WO2019220773A1 - Wireless communication system for vehicles - Google Patents

Abstract

A wireless communication system for vehicles, the system being provided with a vehicle-side device (1) and a portable terminal (2), and the vehicle-side device and the portable terminal carrying out wireless communication. The portable terminal is provided with a portable-side communication unit (22) capable of carrying out wireless communication using an antenna having a linear polarization characteristic, an orientation specification unit (G1) for specifying the orientation of the portable terminal on the basis of a detection result from an orientation sensor, and a polarization-related information transmission unit (G3) for transmitting polarization-related information that indicates the angle of polarization plane, relative to a prescribed reference plane, of the portable-side communication unit, the angle of the polarization plane being determined on the basis of the orientation of the portable terminal. The vehicle-side device is a communication module for carrying out wireless communication, the vehicle-side device being implemented using an antenna having a linear polarization characteristic, and being provided with: a vehicle-side communication unit (12) capable of changing the angle of the polarization plane; and a polarization plane control unit (F2) for adjusting, when polarization-related information is received, the angle of the polarization plane of the vehicle-side communication unit on the basis of the polarization-related information so that the consistency of the polarization planes of the vehicle-side communication unit and the portable terminal increases.

Description

Wireless communication system for vehicles Cross-reference of related applications

This application is based on Japanese Patent Application No. 2018-95470 filed on May 17, 2018, the contents of which are incorporated herein by reference.

The present disclosure relates to a vehicle wireless communication system in which a vehicle-side device mounted on a vehicle and used and a mobile terminal carried by a user of the vehicle perform wireless communication.

Various wireless communication systems for vehicles have been proposed in which a vehicle-side device mounted on a vehicle and a mobile terminal carried by a vehicle user directly perform wireless communication. For example, Patent Document 1 describes a configuration in which a mobile terminal and a vehicle-side device communicate wirelessly in accordance with the Bluetooth (registered trademark) standard. In Patent Document 1, a smartphone, a mobile phone, or the like is assumed as a mobile terminal.

In Patent Document 1, as an application example of a vehicle wireless communication system, a vehicle-side device mounted on a vehicle and a mobile terminal carried by a user of the vehicle perform wireless communication so that the vehicle-side device is a vehicle. There has been proposed a system for estimating the position of a mobile terminal with respect to (hereinafter, a position estimation system). Specifically, the vehicle-side device of Patent Document 1 sequentially transmits a request signal from one communication device provided near the driver's seat in the passenger compartment, and the portable terminal returns a response signal from the vehicle-side device. When a request signal for requesting is received, a response signal including RSSI (Received Signal Strength Indication) of the request signal is returned. When receiving the response signal returned from the mobile terminal, the vehicle side device stores the RSSI included in the response signal in the memory. The vehicle-side device determines that the mobile terminal is present in the vehicle interior when the average value of the RSSI for the last five times stored in the memory exceeds a predetermined threshold value (hereinafter referred to as the vehicle interior determination threshold value). To do. On the other hand, when the average value of RSSI for the latest five times is less than or equal to the vehicle interior determination threshold, it is determined that the vehicle is outside the vehicle interior.

Communication conforming to a wireless communication standard such as Bluetooth, Wi-Fi (registered trademark), ZigBee (registered trademark) or the like that can have a communication distance within a line of sight of 5 meters or more is referred to as near field communication. In short-distance communication, radio waves in the 2.4 GHz band are mainly used.

JP 2015-214316 A

In wireless communication, if the antenna polarization plane does not match between the transmitting side and the receiving side, the energy loss will be greater than when both planes of polarization are matched. Deteriorates and communication is likely to fail.

Since the portable terminal is carried by the user, the attitude of the portable terminal with respect to the vehicle-side device is indeterminate, and the polarization planes of the portable terminal and the vehicle-side device do not always match. Depending on the attitude of the mobile terminal, the polarization planes of the mobile terminal and the vehicle-side device may be shifted by nearly 90 degrees. That is, in the vehicle wireless communication system, the vehicle-side device and the mobile terminal may not be able to communicate stably due to the attitude of the mobile terminal.

The radio wave of 1 GHz or more used in short-range communication is more straight ahead than the LF band radio wave and has a large human loss. In addition, a point (so-called null point) where the signal intensity sharply attenuates due to multipath is easily formed. That is, in near field communication, the success rate of communication and the strength of received signals are easily affected by the surrounding environment.

In a vehicular wireless communication system in which a vehicle-side device and a mobile terminal perform short-range communication, if the polarization planes of the mobile terminal and the vehicle-side device do not match, the influence of multipath, etc. becomes significant. Lacks stability. For example, the communication connection between the mobile terminal and the vehicle-side device can be intermittent. Note that when the communication is not stable, the received signal strength itself varies, and the configuration of Patent Document 1 has a relatively high possibility of erroneously determining the position of the mobile terminal.

This disclosure aims to provide a vehicular wireless communication system capable of improving the stability of communication between a mobile terminal and a vehicle-side device.

According to one aspect of the present disclosure, a vehicle wireless communication system includes a vehicle-side device that is mounted on a vehicle and used, and a mobile terminal that is carried by a user of the vehicle. Wireless communication is performed using radio waves in a predetermined frequency band. The portable terminal includes a portable communication unit configured to be able to perform wireless communication with the vehicle-side device using an antenna having linear polarization characteristics, and a posture sensor that detects a physical state quantity indicating the posture of the portable terminal. The orientation specifying unit that specifies the orientation of the mobile terminal based on the detection result, and the angle of the polarization plane of the mobile communication unit with respect to a predetermined reference plane that is determined based on the orientation of the mobile terminal specified by the orientation specifying unit directly or A polarization-related information transmitting unit that transmits the polarization-related information indirectly shown in cooperation with the mobile communication unit. The vehicle-side device is a communication module for performing wireless communication with a mobile terminal, and is realized by using an antenna having linear polarization characteristics, and the polarization plane to be transmitted and received can be changed. When the vehicle-side communication unit configured and the vehicle-side communication unit receive polarization-related information, the polarization plane of the vehicle-side communication unit and the polarization plane of the mobile terminal are determined based on the received polarization-related information. A polarization plane control unit that adjusts the angle of the polarization plane of the vehicle-side communication unit.

According to the present disclosure, the polarization plane control unit adjusts the angle of the polarization plane to be transmitted / received by the vehicle-side communication unit based on the polarization related information. As a result, the consistency between the vehicle-side communication unit and the polarization plane to be transmitted / received by each of the mobile terminals increases, and the reception level of signals from the mobile terminals increases. As a result, the stability of communication with the mobile terminal (for example, the success rate of communication) is improved. In addition, once polarization-related information can be transmitted and received between the vehicle-side device and the mobile terminal by wireless communication, the stability of communication quality is improved thereafter. For example, the communication connection between the mobile terminal and the vehicle-side communication unit is intermittent. The fear of becoming can be reduced.

