JP6673155B2 - Vehicle communication system and on-board equipment - Google Patents

Description

  The present invention relates to a vehicle communication system and an in-vehicle device.

A vehicle communication system that locks and unlocks a vehicle door without using a mechanical key has been put to practical use. Specifically, a keyless entry system that locks or unlocks a vehicle door by wireless remote control using a portable device carried by a user, or a user who possesses a portable device approaches a vehicle or simply grasps a door handle. For example, a smart entry (registered trademark) system for unlocking a vehicle door has been put to practical use (for example, see Patent Document 1).
Also, a vehicle communication system for starting a vehicle engine without using a mechanical key has been put to practical use. More specifically, a push start system has been put to practical use in which a user who has a portable device starts an engine simply by pressing an engine start button.
Further, a welcome light system has been put to practical use that turns on an interior light or an exterior light when a user having a portable device approaches a vehicle.

  In the vehicle communication system described above, the in-vehicle device performs wireless communication with the portable device. In the wireless communication, various signals are transmitted from a transmission antenna of a vehicle-mounted device to a portable device using radio waves in an LF (Low Frequency) band, and the portable device receiving the signal transmits the signals using a radio wave in an RF (Radio Frequency) band. This is done by sending a response signal. The in-vehicle device controls unlocking, locking, starting the engine, turning on the welcome light, and the like after performing authentication and position confirmation of the mobile device.

JP 2015-101908 A

  Incidentally, the signal transmitted from the vehicle-mounted device is a signal in the LF band, and the transmission range of the signal is limited to a predetermined range around the vehicle. In order to detect the position of the portable device with high accuracy or to detect the portable device approaching the vehicle early, for example, it is conceivable to increase the current value of the current supplied to the transmitting antenna to extend the communication distance.

  However, when the current value of the current supplied to the transmitting antenna is increased, the dark current increases, which causes a problem that power consumption increases.

  The present invention has been made in view of such circumstances, and provides a vehicle communication system and a vehicle-mounted device that can extend the communication distance between the vehicle-mounted device and the portable device without increasing power consumption. With the goal.

  A communication system for a vehicle according to one embodiment of the present application includes an in-vehicle device that periodically transmits a signal from an antenna provided in a vehicle, a signal transmitted from the in-vehicle device, and a response signal corresponding to the received signal. A communication system for a vehicle, comprising: a portable device that transmits a signal.The communication device for a vehicle includes a rotation drive unit that is connected to the vehicle-mounted device and that rotates the antenna under control from the vehicle-mounted device. A detection unit configured to detect a get-off operation of an occupant in the vehicle, a position detection unit configured to detect a position of the portable device in a time series based on a response signal from the portable device, A specifying unit that specifies a moving direction of the portable device after detecting the getting-off operation based on a change in a time-series position, and the turning unit so that the antenna points in a direction corresponding to the specified moving direction. Controls the operation of the drive And a part.

  An in-vehicle device according to one embodiment of the present application is a in-vehicle device that periodically transmits a signal from an antenna provided in a vehicle and receives a response signal from the portable device to the signal, and includes a circuit for rotating the antenna. A control unit that controls the operation of the dynamic drive unit, a detection unit that detects an unloading operation of an occupant in the vehicle, and a time-series position of the portable device based on a response signal from the portable device. A position detection unit that detects the change in the time-series position of the portable device, based on a change in the time-series position of the portable device, a specifying unit that specifies the moving direction of the portable device after detecting the getting-off operation, the control unit, The operation of the rotation drive unit is controlled such that the antenna points in a direction corresponding to the movement direction specified by the specifying unit.

  According to the present application, the communication distance between the vehicle-mounted device and the portable device can be extended without increasing power consumption.

1 is a schematic diagram illustrating a schematic configuration of a vehicle communication system according to the present embodiment. It is a block diagram explaining the internal structure of an in-vehicle device. FIG. 3 is a block diagram illustrating an internal configuration of the portable device. FIG. 3 is an explanatory diagram illustrating the direction of an LF transmission antenna. FIG. 3 is an explanatory diagram illustrating the direction of an LF transmission antenna. It is a flowchart explaining the procedure of the process which an in-vehicle device performs when an occupant gets off. It is a flowchart explaining the procedure of the process which an in-vehicle device performs when an occupant gets on. FIG. 13 is a diagram illustrating the orientation of the LF transmission antenna changed in the second embodiment. FIG. 15 is a diagram illustrating the orientation of the LF transmission antenna that is changed in Embodiment 3.

  Embodiments of the present invention are listed and described. Further, at least some of the embodiments described below may be arbitrarily combined.

  A communication system for a vehicle according to one embodiment of the present application includes an in-vehicle device that periodically transmits a signal from an antenna provided in a vehicle, a signal transmitted from the in-vehicle device, and a response signal corresponding to the received signal. A communication system for a vehicle, comprising: a portable device that transmits a signal.The communication device for a vehicle includes a rotation drive unit that is connected to the vehicle-mounted device and that rotates the antenna under control from the vehicle-mounted device. A detection unit configured to detect a get-off operation of an occupant in the vehicle, a position detection unit configured to detect a position of the portable device in a time series based on a response signal from the portable device, A specifying unit that specifies a moving direction of the portable device after detecting the getting-off operation based on a change in a time-series position, and the turning unit so that the antenna points in a direction corresponding to the specified moving direction. Controls the operation of the drive And a part.

