LOCATION SYSTEM

Abstract

A positioning system for a vehicle for performing wireless communication with a portable terminal carried by a user of the vehicle by using a radio wave of 1 GHz or higher to determine a position of the portable terminal with respect to the vehicle, the positioning system comprising: a vehicle external communication device (12β, 12L, 12M, 12N) configured to be arranged on an outer surface portion of the vehicle, which is a side surface portion of the vehicle and / or a rear surface portion of the vehicle, and including an antenna (121) configured to receive a wireless signal transmitted from the portable terminal; and a position determination unit (F4) configured to determine the position of the portable terminal based on a reception status of the wireless signal received by the vehicle external communication device from the portable terminal, wherein the vehicle external communication device includes an operation mode having a first mode and a second mode, wherein, in the first mode of the operation mode, a linearly polarized wave whose electric field vibration direction is perpendicular to the outer surface portion is radiated in a direction parallel to the outer surface portion to which the vehicle external communication device is attached, wherein in the second mode of the operating mode, a linearly polarized wave is radiated whose electric field vibration direction is parallel to the outer surface portion, and wherein the positioning unit is further designed based on the reception status of the wireless signal received by the vehicle exterior communication device from the portable terminal in the first mode of the operation mode, determine whether the portable terminal is present in an outdoor operation area, which is an area outside a vehicle cabin within a predetermined operation distance from the vehicle; and determine whether the portable terminal is present inside the vehicle cabin based on the reception status of the wireless signal received by the vehicle exterior communication device from the portable terminal in the second mode of the operation mode.

Description

Technical area

[0001] The present invention relates to a positioning system. The positioning system estimates a relative position of a portable terminal with respect to a vehicle based on the reception strength of a wireless signal using a radio wave of 1 GHz or higher, which is transmitted from the portable terminal carried by a user. State of the art

[0002] Various positioning systems have been proposed for performing wireless communication with a portable terminal carried by a vehicle user to estimate a position of the portable terminal relative to the vehicle. For example, JP 5 438 048 B2 describes a configuration for transmitting a response request signal via radio in an LF (low frequency) band from a vehicle to a portable terminal and determining, based on the reception of a response signal to the response request signal, whether the portable terminal is present in the vicinity of the vehicle outside the cabin (hereinafter referred to as the outdoor operating area).

[0003] The outdoor operating range corresponds to an area that allows automatic door unlocking using wireless communication from the portable terminal. The outdoor operating range is generally set within 1 meter or 0.7 meters of the vehicle. The reason why a vehicle uses a radio wave in the low-frequency band to transmit a signal to a portable device is because the arrival range of the wireless signal is limited to the vicinity of the vehicle. The antenna in the vehicle for transmitting the radio wave in the low-frequency band is adjusted, for example, in terms of transmission power, to allow the wireless signal to reach only the outdoor operating range.

[0004] Such a positioning system is used in an electronic vehicle key system for predetermined vehicle control based on the position of the portable terminal. The electronic vehicle key system is a passive entry passive start system (PEPS) that performs predetermined vehicle control based on the position of the portable terminal.

[0005] Portable information processing devices such as smartphones or wearable devices can serve as vehicle keys. In light of this situation, there is a need for a configuration that can determine the position of a portable device relative to a vehicle using the reception strength of high-frequency radio waves used for short-range communication such as Bluetooth. Smartphones generally do not have the ability to transmit or receive radio waves in the low-frequency band. However, smartphones usually have a short-range communication function such as Bluetooth (brand) or Wi-Fi (brand) as standard.

[0006] JP 6 313 114 B2 discloses an in-vehicle device. The in-vehicle device performs wireless communication according to the Bluetooth (trademark) standard with the portable terminal carried by a user of a vehicle to estimate the position of the portable terminal relative to the vehicle. Specific examples are described below. The in-vehicle device disclosed in JP 6 313 114 B2 periodically transmits a request signal from a communication device (hereinafter referred to as an in-vehicle communication device) to the portable terminal to request the portable terminal to return a response signal. The in-vehicle communication device is arranged on the floor surface within a vehicle cabin, for example, a location in the vicinity of a foot position of a driver's seat.The portable terminal returns a response signal including an RSSI (received signal strength indication) of a request signal when the request signal requesting return of a response signal is received by the on-vehicle communication device. The on-vehicle device stores in the memory the RSSI included in the response signal returned from the portable terminal. The on-vehicle device determines that the portable terminal is present in a vehicle cabin when an average of the RSSIs over the past five times stored in a memory exceeds a predetermined threshold. On the other hand, if the average of the RSSIs over the past five times is equal to or less than the threshold, the on-vehicle device determines that the vehicle is present outside the vehicle cabin.

[0007] Hereinafter, communication based on a predetermined wireless communication standard with a communication range of, for example, several tens of meters, such as Bluetooth, is referred to as short-range communication. A radio wave of 1 GHz or more (for example, 2.4 GHz) can be used for short-range communication. Hereinafter, the radio wave is referred to as a high-frequency radio wave. Such a high-frequency radio wave has stronger straightness than a radio wave in the low-frequency band and is easily reflected by a metal body such as a vehicle body.

[0008] US 2015 / 0 208 207 A1 discloses a vehicle system comprising a portable device configured to provide a wireless signal, and at least three base stations positionable around a vehicle. Each base station is configured to receive the wireless signal and generate a message indicating the travel time of the wireless signal. The vehicle system also includes a main base station positioned in the vehicle and configured to determine a general location of the portable device in one of a plurality of zones around the vehicle and, based on the message, to determine a three-dimensional location of the portable device using a first estimate when the portable device is in a first zone.

[0009] In the publication by HALL, Peter S.; LEE, E.; SONG, CTP: "Planar inverted-F antennas (Chapter 7). Hoboken, NJ, US: John Wiley & Sons, 2007 (Waterhouse, R. (Ed.)): Printed Antennas for Wireless Communications - Part II - Small printed antennas for wireless systems)", pp. 195-227, microstrip antennas for wireless systems are discussed.

[0010] JP 2012-172334 A discloses a vehicle radio device, wherein external antennas and vehicle antennas are installed in pairs outside and inside a vehicle above its body. Detectors calculate the signal strength of the radio signals received by a portable device via the antennas outside the vehicle and the antennas inside the vehicle. An electronic control unit compares the signal strength of the antennas outside the vehicle with the signal strength of the antennas inside the vehicle calculated by the detectors and determines whether the portable device is located in the vehicle cabin or not. Summary of the invention

[0011] However, JP 6 313 114 B2 does not explicitly mention a method for determining whether the portable terminal is present in an outdoor operation area outside the vehicle cabin or in a prohibited area. In the configuration concerning the above determination, the communication range of the on-vehicle device is limited to within 1 meter of the vehicle by adjusting the power of the antenna for near-field communication arranged inside the vehicle cabin. However, the high-frequency radio wave used in short-distance communication such as Bluetooth has a stronger straightness than the radio wave in the low-frequency band and is easily reflected by a metal plate such as a vehicle body.Therefore, in practice, it may be difficult to set the communication range outside the vehicle cabin to 1 meter while maintaining a high signal strength throughout the entire area inside the vehicle cabin. In other words, the configuration disclosed in JP 6 313 114 B2 cannot determine whether the portable terminal is present in the outdoor operation area or in the prohibited area.

[0012] As one of the solutions, it was considered that by using the reception strength of the signal received by the portable terminal and transmitted from the vehicle, similar to the determination of whether the portable terminal is inside the vehicle cabin, it can be determined whether the portable terminal is in the outdoor operation area outside the vehicle cabin or in the prohibited area. However, a structure such as the body of a vehicle is not present outside the vehicle cabin between the outdoor operation area and the prohibited area. The radio wave from the antenna arranged inside the vehicle cabin is continuously attenuated or attenuated from the outdoor area to the prohibited area.In addition, the rear side of the door module, in other words, the lower side of the outdoor operating area, is outside the view of the antenna inside the vehicle cabin, so the reception intensity of the portable terminal is low. Therefore, there is no significant difference in the signal strength transmitted by the antenna inside the vehicle cabin between the outdoor operating area and the prohibited area.

[0013] In practice, it may be difficult to determine whether the portable terminal is present in the outdoor operation area or in the prohibition area outside the vehicle cabin based on the reception strength of the signal received by the portable terminal from the communication device located in the vehicle cabin. Even if the portable terminal is present in the outdoor operation area, it may be erroneously determined that the portable terminal is present in the prohibition area. Since the door will not be unlocked if the portable terminal is erroneously determined to be in the prohibition area, this may affect the user's comfort.

[0014] To improve the user's comfort in using the vehicle, it is necessary to detect at least the presence in the outdoor operating area with higher accuracy. To ensure the safety of the vehicle, it is necessary to reduce the probability of erroneously determining that the portable terminal is present in the outdoor operating area even when the portable terminal is present in the prohibited area. To improve the accuracy of determining the presence in the outdoor operating area, it may be advantageous to install an antenna on the outer surface of the vehicle so that the outdoor operating area is uniformly set as an area of ​​strong electric field, and the electric field level is weaker in the area farther from the vehicle.

[0015] Based on this, the inventors of the present invention conducted various tests and found that by installing a dipole antenna in a position perpendicular to the side surface of the vehicle, it is possible to uniformly adjust the area of ​​a strong electric field in the outdoor operation area while reducing the electric field strength in the prohibition area to a sufficiently low level. According to the mode in which the dipole antenna is installed in the above position, it is assumed that the vibration of the electric field, whose starting direction is perpendicular to the side surface portion, is in a direction parallel to the side surface portion of the vehicle. Radio waves, whose vibration direction of the electric field is perpendicular to the metal surface, propagate along the metal plate.Therefore, it is possible to adjust the range of a strong electric field uniformly in the outdoor operating area.

[0016] Since the vibration direction of the radio wave electric field is perpendicular to the metal surface, it is possible to establish a strong electric field area not only in the outdoor operating area but also inside the vehicle cabin. In a configuration where the dipole antenna is installed in a position perpendicular to the side surface portion of the vehicle, it may be difficult to determine whether the portable terminal is located inside the vehicle cabin or in the outdoor operating area, because it is not easy to create a meaningful distinction between the outdoor operating area and the vehicle cabin.

[0017] It is an object of the present invention to provide a positioning system that can reduce an erroneous determination that the portable terminal is present outside the vehicle cabin, mainly an outdoor operation area, even when the portable terminal is present inside the vehicle cabin, while improving the detection rate of detecting that the portable terminal is present in the outdoor operation area.

[0018] A positioning system for a vehicle according to one aspect of the present invention performs wireless communication with a portable terminal carried by a user of the vehicle using a radio wave of 1 GHz or higher to determine a position of the portable terminal with respect to the vehicle. The positioning system includes a vehicle-external communication device and a position determination unit. The vehicle-external communication device is arranged on an outer surface portion of the vehicle, which is at least one of a side surface portion and a rear surface portion of the vehicle, and includes an antenna that receives a wireless signal transmitted from the portable terminal. The position determination unit determines the position of the portable terminal based on a reception status of the wireless signal received from the portable terminal by the vehicle-external communication device.The vehicle exterior communication device includes an operation mode comprising a first mode and a second mode. In the first mode of the operation mode, a linearly polarized wave whose electric field vibration direction is perpendicular to the outer surface portion is radiated in a direction parallel to the outer surface portion to which the vehicle exterior communication device is attached. In the second mode of the operation mode, a linearly polarized wave whose electric field vibration direction is parallel to the outer surface portion is radiated.The positioning unit determines whether the portable terminal is present in an outdoor operating area, which is an area outside a vehicle cabin within a predetermined operating distance from the vehicle, based on the reception status of the wireless signal received by the vehicle-external communication device from the portable terminal in the first mode of the operating mode. The positioning unit determines whether the portable terminal is present inside the vehicle cabin based on the reception status of the wireless signal received by the vehicle-external communication device from the portable terminal in the second mode of the operating mode.