The above and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description with reference to the accompanying drawings. In the accompanying drawings,
FIG. 1 is a diagram showing a schematic configuration of a vehicular radio communication system, FIG. 2 is a block diagram showing a schematic configuration of the mobile terminal. FIG. 3 is a block diagram for explaining the functions of the portable control unit. FIG. 4 is a block diagram showing a schematic configuration of the in-vehicle system. FIG. 5 is a diagram conceptually showing the locking / unlocking area set in the vehicle. FIG. 6 is a diagram illustrating an example of the mounting position of the in-vehicle communication device, FIG. 7 is a diagram showing a schematic configuration of the in-vehicle communication device, FIG. 8 is a flowchart of the vehicle-side process performed by the communication ECU. FIG. 9A is a diagram for explaining the effect of controlling the polarization plane of the in-vehicle communication device based on the polarization-related information from the mobile terminal; FIG. 9B is a diagram for explaining the effect of controlling the polarization plane of the in-vehicle communication device based on the polarization-related information from the mobile terminal; FIG. 10 is a block diagram showing the configuration of the in-vehicle communication device of Modification Example 3, FIG. 11 is a block diagram showing the configuration of the in-vehicle communication device of Modification 4. FIG. 12 is a block diagram for explaining the configuration of the mobile terminal in the modification 5. FIG. 13 is a diagram for explaining a configuration of a vehicle radio communication system according to the sixth modification.

Hereinafter, an exemplary embodiment of the vehicle wireless communication system 100 according to the present disclosure will be described with reference to the drawings. FIG. 1 is a diagram illustrating an example of a schematic configuration of a vehicle wireless communication system 100 according to the present disclosure. As shown in FIG. 1, the vehicular wireless communication system 100 includes an in-vehicle system 1 mounted on a vehicle Hv and a mobile terminal 2 that is a communication terminal carried by a user of the vehicle Hv. The in-vehicle system 1 corresponds to a vehicle side device.

Each of the in-vehicle system 1 and the mobile terminal 2 is configured to be able to perform communication (hereinafter referred to as short-range communication) compliant with a predetermined short-range wireless communication standard. The short-range wireless communication standard here is a communication standard in which the communication distance within the line-of-sight is 5 m or more (for example, 10 m). As such a short-range wireless communication standard, for example, Bluetooth Low Energy (BLE, Bluetooth is a registered trademark), Wi-Fi (registered trademark), ZigBee (registered trademark), or the like can be adopted. Here, as an example, the in-vehicle system 1 and the mobile terminal 2 are configured to perform wireless communication (hereinafter referred to as BLE communication) compliant with the BLE standard.

(Configuration of mobile device)
The configuration of the mobile terminal 2 will be described. The portable terminal 2 may be any device that is equipped with the above-described short-range communication function and can be carried by the user. For example, a smartphone can be used as the mobile terminal 2. The portable terminal 2 may be a tablet terminal, a wearable device, a portable music player, a portable game machine, or the like. For example, the mobile terminal 2 is associated with the in-vehicle system 1 and is configured to function as an electronic key of the vehicle Hv.

The portable terminal 2 includes a portable control unit 21, a portable communication device 22, and an acceleration sensor 23, as shown in FIG. The portable control unit 21 is communicably connected to each of the portable communication device 22 and the acceleration sensor 23.

The mobile control unit 21 is configured to control the operation of the mobile terminal 2 as a whole. The portable control unit 21 is configured mainly with a computer. That is, the mobile control unit 21 is realized using the CPU 211, the flash memory 212, the RAM, the I / O, and the like. The mobile control unit 21 may be realized using a GPU, MPU, or IC instead of the CPU 211. Furthermore, it may be realized by combining a CPU, GPU, MPU, and IC.

The flash memory 212 stores a program for causing the computer to function as the mobile control unit 21 (hereinafter, a mobile terminal program). In addition to the program, the flash memory 212 stores a device ID, an encryption key used for communication connection with the in-vehicle system 1, and the like. Note that the program for the portable device may be an application program provided from the outside by downloading or the like and installed in the portable terminal 2. Functions provided by the portable control unit 21 when the CPU 211 executes the portable device program stored in the flash memory 212 will be described later.

The flash memory 212 stores data (hereinafter referred to as antenna configuration data) indicating the polarization characteristics of the antenna for near field communication built in the mobile terminal 2. An antenna for near field communication built in the portable terminal 2 corresponds to the portable built-in antenna 221. The polarization characteristic of the portable built-in antenna 221 indicates the polarization direction and plane of polarization of the radio wave radiated from the portable built-in antenna 221 (and hence the portable terminal 2). The polarization direction refers to the direction in which the electric field vibrates with respect to the traveling direction of the radio wave. Since the antenna transmission operation and the reception operation are reversible, the polarization plane of the radio wave radiated from the portable built-in antenna 221 is the polarization plane that the portable built-in antenna 221 receives, that is, the reception efficiency is the best. Refers to the plane of polarization. The polarization plane of the radio wave radiated from the portable built-in antenna 221 is simply described as the polarization plane of the portable built-in antenna 221. Of the storage areas provided in the flash memory 212, the area where the antenna configuration data is stored corresponds to the antenna configuration storage unit. Of the storage areas provided in the flash memory 212, an area in which antenna configuration data is stored is also referred to as a portable antenna configuration storage unit.

The mobile communication device 22 is a communication module for performing short-range communication. The portable communication device 22 is realized by using a portable built-in antenna 221 that is an antenna for transmitting and receiving radio waves in a frequency band used in short-range communication, a modulation circuit, a demodulation circuit, and the like. The modulation circuit and the demodulation circuit can be realized using a dedicated IC. The portable side communication device 22 corresponds to a portable side communication unit.

The portable built-in antenna 221 is an antenna having linear polarization characteristics. The antenna having the vertical polarization characteristic here is an antenna capable of transmitting and receiving vertical polarization. That is, the portable built-in antenna 221 is configured to radiate linearly polarized waves. The polarization direction, the polarization plane, and the directivity of the radio wave radiated from the portable built-in antenna 221 are determined by the structure of the portable built-in antenna 221. The portable built-in antenna 221 is realized using, for example, a dipole antenna, a monopole antenna, an inverted F antenna, or the like. The portable built-in antenna 221 can employ various antenna structures, and a specific configuration may be designed as appropriate.

The polarization plane of the built-in portable antenna 221 is constant for the portable terminal 2. However, since the attitude of the mobile terminal 2 with respect to the ground plane is variable, the polarization plane of the mobile terminal 2 with respect to the ground plane can change dynamically. That is, the angle formed by the polarization plane of the mobile terminal 2 with respect to the ground plane is determined by the attitude of the mobile terminal 2. The ground plane corresponds to a plane perpendicular to the direction of gravity action. Here, as an example, the direction of the polarization plane will be described using the ground plane as a reference plane (or a predetermined reference plane), but the present invention is not limited to this. The reference plane for explaining the direction of the polarization plane can be changed as appropriate.

The portable communication device 22 is configured to be able to wirelessly communicate with other devices (for example, the in-vehicle system 1) existing within, for example, 10 m. The portable communication device 22 receives, for example, a signal conforming to the Bluetooth standard transmitted from the in-vehicle system 1 and provides the signal to the portable control unit 21. In addition, the mobile communication device 22 modulates data input from the mobile control unit 21 and transmits the data to the in-vehicle system 1. The operation of the portable side communication device 22 is controlled by the portable control unit 21.

The mobile terminal 2 is executing a key exchange protocol (so-called pairing) with the in-vehicle system 1 based on a user operation. Information (hereinafter referred to as connection destination information) about the in-vehicle system 1 acquired by pairing is stored in a nonvolatile memory included in the mobile communication device 22. The connection destination information is, for example, a communication connection key exchanged by pairing or a terminal ID. Saving the exchanged key is also called bonding. The mobile communication device 22 is configured to be able to register up to seven devices to be connected.