  In the above aspect, the moving direction of the occupant at the time of getting off is specified by detecting the position of the portable device, and the direction of the antenna is changed according to the specified moving direction, so that the current value of the current supplied to the antenna is increased. The communication distance can be extended without causing the communication distance. When the occupant approaching the vehicle from the same direction carries the portable device, the in-vehicle device can quickly detect the presence of the portable device.

  An in-vehicle device according to one embodiment of the present application is a in-vehicle device that periodically transmits a signal from an antenna provided in a vehicle and receives a response signal from the portable device to the signal, and includes a circuit for rotating the antenna. A control unit that controls the operation of the dynamic drive unit, a detection unit that detects an unloading operation of an occupant in the vehicle, and a time-series position of the portable device based on a response signal from the portable device. A position detection unit that detects the change in the time-series position of the portable device, based on a change in the time-series position of the portable device, a specifying unit that specifies the moving direction of the portable device after detecting the getting-off operation, the control unit, The operation of the rotation drive unit is controlled such that the antenna points in a direction corresponding to the movement direction specified by the specifying unit.

  In the above aspect, the moving direction of the occupant at the time of getting off is specified by detecting the position of the portable device, and the direction of the antenna is changed according to the specified moving direction, so that the current value of the current supplied to the antenna is increased. The communication distance can be extended without causing the communication distance. When the occupant approaching the vehicle from the same direction carries the portable device, the in-vehicle device can quickly detect the presence of the portable device.

  The in-vehicle device according to one aspect of the present application determines whether or not a response signal from the portable device to a signal transmitted from the antenna is received in a state where the antenna faces in a direction corresponding to the moving direction. When the control unit determines that the response signal has been received, the control unit controls the operation of the rotation driving unit so that the antenna is oriented in a preset direction.

  In the above aspect, when a response signal transmitted from the portable device is received when the occupant gets on the vehicle, the antenna is controlled so as to face a preset direction, so that the position of the portable device is always detected in the same posture. Since it can be performed, the accuracy of position detection can be maintained.

  In the vehicle-mounted device according to one aspect of the present application, the antenna has directivity, and the control unit determines a direction in which a radiation intensity of a radio wave emitted from the antenna is maximum, and the movement specified by the identification unit. The operation of the rotation drive unit is controlled so that the directions match.

  In the above aspect, the rotation drive unit is controlled such that the direction in which the radiation intensity of the radio wave emitted from the antenna becomes maximum matches the moving direction of the portable device specified when the occupant gets off the vehicle. The occupant who gets off the vehicle often approaches the vehicle at the next getting on from the same direction as the moving direction at the time of getting off. In the above aspect, the direction of the antenna is changed so that the direction in which the intensity of the radio wave becomes maximum coincides with the moving direction specified at the time of getting off, so that the occupant approaching the vehicle from the same direction can carry the portable device. If so, the portable device can be detected quickly.

  The in-vehicle device according to one aspect of the present application, the specifying unit is configured such that the position of the portable device first detected by the position detecting unit within the communication range of the antenna, and the position of the portable device detected last. The moving direction is specified by the direction of a straight line connecting.

  In the above aspect, the direction of the straight line connecting the position of the portable device detected first in the communication range of the antenna and the position of the portable device detected last is determined by moving the portable device when the occupant gets off the vehicle. Specify as a direction. When the vehicle is equipped with multiple antennas, the orientation of each antenna is changed according to the specified direction of movement, so that the portable device carried by the occupant approaching the vehicle from the same direction as when getting off can be viewed from a greater distance. It becomes possible to detect.

  In the vehicle-mounted device according to an aspect of the present application, the specifying unit specifies the moving direction by a direction of a straight line connecting an antenna center of the antenna and a position of the portable device last detected by the position detecting unit. .

  In the above aspect, the direction of a straight line connecting the antenna center of the antenna and the position of the portable device last detected in the communication range of the antenna is specified as the moving direction of the portable device when the occupant gets off the vehicle. When the vehicle is equipped with multiple antennas, the orientation of each antenna is individually changed in accordance with the specified moving direction, so that the portable device carried by the occupant approaching the vehicle from the same direction as when getting off can be improved. It becomes possible to detect from a distant place.

Hereinafter, the present invention will be specifically described with reference to the drawings showing the embodiments.
(Embodiment 1)
FIG. 1 is a schematic diagram illustrating a schematic configuration of a vehicle communication system according to the present embodiment. The vehicle communication system according to the present embodiment includes, for example, an in-vehicle device 100 mounted on a vehicle C and a portable device 200 operated by an occupant.