[0019] The linearly polarized wave whose electric field vibration direction is perpendicular to the metal surface is likely to propagate along the metal. Therefore, when the vehicle exterior communication device operates in the first mode, it is possible to uniformly set the area of ​​a strong electric field in the vicinity of the vehicle outside the vehicle cabin. Therefore, it is possible to improve the detection rate of the portable terminal being present in the outdoor operation area to determine whether the portable terminal is present in the outdoor area by using the reception status of the wireless signal from the portable terminal when the vehicle exterior communication device operates in the first mode.

[0020] The linearly polarized waves to be transmitted or received by the vehicle exterior communication device in the first mode are easily transmitted through the metal of the vehicle's side surface portion and then enter the vehicle cabin. Therefore, in the first mode, a strong electric field region can also be formed within the vehicle cabin. Since the propagation path of the wireless signal is reversible, this means that the vehicle exterior device is likely to receive the signal from the portable terminal present within the vehicle cabin when the vehicle exterior communication device operates in the first mode.

[0021] The linearly polarized waves transmitted or received by the vehicle exterior communication device in the second mode are unlikely to circulate inside the vehicle cabin. The linearly polarized waves whose electric field vibration direction is parallel to the metal arranged for the vehicle exterior surface portion are likely to be repelled or reflected by the metal. As a result, the electric field level inside the vehicle cabin is low in the second mode. Since the propagation path of the wireless signal is reversible, this means that the vehicle exterior device is unlikely to receive the signal from the portable terminal provided inside the vehicle cabin when the vehicle exterior communication device is operating in the second mode.

[0022] Therefore, it is possible to improve the detection rate of the presence of the portable terminal inside the vehicle cabin to determine whether the portable terminal is inside the vehicle cabin by using the reception status of the wireless signal from the portable terminal when the vehicle exterior communication device is operating in the second mode. According to the above configuration, it is possible to reduce the probability of erroneous determination of the presence of the portable terminal in the outdoor operation area even when the portable terminal is inside the vehicle cabin, while improving the detection rate of the presence of the portable terminal in the outdoor operation area. Short description of the drawings

[0023] The above and other objects, features, and advantages of the present invention will become apparent from the following detailed description with reference to the accompanying drawings. Fig. 1 shows a schematic configuration of an electronic vehicle key system; Fig. 2 a configuration of a vehicle; Fig. 3 is a block diagram showing a schematic configuration of an on-vehicle system; Fig. 4 conceptually shows an example of mounting positions of the vehicle's communication device; Fig. 5 is a block diagram showing a schematic configuration of an on-vehicle communication device; Fig. 6 is a diagram illustrating an example of the configuration of a vehicle exterior communication device; Fig. 7 is an external perspective view of the configuration of a printed circuit board; Fig. 8 a cross-sectional view along the line VIII-VIII of the Fig. 7; Fig. 9 is a diagram for explaining the positional relationship between the grounding plate and the opposite conducting plate; Fig. 10 a current, a voltage and an electric field distribution in a zero-order resonance mode; Fig. 11 a radiation characteristic in the zero-order resonance mode; Fig. 12 a radiation characteristic in the zero-order resonance mode; Fig. 13 is a diagram explaining the operating principle of the earth plate excitation mode; Fig. 14 is a diagram explaining the operating principle of the earth plate excitation mode; Fig. 15 an example of the frequency characteristics of the gain in each mode; Fig. 16 an example of the frequency characteristics of the gain in each mode; Fig. 17 shows an example of an installation position and an installation attitude of a left outdoor communication device; Fig. 18 shows the directivity and the polarized wave in each of the operating modes of the vehicle external communication device as a cross-communication device; Fig. 19 Radiation characteristics of the outside communication device as the side communication device; Fig. 20 shows the electric field strength distribution when the left external communication device is operated in the zero-order resonance mode; Fig. 21 shows the electric field strength distribution when the left outdoor communication device is operated in the ground plate excitation mode; Fig. 22 the function of an intelligent ECU; Fig. 23 is a flowchart showing a process concerning a connection; Fig. 24 is a flowchart showing a location determination process; Fig. 25 Requirements for the electronic vehicle key system; Fig. 26 shows a modified example of the configuration of the vehicle external communication device; Fig. 27 shows a modified example of the configuration of the vehicle external communication device; Fig. 28 shows a modified example of the configuration of the vehicle exterior antenna; Fig. 29 shows a current distribution at an opposite line plate when a short-circuit portion is formed in the center of the opposite line plate; Fig. 30 shows a current distribution at the opposite conducting plate and its operation when a short-circuit portion is formed at a position away from the center of the opposite conducting plate; Fig. 31 the electric field strength distribution when the vehicle exterior antenna is operated in the zero-order resonance mode; Fig. 32 shows a modified example of the configuration of the vehicle exterior antenna; Fig. 33 an external vehicle antenna whose operating mode is changeable; Fig. 34 shows a modified example of the intelligent ECU and the vehicle external communication device; Fig. 35 a modified example of the configuration of the vehicle exterior antenna; and Fig. 36 shows a modified example of the configuration for switching the operation mode of the vehicle external communication device. Detailed description of the embodiments

[0024] An embodiment of a positioning system according to the present invention will be described below with reference to the drawings. Fig. 1 is a diagram showing an example of a schematic configuration of an electronic vehicle key system to which the positioning system according to the present invention is applied. As shown in Fig. 1, the electronic vehicle key system includes an on-vehicle system 1 arranged on a vehicle Hv, and a portable terminal 2 which is a communication terminal carried by a user of the vehicle Hv. Overall outline

[0025] The in-vehicle system 1 performs predetermined vehicle control according to the position of the portable terminal 2 by performing wireless communication using a radio wave in a predetermined frequency band. The in-vehicle system 1, for example, locks and unlocks the door based on the condition that the portable terminal 2 is present in an outdoor operating area Rx preset for the vehicle Hv.

[0026] The external operation range Rx corresponds to a range outside the vehicle cabin that enables the execution of vehicle control by the in-vehicle system 1. The external operation range Rx is set to a range that enables the execution of vehicle control such as locking and unlocking the door by the in-vehicle system 1 according to an example of the present invention. The external operation range Rx is limited to a range near or adjacent to the vehicle Hv. As an example of the present embodiment, an area outside the vehicle cabin within a predetermined distance (for example, 0.7 meters) from the door handle at the driver's seat and / or the door handle at the passenger's seat is set as the external operation range Rx. The external operation distance that defines the size of the operation range Rx may also be 1 meter or 1.5 meters.The operating distance can be set to less than a prohibition distance (e.g., 2 meters), which is defined as the size of the prohibition area, as described later. The exterior door handle refers to a gripping element located on the outer surface of the door for opening and closing the door. The exterior door handle can be a door handle recessed into the door panel, such as a flush handle or a pop-up handle.

[0027] The in-vehicle system 1 and the portable terminal 2 of the present embodiment are capable of communicating with each other (hereinafter referred to as short-range communication) based on a predetermined short-range wireless communication standard having a communication range of, for example, approximately ten meters. In this example, the short-range wireless communication standard may be, for example, Bluetooth Low Energy (Bluetooth is a registered trademark), Wi-Fi (registered trademark), ZigBee (registered trademark), or the like. The short-range wireless communication standard may be any one that can provide a communication range of, for example, several meters to several tens of meters.According to one example, the on-vehicle system 1 and the portable terminal 2 of the present embodiment are configured to perform wireless communication based on the Bluetooth Low Energy standard.

[0028] The portable terminal 2 interacts with the on-vehicle system 1 and serves as an electronic key of the vehicle Hv. The portable terminal 2 is a communication device that can be carried by a user and has the short-distance communication function described above. For example, a smartphone can be used as the portable terminal 2. According to another example, the portable terminal 2 can be a tablet, a wearable device, a portable music player, a portable game device, or the like. The signal transmitted from the portable terminal 2 based on the short-distance communication includes transmission source information. The transmission source information is, for example, predetermined identification information (hereinafter referred to as terminal ID) assigned to the portable terminal 2 in advance.The terminal ID serves as identification information of the portable terminal 2 for another communication terminal.

[0029] The portable terminal 2 wirelessly transmits a communication packet containing the transmission source information at a predetermined transmission interval, thereby notifying a nearby communication terminal having the short-distance communication function of the presence of the portable terminal 2 (i.e., announcement). In the following description, the communication packets periodically transmitted for announcement are referred to as announcement packets for convenience.

[0030] The on-vehicle system 1 receives a signal (e.g., an announcement packet) transmitted from the portable terminal 2 using the short-range communication function described above, thereby detecting that the portable terminal 2 is present within an area where the on-vehicle system 1 can perform short-range communication. In the following description, an area where the on-vehicle system 1 can exchange data or communicate with the portable terminal 2 based on the short-range communication function is also referred to as a communication area.

[0031] In the present embodiment, according to one example, the on-vehicle system 1 is configured to detect the presence of the portable terminal 2 within the communication area by receiving the announcement packets sequentially transmitted from the portable terminal 2, but the present invention is not limited to the above configuration. According to another example, the on-vehicle system 1 may be configured to sequentially transmit the announcement packets and detect the presence of the portable terminal 2 within the communication area based on the establishment of a communication link (so-called link) with the portable terminal 2. Vehicle configuration Hv

[0032] First, the configuration of the vehicle Hv with respect to Fig. 2. The vehicle Hv is, for example, a passenger vehicle that can accommodate five people. According to one example, the vehicle Hv includes a front seat and a rear seat, and the driver's seat (in other words, the steering wheel) is arranged on the left side. The vehicle Hv may, for example, be a vehicle that has the driver's seat on the right side. The vehicle Hv may be a vehicle without a rear seat. The vehicle Hv may be a truck such as a van. The vehicle Hv may be a taxi or a camping vehicle. Furthermore, the vehicle Hv may be a vehicle provided for a vehicle rental service (so-called rental car) or may be a vehicle provided for a car-sharing service (so-called shared vehicle).The shared vehicle may also include a vehicle used for a service of lending one's own vehicle to another person during a period when the vehicle owner is not using the vehicle. In the case where the vehicle Hv is a vehicle that provides the above service (hereinafter referred to as a service vehicle), a person who has a contract to use the service may be a user. In other words, a person who has the right to use the vehicle Hv may be a user.

[0033] The vehicle body includes metal elements. The body described herein includes a frame that provides a body main portion such as a B-pillar, and also includes a body panel. The body panels include side body panels, a roof panel, a rear panel, a hood panel, door panels, and the like. However, according to an example of the present invention, it is assumed that a portion of the door panel that overlaps with the B-pillars 42B or a portion of the door panel that serves as a window frame portion is made of resin.

[0034] Since a metal plate has the property of reflecting radio waves, the body of the vehicle Hv reflects radio waves. In other words, the vehicle Hv includes a body that blocks linear propagation of the radio waves. In this example, the radio wave refers to a radio wave in a frequency band used for wireless communication between the on-vehicle system 1 and the portable terminal 2. Hereinafter, the radio wave is referred to as a radio wave used for a system. The radio wave used by the system here refers to a radio wave in the 2.4 GHz band. The blocking described here ideally means reflection, but is not limited to reflection. A configuration capable of attenuating the radio wave to a predetermined level (hereinafter referred to as the target attenuation level orAttenuating or attenuating the signal by a factor of 1 or more (referred to as the target attenuation level) corresponds to a configuration for blocking the propagation of the radio wave. The target attenuation level can be a value at which a significant difference occurs between the signal strength of the radio wave inside the vehicle cabin and the signal strength of the radio wave outside the vehicle cabin. For example, the target attenuation level is set to 10 dB. Alternatively, the target attenuation level can be set to equal to or greater than 5 dB (for example, 10 dB or 20 dB).

[0035] The vehicle Hv has a roof portion 41 provided by the roof panel and includes a plurality of pillars 42 for supporting the roof panel. The vehicle Hv includes A-pillars 42A, B-pillars 42B, and C-pillars 42C as pillars 42. The A-pillars 42A are pillars arranged in front of the front seats. The B-pillars 42B are pillars 42 arranged between the front seats and the rear seats. The C-pillars 42C are pillars 42 arranged diagonally behind the rear seats. Part or all of each pillar 42 is formed of a metal member such as a high-tensile steel plate. According to another embodiment, the pillar 42 may be made of carbon fiber or resin. Furthermore, the pillar may be made of a combination of different materials.