The acceleration sensor 23 is a sensor that is built in the mobile terminal 2 and detects acceleration acting on the mobile terminal 2. The acceleration sensor 23 is, for example, a triaxial acceleration sensor that detects acceleration in three axial directions orthogonal to each other. The detection result of the acceleration sensor 23 indicates the attitude of the mobile terminal 2 with respect to the ground plane. That is, the acceleration sensor 23 corresponds to an attitude sensor. Note that the mobile terminal 2 may include a gyro sensor, a geomagnetic sensor, a tilt sensor, and the like as the posture sensor. The acceleration, angular velocity, geomagnetism, etc. acting on the mobile terminal 2 correspond to physical state quantities indicating the attitude of the mobile terminal 2.

The mobile control unit 21 provides functions corresponding to the various functional blocks shown in FIG. 3 by executing the mobile terminal program. That is, the portable control unit 21 includes a posture specifying unit G1, a polarization plane specifying unit G2, and a communication processing unit G3 as functional blocks.

The posture specifying unit G1 specifies the posture (for example, the tilt angle) of the mobile terminal 2 with respect to the ground plane based on the detection result of the acceleration sensor 23. In addition, the attitude | position specific part G1 may be comprised so that the attitude | position of the portable terminal 2 may be specified based on detection results, such as a gyro sensor, a geomagnetic sensor, and an inclination sensor. Moreover, the attitude | position specific part G1 may be comprised so that the attitude | position of the portable terminal 2 may be specified by combining the detection result of multiple types of sensor.

Based on the attitude of the mobile terminal 2 specified by the attitude specifying unit G1 and the antenna configuration data registered in the flash memory 212, the polarization plane specifying unit G2 is based on the current plane of polarization of the mobile terminal 2. Identify the angle. The polarization plane identification unit G2 corresponds to a configuration that identifies the angle of the polarization plane of the real-time portable communication device 22 with respect to the ground plane, which is determined by the attitude of the mobile terminal 2. The angle formed by the plane of polarization with respect to the ground plane is also abbreviated as the angle of the plane of polarization.

The communication processing unit G3 is configured to perform data transmission / reception with the in-vehicle system 1 in cooperation with the portable communication device 22. For example, the communication processing unit G3 receives data from the in-vehicle system 1 received by the mobile communication device 22. In addition, the communication processing unit G <b> 3 generates data addressed to the in-vehicle system 1 and outputs the data to the mobile communication device 22. Thereby, a signal corresponding to desired data is transmitted as a radio wave. Note that the signal transmitted by the mobile terminal 2 through short-range communication includes transmission source information. The transmission source information is, for example, a terminal ID as unique identification information assigned to the mobile terminal 2. The terminal ID functions as information for identifying another communication terminal and the mobile terminal 2.

While the communication connection with the in-vehicle system 1 is established, the communication processing unit G3 periodically includes a signal including polarization-related information indicating the angle of the polarization plane identified by the polarization plane identification unit G2 (hereinafter, (Polarization report signal) is generated and transmitted to the in-vehicle system 1 in cooperation with the portable communication device 22. In the present embodiment, the polarization-related information is, for example, an angle formed by a polarization plane to be transmitted / received by the mobile terminal 2 with respect to the ground plane.

For example, when the mobile terminal 2 is in a posture to transmit and receive horizontal polarization, the communication processing unit G3 indicates that the angle formed by the polarization plane with respect to the ground plane is 0 degree as polarization related information. Send a polarization report signal. Further, when the mobile terminal 2 is in a posture to transmit / receive vertical polarization, the communication processing unit G3 has an angle formed by the polarization plane of the mobile terminal 2 with respect to the ground plane as 90 degrees as polarization-related information. A polarization report signal indicating that is transmitted.

The angle formed by the plane of polarization of the mobile terminal 2 with respect to the ground plane is 30 degrees or 45 degrees in addition to 0 degrees (that is, horizontal) or 90 degrees (that is, vertical), and is an intermediate between vertically polarized waves and horizontally polarized waves. Can also take a natural angle. The polarization related information may be information indicating the angle of the polarization plane of the mobile terminal 2 specified by the polarization plane specifying unit G2. As another aspect, the polarization-related information may simply indicate whether it belongs to horizontal polarization or vertical polarization (in other words, whether it is close). The angle formed by the plane of polarization with respect to the ground plane as polarization-related information is roughly expressed in two stages of 0 degrees and 90 degrees, and in four stages of 0 degrees, 45 degrees, 90 degrees M, and 135 degrees. May be. The interval at which the communication processing unit G3 transmits the polarization report signal may be set to 200 milliseconds, for example. The communication processing unit G3 that transmits the polarization report signal corresponds to the polarization related information transmission unit.

In addition, the communication processing unit G3 wirelessly transmits a communication packet including the transmission source information at a predetermined transmission interval, thereby notifying the surrounding communication terminals having a short-range communication function of the presence of itself ( In other words, advertise). A communication packet periodically transmitted for the purpose of advisory is referred to as an advertisement packet.

(In-vehicle system configuration)
Next, the configuration of the in-vehicle system 1 will be described. As shown in FIG. 4, the in-vehicle system 1 includes a communication ECU 11 and an in-vehicle communication device 12. The in-vehicle system 1 executes a key exchange protocol with the mobile terminal 2 based on a user operation (so-called pairing). Information (that is, connection destination information) about the mobile terminal 2 acquired by pairing is stored in, for example, the flash memory 112 provided in the communication ECU 11. As described above, the connection destination information is a key exchanged by pairing, a terminal ID of the mobile terminal 2, or the like. The connection destination information may be stored in the in-vehicle communication device 12.

The communication ECU 11 is an electronic control unit (ECU: Electronic Control Unit) that performs short-range communication with the mobile terminal 2 in cooperation with the vehicle-mounted communication device 12 (in other words, cooperation). Further, the communication ECU 11 has a function of determining the position of the mobile terminal 2 relative to the vehicle Hv based on the communication status with the mobile terminal 2. The communication ECU 11 is realized using a computer. That is, the communication ECU 11 includes a CPU 111, a flash memory 112, a RAM 113, an I / O, and a bus line that connects these configurations. The communication ECU 11 may be realized using an MPU or a GPU instead of the CPU 111. Communication ECU11 may be realized combining CPU111, MPU, and GPU.

The flash memory 112 is a rewritable nonvolatile storage medium. In the flash memory 112, a terminal ID assigned to the mobile terminal 2 owned by the user is registered. The flash memory 112 stores a program (hereinafter referred to as a vehicle program) for causing the computer to function as the communication ECU 11. Note that the above-described vehicle program only needs to be stored in a non-transitory tangible recording medium (non-transitory tangible storage storage medium). Executing the vehicle program by the CPU 111 corresponds to executing a method corresponding to the vehicle program. The communication ECU 11 will be described later with respect to functions realized by the CPU 111 executing the vehicle program stored in the flash memory 112.

Further, in the flash memory 112, the indoor equivalent value and the unlocked / unlocked area equivalent value are used as determination threshold values for the communication ECU 11 to determine the position of the portable terminal 2 based on the reception intensity of the signal from the portable terminal 2. Two parameters are stored. The indoor equivalent value is a threshold value for determining that the mobile terminal 2 is present in the vehicle interior.

