 (step S38). Next, control unit 69 acquires date and time data from clock unit 67 (step S39), and writes the vehicle intensity data acquired in step S38 in storage unit 68 in association with the date and time data acquired in step S39 (step S40). The date and time data acquired in step S39 indicates the date and time of acquisition time. After executing step S40, the control unit 69 ends the writing process.

As described above, in the on-vehicle apparatus 10, when the value of the flag is 1, that is, when the vehicle reception unit 51 receives the response signal, the control unit 69 starts periodic execution of the writing process, The vehicle transmission unit 50 starts repeated transmission of the second request signal. The vehicle transmission unit 50 also functions as a transmission unit.
When the vehicle transmission unit 50 repeatedly transmits the second request signal, the vehicle intensity data is written in the storage unit 68 in association with the date and time data each time the vehicle reception unit 51 receives the second response signal. Accordingly, the storage unit 68 stores the reception intensity of the second response signal in association with the date and time when the vehicle reception unit 51 receives the second response signal. Since the vehicle transmission unit 50 repeatedly transmits the second request signal, the storage unit 68 stores a plurality of reception strengths detected by the strength detection unit 52.

FIG. 8 is a flowchart showing the procedure of the first door process. The control unit 69 executes the first door process when the lock reception data or the unlock reception data is input to the input unit 64 when the value of the flag is zero. The control unit 69 executes the separation detection process and the first door process in parallel in a time division manner.
First, the control unit 69 reads vehicle identification data from the storage unit 68 (step S51), and instructs the output unit 60 to output second request data including the read vehicle identification data (step S52). Thus, the output unit 60 outputs the second request data to the vehicle transmission unit 50, and the vehicle transmission unit 50 transmits the second request signal including the second request data input from the output unit 60 via the transmission antenna Tc. And transmit to the wireless terminal 20 by radio.

  After executing Step S52, the control unit 69 instructs the second timer 66 to start timing (Step S53). Thereby, the second timer 66 starts clocking. Next, as in step S34 of the writing process, the control unit 69 determines whether second response data including terminal identification data is input to the input unit 62 (step S54).

  When it is determined that the second response signal is not input (S54: NO), the control unit 69 determines whether or not the second timed time measured by the second timer 66 is equal to or longer than the reference time (S54). Step S55). If the control unit 69 determines that the second timed time is less than the reference time (S55: NO), the control unit 69 executes step S54, and the second response data is input to the input unit 62, or the second timed Wait until the time exceeds the reference time.

  When it is determined that the second clocked time is equal to or longer than the reference time (S55: YES), the control unit 69 instructs the second timer 66 to end the clocking (step S56). As a result, the second timer 66 ends clocking. After executing step S56, the control unit 69 ends the first door process.

  When the second response data is input, that is, when it is determined that the vehicle reception unit 51 receives the second response signal (S 54: YES), the control unit 69 instructs the second timer 66 to finish counting ( Step S57). As a result, the second timer 66 ends clocking. Next, the control unit 69 instructs the output unit 61 to output lock data or unlock data (step S58).

In step S58, when the first door process is started by inputting the lock acceptance data into the input unit 64, the control unit 69 instructs the output of the lock data. When the first door process is started by inputting the unlocking reception data into the input unit 64, the control unit 69 instructs the output of the unlocking data. The output unit 61 outputs locking data or unlocking data in accordance with an instruction from the control unit 69. When the output unit 61 outputs locking data, the plurality of doors 11, 11, ... are locked. When the output unit 61 outputs unlocking data, the plurality of doors 11, 11,... Are unlocked.
After executing step S58, the control unit 69 ends the first door process.

  As described above, in the on-vehicle apparatus 10, when the lock reception data or the unlock reception data is input to the input unit 64 when the value of the flag is zero, the vehicle transmission unit 50 transmits the second request signal. . If the value of the flag is zero, that is, if the wireless terminal 20 is not separated from the vicinity of the on-vehicle apparatus 10, there is a possibility that the second request signal or the second response signal is relayed by a plurality of relays. Low. Therefore, when the value of the flag is zero, when the vehicle reception unit 51 receives the second response signal, the output unit 61 outputs the locking data or the unlocking data, and the plurality of doors 11, 11,. Locking or unlocking is performed.