  The on-vehicle device 100 is one of a plurality of ECUs (Electronic Controller Units) mounted on the vehicle, and controls the locking and unlocking of the vehicle door, as well as the air conditioner, the interior and exterior lights, and the body. This is a so-called BCM (Body Control Module) that performs integrated control of the operation of the system actuator and the like.

  The in-vehicle device 100 includes a plurality of LF transmission antennas 105a to 105d and an RF reception antenna 106a for performing wireless communication with the portable device 200. The LF transmission antennas 105a to 105d are, for example, antennas provided around each vehicle door, in each tire house, and the like, and transmit a signal having an LF band frequency (hereinafter, also referred to as an LF signal). In the present embodiment, an LF transmission antenna 105a having a communication range Ra within the vehicle is provided inside the vehicle C. Further, in the present embodiment, LF transmission antennas 105b to 105d having predetermined areas outside the vehicle as communication ranges Rb to Rd are provided near the vehicle door on the driver side, the vehicle door on the passenger side, and the rear door, respectively. ing. The RF receiving antenna 106a is, for example, an antenna built in the vehicle-mounted device 100, and receives a signal having an RF band frequency (hereinafter, also referred to as an RF signal). The number and arrangement of the antennas mounted on the vehicle C are not limited to the example of FIG.

  The portable device 200 includes an unlock button 203a and a lock button 203b in order to receive operations for unlocking and locking the vehicle door (see FIG. 3). In addition, the portable device 200 includes an LF receiving unit 204 and an RF transmitting unit 205 for performing wireless communication with the in-vehicle device 100 mounted on the vehicle C (see FIG. 3). When the portable device 200 receives an operation related to unlocking or locking the vehicle door by the unlock button 203a or the lock button 203b, the portable device 200 transmits a signal instructing unlocking or locking of the vehicle door from the RF transmission unit 205. Is possible.

  In such a vehicular communication system between the on-vehicle device 100 and the portable device 200, the communication range of the wireless communication using the RF signal is about several tens of meters, whereas the communication range of the wireless communication using the LF signal is It is about several meters. In the present embodiment, in order to extend the communication distance using the LF transmission antennas 105a to 105d without increasing the current value of the current supplied to the LF transmission antennas 105a to 105d, it is necessary to adjust the situation when the occupant gets off the vehicle. , The direction of the LF transmission antennas 105a to 105d is changed.

  FIG. 2 is a block diagram illustrating an internal configuration of the vehicle-mounted device 100. The in-vehicle device 100 includes a control unit 101, a storage unit 102, an input unit 103, an in-vehicle communication unit 104, an LF transmission unit 105, an RF reception unit 106, an output unit 107, and the like.

  The control unit 101 includes, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The CPU in the control unit 101 controls the operation of the hardware provided in the vehicle-mounted device 100 by executing the control program stored in the ROM, and causes the entire device to function as the vehicle-mounted device of the present application. Various data generated during the execution of the control program is stored in the RAM in the control unit 101. Note that the control unit 101 may include functions such as a timer for measuring an elapsed time from when a measurement start instruction is given to when a measurement end instruction is given, and a counter for counting the number.

  The storage unit 102 is configured by a nonvolatile memory such as an EEPROM (Electronically Erasable Programmable Read Only Memory), and stores various information. Here, various types of information stored in the storage unit 102 include, for example, authentication information such as an ID (Identifier) of the vehicle C on which the vehicle-mounted device 100 is mounted, an ID of the portable device 200 as a communication partner, and key information used for encryption processing. Is included.

  The input unit 103 includes an interface for connecting a shift sensor 111, a vehicle speed sensor 112, a seat sensor 113, a buckle SW (switch) 114, a courtesy SW (switch) 115, an in-vehicle camera 116, and the like.

  The shift sensor 111 is a sensor that detects an operation position of a shift lever included in the vehicle C. When the shift lever is operated, the shift sensor 111 detects the operated position of the shift lever after the operation, and outputs a detection result to the vehicle-mounted device 100. Note that the shift sensor 111 may be a sensor that detects the operation position of the shift switch instead of the operation position of the shift lever.

  The vehicle speed sensor 112 is a sensor that measures the traveling speed (vehicle speed) of the vehicle C. The vehicle speed sensor 112 outputs the measured vehicle speed to the vehicle-mounted device 100.

  The seat sensor 113 is a sensor for detecting a seated state of the occupant. The seating sensor 113 is provided in each seat of the vehicle C such as a driver seat, a passenger seat, and a rear seat, and detects a seating state of an occupant for each seat based on weight or pressure applied to the seat. I do. The seat sensor 113 outputs a signal indicating the detection result to the vehicle-mounted device 100.

  The buckle SW 114 is a switch for detecting the attachment / detachment of the seat belt. The buckle SW 114 is provided, for example, on a buckle of the seat belt, and detects attachment / detachment of the seat belt by detecting a tongue inserted into the buckle, and outputs a detection result to the vehicle-mounted device 100.