The lock / unlock area equivalent value is a threshold value for determining that the mobile terminal 2 exists in the lock / unlock area set in advance for the vehicle Hv. The locking / unlocking area is an area for executing predetermined vehicle control such as locking and unlocking doors based on the presence of the mobile terminal 2 in the area. As shown in FIG. 5, the locking / unlocking area is set within 1 to 2 meters from various doors provided on the vehicle Hv including the trunk door outside the passenger compartment. In FIG. 5, the hatched portion of the dot pattern conceptually represents the lock / unlock area.

The in-vehicle communication device 12 is a communication module for performing near field communication. The in-vehicle communication device 12 receives, for example, a signal conforming to the Bluetooth standard transmitted from the mobile terminal 2 and provides the signal to the communication ECU 11. The in-vehicle communication device 12 modulates data input from the communication ECU 11 and wirelessly transmits the data to the mobile terminal 2. The operation of the in-vehicle communication device 12 is controlled by the communication ECU 11. The in-vehicle communication device 12 is configured to be able to wirelessly communicate with other devices (for example, the mobile terminal 2) existing within 10 m, for example. A range in which the in-vehicle communication device 12 can perform near field communication with the mobile terminal 2 is also referred to as a communication area. The in-vehicle communication device 12 corresponds to a vehicle side communication unit.

The in-vehicle communication device 12 is preferably arranged at a position where the vicinity of the door outside the passenger compartment and the entire interior of the passenger compartment can be seen. The line-of-sight for the in-vehicle communication device 12 is an area where a signal transmitted from the in-vehicle communication device 12 can be directly reached. Since the propagation path of the wireless signal is reversible, the line-of-sight for the in-vehicle communication device 12 is, in other words, the in-vehicle communication device 12 can directly receive the signal transmitted from the mobile terminal 2. Corresponds to the area. Further, even when the mobile terminal 2 is out of line of sight of the in-vehicle communication device 12, the signal transmitted from the mobile terminal 2 can reach out of line of sight by being reflected by various structures. That is, even when the mobile terminal 2 is outside the line-of-sight of the in-vehicle communication device 12, the mobile terminal 2 and the in-vehicle communication device 12 can perform wireless communication due to reflection on a structure or the like.

In the vehicle Hv, the position where the vicinity of the door outside the passenger compartment and the entire interior of the passenger compartment can be seen is, for example, a ceiling portion in the passenger compartment. In addition, if the vehicle Hv includes a resin pillar, the pillar portion also corresponds to a position where the vehicle interior and the vicinity of the door outside the vehicle interior can be seen. As an example, the in-vehicle communication device 12 of this embodiment is provided in an overhead console 31 as shown in FIG. Such an arrangement mode corresponds to an example of a configuration in which the in-vehicle communication device 12 is provided in the upper end portion of the windshield or a configuration in which the in-vehicle communication device 12 is provided in the vicinity of the room mirror.

The in-vehicle communication device 12 may be provided in a place other than the vicinity of the room mirror, such as the center of the ceiling surface in the vehicle interior. The in-vehicle communication device 12 may be provided in the A pillar 32A, the B pillar 32B, the C pillar 32C, the D pillar, or the like. Moreover, the vehicle-mounted communication apparatus 12 may be provided in the outer surface part of the vehicle Hv. Here, the outer surface portion is a body portion that contacts the vehicle exterior space in the vehicle Hv, and includes a side surface portion, a rear surface portion, and a front surface portion of the vehicle Hv. For example, the in-vehicle communication device 12 may be provided in / near a door handle (hereinafter referred to as an outer door handle) disposed on the outer surface of the vehicle Hv. Here, the outer door handle refers to a gripping member provided on the outer surface of the door for opening and closing the door.

6 shows only one in-vehicle communication device 12, but a plurality of in-vehicle communication devices 12 may be provided. For example, the vehicle-mounted communication device 12 may be provided one by one inside the overhead console 31 and a plurality of outer door handles included in the vehicle Hv. When the vehicle-mounted system 1 includes a plurality of vehicle-mounted communication devices 12, all of the vehicle-mounted communication devices 12 are connected to the communication ECU 11 so as to be able to communicate with each other.

The in-vehicle communication device 12 includes antennas 121X, 121Y, and 121Z, an antenna switching circuit 122, and a transmission / reception unit 123, as shown in FIG. The antennas 121X, 121Y, and 121Z are antennas for transmitting and receiving radio waves in a frequency band (for example, 2.4 GHz band) used for near field communication. The antennas 121X, 121Y, and 121Z are all configured to transmit and receive linearly polarized waves. When the antennas 121X, 121Y, and 121Z are not distinguished from each other, they are simply referred to as the antenna 121.

The antennas 121X, 121Y, and 121Z are antenna groups in which, for example, antennas having the same configuration are arranged in an orthogonal posture (in other words, an orientation). The antennas 121X, 121Y, and 121Z are configured to form polarization directions in directions orthogonal to each other. For example, the antenna 121X is attached in a posture in which the polarization direction is parallel to the vehicle longitudinal direction. The antenna 121Y is attached in a posture in which the polarization direction is parallel to the vehicle width direction. Both the antenna 121X and the antenna 121Y are antennas having a plane of polarization parallel to the vehicle horizontal plane. Here, the vehicle horizontal plane is a plane orthogonal to the vehicle height direction. Therefore, when the vehicle Hv is stopped on a horizontal road surface, the antenna 121X and the antenna 121Y function as antennas for transmitting and receiving horizontally polarized waves.

The antenna 121Z is attached in a posture in which the polarization direction is parallel to the vehicle height direction. That is, the antenna 121Z is an antenna having a polarization plane parallel to the vehicle height direction (in other words, orthogonal to the vehicle horizontal plane). As described above, the in-vehicle communication device 12 of the present embodiment includes the antennas 121X and 121Y having polarization planes parallel to the vehicle horizontal plane and the antenna 121Z having a polarization plane perpendicular to the vehicle horizontal plane. Note that the antennas 121X to 121Z do not necessarily have to be configured such that the polarization directions are orthogonal. Each of the polarization directions may be configured to intersect at an angle of 45 degrees or more. Here, as an example, the in-vehicle communication device 12 includes three short-distance communication antennas that form polarization directions in different directions, but is not limited thereto. The in-vehicle communication device 12 may have two near field communication antennas. For example, you may be comprised so that only the antenna 121X and the antenna 121Z may be provided.

The antenna switching circuit 122 is connected to the antennas 121X to 121Z and the receiving circuit. The antenna switching circuit 122 is configured such that only one of the three antennas 121X to 121Z is connected to the transmission / reception unit 123. That is, the antenna switching circuit 122 is configured to switch the antenna used for communication with the mobile terminal 2 based on the control signal Sg output from the communication ECU 11.

Specifically, the antenna switching circuit 122 includes first to third connection states as connection states. The first connection state is a state in which the transmission / reception unit 123 and the antenna 121X are electrically connected. The second connection state is a state in which the transmission / reception unit 123 and the antenna 121Y are electrically connected. The third connection state is a state in which the transmission / reception unit 123 and the antenna 121Z are electrically connected. The connection state of the antenna switching circuit 122 is controlled by the communication ECU 11. Since the antennas 121X to 121Z have different polarization directions, the antenna switching circuit 122 corresponds to a configuration for changing the polarization direction to be transmitted / received by the in-vehicle communication device 12. The antennas 121X and 121Y provide a plane of polarization parallel to the vehicle horizontal plane, while the antenna 121Z provides a plane of polarization orthogonal to the vehicle horizontal plane. Therefore, the antenna switching circuit 122 corresponds to a configuration (that is, an antenna switching unit) for changing the polarization plane to be transmitted / received by the in-vehicle communication device 12.