  FIG. 9 is a flowchart showing the procedure of the second door process. When the value of the flag is 1, that is, when the wireless terminal 20 is separated from the vicinity of the in-vehicle apparatus 10 at least once, when the lock reception data or the unlock reception data is input to the input unit 64. Execute the second door processing.

First, based on the plurality of vehicle strength data stored in storage unit 68, control unit 69 determines whether the reception strength of the second response signal has increased over time (step S61). When the second request signal is received by the wireless terminal 20 that is the transmission source of the second response signal, and the wireless terminal 20 approaches the on-vehicle device 10 that is the transmission source of the second request signal, The reception intensity of the second response signal increases with time. The fact that the reception intensity of the second response signal increases with time means that the wireless terminal 20 is present in the vicinity of the on-vehicle device 10. The control unit 69 detects the presence of the wireless terminal 20 in the vicinity of the on-vehicle apparatus 10 by executing step S61. The control unit 69 functions as a rise determination unit.
In step S61, when the number of vehicle strength data stored in storage unit 68 is zero or one, control unit 69 determines that the reception strength has not increased over time.

  When the control unit 69 determines that the reception intensity of the second response signal does not increase with time (S61: NO), the wireless terminal 20 is locked in the output unit 61, assuming that the wireless terminal 20 does not exist in the vicinity of the on-vehicle device 10. The second door process is terminated without instructing the output of data or unlocking data.

  When control unit 69 determines that the reception intensity of the second response signal is increasing with time (S61: YES), the latest reception intensity among the plurality of reception intensities stored in storage unit 68 is the vehicle. It is determined whether or not it is equal to or greater than the threshold (step S62). The vehicle threshold is a constant value and is preset. If the latest reception strength is equal to or higher than the vehicle threshold, that is, if the latest reception strength is strong, it is certain that the wireless terminal 20 is present in the vicinity of the on-vehicle apparatus 10. The control unit 69 also functions as a strength determination unit.

  If the control unit 69 determines that the latest reception intensity is less than the vehicle threshold (S62: NO), it is determined that the presence of the wireless terminal 20 in the vicinity of the on-vehicle device 10 is not certain. The second door process is terminated without giving an instruction to output the lock data.

  When the control unit 69 determines that the latest reception intensity is equal to or higher than the vehicle threshold (S62: YES), the control unit 69 instructs the output unit 61 to output lock data or unlock data (step S63). In step S63, when the second door process is started by inputting the lock acceptance data into the input unit 64, the control unit 69 instructs the output of the lock data. When the second door process is started by inputting the unlocking reception data into the input unit 64, the control unit 69 instructs the output of the unlocking data. The output unit 61 outputs locking data or unlocking data in accordance with an instruction from the control unit 69.

  After executing step S63, the control unit 69 sets the value of the flag to zero (step S64), deletes the plurality of vehicle strength data stored in the storage unit 68 (step S65), and executes the second door process. Finish.

  As described above, in the on-vehicle apparatus 10, when the lock reception data or the unlock reception data is input to the input unit 64 when the value of the flag is 1, the second door process is performed, and the second response is performed. It is determined whether or not the signal reception intensity increases with time. When the control unit 69 determines that the reception intensity of the second response signal is increasing with time and determines that the latest reception intensity is equal to or higher than the vehicle threshold, the wireless terminal 20 is in the vicinity of the on-vehicle device 10 The output unit 61 outputs locking data or unlocking data on the assumption that it is present. Thereby, locking or unlocking of the plurality of doors 11, 11,... Is performed.

  FIG. 10 is a sequence diagram illustrating an operation example of the communication system 1. When the vehicle 100 is parked and the flag value is zero, the in-vehicle device 10 repeatedly transmits the first request signal to the wireless terminal 20. The wireless terminal 20 does not transmit the first response signal to the on-vehicle apparatus 10 as not being far from the vicinity of the on-vehicle apparatus 10 when the reception intensity of the first request signal is equal to or higher than the terminal threshold. When the reception intensity of the first request signal becomes less than the terminal threshold, the wireless terminal 20 transmits the first response signal to the on-vehicle apparatus 10 assuming that it is separated from the vicinity of the on-vehicle apparatus 10.