[0036] The vehicle Hv is configured as a whole such that, when all doors are closed, the radio wave used in the system enters the vehicle cabin from the vehicle exterior only through the windows 43, or exits the vehicle cabin from the vehicle exterior only through the windows 43. In other words, the windows 43 serve as paths for the radio wave used in the system. In this example, the windows 43 are a front window (windshield), windows arranged on the side surfaces of the vehicle Hv (so-called side windows), a rear window (rear window), or the like.

[0037] According to another example, window panes arranged at the doors of the vehicle Hv or the like can also be designed to block the linear propagation of the radio wave used in the system. In this example, the window panes are transparent elements arranged in the windows 43 of the vehicle Hv, and the material of the window panes does not necessarily have to be glass. The window panes can be made of acrylic resin or the like, for example. In other words, in this example, the window panes are transparent elements that serve as windshields. Configuration of the vehicle's own system 1

[0038] The following describes the configuration and operation of the vehicle's own system 1. As described in Fig. 3, the on-vehicle system 1 includes an intelligent ECU 11, on-vehicle communication devices 12, a door knob 13, a start button 14, an engine ECU 15, and a body ECU 16. The ECUs in the element names are abbreviations for electronic control unit and electronic control device, respectively, and mean electronic control units.

[0039] The smart ECU 11 is an electronic control unit (ECU) that performs wireless communication with the portable terminal 2 to perform vehicle control such as locking and unlocking the door, starting the engine, or the like. The smart ECU 11 is implemented using a computer. In other words, the smart ECU 11 includes, for example, a CPU 111, a flash memory 112, a RAM 113, an I / O interface 114 (input / output interface), and a bus line for connecting these components. The CPU 111 is an arithmetic processing unit that performs various calculations. The flash memory 112 is a writable non-volatile storage medium. The RAM 113 is a volatile storage medium.The I / O interface 114 is a circuit module that serves as an interface for the smart ECU 11, allowing it to communicate with other devices mounted on the vehicle Hv, such as the in-vehicle communication device 12. The I / O interface 114 can be implemented using an analog circuit element, an IC, or the like.

[0040] A terminal ID assigned to the portable terminal 2 owned by the user is registered in the flash memory 112. The flash memory 112 also stores a program (hereinafter referred to as a positioning program) for controlling a general-purpose computer serving as the intelligent ECU 11. Note that the positioning program described here may be stored in a non-volatile tangible storage medium. The execution of the positioning program by the CPU 111 corresponds to the execution of a process corresponding to the positioning program.

[0041] The flash memory 112 stores two parameters, that is, an indoor correspondence value Pin and an operation threshold value Prx, as threshold values ​​(hereinafter referred to as a determination threshold value) on the basis of which the smart ECU 11 determines, with reference to the reception strength of the signal transmitted from the portable terminal 2, whether the portable terminal 2 is present inside the vehicle cabin. The indoor correspondence value Pin is a threshold value on the basis of which the authentication ECU determines whether or not the portable terminal 2 is present inside the vehicle cabin. The operation threshold value Prx is a threshold value for determining whether or not the portable terminal 2 is present in the outdoor operation area Rx outside the vehicle cabin. The indoor correspondence value Pin corresponds to an indoor determination value.The technical meaning and setting method for the internal correspondence value Pin and the operation threshold value Prx as well as the operation of the intelligent ECU 11 will be explained later.

[0042] The in-vehicle communication device 12 is a communication module mounted on the vehicle Hv for performing short-distance communication. Each in-vehicle communication device 12 can transmit and receive radio waves of 2400 MHz to 2500 MHz (in other words, 2.4 GHz ISM band radio waves). Each in-vehicle communication device 12 can be connected to the intelligent ECU 11 via a dedicated communication line or an in-vehicle network, so that each in-vehicle communication device 12 can communicate with the intelligent ECU 11. Each in-vehicle communication device 12 is assigned a unique communication device number. The communication device number is information corresponding to the terminal ID of the portable terminal 2. The communication device number serves as information for identifying the in-vehicle communication device 12.

[0043] The on-vehicle system 1 of the present embodiment includes at least one in-vehicle communication device 12α and a plurality of out-vehicle communication devices 12β as on-vehicle communication devices 12, as shown in Fig. 4. The in-vehicle communication device 12α is an on-vehicle communication device 12 disposed inside the vehicle cabin, and the out-vehicle communication device 12β is an on-vehicle communication device 12 disposed on an outer surface portion of the vehicle Hv. In the present invention, the outer surface portion is a body portion that contacts a vehicle exterior of the vehicle Hv and includes a side surface, a rear surface, and a front surface of the vehicle Hv. The on-vehicle system 1 according to the present embodiment includes a left outside communication device 12L, a right outside communication device 12M, and a rear outside communication device 12N as the out-vehicle communication devices 12β.

[0044] The respective in-vehicle communication devices 12 provide a reception strength of the signals transmitted from the portable terminal 2 to the intelligent ECU 11. The in-vehicle communication device 12α, as a data communication device, transmits data to and receives data from the portable terminal 2 through the intelligent ECU 11. Fig. 4 is a conceptual top view of the vehicle Hv and shows a roof portion 41 in a transparent manner to also show the installation position of the in-vehicle communication device 12α.

[0045] Fig. 5 is a diagram schematically showing an electrical configuration of the on-vehicle communication device 12. As shown in Fig. As shown in Fig. 5, the on-vehicle communication device 12 includes an antenna 121, a transceiver 122, and a communication microcomputer 123.

[0046] The antenna 121 is an antenna for transmitting and receiving a radio wave in a frequency band used for communication with the portable terminal 2 (i.e., the radio wave used in the system). Here, the frequency band used in the system is a 2.4 GHz band from 2400 MHz to 2500 MHz. The frequency band used by the system corresponds to the operating band for the antenna 121. The frequency band used by the system may include 2400 MHz to 2480 MHz, which is used in the Bluetooth standard. The upper limit frequency and the lower limit frequency of the frequency band used by the system can be appropriately changed according to the communication standard used with the portable terminal 2.

[0047] The antenna 121 is electrically connected to the transceiver 122. The specific configuration of the antenna 121 will be described later. The transceiver 122 demodulates a signal received by the antenna 121 and outputs the demodulated signal to the communication microcomputer 123. Furthermore, the transceiver 122 modulates the signal input from the intelligent ECU 11 via the communication microcomputer 123 and outputs the modulated signal to the antenna 121, which radiates the output signal as a radio wave. The transceiver 122 is communicatively connected to the communication microcomputer 123.

[0048] In addition, the transceiver 122 includes a reception strength detector 124 that sequentially detects the strength of the signal received by the antenna 121. The reception strength detector 124 can be implemented using various circuit configurations. The reception strength detected by the reception strength detector 124 is sequentially provided to the communication microcomputer 123 in association with the terminal ID included in the reception data. The channel number indicates a frequency used in communication with the portable terminal. The reception strength can be expressed, for example, in the unit of power [dBm]. Data in which the reception strength and the terminal ID are associated with each other is referred to as reception strength data. The reception strength detector 124 corresponds to a strength detector.

[0049] The communication microcomputer 123 is a microcomputer for controlling the operation of the transceiver 122. In other aspects, the communication microcomputer 123 corresponds to a microcomputer for controlling the exchange of data with the smart ECU 11. The communication microcomputer 123 provides the reception data input from the transceiver 122 to the smart ECU 11 based on the reception strength. The communication microcomputer 123 also has a function of authenticating the terminal ID of the portable terminal 2 and performing cryptographic communication with the portable terminal 2 based on a request from the smart ECU 11. As the encryption method, various methods such as a method specified by Bluetooth can be used.Various methods such as the method specified according to Bluetooth can also be used for the ID authentication method.

[0050] The doorknob 13 is a button for the user to unlock and lock the door of the vehicle Hv. The doorknob 13 is arranged, for example, on an exterior door handle or near the exterior door handle on the respective door of the vehicle Hv. When the user presses the doorknob 13, the doorknob 13 outputs an electrical signal indicating a corresponding instruction to the smart ECU 11. The doorknob 13 corresponds to a configuration according to which the smart ECU 11 receives a user instruction to lock or unlock. A touch-sensitive sensor can be used as a configuration for receiving at least the locking instruction and / or the unlocking instruction from the user.

[0051] The start button 14 is a push switch for the user to start a power source (for example, the internal combustion engine). When the user performs a push operation of the start button 14, the start button 14 outputs an electrical signal indicating the push operation to the smart ECU 11. According to one example, the vehicle Hv is a vehicle having an internal combustion engine as a power source, but the present invention is not limited to the above example. The vehicle Hv may be an electric vehicle or a hybrid vehicle. When the vehicle Hv is a vehicle having an electric motor as a power source, the start button 14 is a switch for starting the electric motor for propulsion.

[0052] The engine ECU 15 is an ECU for controlling the operation of the engine mounted in the vehicle Hv. For example, when the engine ECU 15 acquires a start command signal instructing the engine to start from the smart ECU 11, the engine ECU 15 starts the engine.

[0053] The body ECU 16 is an ECU configured to control an on-vehicle actuator 17 in response to a request from the smart ECU 11. The body ECU 16 is communicatively connected to various on-vehicle actuators 17 and various on-vehicle sensors 18. In this example, the on-vehicle actuators 17 include, for example, a door lock motor that forms a locking mechanism of each door, an actuator for adjusting a seat position (hereinafter referred to as a seat actuator), and the like. In this example, the vehicle-mounted sensors 18 are auxiliary switches or the like arranged for each door. The auxiliary switches are sensors for detecting door opening and closing.For example, the body ECU 16 outputs a predetermined control signal to the door lock motors arranged at the respective doors of the vehicle Hv based on a request from the smart ECU 11, thereby locking or unlocking the doors of the vehicle Hv. Role and configuration of the in-vehicle communication device 12α

[0054] The in-vehicle communication device 12α is arranged at a predetermined position within the vehicle cabin, so that a strong electric field region is formed within the vehicle cabin. The strong electric field region is a region where a signal transmitted from the in-vehicle communication device 12 propagates while maintaining a strength equal to or greater than a predetermined threshold (hereinafter referred to as the strong electric field threshold). The strong electric field threshold is set to a sufficiently strong level as a signal for short-distance communication. The strong electric field threshold is, for example, -35 dBm (-0.316 µW).According to another aspect, since the propagation path of the radio signal is reversible, the strong electric field region is also a region in which the reception strength of the signal transmitted from the portable terminal 2 and received by the on-vehicle communication device 3 is equal to or greater than a threshold value.

[0055] The in-vehicle communication device 12α can be arranged at any position within the vehicle cabin. It is preferable that the in-vehicle communication device 12α, which also serves as a data communication device, be arranged at a position from which the vicinity of the door on the inside of the vehicle cabin and the outside of the vehicle cabin can be seen. The position at which the vicinity of the door on the vehicle interior and the vehicle exterior can be seen is, for example, a roof portion in the vehicle cabin. According to one example of the present invention, the in-vehicle communication device 12α is arranged at a central portion of the upper end of the windshield, in other words, near a rearview mirror.For example, a central portion of an instrument panel 49 in the vehicle width direction, an overhead console, or a central portion of the roof can be used as the installation position of the in-vehicle communication device 12α. Even in a situation where the portable terminal 2 is out of sight of the in-vehicle communication device 12α, wireless communication between the portable terminal 2 and the in-vehicle communication device 12α can be performed via, for example, reflection from a structure. Therefore, the in-vehicle communication device 12α can also be arranged at a position where the exterior of the vehicle cabin is out of sight, for example, at the center console 48 or the foot position or the floor portion of the driver's seat.

[0056] The visible range from the position of the in-vehicle communication device 12 refers to an area that can be directly reached by a signal transmitted from the in-vehicle communication device 12. Since the propagation path of the radio signal is reversible, the visible range of the in-vehicle communication device 12 also refers to an area in which the in-vehicle communication device 12 can directly receive the signal transmitted from the portable terminal 2. An area beyond the visible range of the in-vehicle communication device 12 is an area that the signal transmitted from the in-vehicle communication device 12 cannot directly reach.Since the propagation path of the radio signal is reversible, the area beyond the visible range of the on-vehicle communication device 12 also refers to an area in which the on-vehicle communication device 12 cannot directly receive the signal transmitted from the portable terminal 2. The signal transmitted from the portable terminal 2 may reach the area beyond the visible range by reflection from various structures.