Among the antennas 121X to Z, the antenna 121 connected to the transmission / reception unit 123 is referred to as a connection antenna. The transmission / reception unit 123 receives a reception signal received by the connection antenna.

The transmission / reception unit 123 demodulates the signal received by the connection antenna 121 and provides it to the communication ECU 11. Further, the signal input from the communication ECU 11 is modulated and output to the connection antenna to be radiated as a radio wave. The transmission / reception unit 123 performs signal processing related to transmission / reception of signals with the mobile terminal 2, that is, the transmission / reception unit 123 has a configuration that functions as a modulation circuit and a demodulation circuit. The transmission / reception unit 123 is connected to the communication ECU 11 so as to communicate with each other.

The transmission / reception unit 123 includes a reception intensity detection unit 1231 that sequentially detects the intensity of the signal received by the connection antenna. The reception intensity detection unit 1231 can be realized by various circuit configurations. The reception intensity detected by the reception intensity detection unit 1231 is sequentially provided to the communication ECU 11 in association with the terminal ID included in the reception data. Note that the reception intensity may be expressed in units of power [dBm], for example. Data in which the reception intensity is associated with the terminal ID is referred to as reception intensity data.

(Communication ECU function)
The communication ECU 11 includes a communication processing unit F1, a polarization plane control unit F2, and a position determination unit F3 as functional blocks realized by the CPU 111 executing a vehicle program stored in the flash memory 112. The communication processing unit F <b> 1 is configured to perform data transmission / reception with the mobile terminal 2 in cooperation with the in-vehicle communication device 12. For example, the communication processing unit F <b> 1 generates data addressed to the mobile terminal 2 and outputs the data to the in-vehicle communication device 12. As a result, a signal corresponding to the data generated by the communication processing unit F1 is radiated to the space as a radio wave. Further, the communication processing unit F1 receives data from the mobile terminal 2 received by the in-vehicle communication device 12. For example, the communication processing unit F <b> 1 receives polarization related information transmitted from the mobile terminal 2. The received polarization related information is provided to the polarization plane control unit F2.

The communication processing unit F1 detects that the portable terminal 2 exists in the communication area of the in-vehicle system 1 by receiving a signal (for example, an advertisement packet) transmitted from the portable terminal 2. When receiving the advertisement packet from the mobile terminal 2, the communication processing unit F1 automatically establishes a communication connection with the mobile terminal 2 using the connection destination information stored in the flash memory 112. Then, the communication ECU 11 performs data transmission / reception with the mobile terminal 2.

In the present embodiment, as an example, the communication ECU 11 is configured to detect the presence of the mobile terminal 2 in the communication area by receiving advertisement packets sequentially transmitted from the mobile terminal 2. However, it is not limited to this. As another aspect, the vehicle-mounted system 1 detects the presence of the mobile terminal 2 in the communication area based on the fact that the in-vehicle system 1 sequentially transmits the advertisement packet and the communication connection (so-called connection) with the mobile terminal 2 is established. It may be configured.

Based on the polarization related information received by the communication processing unit F1, the polarization plane control unit F2 is configured so that the in-vehicle communication device 12 increases the consistency between the polarization plane of the in-vehicle communication device 12 and the polarization plane of the mobile terminal 2. In this configuration, the angle of the polarization plane to be transmitted / received is adjusted. The polarization plane control unit F2 according to the present embodiment changes the direction of the polarization plane to be transmitted / received by the in-vehicle communication device 12 by changing the connection antenna.

Specifically, the polarization plane control unit F2 specifies the antenna 121 according to the current attitude of the mobile terminal 2 based on the polarization related information received by the communication processing unit F1. Then, the control signal Sg for setting the antenna 121 corresponding to the attitude of the mobile terminal 2 (and hence its polarization plane) among the three antennas 121X to 121Z to the connection antenna is output to the antenna switching circuit 122.

The antenna 121 corresponding to the current attitude of the mobile terminal 2 is an antenna 121 having a plane of polarization closest to the plane of polarization of the radio wave transmitted by the mobile terminal 2. For example, when the polarization plane of the mobile terminal 2 is closer to the horizontal polarization than the vertical polarization, the polarization plane control unit F2 selects the antenna 121X or the antenna 121Y having a polarization plane parallel to the vehicle horizontal plane as the connection antenna. . When the polarization plane of the mobile terminal 2 is closer to the horizontal polarization than the vertical polarization, it may be set in advance which of the antenna 121X and the antenna 121Y is selected. For example, the polarization plane control unit F2 is configured to set the antenna 121X as a connection antenna when the polarization plane of the mobile terminal 2 is closer to horizontal polarization than vertical polarization.

When the polarization plane of the mobile terminal 2 is closer to the vertical polarization than the horizontal polarization, the antenna 121Z having the polarization plane in the vehicle height direction is selected. FIG. 8 is a flowchart showing a series of processing (hereinafter, vehicle-side processing) executed by the communication ECU 11 in order to control the polarization plane of the in-vehicle communication device 12. The flowchart shown in FIG. 8 may be executed when a signal from the mobile terminal 2 is received, for example. The vehicle side processing includes S1 to S3. In S1, the communication processing unit F1 determines whether or not the signal received from the mobile terminal 2 is a signal including polarization related information (that is, a polarization report signal). If the received signal is a polarization report signal, S1 is affirmed and S2 is executed. On the other hand, when the received signal is not a polarization report signal, this flow ends.

In S2, the communication processing unit F1 provides the polarization plane control unit F2 with data indicating the polarization plane angle included in the received polarization report signal as polarization related information, and proceeds to S3. In S3, the polarization plane control unit F2 outputs the control signal Sg to the antenna switching circuit 122, sets the antenna 121 corresponding to the polarization plane angle of the mobile terminal 2 as a connection antenna, and ends this flow.

As described above, by matching the polarization plane of the in-vehicle communication device 12 and the polarization plane of the mobile terminal 2, the signal reception level from the mobile terminal 2 is increased. As a result, the stability of communication such as the success rate of communication with the mobile terminal 2 can be improved. The consistency with the polarization plane corresponds to the degree of coincidence of the polarization planes. Further, increasing the consistency between the polarization planes of the in-vehicle communication device 12 and the portable terminal 2 corresponds to reducing the degree of deviation between the polarization plane of the in-vehicle communication device 12 and the polarization plane of the portable terminal 2.

The position determination unit F3 determines whether the mobile terminal 2 is present in the vehicle interior, the unlocked area, or other external area based on the reception strength of the signal from the mobile terminal 2 provided from the in-vehicle communication device 12. It is the structure which determines. Since the mobile terminal 2 is basically carried by the user, determining the position of the mobile terminal 2 corresponds to determining the position of the user.

The position determination unit F3 sequentially acquires the reception intensity of the signal from the mobile terminal 2 from the in-vehicle communication device 12 as a preparation process for determining the position of the mobile terminal 2, and the acquired reception intensity for each acquisition source. It distinguishes and preserves in RAM113. Then, the position determination unit F3 determines whether or not the mobile terminal 2 exists in the vehicle interior based on the reception intensity stored in the RAM 113 and various determination threshold values registered in the flash memory 112.