  When the on-vehicle apparatus 10 receives the first response signal, it is assumed that the wireless terminal 20 that is the transmission source of the first response signal is separated from the on-vehicle apparatus 10 that is the transmission source of the first request signal. To repeat transmission of the second request signal to the wireless terminal 20. When the wireless terminal 20 receives the second request signal, the wireless terminal 20 transmits a second response signal to the on-vehicle device 10. When the second response signal is received, the in-vehicle apparatus 10 stores the reception intensity of the received second response signal in association with the date and time when the second response signal is received. When the owner of the wireless terminal 20 approaches the on-vehicle apparatus 10, the reception intensity of the second response increases with time.

  When the value of the flag is 1, it is assumed that the push button provided on the doorknob of the door 11 is pressed, and the lock reception data or the unlock reception data is input to the in-vehicle device 10. In this case, the in-vehicle device 10 determines whether the reception intensity of the second response signal is increasing with time based on the plurality of reception intensities stored. When it is determined that the reception intensity of the second response signal is increasing with time, the in-vehicle device 10 determines whether the latest reception intensity of the second response signal is equal to or higher than the vehicle threshold. When it is determined that the latest reception strength is equal to or higher than the vehicle threshold value, the in-vehicle device 10 outputs locking data or unlocking data, and locking or unlocking of the plurality of doors 11, 11,.

When the relay attack is used, the first repeater is disposed in the vicinity of the on-vehicle apparatus 10, and the second repeater is disposed in the vicinity of the wireless terminal 20. The first and second relays relay the first request signal, the second request signal, the first response signal, and the second response signal. When the relay attack is used, the reception strength of the second response signal does not increase with time because the first relay is fixed. Therefore, the on-vehicle apparatus 10 does not erroneously detect the presence of the wireless terminal 20 in the vicinity of the on-vehicle apparatus 10.
In the on-vehicle apparatus 10, the control unit 69 appropriately detects the presence of the wireless terminal 20 in the vicinity of the on-vehicle apparatus 10 by determining whether the reception intensity of the second response signal is increasing with time. Can.

Second Embodiment
The device that detects that the wireless terminal 20 has left the vicinity of the on-vehicle device 10 once is not limited to the wireless terminal 20, and may be the on-vehicle device 10.
The differences between the second embodiment and the first embodiment will be described below. The configuration other than the configuration to be described later is common to the first embodiment. For this reason, the same reference numerals as those of the first embodiment are given to constituent parts common to the first embodiment, and the description thereof is omitted.

When Embodiment 2 is compared with Embodiment 1, the separation detection process performed by the control unit 69 of the in-vehicle apparatus 10 is different.
FIG. 11 is a flowchart illustrating the procedure of the separation detection process according to the second embodiment. As in the first embodiment, when the vehicle 100 is parked, when the value of the flag is zero, the control unit 69 of the in-vehicle device 10 periodically executes the separation detection process. When the vehicle 100 parks, the value of the flag is zero. Steps S71, S73, S75 to S77, and S80 executed by the control unit 69 in the second embodiment are the same as steps S21, S23, S25 to S27, and S28 executed by the control unit 69 in the first embodiment. Therefore, detailed description of steps S71, S73, S75 to S77, and S80 will be omitted.

  After executing step S71, the control unit 69 instructs the output unit 60 to output the second request data not including the first request data but including the vehicle identification data read in step S71 (step S72). Thus, the output unit 60 outputs the second request data to the terminal transmission unit 32, and the terminal transmission unit 32 transmits a second request signal including the second request data. When receiving the second request signal, the wireless terminal 20 transmits a second response signal. After executing step S72, the control unit 69 executes step S73.

  After executing step S73, the control unit 69 determines whether second response data including terminal identification data is input to the input unit 62 (step S74). When the controller 69 determines that the second response data is not input (S74: NO), the controller 69 executes step S75. If the controller 69 determines that the first clocked time is less than the reference time (S75: NO), the controller 69 executes step S74, and the second response data is input to the input unit 62, or the first clocked time Wait until the time exceeds the reference time. When the controller 69 determines that the first clocked time is equal to or longer than the reference time (S75: YES), the controller 69 executes step S76.