[0057] Terminal information is stored in the non-volatile memory included in the in-vehicle communication device 12α as the data communication device. The terminal information includes, for example, an authentication key or a terminal ID. The terminal information can be registered by a user performing a key exchange protocol, in other words, pairing. When the vehicle Hv is a service vehicle, the terminal information can be sent from an external server that manages the user operation (e.g., reservation condition or driving condition) of the service vehicle. In a case where the vehicle Hv is used by multiple users, the terminal information of the portable terminal 2 carried by each user is stored in the communication microcomputer.

[0058] When the in-vehicle communication device 12α, as a data communication device, receives an announcement packet from the portable terminal 2, the in-vehicle communication device 12α automatically establishes a communication link with the portable terminal 2 using the stored terminal information. Then, the smart ECU 11 transmits and receives data to and from the portable terminal 2. When the communication link with the portable terminal 2 is established, the in-vehicle communication device 12α provides the terminal ID of the portable terminal 2 that is in communication link with the smart ECU 11.

[0059] According to the Bluetooth standard, encrypted data communication is performed using frequency hopping. Frequency hopping is a communication method in which channels to be used for communication are sequentially switched over time. Specifically, in the Bluetooth standard, data communication is performed using frequency hopping spread spectrum (FHSS). According to Bluetooth Low Energy (hereinafter referred to as Bluetooth LE), 40 channels numbered 0 to 39 are prepared, and 37 channels numbered 0 to 36 are available for data communication. The three channels numbered 37 to 39 are used for transmitting announcement packets (hereinafter referred to as announcement channels).

[0060] In a state where the communication link with the portable terminal 2 is established, the in-vehicle communication device 12α performs data transmission and reception with the portable terminal 2 while sequentially switching the 37 channels. At this time, the in-vehicle communication device 12α sequentially provides information indicating a channel used for communication with the portable terminal 2 (hereinafter referred to as channel information) to the smart ECU 11. The channel information may be a specific channel number or may be a parameter (so-called skip increment) indicating a transition rule of a usage channel. The skip increment is a number from 5 to 16 randomly determined during the communication link. The channel information preferably includes a current channel number and a skip increment.

[0061] The number of in-vehicle communication devices 12α may be more than one. The number of in-vehicle communication devices 12α may be two, three, four, or more. For example, two in-vehicle communication devices 12α may be provided as the in-vehicle communication device 12 disposed near a foot position of the driver's seat and one in-vehicle communication device 12 disposed at the floor portion of the trunk area. One in-vehicle communication device 12α may be disposed on the respective side surfaces of the left and right B-pillars 42B inside the cabin. In addition, one in-vehicle communication device 12α may be disposed on the side surface of the rear seat door or the floor surface of the rear seat.The in-vehicle communication device 12α, which can serve as a data communication device, can preferably be arranged at a position where the outside of the vehicle cabin becomes the area beyond the visible range of the in-vehicle communication device 12α. One or more in-vehicle communication devices 12α can be arranged at predetermined positions such that most of the area inside the vehicle cabin, or preferably the entire area inside the vehicle cabin, forms the area of ​​a strong electric field.

[0062] A variety of antenna structures, such as a patch antenna, a dipole antenna, a monopole antenna, a plate-shaped or line-shaped inverted-F antenna, an inverted-L antenna, or a zero-order resonant antenna, can be used as the antenna. The antenna 121 of the in-vehicle communication device 12α can be a ground-plate-extended zero-order antenna or a half-wave zero-order antenna. The installation position, orientation, or number of installations for the in-vehicle communication device 12α can be appropriately designed in consideration of the configuration inside the vehicle cabin. Structure of the vehicle external communication device 12β

[0063] The structure of the vehicle external communication device 12β is described below. As the vehicle external communication devices 12β, a left external communication device 12L, a right external communication device 12M, and a rear external communication device 12N have the same antenna structure. Hereinafter, "λ" represents the wavelength of the radio wave of the center frequency (here, 2.45 GHz) used in the system. For example, "λ / 2" and "0.5λ" refer to half the length of the target wavelength, and "λ / 4" and "0.25λ" refer to one-quarter the length of the target wavelength. The wavelength of the 2.45 GHz radio wave (i.e., λ) in vacuum and air is 122 mm.

[0064] As it is in Fig. 6, the vehicle exterior communication device 12β includes a circuit board 5 and a housing 6. The circuit board 5 includes a ground plate 51, a support plate 52, an opposing lead plate 53, a short-circuit portion 54, and a circuit portion 55. The configuration including the combination of the ground plate 51, the opposing lead plate 53, and the short-circuit portion 54 corresponds to the antenna 121 (hereinafter referred to as the vehicle exterior antenna 121β) for the vehicle exterior communication device 12β. Fig. 7 is an external perspective view of the configuration of the circuit board 5. Fig. Figure 8 is a cross-sectional view taken along line VIII-VIII of Fig. 7. In the Fig. 7 and Fig. 8, the illustration of the housing 6 is omitted. For simplicity, each part will be described below such that the side on which the opposing conduction plate 53 is arranged with respect to the grounding plate 51 is the upper side for the vehicle exterior communication device 12β. That is, the direction from the grounding plate 51 to the opposing conduction plate 53 corresponds to the upward direction for the vehicle exterior communication device 12β. The direction from the opposing conduction plate 53 to the grounding plate 51 corresponds to the downward direction for the vehicle exterior communication device 12β.

[0065] The ground plate 51 is a conductive member having a plate shape and made of a conductor such as copper. The ground plate 51 is arranged along the lower surface of the support plate 52. Here, the plate shape also includes a thin-film shape such as a metal foil. That is, the ground plate 51 may be a pattern formed on the surface of a resin plate such as a printed circuit board by electroplating or the like. The ground plate 51 is electrically connected to an outer conductor, which is a coaxial cable or a ground layer included in the support plate 52, and provides a ground electrical potential (in other words, ground electrical potential) in the vehicle exterior communication device 12β.

[0066] The ground plate 51 is formed in a rectangular shape. The electrical length of the short side of the ground plate 51 is set to a value corresponding to, for example, 0.4λ. Furthermore, the electrical length of the long side of the ground plate 51 is set to 1.2λ. In this case, the electrical length is an effective length taking into account electric field constriction, a wavelength shortening effect by a dielectric substance, and the like. When the support plate 52 is formed using a dielectric material having a permittivity of 4.3, the wavelength on the surface of the ground plate 10 is approximately 60 mm due to the wavelength shortening effect of the dielectric material serving as the support plate 52. Therefore, the length electrically corresponding to 1.2λ is 22 mm.

[0067] The ones in various drawings such as the Fig. The X-axis shown in FIG. 6 represents the longitudinal direction of the grounding plate 51, the Y-axis represents the transverse direction of the grounding plate 51, and the Z-axis represents the vertical direction. The three-dimensional coordinate system (hereinafter referred to as the antenna coordinate system) including the X-axis, the Y-axis, and the Z-axis is a concept for explaining the configuration of the external communication device 12β. According to another aspect, when the grounding plate 51 has a square shape, the direction along any side may be the X-axis. When the grounding plate 51 is circular, any direction parallel to the grounding plate 51 may be set as the X-axis. The Y-axis may be a direction parallel to the grounding plate 51 and orthogonal to the X-axis.When the ground plate 51 has a shape such as a rectangle or an ellipse, which has a longitudinal direction and a transverse direction, the longitudinal direction may be the X-axis direction. The Z-axis is set so that the upward direction for the antenna 121 is a positive direction.

[0068] It may be advantageous for the grounding plate 51 to have a line-symmetrical shape (hereinafter referred to as a bidirectional line-symmetrical shape) in which two straight lines orthogonal to each other are axes of symmetry. The bidirectional line-symmetrical shape refers to a figure that is line-symmetrical with respect to a first straight line as an axis of symmetry and that is also line-symmetrical with respect to a second straight line orthogonal to the first straight line. The bidirectional line-symmetrical shape corresponds, for example, to an ellipse, a rectangle, a circle, a square, a regular hexagon, a regular octagon, a rhombus, or the like. The grounding plate 51 may have a size larger than a circle having a diameter of one wavelength. The planar shape of an element refers to the shape of the element as viewed from above.

[0069] The support plate 52 is a rectangular flat plate member. The support plate 52 is a plate-shaped member for arranging the grounding plate 51 and the opposing conductive plate 53 so that they are opposed to each other at a predetermined distance. The support plate 52 may have a size substantially identical to the size of the grounding plate 51. The support plate 52 is realized using a dielectric material having a predetermined permittivity. For example, a printed circuit board comprising a base material such as glass epoxy resin may be used as the support plate 52. Here, according to one example, the support plate 52 is realized using glass epoxy resin having a permittivity of 4.3 (in other words, FR4: Flame Retardant Type 4).

[0070] In the present embodiment, as an example, the thickness of the support plate 52 is 1.5 mm. The thickness of the support plate 52 corresponds to the distance between the grounding plate 51 and the opposing conductive plate 53. By adjusting the thickness of the support plate 52, the distance between the opposing conductive plate 53 and the grounding plate 51 can be adjusted. The specific value of the thickness of the support plate 52 can be appropriately determined through simulations or experiments. The thickness of the support plate 52 may be 2.0 mm, 3.0 mm, or the like. The wavelength of the support plate 52 is approximately 60 mm due to the wavelength shortening effect of the dielectric material. Therefore, the 1.5 mm thickness value electrically corresponds to 1 / 40 of the target wavelength (i.e., λ / 40).Furthermore, in the present embodiment, a configuration in which a resin is alternatively filled as the support plate 52 between the grounding plate 51 and the opposing lead plate 53 is used, but the present invention is not limited to this. The space between the grounding plate 51 and the opposing lead plate 53 may be hollow or a vacuum. Furthermore, the above-exemplified structures may be combined.

[0071] The opposing conductive plate 53 is a conductive member having a plate shape and made of a conductor such as copper. As described above, the plate shape here also includes a thin-film shape such as copper foil. The opposing conductive plate 53 is arranged to face the grounding plate 51 with the support plate 52 interposed therebetween. Similar to the grounding plate 51, the opposing conductive plate 53 may also have a pattern formed on the surface of a resin plate, such as a printed circuit board. The term "parallel" used here does not necessarily mean perfectly parallel. The opposing conductive plate 53 may be inclined by several degrees to tens of degrees with respect to the grounding plate 51. That is, the term "parallel" includes a substantially parallel state.

[0072] By arranging the opposing conduction plate 53 and the grounding plate 51 facing each other, a capacitance is formed according to the area of ​​the opposing conduction plate 53 and the distance between the opposing conduction plate 53 and the grounding plate 51. The opposing conduction plate 53 is formed to have a size that forms a capacitance that resonates in parallel with the inductance of the short-circuit portion 54 at a predetermined first frequency. The first frequency is any frequency belonging to the frequency band used in the system. The first frequency is, for example, 2420 MHz. According to another aspect, the first frequency may be set to an announcement channel, for example, 2402 MHz, 2426 MHz, or 2480 MHz.When it is necessary to distinguish between the wavelength of the first-frequency radio wave and the target wavelength, the wavelength of the first-frequency radio wave is also referred to as "λ1" hereinafter. The difference between λ1 and λ in air is approximately 1.5 mm, and this difference can be neglected in this embodiment.

[0073] The surface of the opposing conduction plate 53 can be suitably designed to provide the desired capacitance (and thus operate at the desired frequency). For example, the opposing conduction plate 53 is electrically formed into a square shape with a side length of 12 mm. Since the wavelength of the surface of the opposing conduction plate 53 is approximately 60 mm due to the wavelength shortening effect of the support plate 52, the value of 12 mm electrically corresponds to 0.2λ. Of course, the length of one side of the opposing conduction plate 53 can be suitably changed and can be 14 mm, 15 mm, 20 mm, 25 mm, or the like.