Specifically, it is a value for calculating the representative strength value based on the received strength stored in the RAM 113 within the latest predetermined time. The strength representative value is a value representatively representing the reception strength within the latest predetermined time. Here, as an example, the strength representative value is an average value of the latest N received strengths. Such an intensity representative value corresponds to a moving average value of received intensity. The intensity representative value may be a median value, a maximum value, a second largest value, or the like. N may be a natural number equal to or greater than 2, and may be, for example, 5. In another embodiment, N may be 1. The configuration in which N = 1 corresponds to a configuration in which the latest reception strength is directly used as the strength representative value.

And the position determination part F3 determines with the portable terminal 2 existing in a vehicle interior, when an intensity | strength representative value is more than an indoor equivalent value. In addition, when the strength representative value is less than the room equivalent value and is equal to or greater than the lock / unlock area equivalent value, it is determined that the mobile terminal 2 exists in the lock / unlock area. When the strength representative value is less than the value corresponding to the unlocking / unlocking area, it is determined that the mobile terminal 2 exists outside the unlocking / unlocking area. When the in-vehicle system 1 includes a plurality of in-vehicle communication devices 12, the above-described processing may be performed separately for each of the plurality of in-vehicle communication devices 12.

The position determination unit F3 of the present embodiment uses only the received intensity acquired after the time point when the polarization plane control unit F2 adjusts the polarization plane of the in-vehicle communication device 12 to match the polarization plane of the mobile terminal 2. The position of 2 is determined. In other words, the received intensity acquired in a state where the polarization plane of the in-vehicle communication device 12 is not adjusted so as to match the polarization plane of the mobile terminal 2 by the polarization plane control unit F2 at the time of communication connection with the mobile terminal 2 or the like. It is not used for the position determination process. According to such a configuration, since the position of the mobile terminal 2 is determined based on the received intensity acquired in a state where the stability of communication with the mobile terminal 2 is ensured, the position of the mobile terminal 2 is determined. Accuracy can be increased.

In the above configuration, the polarization plane control unit F2 switches the connection antenna according to the polarization plane of the mobile terminal 2 indicated in the polarization related information. Thereby, the consistency (degree of coincidence) between the polarization plane of the in-vehicle communication device 12 and the polarization plane of the mobile terminal 2 is increased, and the reception level of the signal from the mobile terminal 2 is increased. As a result, it is possible to improve the stability of communication with the mobile terminal 2 (for example, the success rate of communication). In addition, by matching the polarization plane of the in-vehicle communication device 12 and the polarization plane of the mobile terminal 2, as shown in FIGS. 9A and 9B, an area where the communication success rate is equal to or higher than a predetermined threshold (hereinafter, communication success) Area) can be relatively enlarged.

FIGS. 9A and 9B are diagrams showing results of simulating a region that is a communication success area when the polarization plane of the in-vehicle communication device 12 and the polarization plane of the mobile terminal 2 are matched with each other. It is. FIG. 9A shows a communication success area when the polarization plane of the in-vehicle communication device 12 and the polarization plane of the mobile terminal 2 are shifted by 90 degrees. FIG. 9B shows a communication success area when the polarization plane of the in-vehicle communication device 12 and the polarization plane of the mobile terminal 2 coincide.

According to the configuration of the present embodiment, even when communication is connected (in other words, at the beginning of communication), even if the polarization planes of the mobile terminal 2 and the in-vehicle communication device 12 are shifted by nearly 90 degrees, reception of polarization related information is received. Thereafter, the polarization plane of the in-vehicle communication device 12 is adjusted, so that communication with the portable terminal 2 is stabilized. That is, once the communication ECU 11 can receive the polarization related information from the mobile terminal 2, the communication quality with the mobile terminal 2 is stabilized thereafter. Therefore, the possibility that the communication connection between the mobile terminal 2 and the in-vehicle communication device 12 becomes intermittent can be reduced.

In addition, radio waves of 1 GHz or higher used in various short-range wireless communication standards have higher straightness and greater human loss than LF band radio waves. In addition, a point (so-called null point) where the signal intensity sharply attenuates due to multipath is likely to be formed. That is, in near field communication, the success rate of communication and the strength of received signals are easily affected by the surrounding environment. That is, in near field communication, the received signal strength is likely to fluctuate in near field communication due to the influence of the surrounding environment such as multipath and human body. In response to such a problem, according to the above configuration, the communication success rate between the in-vehicle system 1 and the mobile terminal 2 in a multipath environment or the like can be increased.

The position determination unit F3 of the embodiment described above determines the position of the mobile terminal 2 using the received intensity acquired in a state where the polarization plane control unit F2 adjusts the polarization plane of the in-vehicle communication device 12 based on the polarization related information. To do. In other words, the received intensity acquired in a state where the polarization plane of the in-vehicle communication device 12 is not adjusted so as to match the polarization plane of the mobile terminal 2 by the polarization plane control unit F2 is not used for the position determination process. According to such a configuration, since the position of the mobile terminal 2 is determined based on the reception intensity acquired in a state where the stability of communication with the mobile terminal 2 is ensured, the position determination accuracy can be improved. it can.

The embodiments of the present disclosure have been described above. However, the present disclosure is not limited to the above-described embodiments, and various modifications described below are also included in the technical scope of the present disclosure. However, various modifications can be made without departing from the scope of the invention. For example, the following various modifications can be implemented in appropriate combination within a range where no technical contradiction occurs. In addition, about the member which has the same function as the member described in the above-mentioned embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted. In addition, when only a part of the configuration is mentioned, the configuration of the above-described embodiment can be applied to the other portions.

(Modification 1)
In the above-described embodiment, the antenna 121X and the antenna 121Y have been disclosed so as to form a polarization plane parallel to the vehicle horizontal plane, but the embodiment is not limited thereto. The antenna 121Y may be configured to have a polarization plane inclined by 45 degrees or 135 degrees with respect to the vehicle horizontal plane.

The in-vehicle communication device 12 includes an antenna 121 for vertical polarization, an antenna 121 for horizontal polarization, an antenna 121 having a polarization plane inclined by 45 degrees with respect to the vehicle horizontal plane, and an inclination of 135 degrees with respect to the vehicle horizontal plane. A total of four antennas 121 including the antenna 121 having a polarization plane may be provided. In the configuration in which the polarization plane of the in-vehicle communication device 12 is changed using the antenna switching circuit 122, the in-vehicle communication device 12 has at least two short-distance communication antennas having polarization directions in different directions. Good.

(Modification 2)
In embodiment mentioned above, although communication ECU11 disclosed the aspect provided with the polarization plane control part F2, the aspect of implementation is not restricted to this. The in-vehicle communication device 12 may have a function corresponding to the polarization plane control unit F2. Further, the in-vehicle communication device 12 may have a function of extracting the polarization related information included in the received signal.

(Modification 3)
In the above-described embodiment, the aspect in which the polarization plane of the in-vehicle communication device 12 is adjusted by switching the connection antenna using the antenna switching circuit 122 is disclosed, but the embodiment is not limited thereto. For example, the in-vehicle communication device 12 may be configured such that the plane of polarization can be adjusted by adjusting the weight of the signal received by each of the plurality of antennas 121. Hereinafter, a configuration corresponding to the above idea will be described as a third modification with reference to FIG. FIG. 10 conceptually shows an example of the configuration of the in-vehicle communication device 12 corresponding to the above idea.