  When it is determined that the second response data is input (S74: YES), the control unit 69 executes step S77, and receives the reception intensity of the second response signal corresponding to the second response data input to the input unit 62. The vehicle strength data shown is acquired from the input unit 62 (step S78). As described in the first embodiment, the reception intensity of the second response signal is detected by the intensity detection unit 52. Next, the control unit 69 determines whether or not the reception intensity of the second response signal indicated by the vehicle intensity data acquired in step S78 is less than the second vehicle threshold (step S79). The second vehicle threshold is a constant value and is preset. The second vehicle threshold is less than the vehicle threshold. The second vehicle threshold corresponds to a third threshold. The control unit 69 also functions as a second strength determination unit.

  If the control unit 69 determines that the reception intensity of the second response signal is equal to or higher than the second vehicle threshold (S79: NO), the wireless terminal 20 is not separated from the vicinity of the on-vehicle apparatus 10, and the flag value is zero. The separation detection process is ended in the state maintained at.

  After executing step S76, or when determining that the received intensity of the second response signal is less than the second vehicle threshold (S79: YES), the control unit 69 moves away from the vicinity of the on-vehicle apparatus 10 In step S80, the flag value is set to 1. After executing step S80, the control unit 69 ends the separation detection process. After the flag value is set to 1, the control unit 69 executes the writing process and the second door process as in the first embodiment, and the reception intensity of the second response signal increases with time. Determine if

  FIG. 12 is a sequence diagram illustrating an operation example of the communication system 1. When the value of the flag is zero when the vehicle 100 is parked, the on-vehicle apparatus 10 repeatedly transmits the second request signal to the wireless terminal 20 instead of the first request signal. Every time the wireless terminal 20 receives the second request signal, the wireless terminal 20 transmits a second response signal to the on-vehicle device 10. When the reception intensity of the second response signal is less than the second vehicle threshold, the on-vehicle apparatus 10 sets the value of the flag to 1 on the assumption that the wireless terminal 20 is separated from the vicinity of the on-vehicle apparatus 10. Repeated transmission of the second request signal is started again.

Further, even though the on-vehicle apparatus 10 transmits the second request signal to the wireless terminal 20, the flag on the assumption that the wireless terminal 20 is separated from the vicinity of the on-vehicle apparatus 10 even when the second response signal is not received Is set to 1, and repetitive transmission of the second request signal to the wireless terminal 20 is started again.
The operation of the communication system 1 after the in-vehicle device 10 restarts repeated transmission of the second request signal is the same as that of the first embodiment.

The on-vehicle apparatus 10 according to the second embodiment detects that the wireless terminal 20 is separated from the vicinity of the on-vehicle apparatus 10 based on the reception intensity of the first request signal among the effects exhibited by the on-vehicle apparatus 10 according to the first embodiment. There are other effects except the effects obtained by
In the communication system 1 according to the second embodiment, the in-vehicle device 10 does not transmit the first request signal. Therefore, the control unit 44 of the wireless terminal 20 does not have to execute the first transmission process.

(Embodiment 3)
In the first embodiment, the control unit 44 of the wireless terminal 20 determines whether the reception strength of the first request signal is weak. However, the control unit 69 of the in-vehicle apparatus 10 may determine whether the reception intensity of the first request signal is weak.
The differences between the third embodiment and the first embodiment will be described below. The configuration other than the configuration to be described later is common to the first embodiment. For this reason, the same reference numerals as those of the first embodiment are given to constituent parts common to the first embodiment, and the description thereof is omitted.

  When Embodiment 3 is compared with Embodiment 1, the first transmission process performed by the control unit 44 of the wireless terminal 20 and the separation detection process performed by the control unit 69 of the on-vehicle apparatus 10 are different.

  FIG. 13 is a flowchart showing the procedure of the first transmission process. As in the first embodiment, the control unit 44 executes the first transmission process each time the first request data including the vehicle identification data is input from the terminal receiving unit 30 to the input unit 40. Steps S91 and S92 performed by the control unit 44 in the first transmission process of the third embodiment are the same as steps S1 and S3 of the first transmission process in the first embodiment. Therefore, detailed description of steps S91 and S92 is omitted.