[0074] Here, for example, the shape of the opposing conduction plate 53 is square. However, according to another configuration, the surface shape of the opposing conduction plate 53 may be circular, regular octagonal, regular hexagonal, or the like. Furthermore, the opposing conduction plate 53 may have a rectangular shape or an elongated shape. The opposing conduction plate 53 may have a bidirectional line-symmetric shape. The opposing conduction plate 53 may have a point-symmetric shape such as a circle, a square, a rectangle, or a parallelogram.

[0075] The opposing conduction plate 53 may have slits or may have rounded corners. An edge portion of the opposing conduction plate 53 may be partially or entirely formed into a meander shape. The bidirectional line-symmetrical shape also includes a shape in which minute irregularities (about several mm) may be located at the edge of the bidirectional line-symmetrical shape. Irregularities located at the edge portion of the opposing conduction plate 53 that do not affect operation can be ignored. The technical idea for the surface shape of the opposing conduction plate 53 is similar to that of the grounding plate 51 described above.

[0076] The opposing circuit board 53 is connected to the circuit section 55 using a microstrip line 551. The connection point between the opposing circuit board 53 and the microstrip line 551 corresponds to the feeding point 531 for the antenna 121. The microstrip line 551 corresponds to a feeding line. Various methods, such as a direct connection power supply method and an electromagnetic coupling method, can be used as a power supply method for the opposing circuit board 53. The electromagnetic coupling method refers to a power supply method using electromagnetic coupling between a microstrip line or the like for power supply and the opposing circuit board 53.The feeding point 531 can be arranged at a position where the input impedance and output impedance of the antenna 121 match when viewed from the circuit section 55. In other words, the feeding point 531 can be arranged at a position where the return loss or reflection loss assumes a predetermined allowable level. The feeding point 531 can be arranged at any position, for example, in the central region or the edge portion of the opposite conductive plate 53.

[0077] As it is in Fig. 9, the opposing conductive plate 53 is arranged facing the ground plate 51 such that one set of opposing sides is parallel to the X-axis and another set of opposing sides is parallel to the Y-axis. Here, the center thereof is arranged to be deviated from the center of the ground plate 51 by a predetermined amount in the X-axis direction. Specifically, the opposing conductive plate 53 is arranged such that its center in the X-axis direction is electrically deviated from the center of the ground plate 51 by 1 / 25 (i.e., 0.04λ) of the target wavelength. According to another aspect, this configuration corresponds to a configuration in which the ground plate 51 is arranged asymmetrically with respect to the opposing conductive plate 53.

[0078] The distance in the X-axis direction between the center of the grounding plate 51 (hereinafter referred to as the grounding plate center) and the center of the opposing conductive plate 53 (hereinafter referred to as the grounding plate offset amount ΔSa) is not limited to 0.05λ. The grounding plate offset amount ΔSa may be 0.08λ, 0.04λ, 0.25λ, or the like. The grounding plate offset amount ΔSa may be set to 0.125λ (=λ / 8). The grounding plate offset amount ΔSa may be appropriately changed within a range in which the opposing conductive plate 53 does not protrude to the outside of the grounding plate 51 when viewed from above. The opposing conductive plate 53 is arranged such that at least the entire area (in other words, the entire surface) faces the grounding plate 51.The ground plate offset amount ΔSa corresponds to the amount of deviation between the center of the ground plate 51 and the center of the opposite conduction plate 53. The ground plate offset amount ΔSa may be designed such that the ground plate 51 serves as a radiating element at a second frequency described later.

[0079] In Fig. 9, the support plate 52 is drawn transparently (i.e., not shown) in order to clarify the positional relationship between the grounding plate 51 and the opposite conducting plate 53. The alternate long and short dashed line Lx1 shown in Fig. 9 represents a straight line passing through the center of the grounding plate 51 and parallel to the X-axis, and the alternate long and short dashed line Ly1 represents a straight line passing through the center of the grounding plate 51 and parallel to the Y-axis. The alternate long and short dashed line Ly2 represents a straight line passing through the center of the opposing conducting plate 53 and parallel to the Y-axis. In another aspect, the straight line Lx1 corresponds to an axis of symmetry of the grounding plate 51 and the opposing conducting plate 53. The straight line Ly1 corresponds to an axis of symmetry of the grounding plate 51. The straight line Ly2 corresponds to an axis of symmetry of the opposing conducting plate 53.

[0080] Since the opposing conducting plate 53 is arranged to be shifted by a predetermined amount in the X-axis direction from a position concentric with the grounding plate 51, the alternate long and short dashed line Lx1 also passes through the center of the opposing conducting plate 53. That is, the alternate long and short dashed line Lx1 is a straight line parallel to the X-axis and corresponds to a straight line passing through the center of the grounding plate 51 and the opposing conducting plate 53, respectively. The intersection point between the straight line Lx1 and the straight line Ly1 corresponds to the center of the grounding plate, and the intersection point between the straight line Lx1 and the straight line Ly2 corresponds to the center of the opposing conducting plate 53 (hereinafter referred to as the conducting plate center). The conducting plate center corresponds to the center of gravity of the opposing conducting plate 53.Since the opposing conducting plate 53 has a square shape in the present embodiment, the center of the conducting plate corresponds to the intersection point between two diagonal lines of the opposing conducting plate 53. The arrangement mode in which the grounding plate 51 and the opposing conducting plate 53 are concentric corresponds to an arrangement mode in which the center of the opposing conducting plate 53 and the center of the grounding plate 51 overlap in plan view.

[0081] The short-circuiting portion 54 is a conductive element that electrically connects the grounding plate 51 and the opposing conductive plate 53. The short-circuiting portion 54 may be a linear element, one end of which is electrically connected to the grounding plate 51 and the other end of which is electrically connected to the opposing conductive plate 53. The short-circuiting portion 54 uses vias formed on the circuit board, such as the support plate 52. The short-circuiting portion 54 may use a conductive stud. By adjusting the diameter and length of the short-circuiting portion 54, the inductance provided by the short-circuiting portion 54 can be adjusted.

[0082] The short-circuit portion 54 is arranged, for example, to be located at a center of the circuit board. Note that a position where the short-circuit portion 54 is formed does not have to exactly coincide with the center of the circuit board. The short-circuit portion 54 may be shifted from the center of the circuit board by about several millimeters. The short-circuit portion 54 may be formed in a central region of the opposing circuit board 53. The central region of the opposing circuit board 53 refers to a region within the line connecting the points that internally divide the circuit board from the center to the edge portion at a ratio of 1:5. In another aspect, the central region corresponds to a region where concentric figures, in which the opposing circuit board 53 is similarly reduced to about 1 / 6, overlap.

[0083] The circuit section 55 is a circuit module that includes, for example, the transceiver 122, the communication microcomputer 123, and a power supply circuit. The circuit section 55 is an electrical assembly of various parts such as an IC, an analog circuit element, and a connector. The circuit section 55 is formed on a surface of the support plate 52 (hereinafter referred to as the support plate surface 52a) on the side where the opposing line plate 53 is arranged. The circuit section 55 uses, for example, a region of the support plate surface 52a located above the asymmetry section 511. The microstrip line 551 is a linear conductor for supplying power to the opposing line plate 53.One end of the microstrip line 551 is connected to the opposite circuit board 53, and the other end of the microstrip line 551 is connected to the circuit section 55. The microstrip line 551 may be formed within the support board 52.

[0084] The housing 6 accommodates the printed circuit board 5. The housing 6 is formed by combining, for example, an upper housing part and a lower housing part that are vertically separable. The housing 6 is constructed using, for example, polycarbonate resin (PC resin). Various resins, such as a synthetic resin obtained by blending an acrylonitrile-butadiene-styrene copolymer (so-called ABS) with a PC resin and polypropylene (PP), can be used as the material of the housing 6.

[0085] The housing 6 includes a housing bottom portion 61, a housing side wall portion 62, and a housing top plate portion 63. The housing bottom portion 61 forms the bottom of the housing 6. The housing bottom portion 61 is formed in a flat plate shape. The circuit board 5 inside the housing 6 is arranged such that the grounding plate 51 faces the housing bottom portion 61 via the rib 611 (hereinafter referred to as the lower rib) formed on the housing bottom portion 61. The lower rib 611 regulates the position of the circuit board 5 in the housing 6. The lower rib 611 has a convex structure integrally formed upward from a predetermined position of the housing bottom portion 61. The lower rib 611 is arranged to contact the edge portion of the grounding plate 51.The lower rib 611 is formed such that the distance between the grounding plate 51 and the housing bottom portion 61 is equal to or less than λ / 25, in other words, equal to or less than 5 mm. The lower rib 611 may be formed to protrude from the inner surface of the housing sidewall portion 62 toward the interior of the housing. The lower rib 611 may support the circuit board 6 from a lower side or may be formed integrally with the housing sidewall portion 62.

[0086] The housing side wall portion 62 forms the side surface of the housing 6 and extends upward from the edge portion of the housing bottom portion 61. The height of the housing side wall portion 62 is formed such that, for example, the distance between the inner surface of the housing top plate portion 63 and the opposing conducting plate 53 is equal to or less than λ / 25. The housing top plate portion 63 forms an upper surface portion of the housing 6. The housing top plate portion 63 of this embodiment is formed in a flat plate shape. Various other shapes, such as a dome shape, can be used as the shape of the housing top plate portion 63. The housing top plate portion 63 is formed such that its inner surface faces the support plate surface 52a (and thus the opposing conducting plate 53). An upper rib 631 is formed on the inner surface of the housing top plate portion 63.

[0087] The upper rib 631 has a convex structure formed downward from a predetermined position on the inner surface of the housing top plate portion 63. The upper rib 631 contacts the edge portion of the opposing lead plate 53. The upper rib 631 is formed integrally with the housing 6. The upper rib 631 regulates the position of the support plate 52 in the housing 6. A metal pattern such as a copper foil may be arranged on the vertical surface (i.e., the outer surface) of the upper rib 631, which is connected to the edge of the opposing lead plate 53. The upper rib 631 may be any element and may not be present.

[0088] For example, a sealing material 7 is filled into the housing 6. The sealing material 7 corresponds to a sealing member. Various materials such as urethane resin (e.g., polyurethane prepolymer), epoxy resin, and silicone resin can be used as the sealing material. According to a configuration in which the sealing material 7 is filled into the housing 6, waterproofness, dustproofness, and vibration resistance can be improved. According to the configuration in which the housing 6 is filled with the sealing material 7, the sealing material 7, which is arranged above the opposing lead plate 53, prevents the vertical polarization of the ground plate from wrapping around from the end portion of the opposing lead plate 53 to the upper side, thereby improving the radiation gain in the horizontal direction of the ground plate. The horizontal direction of the ground plate, orThe grounding plate horizontal direction refers to a direction from the center region to the edge of the opposing conducting plate 53. In another aspect, the grounding plate horizontal direction refers to a direction perpendicular to a line perpendicular to the grounding plate 51 passing through the center of the opposing conducting plate 53. The grounding plate horizontal direction corresponds to a transverse direction, in other words, the side of the vehicle exterior communication device 12β. The sealing material 7 is an optional element and not a necessary element. Fig. 6, a slash line of the sealing material 7 is not shown in order to maintain the visibility of the drawing.

[0089] The upper rib 631 and the sealing material 7 correspond to a configuration (hereinafter referred to as a radio wave shield) that prevents the vertical electric field radiated by the zero-order resonance mode from circulating from the edge portion of the opposing conductive plate 53 to the upper side. The configuration described as the second modification corresponds to a configuration in which a radio wave shielding body formed using a conductor or a dielectric material is arranged on the upper side of the opposing conductive plate 53. The casing 6 including the upper rib 631 and the sealing material 7 may preferably have a high permittivity and a small dielectric loss factor.For example, it is advantageous if the relative permittivity is equal to or greater than 2.0 and the dielectric loss factor is equal to or less than 0.03. When the dielectric loss factor is high, the amount of radiated energy loss as heat loss is larger. Therefore, it is advantageous if the casing 6 and the sealing material 7 are realized using a material having a smaller dielectric loss factor. The casing 6 and the sealing material 7 serve to prevent the electric field from circulating when the dielectric constant increases. In other words, the higher the dielectric constant of the casing 6 and the sealing material 7, the better the gain increasing effect in the horizontal direction of the ground plate. Therefore, it is advantageous if the casing 6 and the sealing material 7 are made of a dielectric material with a high dielectric constant. Operation of the vehicle external communication device 12β

[0090] The following describes the operation of the vehicle-external communication device 12β configured as described above. The opposing lead plate 53 in the vehicle-external communication device 12β is short-circuited to the ground plate 51 via the short-circuit portion 54 located in the center of the opposing lead plate 53, and the area of ​​the opposing lead plate 53 is equal to an area for forming an electrostatic capacitance that resonates at the target frequency in parallel with the inductance of the short-circuit portion 54.