The in-vehicle communication device 12 in Modification 3 includes a weight adjustment unit F4. The weight adjustment unit F4 is a configuration for adjusting the weight of the signal received by each of the plurality of antennas 121. In this case, the weight of the signal refers to the amplification factor of the signal to be transmitted. The weight adjustment unit F4 includes a gain adjustment unit F41 for adjusting the gain of each antenna 121 and a coupling unit F42.

The gain adjusting unit F41 is configured to be able to adjust the signal amplification factor between 0 and 1. The gain adjustment unit corresponds to the signal level adjustment unit. The gain adjusting unit F41 is provided for each antenna 121 between the antenna 121 and the coupling unit F42. The gain adjustment unit F41 may be configured as software, or may be realized using a variable gain amplifier. The coupling unit F42 is configured to add the output signals of the plurality of gain adjustment units F41 and output the added signals to the transmission / reception unit 123, or to distribute the output signals from the transmission / reception unit 123 to the gain adjustment units F41.

The polarization plane control unit F2 in the present modification adjusts the polarization plane of the in-vehicle communication device 12 by adjusting the signal amplification factor of each gain adjustment unit F41. For example, when the polarization plane of the mobile terminal 2 is closer to the horizontal polarization than the vertical polarization, the signal amplification factor of the gain adjustment unit F41 connected to the antenna 121X having a polarization plane parallel to the vehicle horizontal plane is set to 1. The amplification factor of the antenna 121Z is set to zero. When the polarization plane of the mobile terminal 2 is closer to the vertical polarization than the horizontal polarization, the signal amplification factor of the gain adjustment unit F41 connected to the antenna 121Z is set to 1 and the amplification of the antenna 121X and the antenna 121Y is performed. Set the rate to zero.

Even with such a configuration, the same effect as the above-described embodiment can be obtained. The polarization plane control unit F2 sets the gain of the gain adjustment unit F41 connected to each of the antenna 121X and the antenna 121Y to 0.71 when the polarization plane of the mobile terminal 2 is closer to the horizontal polarization than the vertical polarization. It may be configured to set. The polarization plane control unit F <b> 2 uses the gain of the gain adjustment unit F <b> 41 connected to the antenna 121 having the polarization plane closest to the polarization plane of the mobile terminal 2 to the gain adjustment unit F <b> 41 connected to the other antenna 121. What is necessary is just to be comprised so that it may set to a larger value than an amplification factor.

(Modification 4)
In the above-described embodiment, the mode in which the polarization plane of the in-vehicle communication device 12 is adjusted by switching the connection antenna using the antenna switching circuit 122 or the weight adjustment unit F4 is disclosed. However, the polarization plane of the in-vehicle communication device 12 is adjusted. The method is not limited to this. For example, the in-vehicle communication device 12 may include one antenna 121 and a motor 124 for changing the attitude of the antenna 121, and the polarization plane may be adjusted by changing the attitude of the antenna 121. Hereinafter, a configuration corresponding to the above idea will be described as a fourth modification with reference to FIG. FIG. 11 conceptually shows an example of the configuration of the in-vehicle communication device 12 corresponding to the above idea.

Based on the polarization related information received by the communication processing unit F 1, the polarization plane control unit F 2 in this modification is configured so that the polarization plane to be transmitted / received by the in-vehicle communication device 12 matches the polarization plane of the mobile terminal 2. The motor 124 is driven. For example, when the polarization plane of the mobile terminal 2 is vertical polarization, the motor 124 is operated so that the polarization plane of the antenna 121 is vertical polarization. The motor 124 corresponds to an actuator for changing the attitude of the antenna 121 with respect to the vehicle. In addition, as an actuator for changing the posture of the antenna 121 with respect to the vehicle, various configurations such as a piezoelectric actuator can be employed.

(Modification 5)
In the above-described embodiment, the mobile terminal 2 has disclosed the aspect configured to periodically transmit the polarization report signal while the communication connection with the in-vehicle system 1 is established. Not limited to this. The mobile terminal 2 once transmits a polarization report signal at the time of communication connection, and thereafter, the attitude of the mobile terminal 2 changes by more than a predetermined angle (for example, 30 degrees) from the attitude at the time when the previous polarization report signal was transmitted. In this case, the polarization report signal may be retransmitted. Hereinafter, a configuration corresponding to the above concept will be described as a fifth modification with reference to FIG. FIG. 12 conceptually shows an example of the configuration of the mobile terminal 2 corresponding to the above idea.

The portable terminal 2 in this modification includes an attitude information holding unit G4. The posture information holding unit G4 is realized using a flash memory 212 provided in the portable control unit 21 or a RAM (not shown). The attitude information holding unit G4 is configured to hold information (hereinafter, attitude information) indicating the attitude of the mobile terminal 2 when the communication processing unit G3 transmits a polarization report signal in cooperation with the mobile communication device 22. is there. When the communication processing unit G3 establishes a communication connection with the in-vehicle system 1, the communication processing unit G3 once transmits a signal indicating polarization related information (that is, a polarization report signal) based on the attitude of the mobile terminal 2 at that time. In addition, the posture specifying unit G1 stores posture information at the time when the communication processing unit G3 transmits the polarization report signal in the posture information holding unit G4.

Thereafter, the communication processing unit G3 compares the posture information stored in the posture information holding unit G4 with the current posture of the mobile terminal 2 specified by the posture specifying unit G1, and the posture of the mobile terminal 2 is It is determined whether or not the angle changes more than a predetermined angle from the time when the previous polarization report signal was transmitted. The communication processing unit G3 transmits the polarization report signal again when the attitude of the mobile terminal 2 changes by a predetermined angle or more from the time when the previous polarization report signal was transmitted.

According to such a configuration, the attitude report signal is transmitted only when the orientation of the mobile terminal 2 changes, and the amount of communication from the mobile terminal 2 to the in-vehicle system 1 can be reduced. Note that the attitude information corresponds to polarization-related information that indirectly indicates an angle formed by the polarization plane of the mobile communication device 22 with respect to the reference plane.

(Modification 6)
In the embodiment described above, the polarization-related information has disclosed an aspect in which the polarization plane to be transmitted / received by the mobile terminal 2 is an angle formed with respect to the ground plane, but the embodiment is not limited thereto. The polarization-related information may be information that allows the polarization plane control unit F2 to finally specify the polarization plane of the mobile terminal 2. For example, the polarization related information may be attitude information of the mobile terminal 2. In that case, in the flash memory 112 of the communication ECU 11, the antenna configuration data of the portable terminal 2 is registered in order to identify the current orientation of the polarization plane of the portable terminal 2 from the attitude information of the portable terminal 2. And Then, the polarization plane control unit F2 determines the current orientation of the polarization plane of the mobile terminal 2 based on the attitude information of the mobile terminal 2 received as the polarization related information and the antenna configuration data stored in the flash memory 112. Identify. That is, the communication ECU 11 may have a function corresponding to the polarization plane specifying unit G2. The flash memory 112 can also correspond to an antenna configuration storage unit. The flash memory 112 is also called a vehicle-side antenna configuration storage unit.