  After executing step S91, the control unit 44 executes step S92 without determining whether the reception intensity of the first request signal is less than the terminal threshold. After executing step S92, the control unit 44 instructs the output unit 42 to output the first response data including the terminal strength data acquired in step S91 and the terminal identification data read in step S92 (step S93). . Thereby, the output unit 42 outputs the first response data to the terminal transmission unit 32, and the terminal transmission unit 32 wirelessly transmits the first response signal including the first response data to the on-vehicle apparatus 10. After executing step S93, the control unit 44 ends the first transmission process.

  As described above, each time the wireless terminal 20 receives the first request signal from the in-vehicle apparatus 10, the wireless terminal 20 transmits, to the in-vehicle apparatus 10, the first response signal including the terminal strength data indicating the reception intensity of the first request signal.

FIG. 14 is a flowchart showing the procedure of the separation detection process. As in the first embodiment, when the value of the flag is zero when the vehicle 100 is parked, the control unit 69 periodically executes the separation detection process. When the vehicle 100 parks, the value of the flag is zero.
Steps S101 to S107 and S109 executed by the control unit 69 in the separation detection process in the third embodiment are the same as steps S21 to S27 and S28 in the first embodiment. For this reason, detailed description of steps S101 to S107, S109 is omitted.

  After executing step S107, control unit 69 determines whether or not the reception intensity of the first request signal indicated by the terminal intensity data of the first response data input to input unit 63 is less than the third vehicle threshold value. (Step S108).

  If the control unit 69 determines that the reception intensity of the first request signal is equal to or higher than the third vehicle threshold (S108: NO), the wireless terminal 20 is not separated from the vicinity of the on-vehicle apparatus 10, and the flag value is zero. The separation detection process is ended in the state maintained at.

  After executing step S106, or when determining that the reception intensity of the first request signal is less than the third vehicle threshold (S108: YES), the control unit 69 moves away from the vicinity of the on-vehicle apparatus 10 In step S109, the flag value is set to 1. After executing step S109, the control unit 69 ends the separation detection process. After the flag value is set to 1, the control unit 69 executes the writing process and the second door process as in the first embodiment, and the reception intensity of the second response signal increases with time. Determine if

  As described above, when the value of the flag is zero, the control unit 69 of the in-vehicle device 10 periodically executes the separation detection processing, and the vehicle transmission unit 50 repeatedly transmits the first request signal to the wireless terminal 20 wirelessly. The vehicle receiving unit 51 wirelessly receives the first response signal including the terminal strength data from the wireless terminal 20. In the separation detection process, the control unit 69 determines whether the reception intensity of the first request signal indicated by the terminal intensity data of the first response data included in the first response signal is less than the third vehicle threshold. Do. If the reception strength is less than the third vehicle threshold or the vehicle reception unit 51 does not receive the first response signal, the control unit 69 determines that the wireless terminal 20 is separated from the vicinity of the on-vehicle device 10, a flag Set the value of to 1. Thereafter, the control unit 69 periodically executes the writing process, and the vehicle transmission unit 50 starts repeated transmission of the second request signal.

The vehicle transmission unit 50 also functions as a third transmission unit. The vehicle reception unit 51 also functions as a third reception unit. The control unit 69 also functions as a third strength determination unit. The third vehicle threshold corresponds to a fourth threshold.
In the third embodiment, the first request signal and the first response signal correspond to a third request signal and a third response signal, respectively.

  FIG. 15 is a sequence diagram showing an operation example of the communication system 1. When the vehicle 100 is parked, the in-vehicle device 10 repeatedly transmits the first request signal to the wireless terminal 20 when the value of the flag is zero. Every time the wireless terminal 20 receives the first request signal, the wireless terminal 20 transmits, to the on-vehicle apparatus 10, a second response signal including terminal intensity data indicating the reception intensity of the first request signal. When the reception intensity of the first request signal becomes less than the third vehicle threshold, the on-vehicle apparatus 10 sets the value of the flag to 1 on the assumption that the wireless terminal 20 is separated from the vicinity of the on-vehicle apparatus 10. The repeated transmission of the second request signal of After that, it is determined whether the reception intensity of the second response signal is increasing with time.

Also, even though the on-vehicle apparatus 10 transmits the first request signal to the wireless terminal 20, the flag on the assumption that the wireless terminal 20 is separated from the vicinity of the on-vehicle apparatus 10 even when the first response signal is not received Is set to 1, and repetitive transmission of the second request signal to the wireless terminal 20 is started.
The operation of the communication system 1 after the in-vehicle device 10 starts repetitive transmission of the second request signal is the same as that of the first embodiment.