  The courtesy SW 115 is a switch that detects opening and closing of a vehicle door. The courtesy SW 115 detects the opening and closing of the vehicle doors of the vehicle C such as the driver's seat door, the passenger's seat door, the rear seat door, and the rear door for each door. The courtesy SW 115 outputs the detection result to the vehicle-mounted device 100.

  The in-vehicle camera 116 is an imaging device that captures an image of the inside of the vehicle C. The in-vehicle camera 116 is installed at an appropriate place in the vehicle so that an occupant including a driver can be imaged, and outputs image data obtained by imaging to the vehicle-mounted device 100.

  The in-vehicle communication unit 104 includes, for example, a CAN communication interface (CAN: Controller Area Network), and is connected to another ECU included in the vehicle C via a CAN bus. The in-vehicle communication unit 104 transmits and receives data to and from another ECU (not shown) according to the CAN protocol.

  The LF transmission unit 105 includes a signal generation circuit that generates an LF signal based on the signal output from the control unit 101, an amplification circuit that amplifies the generated signal, and the like, and outputs the amplified signal to the LF transmission antennas 105a to 105d. Send more externally. The LF transmitting unit 105 intermittently transmits, for example, a detection signal (LF signal) for detecting the position of the portable device 200 from the LF transmitting antennas 105a to 105d according to an instruction from the control unit 101. Here, it is assumed that the authentication information stored in the storage unit 102 is added to the LF signal transmitted from the LF transmission unit 105.

  The RF receiving unit 106 is connected to the RF receiving antenna 106a, and includes a receiving circuit or the like that receives an RF signal through the RF receiving antenna 106a. In the present embodiment, after transmitting a signal for detecting the position of portable device 200 through LF transmitting section 105, a response signal in the RF band transmitted from portable device 200 is received through RF receiving antenna 106a. RF receiving section 106 outputs information included in the received response signal to control section 101. The information included in the response signal includes, for example, authentication information added by the portable device 200, and the control unit 101 performs an authentication process of the portable device 200 based on the authentication information input from the RF receiving unit 106. Can be performed.

  The output unit 107 includes an interface that connects the LF antenna rotation driving units 120a to 120d. The LF antenna rotation drive unit 120a includes a rotation mechanism that rotates the LF transmission antenna 105a provided inside the vehicle C around a predetermined rotation axis, an electric motor that drives the rotation mechanism, and the like. Similarly, the LF antenna rotation drive units 120b to 120d respectively control the LF transmission antennas 105b to 105d provided in the vicinity of the vehicle door on the driver's seat side, the vehicle door on the passenger's seat side, and the rear door. And an electric motor for driving the rotating mechanism. The control unit 101 outputs a control signal for controlling the operation of the LF antenna rotation drive units 120a to 120d from the output unit 107, and controls the operation of the LF antenna rotation drive units 120a to 120d, thereby controlling the LF antenna rotation drive units 120a to 120d. The transmitting antennas 105a to 105d can be individually rotated.

  FIG. 3 is a block diagram illustrating the internal configuration of the portable device 200. The portable device 200 includes a control unit 201, a storage unit 202, an operation unit 203, an LF reception unit 204, an RF transmission unit 205, and the like.

  The control unit 201 includes, for example, a CPU, a ROM, and the like. The CPU in the control unit 201 controls the operation of each hardware included in the portable device 200 by executing the control program stored in the ROM, and causes the entire device to function as the portable device of the present application. Note that the control unit 201 may include functions such as a timer that measures the elapsed time from when a measurement start instruction is given to when a measurement end instruction is given, and a counter that counts the number.

  The storage unit 202 is configured by a nonvolatile memory such as an EEPROM, and stores various information. Here, the various information stored in the storage unit 202 includes, for example, authentication information such as an ID of the portable device 200, an ID of the vehicle C on which the in-vehicle device 100 as a communication partner is mounted, and key information used for encryption processing. .

  The operation unit 203 includes an interface for receiving an operation by an occupant. In the present embodiment, the operation unit 203 includes an unlock button 203a operated when unlocking the door of the vehicle C and a lock button 203b operated when locking the door of the vehicle C. When the unlock button 203a (or the lock button 203b) is operated by the occupant, the operation unit 203 outputs to the control unit 201 a signal indicating that the unlock button 203a (or the lock button 203b) is operated. When receiving a signal indicating that the unlock button 203a (or the lock button 203b) has been operated, the control unit 201 sends a control signal for instructing unlocking (or locking) of the door of the vehicle C to the RF transmitting unit 205. I do.

  The LF receiving unit 204 is connected to the LF receiving antenna 204a, and includes a receiving circuit that receives the LF signal through the LF receiving antenna 204a, a measuring circuit that measures the signal strength of the received signal, and the like. In the present embodiment, when signals transmitted from LF transmitting antennas 105a to 105d of vehicle C are received by LF receiving antenna 204a, LF receiving section 204 measures the signal strength of the received signal and receives the received signal. And information of the measured signal strength (RSSI: Received Signal Strength Indicator) is output to the control unit 201.