[0091] At the first frequency and frequencies near the first frequency, parallel resonance (so-called LC parallel resonance) occurs due to energy exchange between the inductance and the capacitance, and a vertical electric field perpendicular to the ground plate 51 and the opposite conduction plate 53 is generated between the ground plate 51 and the opposite conduction plate 53. This vertical electric field propagates from the short-circuit portion 54 toward the edge portion of the opposite conduction plate 53, and from the edge portion of the opposite conduction plate 53, the vertically polarized ground plate wave propagates into space. The vertically polarized ground plate wave here refers to a radio wave in which the vibration direction of the electric field is perpendicular to the ground plate 51 and the opposite conduction plate 53.When the vehicle exterior communication device 12β is used in a position parallel to the horizontal plane, the vertically polarized wave of the ground plate refers to a wave polarized perpendicular to the ground plate (so-called ordinary vertically polarized wave).

[0092] As it is in Fig. 10, the propagation direction of the vertical electric field is symmetrical with respect to the short-circuit section 54. As shown in Fig. As shown in Figure 11, the radiation pattern for the direction parallel to the ground plate is non-directional, in other words, omnidirectional. When the ground plate 51 is arranged horizontally, the vehicle external communication device 12β serves as an antenna whose main beam extends in the horizontal direction. The direction parallel to the ground plate corresponds to the radiation direction of the main polarization wave. The ground plate parallel plane refers to a plane parallel to the ground plate 51 and the opposite conducting plate 53.

[0093] Since the short-circuit portion 54 is located at the center of the opposing conduction plate 53, a current flowing through the opposing conduction plate 53 is symmetrical about the short-circuit portion 54. Therefore, a radio wave in the antenna height direction generated by a current flowing through the opposing conduction plate 53 in a certain direction from the center of the opposing conduction plate 53 is canceled by a radio wave generated by the current flowing in the opposite direction. That is, the current excited by the opposing conduction plate 53 does not contribute to the emission of radio waves. As shown in Fig. As shown in Figure 12, the radio wave is not radiated in a direction perpendicular to the ground plate 51 (hereinafter referred to as a direction perpendicular to the ground plate). The direction perpendicular to the ground plate corresponds to the positive direction of the Z-axis in the drawing. Hereinafter, for the sake of simplicity, a mode driven by LC parallel resonance in which the capacitance formed between the ground plate 51 and the opposing lead plate 53 and the inductance of the short-circuit portion 54 exist is referred to as a zero-order resonance mode. The vehicle exterior antenna 121β in the zero-order resonance mode corresponds to a voltage antenna.The antenna having the above configuration corresponds to an antenna in which the electrostatic capacitance formed by the opposing conductive plate 53 and the ground plate 51 and the inductance contained in the short-circuit portion 54 are used for parallel resonance at the communication frequency as a frequency for wireless communication. The resonance frequency of the zero-order resonance mode can be adjusted using a tuning element.

[0094] The external antenna 121β also radiates radio waves from the ground plate 51 because the ground plate 51 is asymmetrical from the perspective of the opposing conductive plate 53. Specific examples will be described below. In the vehicle external communication device 12β of the present embodiment, the opposing conductive plate 53 is arranged to deviate or shift by 0.04λ in the X-axis direction from a position concentric with the ground plate 53. According to the embodiment in which the ground plate offset amount ΔSa is set to 0.04λ, the area within 0.08λ from the edge portion in the X-axis direction is the asymmetry portion 511 for the opposite conduction plate 53. The asymmetry portion 511 here refers to a portion of the ground plate 51 that is asymmetrical as viewed from the opposite conduction plate 53.The length of the asymmetry section 511 (hereinafter referred to as the asymmetry section width W) can be appropriately modified. For example, the asymmetry section width W can be set to 0.1λ, 0.125λ, 0.25λ, or 0.5λ. The asymmetry section width W corresponds to twice the value of the ground plate offset amount ΔSa. Therefore, the configuration where the asymmetry section width W is 0.25λ corresponds to the configuration where the ground plate offset amount ΔSa is set to 0.125λ.

[0095] In the Fig. 13 and Fig. In Figure 14, the asymmetry portion 511 is obliquely dashed with a dot pattern to illustrate this area. The maximum area of ​​the grounding plate 51 that is symmetrical with respect to the opposing conducting plate 53 is also referred to as the symmetry-maintaining portion 512. The symmetry-maintaining portion 512 includes a part of the edge portion of the grounding plate 51. The length of the symmetry-maintaining portion 512 in the X-axis direction from the center portion to the end portion is equal to (L / 2 - ΔSa). The center of the symmetry-maintaining portion 512 and the center of the opposing conducting plate 53 coincide in plan view.

[0096] Fig. Figure 13 is a diagram conceptually showing the current flowing through the ground plate 51. As a result of a simulation, it was confirmed that the current flowing through the ground plate 51 due to the LC parallel resonance mainly flows along the edge of the ground plate 51. In Fig. 13, the size of the arrow represents the amplitude of the current. In Fig. 13, the carrier plate 52 is shown transparent (i.e., not shown).

[0097] The current flowing from the opposing conduction plate 53 through the short-circuit portion 54 and into the grounding plate 51 flows from the short-circuit portion 54 in the X-axis direction to both ends of the grounding plate 51. The short-circuit portion 54, which serves as the input and output of the current for the grounding plate 51, is arranged in the longitudinal center of the symmetry-maintaining portion 512. Therefore, in the symmetry-maintaining portion 512, the currents flowing from the short-circuit portion 54 toward both ends in the X-axis direction have opposite directions and the same magnitude.Therefore, the electromagnetic wave generated by the current flowing in a certain direction (for example, the positive direction of the X-axis) from the center of the symmetry holding portion 512 is canceled by the electromagnetic wave formed by the current flowing in the opposite direction (for example, the negative direction of the X-axis), as shown in FIG. Fig. 14. Therefore, substantially no radio wave is emitted from the symmetry holding portion 512.

[0098] However, a radio wave generated by the current flowing through the asymmetry portion 511 is not extinguished. In other words, the edge of the asymmetry portion 511 serves as a radiating element (actually a linear antenna). The radio waves radiated from the ground plate 51 are linearly polarized waves in which the electric field oscillates in a direction parallel to the ground plate 51 (hereinafter referred to as horizontally polarized ground plate waves). Specifically, the radio wave radiated from the ground plate 51 is linearly polarized (hereinafter referred to as X-axis parallel polarized wave), with the vibration direction of the electric field parallel to the X-axis. The horizontally polarized ground plate wave is radiated in a direction orthogonal to the X-axis.That is, the horizontally polarized wave of the ground plate is also radiated in the upward direction (hereinafter: direction perpendicular to the ground plate) of the vehicle external communication device 12β.

[0099] Hereinafter, the operation mode using the linear current flowing through the edge of the asymmetry portion 511 of the ground plate 51 is referred to as the ground plate excitation mode. The ground plate excitation mode corresponds to an operation mode in which linearly polarized waves whose electric field vibrates in the direction in which the asymmetry portion 511 and the symmetry holding portion 512 are connected (here, the X-axis direction) are radiated in the direction perpendicular to the edge portion. The vehicle exterior communication device 12β according to the ground plate excitation mode corresponds to a current-based antenna that radiates radio waves by an induced current.When the vehicle external communication device 12β is used in a position parallel to the horizontal plane, the horizontally polarized wave of the ground plate corresponds to the linearly polarized wave (i.e., the horizontally polarized wave) with the vibration direction of the electric field parallel to the ground. Fig. 15 illustrates a result of simulation of the radiation characteristics of the vehicle external communication device 12β in the ground plate excitation mode, wherein the electrical length of the ground plate offset amount ΔSa is set to 0.05λ.

[0100] The vehicle external communication device 12β of the present embodiment has the above structure for simultaneously operating in the zero-order resonance mode to form a beam in the direction parallel to the ground plate and operating in the ground plate excitation mode to form a beam in the direction perpendicular to the ground plate. Accordingly, the ratio of the gain in the direction perpendicular to the ground plate to the gain in the direction parallel to the ground plate varies according to the asymmetry section width W. The asymmetry section width W can be appropriately adjusted so that a desired gain ratio can be obtained.

[0101] The ratio of the gain in the ground plate perpendicular direction to the gain in the ground plate parallel direction can be affected not only by the width W of the asymmetry portion, but also by the separation or distance between the ground plate 51 and the metal (e.g., B-pillar 42B) present on the rear surface of the vehicle exterior communication device 12β. In the present embodiment, the asymmetry portion width W is set to a value at which the gain in the ground plate excitation mode dominates over the gain in the zero-order resonance mode at a predetermined second frequency. The second frequency is a frequency different from the first frequency and is within the frequency band used in the system. The second frequency is, for example, 2480 MHz.According to another aspect, the second frequency may be set to an announcement channel, for example, 2402 MHz, 2426 MHz, or 2450 MHz.

[0102] It may be advantageous if the first frequency and the second frequency are separated by 20 MHz or more, for example, by ten or more channels. If it is necessary to distinguish between the wavelength of the radio wave of the second frequency and the target wavelength, the wavelength of the radio wave of the second frequency will be referred to as "λ2" hereinafter. The difference between λ2 and λ in air is approximately 1.5 mm, and this difference can be neglected in this embodiment. The normalized bandwidth of the frequency band used in the system is less than 25% (specifically, approximately 3.3%). The first frequency and the second frequency correspond to frequencies for which the separation in the frequency range is less than a quarter of the center frequency (actually 3.3% or less).The positioning system of the present invention corresponds to a positioning system usable for a wireless communication system in which the normalized bandwidth is set to less than 25%, for example 5% or 10%, of the center frequency.

[0103] Fig. 15 shows the result of simulating the radiation gain in each operating mode for respective frequencies when the ground plate offset amount ΔSa is set to an arbitrary value (for example, 0.08λ). The above-mentioned first frequency corresponds to a frequency at which the gain in the zero-order resonance mode dominates over the gain in the ground plate excitation mode. The above-mentioned second frequency corresponds to a frequency at which the gain in the ground plate excitation mode dominates over the gain in the zero-order resonance mode. In other words, the first frequency corresponds to the frequency at which the antenna 121 operates mainly in the zero-order resonance mode, and the second frequency corresponds to the frequency at which the antenna 121 operates mainly in the ground plate excitation mode.

[0104] Fig. 15 illustrates an example in which the gain in the zero-order resonance mode at the first frequency is greater than the gain in the ground plate excitation mode at the second frequency. However, it is not limited to this example. Since the operating principle of the zero-order resonance mode and that of the ground plate excitation mode are different, the respective resonance frequencies are determined independently. The frequency characteristics of the ground plate excitation mode can be modified, for example, by adjusting a distance between the ground plate 51 and the metal arranged on the rear surface or the asymmetry section width W. The frequency characteristics in the zero-order resonance mode can also be adjusted by adjusting the area of ​​the opposing conduction plate 53 or the diameter of the short-circuit section 54. For example, as shown in Fig. As shown in Figure 16, the gain in the zero-order resonance mode at the first frequency and the gain in the ground plate excitation mode at the second frequency may be matched. It is also possible to match the peak value of the gain in the ground plate excitation mode and the peak value in the zero-order resonance mode in the frequency band used in the system. The vehicle exterior antenna 121β may operate in the zero-order resonance mode on the lower frequency side than a predetermined conversion frequency, and may operate in the ground plate excitation mode on the higher frequency side than the conversion frequency. However, it may also have opposite radiation characteristics.