  In the first to third embodiments, the timing at which it is determined whether the reception intensity of the second response signal increases with time is the timing of locking or unlocking the plurality of doors 11, 11,. It is not limited, For example, the timing which starts the engine of the vehicle 100 may be sufficient. For example, when data indicating that an engine start instruction has been received is input to the in-vehicle apparatus 10, the control unit 69 of the in-vehicle apparatus 10 may perform the same process as the second door process. In this configuration, when the control unit 69 of the in-vehicle apparatus 10 determines that the reception intensity of the second response signal is increasing with time and determines that the latest reception intensity is equal to or higher than the vehicle threshold, The output unit 61 of the device 10 outputs data instructing start of the engine, and the engine is started.

  The disclosed embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the present invention is indicated not by the meaning described above but by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

DESCRIPTION OF SYMBOLS 1 communication system 10 vehicle-mounted apparatus 11 door 20 radio | wireless terminal 30 terminal reception part 31, 52 intensity | strength detection part 32 terminal transmission part 33, 53 microcomputer 40, 41, 62, 63, 64 input part 42, 60, 61 output part 43, 68 Storage unit 44 Control unit 45, 70 Internal bus 50 Vehicle transmission unit (Transmission unit, second transmission unit, third transmission unit)
51 Vehicle Receiver (Receiver, Second Receiver, Third Receiver)
65 first timer 66 second timer 67 clock unit 69 control unit (rise determination unit, strength determination unit, second strength determination unit, third strength determination unit)
100 vehicle E3, E5 storage medium P3, P5 computer program Rc, Rw receive antenna Tc, Tw transmit antenna

Claims (8)

A transmitter for repeatedly transmitting a request signal requesting transmission of a response signal by radio;
A receiving unit that wirelessly receives the response signal;
A detection unit that detects the reception intensity of the response signal received by the reception unit;
And a rise determination unit that determines whether the reception intensity of the response signal is increasing with time based on a plurality of reception intensities detected by the detection unit. The output unit for outputting unlocking data for instructing the unlocking of the door of the vehicle when the rise determination unit determines that the reception intensity of the response signal is increasing with time, The in-vehicle device described. When the rise determination unit determines that the reception intensity of the response signal is increasing with time, whether or not the latest reception intensity among the plurality of reception intensities detected by the detection unit is equal to or more than a threshold value Provided with an intensity determination unit that determines
The in-vehicle apparatus according to claim 2, wherein the output unit outputs the unlocking data when the strength determination unit determines that the latest reception strength is equal to or more than the threshold. A second transmission unit that repeatedly and wirelessly transmits a second request signal requesting transmission of a second response signal;
A second receiving unit that wirelessly receives the second response signal;
The second response signal is transmitted when the reception strength of the second request signal is less than a second threshold,
The in-vehicle apparatus according to any one of claims 1 to 3, wherein the transmission unit starts repeated transmission of the request signal when the second reception unit receives the second response signal. . A second intensity determination unit that determines whether the reception intensity detected by the detection unit is less than a third threshold;
The rise determination unit according to any one of claims 1 to 3, wherein the determination is performed after the second strength determination unit determines that the reception strength is less than the third threshold. In-vehicle device. A third transmission unit that wirelessly and repeatedly transmits a third request signal requesting transmission of a third response signal;
A third receiver wirelessly receiving a third response signal including strength data indicating reception strength of the third request signal;
A third strength determination unit that determines whether the reception strength indicated by the strength data included in the third response signal received by the third reception unit is less than a fourth threshold;
The transmission unit starts repeated transmission of the request signal when it is determined by the third strength determination unit that the reception strength indicated by the strength data is less than the fourth threshold. The vehicle-mounted apparatus as described in any one of Claim 3. Wirelessly repeatedly transmitting a request signal requesting transmission of a response signal;
Determining whether the reception strength of the response signal has increased over time based on a plurality of reception strengths of the plurality of response signals. On the computer,
Repeatedly instructing wireless transmission of a request signal requesting transmission of a response signal;
A computer program for performing, based on a plurality of reception strengths of a plurality of the response signals, determining whether the reception strength of the response signal is increasing with time.

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