  The RF transmission unit 205 includes a signal generation circuit that generates an RF signal in accordance with an instruction from the control unit 201, an amplification circuit that amplifies the generated RF signal, and the like. The amplified RF signal is transmitted from the RF transmission antenna 205a. Send to outside. For example, when a signal transmitted from the LF transmission antennas 105a to 105d of the vehicle C is received by the LF reception antenna 204a, the control unit 201 returns the response signal (RF signal) including the RSSI of the reception signal to return the response signal (RF signal). It instructs the transmission unit 205. The RF transmitting unit 205 transmits an RF signal including the RSSI of the received signal and the authentication information stored in the storage unit 202 from the RF transmitting antenna 205a in response to an instruction from the control unit 201.

Hereinafter, the operation of the vehicle communication system according to the present embodiment will be described.
4 and 5 are explanatory diagrams illustrating the directions of the LF transmission antennas 105a to 105d. FIG. 4 schematically shows the default orientation of each of the LF transmission antennas 105a to 105d. Each of the LF transmission antennas 105a to 105d includes, for example, a rod-shaped magnetic core made of ferrite, and a coil formed by winding a conductive wire around the magnetic core. It has the maximum directivity. By default, the LF transmitting antenna 105a in the vehicle and the LF transmitting antenna 105d in the rear door are located at appropriate positions on the vehicle C such that the direction in which the radiation intensity of the radio wave becomes maximum (the longitudinal direction of the magnetic core) is directed to the vehicle width direction, for example. It shall be installed in In the LF transmission antennas 105b and 105c of the driver's seat side vehicle door and the passenger's seat side vehicle door, by default, the direction in which the radiation intensity of the radio wave is maximum (the longitudinal direction of the magnetic core) is, for example, in the front-back direction of the vehicle C. Thus, it is assumed that it is installed at an appropriate place of the vehicle C. In the following description, the direction in which the radiation intensity of the radio waves emitted from each of the LF transmission antennas 105a to 105d is maximum is simply referred to as the radiation direction.

  In the present embodiment, the directions of the LF transmission antennas 105a to 105d are changed when the occupant carrying the portable device 200 gets on and off the vehicle. Specifically, the in-vehicle device 100 specifies the moving direction of the portable device 200 when the occupant gets off (ie, the moving direction of the occupant carrying the portable device 200), and sets the orientation of the LF transmission antennas 105a to 105d to the default. The direction is changed to the direction according to the moving direction of the portable device 200. Further, when the occupant gets on the vehicle, the occupant carrying the portable device 200 approaches the vehicle C, turns on the vehicle light by the welcome light system, and then sets the orientation of the LF transmission antennas 105a to 105d to the default. Perform the process to return to the orientation. The in-vehicle device 100 detects the position of the portable device 200 after changing the LF transmission antennas 105a to 105d to the default orientation.

  In Embodiment 1, a configuration in which the direction of a specific LF transmission antenna (for example, LF transmission antenna 105b) is changed will be described. In the second and third embodiments, a configuration will be described in which the directions of all the LF transmission antennas 105a to 105d are changed based on the moving direction of the portable device 200.

  FIG. 5 schematically illustrates the directions of the LF transmission antennas 105a to 105d when the occupant carrying the portable device 200 completes the getting-off operation. In the present embodiment, when the occupant carrying the portable device 200 gets off from the vehicle C, the occupant communicates between the in-vehicle device 100 and the portable device 200 periodically (for example, at one-second intervals). Are detected in time series. The example of FIG. 5 illustrates a state in which the in-vehicle device 100 detects the position of the portable device 200 at n points (n is, for example, an integer of 2 or more) at positions P1, P2,.

  The control unit 101 of the in-vehicle device 100 can identify the moving direction of the portable device 200 by detecting the position of the portable device 200 in time series. For example, the control unit 101 determines the position P1 of the portable device 200 first detected in the communication range of any of the LF transmission antennas 105a to 105d and the position Pn of the portable device 200 detected last in the communication range. The direction of the connecting straight line can be specified as the moving direction of the portable device 200. In addition, the control unit 101 may specify the direction of a straight line connecting the antenna centers of the LF transmission antennas 105a to 105d and the position Pn of the portable device 200 that was last detected as the moving direction of the portable device 200.

  When the moving direction of the portable device 200 is specified, the control unit 101 controls the operation of the LF antenna rotation driving units 120a to 120d such that the radiation directions of the LF transmitting antennas 105a to 105d are directed to the moving direction of the portable device 200. Control signal to change the direction of the LF transmission antennas 105a to 105d. In the example of FIG. 5, since the moving direction of the portable device 200 is included in the communication range Rb of the LF transmitting antenna 105b, only the direction of the LF transmitting antenna 105b is changed.