[0105] Furthermore, the first frequency and the second frequency can be determined by back-calculating the frequency characteristics of the respective operating modes of the antenna 121. The second frequency can be set to a frequency at which the gain in the ground plate excitation mode dominates over the gain in the zero-order resonant mode, and the same gain as the gain in the zero-order resonant mode can be obtained at the first frequency. In the present embodiment, for example, the first frequency is set to a frequency such that the gain in the zero-order resonant mode is 3 dB or more (for example, about 5 dB) greater than the gain in the ground plate excitation mode.The second frequency is set, for example, to a frequency at which the gain in the ground plate excitation mode dominates over the gain in the zero-order resonant mode, and the same gain as the gain in the zero-order resonant mode at the first frequency can be obtained. The zero-order resonant mode corresponds to a first mode, and the ground plate excitation mode corresponds to a second mode. The first mode may include a state in which the zero-order resonant mode and the ground plate excitation mode coexist while the antenna 121 is mainly or substantially operated in the zero-order resonant mode based on the relationship of the difference between their gains. The state in which the gain in the zero-order resonant mode is 3 dB or more larger than the gain in the ground plate excitation mode also corresponds, for example, to the first mode.The above idea can also be used for the second mode.

[0106] Furthermore, the operation when the vehicle exterior communication device 12β transmits (i.e., radiates) radio waves and the operation when it receives radio waves have an inverse relationship. That is, according to the vehicle exterior communication device 12β, the vertically polarized wave of the ground plate arriving in the direction parallel to the ground plate can be received, and the horizontally polarized wave of the ground plate arriving in the direction perpendicular to the ground plate can also be received.

[0107] As described above, by operating in the zero-order resonance mode, the vehicle external communication device 12β receives the vertically polarized wave of the ground plate in all directions parallel to the ground plate. At the same time, the vehicle external communication device 12β operates in the ground plate excitation mode, so that the horizontally polarized wave of the ground plate can be transmitted and received in the vertical direction with respect to the earth. The vehicle external communication device 12β can transmit and receive radio waves with different polarization planes in mutually orthogonal directions. Hereinafter, the antenna having the above structure may also be referred to as a zero-order ground plate extension antenna or a zero-order ground plate extension antenna. Installation position, installation location and function of the vehicle external communication device 12β

[0108] The left exterior communication device 12L is an on-vehicle communication device 12 for bringing the periphery of the door near the front seat (hereinafter referred to as the front left door), located on the left side of the vehicle Hv, into the area of ​​a strong electric field. Since the driver's seat is located on the left side of the vehicle Hv in this example, the front left door corresponds to the driver's seat door.

[0109] As it is in Fig. As shown in FIG. 17, the left exterior communication device 12L is installed on the outer surface of the B-pillar 42B disposed on the left side of the vehicle, in a position such that the grounding plate 51 faces the surface of the B-pillar 42B, and the X-axis direction is along the longitudinal direction of the B-pillar 42B. In other words, the left exterior communication device 12L is installed in a position such that the grounding plate 51 faces the outer surface portion, for example, the surface of the B-pillar 42 outside the cabin. Alternatively, the left exterior communication device 12L may be mounted to have the above-described position on an inner portion of the door panel that overlaps with the B-pillar 42B in the door module 45.The mode in which the grounding plate 51 is installed facing the outer surface portion includes a state in which the grounding plate 51 is substantially parallel to the side surface portion of the vehicle. The installation posture may include a configuration in which the grounding plate 51 is installed along the outer surface portion of the vehicle.

[0110] According to the installation posture, the direction perpendicular to the grounding plate for the vehicle exterior communication device 12β is perpendicular to the side surface portion of the vehicle. The direction parallel to the grounding plate is a direction along the side surface portion of the vehicle, in other words, a direction parallel to the side surface portion of the vehicle. In other words, the left exterior communication device 12L is installed in a posture such that the center of the directivity provided by the zero-order resonance mode is parallel to the side surface portion, specifically, to the door panel, and the center of the directivity provided by the grounding plate excitation mode is perpendicular to the side surface portion, as shown in Fig. 18. As shown in Fig. As shown in Figure 18, the direction of vibration of the electric field, in other words, the polarization plane of the linearly polarized wave radiated by the zero-order resonance mode, is perpendicular to the side surface portion of the vehicle. The vibration direction of the electric field of the linearly polarized wave radiated toward a cabin exterior in the ground plate excitation mode is parallel to the side surface portion of the vehicle.

[0111] The term "perpendicular" is not limited to a situation of exactly perpendicular, but can also mean inclined by up to about 30°. That is, perpendicular can also include a situation of substantially perpendicular. Similarly, terms such as parallel and opposite also include a state of inclination of up to about 30°. Hereinafter, the direction perpendicular to the side surface portion of the vehicle and the direction away from the side surface portion of the vehicle may also be referred to as the direction toward the cabin exterior. In other aspects, the direction toward the cabin exterior corresponds to a direction parallel to the vehicle width direction and the direction away from the side surface portion of the vehicle.

[0112] According to the installation location and installation position as shown in Fig. 19, the directivity can be formed both in the direction parallel to the vehicle side surface portion and in the direction toward the cabin exterior. The gain in the vehicle width direction is derived from the asymmetry portion width W. By adjusting the asymmetry portion width W, it is possible to limit the substantial communication area of ​​the vehicle exterior communication device 12β to within 2 meters. As a result, the communication area can be formed substantially in an ellipse shape with the vehicle width direction as the transverse direction at the side of the vehicle Hv, in other words, near the B-pillar.According to the above installation mode, it is possible to further reduce the amount of radio waves radiated in the ground plate excitation mode and entering the vehicle cabin because the B-pillar 42B made of metal serves as the ground plate or reflection plate for the antenna 121 operating in the ground plate excitation mode.

[0113] According to the above installation position and the installation attitude, the linearly polarized wave radiated by the left outdoor communication device 12L in the zero-order resonance mode propagates along the metal plate arranged for the side surface portion of the vehicle as shown in Fig. 18. The radio wave, whose electric field vibration direction is perpendicular to the metal plate, has a characteristic such that it propagates along the metal plate. Therefore, the radio wave radiated in the zero-order resonance mode propagates from the upper end to the lower end in the outdoor operating area and remains at a relatively strong level. The radio waves radiated in the zero-order resonance mode circulate to some extent in the vehicle cabin through the edge of the side window.

[0114] As a result, according to the zero-order resonance mode, it is possible to set almost the entire range of the external operating region Rx to a strong electric field region as shown in Fig. 20. Since the electric field perpendicular to the B-pillar 42B circulates slightly in the vehicle cabin, the electric field strength within the vehicle cabin is also at a relatively high level. The electric field strength and the reception strength of the transmitted signal have different physical quantities. However, due to the reversibility of transmission and reception, these physical quantities have a proportional relationship to each other and can be used as alternative characteristics. As shown in Fig. 20, the electric field strength indicates the maximum value of the respective electric field strengths of three channels, ie, at 2402 MHz, 2442 MHz, and 2480 MHz. Fig. 20 shows a simulation result of an electric field distribution in a case where a dipole antenna is installed perpendicular to the B-pillar 42B, in other words, in a position substantially along the vehicle width direction. It was confirmed from the simulation that the propagation mode of the radio wave radiated by the vehicle exterior communication device 12β installed at the above position and in the above posture is almost identical in the zero-order resonance mode to a case where the dipole antenna is installed in a position perpendicular to the B-pillar 42B. Therefore, Fig. 20 can be considered as a diagram showing the radiation characteristics when the left and right external communication devices 12β are operated in the zero-order resonance mode.

[0115] The linearly polarized wave radiated by the left external communication device 12L in the ground plate excitation mode toward the cabin exterior is easily launched toward the cabin exterior by reflection from the metal portion of the vehicle, such as the door panel. The radio wave, whose electric field vibration direction is parallel to the metal plate, is easily repelled or reflected by the metal plate. Therefore, the radio waves radiated in the ground plate excitation mode hardly penetrate into the vehicle cabin. As shown in Fig. 21, the electric field strength within the vehicle cabin can be reduced to a relatively low level. Fig. 21 shows a simulation result of an electric field strength distribution in a case where a dipole antenna is installed along the longitudinal direction of the B-pillar 42B, in other words, in a position substantially along the vehicle height direction. It was confirmed by the simulation that the propagation mode of the radio wave radiated by the vehicle exterior communication device 12β installed at the above position and in the above posture in the ground plate excitation mode is almost identical to a case where the dipole antenna is installed in a position along the B-pillar 42B. The operating principle of the ground plate excitation mode is similar to a rod antenna such as a dipole antenna or a monopole antenna. Therefore, Fig. 21 can be considered as a diagram showing the radiation characteristics when the left and right outdoor communication devices 12β are operated in the ground plate excitation mode. The dipole antenna has a donut-shaped radiation directivity (a characteristic corresponding to the figure "8") in the direction of the axis of the radiating element. Therefore, in a case where the dipole antenna is installed at a position in the vehicle height direction, the electric field strength in the lower half of the outdoor operation range Rx has a low level. The lower half of the outdoor operation range Rx corresponds to a region where the torso to the legs of the body are located.

[0116] The right exterior communication device 12M is an in-vehicle communication device 12 for bringing the periphery of the door near the front seat (hereinafter referred to as the front right door), located on the right side of the vehicle Hv, into the area of ​​a strong electric field. Since the front passenger seat is located on the right side of the vehicle Hv in this example, the front right door corresponds to the front passenger seat door.

[0117] The right external communication device 12M on the right surface portion of the vehicle Hv is arranged at a position opposite to the left external communication device 12L. The right external communication device 12M corresponds to an in-vehicle communication device 12 that forms a pair with the left external communication device 12L. The right external communication device 12M is installed on the outer surface of the B-pillar 42B located on the right side of the vehicle in a position such that the ground plate 51 faces the surface of the B-pillar 42B and the X-axis direction is along the longitudinal direction of the B-pillar 42B.

[0118] The rear external communication device 12M is an in-vehicle communication device 12 for a strong electric field near the trunk door. The rear external communication device 12M is arranged at a central portion of the rear end portion of the vehicle in the vehicle width direction. For example, the trunk door handle, the vicinity of a license plate, the interior portion, a lower edge portion of a rear bumper, or an upper edge portion of the rear bumper can be used as the installation position of the rear external communication device 12N. The rear external communication device 12N is arranged, for example, inside the trunk outer door handle in a position where the X-axis is along the vehicle width direction and the Z-axis is directed toward the rear of the vehicle.

[0119] Depending on the installation position, it is possible to form directivity in both the direction along the rear surface portion of the vehicle and the direction perpendicular to the rear surface portion of the vehicle. As a result, a communication area in a substantially elongated ellipsoidal shape is formed with the rear external communication device 12N as the center and the vehicle direction as the longitudinal direction. The direction along the rear surface portion of the vehicle includes the vehicle width direction or the height direction. The direction perpendicular to the rear portion of the vehicle corresponds to the rearward direction of the vehicle.Since the gain to the rear of the vehicle is derived from the width W of the asymmetry portion, it is possible to restrict the essential communication range of the rear external communication device 12N for the rear of the vehicle to within 2 meters from the rear end portion of the vehicle.

[0120] Regarding the vehicle exterior communication device 12β, the vehicle exterior communication devices 12 arranged on the left side surface portion and the right side surface portion, for example, the left exterior communication device 12L and the right exterior communication device 12M, may also be referred to as side communication devices. The number of vehicle exterior communication devices 12β included in the vehicle exterior system 1 can be appropriately changed. The number of vehicle exterior communication devices 12β may be two, three, or four. The number of vehicle exterior communication devices 12β included in the vehicle exterior system 1 may be five or more.

[0121] Both the in-vehicle communication device 12α and the out-of-vehicle communication device 12β are designed to primarily report the reception strength of the signal from the portable terminal 2 to the smart ECU 11. Therefore, various types of the in-vehicle communication device 12α and the out-of-vehicle communication device 12β are also referred to as strength monitoring devices. Each of the strength monitoring devices provides the reception strength of the signal transmitted from the portable terminal 2, along with the channel number of the reception signal and the transmission source of the reception signal, to the smart ECU 11. Function of the intelligent ECU 11

[0122] The intelligent ECU 11 executes the positioning programs described above to perform functions corresponding to various function blocks defined in Fig. 22. In other words, the intelligent ECU 11 includes, as functional blocks, a vehicle information acquisition unit F1, a communication processing unit F2, an authentication processing unit F3, a positioning determination unit F4, and a vehicle control unit F5.