Thus, according to the configuration in which the polarization plane based on the attitude of the mobile terminal 2 is specified on the communication ECU 11 side, the computation load on the mobile terminal 2 can be reduced. As shown in FIG. 13, the communication ECU 11 may be configured to acquire the antenna configuration data of the mobile terminal 2 from the external server Sv based on the model number information of the mobile terminal 2. The polarization related information may be attitude information and model number information. The model number information of the portable terminal 2 may be provided from the portable terminal 2 at the time of pairing, for example. The model number information corresponds to information indicating a model number, for example. Communication between the external server Sv and the communication ECU 11 may be performed via, for example, a wide area communication network. The external server Sv is an example of an external device. The device for distributing the antenna configuration data corresponding to the model number information may be a roadside device arranged along the road.

The means and / or function provided by the communication ECU 11 can be provided by software recorded in a substantial memory device and a computer that executes the software, only software, only hardware, or a combination thereof. Part or all of the functions of the communication ECU 11 may be realized as hardware. A mode in which a certain function is realized as hardware includes a mode in which one function or a plurality of ICs are used. Moreover, when a part or all of the functions of the communication ECU 11 is provided by an electronic circuit that is hardware, it can be provided by a digital circuit including a large number of logic circuits or an analog circuit. Further, the communication ECU 11 can be provided by one computer or a set of computer resources linked via a data communication device.

The embodiments, configurations, and aspects of the vehicle wireless communication system according to one aspect of the present disclosure have been illustrated above. However, the embodiments, structures, and aspects according to the present disclosure include the embodiments, configurations, and aspects described above. It is not limited. For example, embodiments, configurations, and aspects obtained by appropriately combining technical sections disclosed in different embodiments, configurations, and aspects are also included in the scope of the embodiments, configurations, and aspects according to the present disclosure.

Here, the flowchart described in the present disclosure, or the process of the flowchart, includes a plurality of steps (or referred to as sections), and each step is expressed as, for example, S1. Further, each step can be divided into a plurality of sub-steps, while a plurality of steps can be combined into one step.

Claims (9)

1. A vehicle-side device (1) mounted on a vehicle and a portable terminal (2) carried by a user of the vehicle, wherein the vehicle-side device and the portable terminal use radio waves in a predetermined frequency band. A wireless communication system for a vehicle that performs wireless communication,
   The portable terminal is
   A mobile communication unit (22) configured to be able to perform wireless communication with the vehicle device using an antenna having linear polarization characteristics;
   A posture identifying unit (G1) that identifies the posture of the mobile terminal based on a detection result of a posture sensor that detects a physical state quantity indicating the posture of the mobile terminal;
   Polarization-related information indicating directly or indirectly the angle of the polarization plane of the mobile communication unit relative to a predetermined reference plane, which is determined based on the mobile terminal specified by the posture specifying unit, A polarization-related information transmitting unit (G3) that transmits in cooperation with the unit,
   The vehicle side device
   A communication module for performing wireless communication with the portable terminal, which is realized using an antenna having linear polarization characteristics, and configured to change an angle of a polarization plane with respect to the reference plane The vehicle side communication unit (12),
   When the vehicle-side communication unit receives the polarization-related information, the consistency between the polarization plane of the vehicle-side communication unit and the polarization plane of the mobile terminal is increased based on the received polarization-related information. And a polarization plane control unit (F2) for adjusting an angle of a polarization plane of the vehicle-side communication unit.
2. The vehicle radio communication system according to claim 1,
   The portable terminal includes a posture information holding unit (G4) that holds posture information when the polarization related information transmission unit previously transmitted the polarization related information,
   The polarization related information transmitting unit, when the attitude of the mobile terminal specified by the attitude specifying unit has changed by a predetermined angle or more with respect to the attitude information held by the attitude information holding unit, A vehicular radio communication system configured to retransmit the polarization related information.
3. The vehicle wireless communication system according to claim 1 or 2,
   The vehicle-side communication unit is
   A plurality of antennas (121X, 121Z) each having a different plane of polarization;
   An antenna switching unit (122) for switching the antenna connected to a transmission / reception unit (123) that performs signal processing related to transmission / reception of signals with the mobile terminal among the plurality of antennas,
   The vehicular radio configured to control a connection state of the antenna switching unit so that the antenna having a polarization plane closest to the polarization plane of the mobile terminal is connected to the transmission / reception unit. Communications system.
4. The vehicle wireless communication system according to claim 1 or 2,
   The vehicle-side communication unit includes an actuator (124) that changes an attitude of the antenna with respect to the vehicle,
   The polarization plane control unit is configured to actuate the actuator based on the polarization related information so as to increase the consistency between the polarization plane of the antenna and the polarization plane of the mobile terminal. Communications system.
5. The vehicle wireless communication system according to claim 1 or 2,
   The vehicle-side communication unit is
   A plurality of antennas (121X, 121Z) each having a different plane of polarization;
   A plurality of signal level adjustment units (F41) provided for each antenna and changing the signal level of the reception signal at the antenna by adjusting the amplification factor;
   The polarization plane control unit determines the amplification factor of the signal level adjustment unit connected to the antenna having the polarization plane closest to the polarization plane of the mobile terminal based on the polarization related information, to another antenna. The vehicle radio | wireless communications system comprised so that it might set to the larger value than the gain of the said signal level adjustment part connected to.
6. The vehicle wireless communication system according to any one of claims 1 to 5,
   The portable terminal is
   An antenna configuration storage unit (212) storing antenna configuration data indicating polarization characteristics of the antenna included in the mobile communication unit;
   Based on the antenna configuration data stored in the antenna configuration storage unit and the attitude of the mobile terminal specified by the attitude specifying unit, an angle of the current polarization plane of the mobile terminal with respect to the reference plane is determined. A polarization plane specifying unit (G2) for specifying,
   The polarization related information transmitting unit is configured to transmit information indicating an angle of a current polarization plane of the mobile terminal identified by the polarization plane identifying unit with respect to the reference plane as the polarization related information. Wireless communication system for vehicles.
7. The vehicle wireless communication system according to any one of claims 1 to 5,
   The polarization related information transmitting unit is configured to transmit information indicating the attitude of the mobile terminal as the polarization related information,
   The vehicle-side device includes an antenna configuration storage unit (112) that stores antenna configuration data indicating polarization characteristics of the antenna included in the mobile communication unit,
   The polarization plane controller is
   Based on the antenna configuration data stored in the antenna configuration storage unit and the attitude of the mobile terminal specified by the attitude specifying unit, the direction of the current polarization plane of the mobile terminal is specified and specified A vehicle wireless communication system configured to adjust a polarization plane of the vehicle-side communication unit based on a result.
8. The vehicle wireless communication system according to claim 7,
   The portable terminal is configured to transmit model number information to the vehicle side device,
   The vehicle radio communication system configured to acquire the antenna configuration data corresponding to the model number information transmitted from the mobile terminal from an external device and store the antenna configuration data in the antenna configuration storage unit.
9. The vehicle radio communication system according to any one of claims 1 to 8,
   The vehicle-side communication unit includes a reception intensity detection unit (1231) that detects reception intensity of a signal from the mobile terminal,
   In the vehicle side device, the reception detected by the reception intensity detection unit after the time when the polarization plane control unit adjusts the polarization plane of the vehicle side communication unit using the polarization related information from the mobile terminal. A vehicle wireless communication system including a position determination unit (F3) for determining the position of the mobile terminal based on strength.
   
   

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