Hereinafter, the procedure of the process executed by the vehicle-mounted device 100 will be described.
FIG. 6 is a flowchart illustrating a procedure of a process executed by the vehicle-mounted device 100 when the occupant gets off the vehicle. The control unit 101 of the in-vehicle device 100 executes the following processing at regular timings while the vehicle C is traveling, for example. The control unit 101 determines whether the stop of the vehicle C is detected (Step S101). For example, the control unit 101 acquires the detection result of the shift sensor 111 and the measurement result of the vehicle speed sensor 112 through the input unit 103, the shift lever is operated to the parking position, and the vehicle speed of the vehicle C is, for example, 0 km / h. When it is determined that there is, the vehicle C can be determined to be in a stopped state. When it is determined that the stop of the vehicle C has not been detected (S101: NO), the control unit 101 ends the processing according to this flowchart without executing the following processing.

  When the stop of the vehicle C is detected (S101: YES), the control unit 101 determines whether or not the getting-off operation of the occupant (for example, the driver) is detected (step S102). The control unit 101 can detect an occupant's getting off operation based on information from various devices input through the input unit 103. For example, the control unit 101 acquires the detection results of the seat sensor 113 and the buckle SW 114, and determines that the occupant has detected the getting-off operation of the occupant when the occupant is in a seated state and the seat belt is not fastened. May be.

  In addition, the control unit 101 acquires the detection result of the open / close state of the vehicle door by the courtesy SW 115, and when determining that the vehicle door has transitioned from the closed state to the open state, determines that the occupant's exit operation has been detected. Is also good. Further, based on the video data obtained by the in-vehicle camera 116, the control unit 101 performs image analysis on the occupant operation related to getting off, such as the occupant operation of unlocking the vehicle door and the occupant operation of removing the seat belt. When it is determined that the occupant has been detected, it may be determined that the occupant's getting off operation has been detected.

  In addition, the control unit 101 detects the occupant's dismounting operation by arbitrarily combining the above-described occupant's seating state, seatbelt wearing state, door lock state, and detection result of the occupant's dismounting operation based on the video data. Is also good. Further, the control unit 101 may be configured to acquire the detection result of the getting-off operation detected by another ECU through the in-vehicle communication unit 104.

  When it is determined that the occupant's getting off operation has not been detected (S102: NO), the control unit 101 ends the processing according to this flowchart without executing the following processing.

  When it is determined that the occupant's getting off operation has been detected (S102: YES), the control unit 101 detects the position of the portable device 200 in a time-series manner (step S103). At this time, the control unit 101 controls the LF transmission unit 105 to periodically transmit a detection signal for detecting the portable device 200 from each of the LF transmission antennas 105a to 105d. Each time the portable device 200 receives the detection signal periodically transmitted from the on-vehicle device 100, the portable device 200 measures the reception intensity and returns a response signal including information (RSSI) of the measured reception intensity. The control unit 101 detects the position of the portable device 200 based on the information of the reception intensity included in the response signal received through the RF reception unit 106.

  When communication with the portable device 200 is interrupted, that is, when it can be determined that the portable device 200 has moved outside the communication range Ra to Rd of the LF transmission antennas 105a to 105d, the control unit 101 The moving direction of the portable device 200 is specified based on the position of the device 200 (step S104). The control unit 101 is a straight line connecting the position P1 of the portable device 200 detected first in any communication range of the LF transmission antennas 105a to 105d and the position Pn of the portable device 200 detected last in the communication range. May be specified as the moving direction of the portable device 200. In addition, the control unit 101 may specify the direction of a straight line connecting the antenna centers of the LF transmission antennas 105a to 105d and the position Pn of the portable device 200 that was last detected as the moving direction of the portable device 200.

  Next, the control unit 101 changes the direction of the LF transmission antenna 105b (or the transmission antennas 105a, 105c, and 105d) based on the moving direction of the portable device 200 specified in step S104 (step S105). For example, in the example of FIG. 5, since the movement route of the portable device 200 is included within the communication range Rb of the LF transmission antenna 105b, the control unit 101 determines that the radiation direction of the LF transmission antenna 105b is the movement direction of the portable device 200. A control signal for controlling the LF antenna rotation drive unit 120b is output from the output unit 107 so as to face the LF transmission antenna 105b, and the direction of the LF transmission antenna 105b is changed. The same applies to the case where the movement route of the portable device 200 is included in the communication ranges Ra, Rc, Rd of the other LF transmission antennas 105a, 105c, 105d.

  FIG. 7 is a flowchart illustrating a procedure of a process executed by the vehicle-mounted device 100 when the occupant gets on the vehicle. The control unit 101 of the on-vehicle device 100 periodically transmits a detection signal for detecting the portable device 200 from each of the LF transmission antennas 105a to 105d through the LF transmission unit 105 (Step S121).

  Next, control unit 101 determines whether or not a response signal transmitted from portable device 200 that has received the detection signal has been received (step S122). There is a high possibility that the occupant approaches the vehicle C from the same direction as the direction in which the occupant moved when getting off. In the present embodiment, the moving direction of the occupant (portable device 200) at the time of getting off is specified, and the radiation direction of the LF transmitting antenna (for example, LF transmitting antenna 105b) whose moving route is included in the communication range is specified. The direction of the LF transmission antenna (for example, the LF transmission antenna 105n) is changed so as to match the moving direction of the portable device 200. Therefore, the communication distance of the LF transmission antenna whose direction has been changed (for example, the LF transmission antenna 105b) extends in the direction in which the occupant has moved when getting off, so that the occupant approaching the vehicle C from the same direction carries the portable device 200. Thus, the presence of the portable device 200 can be detected quickly.

  When determining that the response signal transmitted from portable device 200 has not been received (S122: NO), control unit 101 waits until the response signal is received.

  If the control unit 101 determines that the response signal transmitted from the portable device 200 has been received (S122: YES), the control unit 101 executes a predetermined riding process such as lighting of a vehicle light using a welcome light system (S122). Step S123). Next, the control unit 101 outputs a control signal to the LF antenna rotation driving units 120a to 120d through the output unit 107, thereby changing the orientation of the LF transmission antennas 105a to 105d to the default orientation (step S124). After the change to the default orientation, the in-vehicle device 100 appropriately performs the position detection of the portable device 200 necessary in the keyless entry system, the push start system, and the like, and unlocks the vehicle door and starts the engine as necessary. I do.

  As described above, in the first embodiment, the moving direction of the occupant at the time of getting off is specified by detecting the position of the portable device 200, and the radiation direction of the LF transmitting antennas 105a to 105d is changed according to the specified moving direction. The communication distance can be extended without increasing the current value of the current supplied to the LF transmission antennas 105a to 105d. In addition, when the occupant approaching the vehicle C from the same direction is carrying the portable device 200, the in-vehicle device 100 can quickly detect the presence of the portable device 200.

(Embodiment 2)
In the first embodiment, the direction of the specific LF transmission antenna 105b (or the transmission antennas 105a, 105c, and 105d) is changed. However, the direction of each of the LF transmission antennas 105a to 105d is adjusted according to the moving direction of the portable device 200. May be changed.
In the second embodiment, a configuration will be described in which the directions of the LF transmission antennas 105a to 105d are changed in accordance with the moving direction of the occupant when getting off. Note that the overall configuration of the vehicle communication system and the internal configurations of the in-vehicle device 100 and the portable device 200 are the same as those in the first embodiment, and a description thereof will be omitted.

  FIG. 8 is a diagram illustrating the orientation of the LF transmission antennas 105a to 105d changed in the second embodiment. As described in the first embodiment, the in-vehicle device 100 communicates with the portable device 200 periodically (for example, at one-second intervals) when the occupant carrying the portable device 200 gets off the vehicle C, thereby making the portable device 100 portable. The position of the device 200 is detected in time series. The example of FIG. 8 illustrates a state in which the in-vehicle device 100 detects the position of the portable device 200 at n points (n is, for example, an integer of 2 or more) at positions P1, P2,.

  The control unit 101 of the in-vehicle device 100 can identify the moving direction of the portable device 200 by detecting the position of the portable device 200 in time series. For example, the control unit 101 determines the position P1 of the portable device 200 first detected in the communication range of any of the LF transmission antennas 105a to 105d and the position Pn of the portable device 200 detected last in the communication range. The direction of the connecting straight line can be specified as the moving direction of the portable device 200.

  When the moving direction of the portable device 200 is specified, the control unit 101 controls the operation of the LF antenna rotation driving units 120a to 120d such that the radiation directions of the LF transmitting antennas 105a to 105d are directed to the moving direction of the portable device 200. Control signal to change the direction of the LF transmission antennas 105a to 105d. The example of FIG. 8 illustrates a state in which the directions of the LF transmission antennas 105a to 105d are changed so that the radiation directions of all the LF transmission antennas 105a to 105d included in the vehicle C face the specified moving direction.

  As described above, in the second embodiment, the moving direction of the occupant at the time of getting off is specified by detecting the position of the portable device 200, and the radiation direction of the LF transmitting antennas 105a to 105d is changed according to the specified moving direction. The communication distance can be extended without increasing the current value of the current supplied to the LF transmission antennas 105a to 105d. In the second embodiment, since the directions of the plurality of LF transmission antennas 105a to 105d are changed, even if the occupant's movement path when getting off and the occupant's movement path when getting on are not completely the same, the directions are almost the same. When the occupant approaches the vehicle C from above, the in-vehicle device 100 can quickly detect the presence of the portable device 200.

(Embodiment 3)
In the second embodiment, the configuration is such that the directions of the plurality of LF transmission antennas 105a to 105d are changed to the same direction. However, the configuration may be such that the directions of the plurality of LF transmission antennas 105a to 105d are individually changed.
In the third embodiment, a configuration will be described in which the directions of the plurality of LF transmission antennas 105a to 105d are individually changed according to the moving direction of the occupant when getting off. Note that the overall configuration of the vehicle communication system and the internal configurations of the in-vehicle device 100 and the portable device 200 are the same as those in the first embodiment, and a description thereof will be omitted.

  FIG. 9 is a diagram for explaining the directions of the LF transmission antennas 105a to 105d changed in the third embodiment. As described in the first embodiment, the in-vehicle device 100 communicates with the portable device 200 periodically (for example, at one-second intervals) when the occupant carrying the portable device 200 gets off the vehicle C, thereby making the portable device 100 portable. The position of the device 200 is detected in time series. The example of FIG. 9 illustrates a state in which the on-vehicle device 100 detects the position of the portable device 200 at n points (n is an integer of 2 or more) of the positions P1, P2,..., Pn.

  The control unit 101 of the in-vehicle device 100 can identify the moving direction of the portable device 200 by detecting the position of the portable device 200 in time series. For example, the control unit 101 can specify the direction of a straight line connecting the center of each of the LF transmission antennas 105a to 105d and the position Pn of the portable device 200 that was last detected as the moving direction of the portable device 200.

  When the movement direction of the portable device 200 is specified, the control unit 101 drives the LF antenna to rotate so that the radiation direction of the LF transmission antennas 105a to 105d is directed to the direction of a straight line connecting the center of each antenna and the position Pn. A control signal for controlling the operation of the units 120a to 120d is output to change the directions of the LF transmission antennas 105a to 105d. In the example of FIG. 9, the directions of the LF transmission antennas 105a to 105d are changed so that the radiation directions of the LF transmission antennas 105a to 105d included in the vehicle C are directed to the direction of a straight line connecting the respective antenna centers and the position Pn. The state is shown.

  As described above, in the third embodiment, the moving direction of the occupant at the time of getting off is specified by detecting the position of the portable device 200, and the radiation direction of the LF transmission antennas 105a to 105d is changed according to the specified moving direction. The communication distance can be extended without increasing the current value of the current supplied to the LF transmission antennas 105a to 105d. In the third embodiment, since the directions of the plurality of LF transmission antennas 105a to 105d are individually changed, even when the moving path of the occupant at the time of getting off and the moving path of the occupant at the time of getting on are not exactly the same, they are substantially equal. When the occupant approaches the vehicle C from the same direction, the in-vehicle device 100 can quickly detect the presence of the portable device 200.

  The embodiment disclosed this time is an example in all respects, and should be considered as not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

REFERENCE SIGNS LIST 100 vehicle-mounted device 101 control unit 102 storage unit 103 input unit 104 in-vehicle communication unit 105 LF transmission unit 105 a to 105 d LF transmission antenna 106 RF reception unit 106 a RF reception antenna 107 output unit 111 shift sensor 112 vehicle speed sensor 113 seating sensor 114 buckle SW
115 Courtesy SW
116 In-vehicle camera 120a-120d LF antenna rotation drive unit
200 portable device 201 control unit 202 storage unit 203 operation unit 204 LF reception unit 204a LF reception antenna 205 RF transmission unit 205a RF transmission antenna

Claims (6)

A vehicle communication system comprising: a vehicle-mounted device that periodically transmits a signal from an antenna provided in a vehicle; and a portable device that receives a signal transmitted from the vehicle-mounted device and transmits a response signal according to the received signal. And
A rotation drive unit connected to the on-vehicle device and configured to rotate the antenna under the control of the on-vehicle device;
The in-vehicle device,
A detection unit configured to detect a get-off operation of an occupant in the vehicle,
Based on a response signal from the portable device, a position detection unit that detects the position of the portable device in time series,
A specifying unit that specifies a moving direction of the portable device after detecting the getting-off operation based on a change in a time-series position of the portable device;
A control unit that controls the operation of the rotation drive unit so that the antenna points in a direction corresponding to the specified moving direction. A vehicle-mounted device that periodically transmits a signal from an antenna provided in a vehicle and receives a response signal from the portable device to the signal,
A control unit that controls the operation of a rotation drive unit that rotates the antenna,
A detection unit configured to detect a get-off operation of an occupant in the vehicle,
Based on a response signal from the portable device, a position detection unit that detects the position of the portable device in time series,
A specifying unit that specifies a moving direction of the portable device after detecting the getting-off operation based on a change in a time-series position of the portable device,
The in-vehicle device, wherein the control unit controls an operation of the rotation driving unit such that the antenna is directed in a direction corresponding to the movement direction specified by the specifying unit. A determination unit that determines whether a response signal from the portable device to a signal transmitted from the antenna has been received in a state where the antenna is oriented in a direction corresponding to the moving direction,
The in-vehicle device according to claim 2, wherein, when it is determined that the response signal has been received, the control unit controls the operation of the rotation driving unit so that the antenna faces a preset direction. The antenna has directivity,
The control unit controls the operation of the rotation driving unit such that a direction in which a radiation intensity of a radio wave emitted from the antenna is maximum matches the moving direction specified by the specifying unit. Or the in-vehicle device according to claim 3. The identification unit is
The moving direction is specified by a direction of a straight line connecting a position of the portable device detected first by the position detecting unit and a position of the portable device detected last in a communication range of the antenna. The vehicle-mounted device according to any one of claims 2 to 4. The identification unit is
The moving direction is specified by a direction of a straight line connecting an antenna center of the antenna and a position of the portable device last detected by the position detecting unit. Onboard equipment.

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