[0123] The vehicle information acquisition unit F1 acquires various pieces of information indicating the state of the vehicle Hv (hereinafter referred to as vehicle information) from sensors, ECUs (e.g., the body ECU 16), switches, and the like mounted on the vehicle Hv. The vehicle information includes, for example, an opening / closing state of each door, a locking / unlocking state of each door, whether the door knob 13 is pressed, whether the start button 14 is pressed, and the like. The vehicle information acquisition unit F1 identifies a current state of the vehicle Hv based on the various information described above. For example, when the engine is off and all the doors are locked, the vehicle information acquisition unit F1 determines that the vehicle Hv is parked.It goes without saying that the condition for determining that the vehicle Hv is parked can be appropriately designed, and various determination conditions and the like can be used.

[0124] Acquiring the information indicating the locking / unlocking state of each door corresponds to determining the locking / unlocking state of each door and detecting the locking operation or unlocking operation of the door by the user. Acquiring electrical signals from the door knob 13 and the start button 14 corresponds to detecting the user operation with respect to these knobs. The vehicle information acquired by the vehicle information acquisition unit F1 includes information related to a user operation of the vehicle Hv. Furthermore, the types of information included in the vehicle information are not limited to the examples described above. The vehicle information also includes, for example, a shift position or gear position detected by a shift position sensor.gear position sensor (not shown), a detection result of a brake sensor for detecting whether a brake pedal is depressed, and the operating state of a parking brake.

[0125] The communication processing unit F2 is configured to transmit and receive data to and from the portable terminal 2 in cooperation with the in-vehicle communication device 12 (hereinafter referred to as the in-vehicle communication device 12α) as a data communication device. For example, the communication processing unit F2 generates data addressed to the portable terminal 2 and outputs the data to the in-vehicle communication device 12α. Thus, the communication processing unit F2 transmits a signal corresponding to desired data as a radio wave. Furthermore, the communication processing unit F2 receives data from the portable terminal 2 received by the in-vehicle communication device 12α.In the present embodiment, the wireless communication between the smart ECU 11 and the portable terminal 2 may be performed, for example, in an encrypted manner. In the present embodiment, the smart ECU 11 and the portable terminal 2 encrypt and perform data communication for authentication or the like to enhance security. However, this is not limited to this. In another aspect, the smart ECU 11 and the portable terminal 2 may perform data communication without encryption.

[0126] The communication processing unit F2 detects that the user is present near the vehicle Hv based on the establishment of the communication link between the portable terminal 2 and the in-vehicle communication device 12α. Furthermore, the communication processing unit F2 acquires the terminal ID of the communicatively connected portable terminal 2 from the in-vehicle communication device 12α. According to such a configuration, even when the vehicle Hv is a vehicle shared by multiple users, the smart ECU 11 can determine a user present near the vehicle Hv based on the terminal ID of the portable terminal 2 to which the in-vehicle communication device 12α is communicatively connected.

[0127] The smart ECU 11, as the communication processing unit F2, acquires channel information from the in-vehicle communication device 12α. As a result, the smart ECU 11 determines a channel to be used by the in-vehicle communication device 12α for communication with the portable terminal 2. Furthermore, the communication processing unit F2 distributes the channel information and the terminal ID acquired from the in-vehicle communication device 12α to the respective strength monitoring devices as reference information. The channel information specified in the reference information enables each strength monitoring device to recognize the channel to be used for reception among the many channels included in the Bluetooth standard in order to receive the signal from the portable terminal 2.Even if the strength observation device receives signals from multiple devices, the strength observation device can determine which device should report the reception strength of the signal to the intelligent ECU 11 based on the terminal ID specified in the reference information.

[0128] The authentication processing unit F3 executes a process for confirming that the communication partner is the user's portable terminal 2 (in other words, authentication of the portable terminal 2) in cooperation with the in-vehicle communication device 12α. The communication for authentication is performed in an encrypted manner via the in-vehicle communication device 12α. In other words, the authentication process is performed through cryptographic communication. The authentication process can be performed using various methods such as a challenge-response method. The detailed description of the authentication process is omitted in this example.It is assumed that data (e.g., encryption keys) required for the authentication process are stored in each of the portable terminal 2 and the smart ECU 11. A time at which the authentication processing unit F3 performs the authentication process may be, for example, a time at which the communication link between the in-vehicle communication device 12α and the portable terminal 2 is established. The authentication processing unit F3 may be configured to perform the authentication process in predetermined cycles while the in-vehicle communication device 12α and the portable terminal 2 are in communication with each other.The authentication processing unit F3 may be configured to perform cryptographic communication for the authentication process using a predetermined user operation on the vehicle Hv as a trigger, for example, when the start button 14 is pressed by the user.

[0129] "According to the Bluetooth standard," "that the communication link between the in-vehicle communication device 12α and the portable terminal 2 is established" means that the portable terminal 2, which has been registered in advance, is a communication partner of the in-vehicle communication device 12α. Therefore, the smart ECU 11 may be configured to determine that the portable terminal 2 has been successfully authenticated based on the condition that the communication link between the in-vehicle communication device 12α and the portable terminal 2 has been established.

[0130] The positioning unit F4 performs processing for estimating the position of the portable terminal 2 based on the communication status between the respective on-vehicle communication devices 12 and the portable terminal 2. For example, in the present embodiment, the positioning unit F4 determines whether the portable terminal 2 is located inside the vehicle cabin, within the outdoor operation area Rx, or outside the area based on the reception status and reception strength of the signal of the portable terminal 2 provided by the respective on-vehicle communication devices 12. The term "outside the area" refers to an area outside the vehicle cabin area and an area outside the outdoor operation area Rx.An area outside the area that is at least a predetermined prohibition distance away from the exterior door handle can be referred to as a prohibition area. The prohibition distance is set to 2 meters in view of theft prevention, as described later. Since the portable terminal 2 is basically carried by the user, determining the position of the portable terminal 2 corresponds to determining the position of the user. The prohibition distance may also be, for example, 1.6 meters or 3 meters. The prohibition distance, which defines the size of the prohibition area, can be appropriately modified according to, for example, an area where the vehicle is used.

[0131] As a preparatory process for determining the position of the portable terminal 2, the positioning unit F4 sequentially acquires the reception strengths of the signals from the portable terminal 2 from a plurality of on-vehicle communication devices 12, each of which is a strength monitoring device, and stores the acquired reception strengths in the RAM 113, discriminating the acquired reception strengths according to the respective acquisition sources. Then, the positioning unit F4 determines whether the portable terminal 2 is present in the vehicle cabin based on the reception strengths from the respective strength monitoring devices stored in the RAM 113 and various determination thresholds registered in the flash memory 112.The specific operation of the positioning unit F4, i.e., the method for determining the position of the portable terminal 2 based on the reception strength of a respective strength monitoring device by the positioning unit F4, will be described in more detail later. The determination result of the positioning unit F4 is referenced by the vehicle control unit F5.

[0132] The vehicle control unit F5 is configured to execute vehicle control according to the position of the portable terminal 2 (in other words, the user) and the state of the vehicle Hv in cooperation with the body ECU 16 or the like when the authentication of the portable terminal 2 by the authentication processing unit F3 is successful. The state of the vehicle Hv is determined by the vehicle information acquisition unit F1. The position of the portable terminal 2 is determined by the positioning unit F4.

[0133] For example, when the portable terminal 2 is present outside the vehicle cabin and the user presses the door button 13 while the vehicle Hv is parked, the vehicle control unit F5 unlocks the door lock mechanism in cooperation with the body ECU 16. As another example, when it is determined by the position determination unit F4 that the portable terminal 2 is present in the vehicle cabin and it is detected that the start button 16 has been pressed by the user, the vehicle control unit F5 starts the internal combustion engine in cooperation with the internal combustion engine ECU 15. In this way, the vehicle control section F5 executes vehicle control according to the position of the user and the state of the vehicle Hv, with the user's operation of the vehicle Hv as a trigger.However, some vehicle controls that can be executed by the vehicle control unit F5 can be executed automatically according to the user's position without requiring user operation of the vehicle Hv. Process concerning a connection

[0134] In the following, a connection-related process performed by the on-vehicle system 1 will be described with reference to the flowchart of Fig. 23. The Fig. The connection-related process shown in Figure 23 relates to the establishment of the communication connection between the vehicle-based system 1 and the portable terminal 2. The connection-related process shown in Fig. 19, for example, can be started when the in-vehicle communication device 12α as a data communication device receives an announcement packet from the portable terminal 2.

[0135] In step S101, the in-vehicle communication device 12α establishes a communication link (in other words, a connection) with the portable terminal 2 and then proceeds to step S102. When the in-vehicle communication device 12α has established the communication link with the portable terminal 2, the in-vehicle communication device 12α, which has a communication link with the smart ECU 11, provides the terminal ID of the portable terminal 2. Furthermore, if the strength monitoring device in the smart ECU 11 is in an idle mode at the time the communication link with the portable terminal 2 is established, the in-vehicle communication device 12α outputs a predetermined control signal to the strength monitoring device and enters the standby mode. A pause mode, for example, is a state in which the signal reception function stops.Pause mode includes a state in which the power supply is turned off.

[0136] In step S102, the in-vehicle communication device 12α periodically performs encrypted communication based on an instruction from the smart ECU 11. The content of the data exchanged at this time can be any content, as long as the content requests the portable terminal 2 to send a response signal. The data content may consist of data for authenticating the portable terminal 2, such as a challenge code. Wireless communication with the portable terminal 2 is periodically performed so that the smart ECU 11 can confirm that the portable terminal 2 is present inside the vehicle cabin or around the vehicle.

[0137] In step S103, the in-vehicle communication device 12α and the smart ECU 11 cooperate with each other to start sharing the reference information. Specifically, the in-vehicle communication device 12α sequentially provides the terminal ID and channel information of the portable terminal 2 connected by communication to the smart ECU 11. The smart ECU 11 sequentially distributes the channel information and terminal ID provided by the in-vehicle communication device 12α to the respective strength monitoring devices as reference information.

[0138] In step S104, each strength observation device starts monitoring the reception strength of a signal from the portable terminal 2 using the reference information provided by the intelligent ECU 11. In other words, the strength observation device sets a channel having a number indicated in the channel information as a reception target among a large number of channels included in the Bluetooth standard. The strength observation device sequentially changes the channel for reception according to the channel information provided by the intelligent ECU 11.

[0139] Even when the portable terminal 2 and the in-vehicle communication device 12α perform the wireless communication of the frequency hopping system with each other, the reception strength of the signal from the portable terminal 2 is acquired, and the reception strength is sequentially reported to the intelligent ECU 11. That is, the on-vehicle communication devices 12 included in the on-vehicle system 1 can detect the reception strength of a signal transmitted from the portable terminal 2, ensuring the secrecy (in other words, the security) of the communication between the on-vehicle system 1 and the portable terminal 2.

[0140] In step S105, the strength monitoring device determines whether it has received a signal including the terminal ID indicated in the reference information. If a signal including the terminal ID indicated in the reference information has been received, the process proceeds to step S106. In step S106, the reception strength of the received signal is reported to the smart ECU 11. In steps S105 and S106, each strength monitoring device reports to the smart ECU 11 the reception strength of the signal including the terminal ID indicated in the reference information according to the channel number indicating a frequency at which the signal is received. If, in step S105, the signal from the portable terminal 2 has not been received for a predetermined period of time, step S108 may be performed.

[0141] In step S107, the smart ECU 11 executes a process of storing the reception strengths provided by the respective strength observers in the RAM 113, distinguishing between the respective reception strengths corresponding to the respective strength observers serving as the provider. The reception strength provided by the strength observer is stored separately for each channel number, in other words, each frequency used for reception. Specifically, the smart ECU 11 of the present embodiment classifies the reception intensities for each of the frequencies provided by the respective strength observers into the reception strength of the first frequency band and the reception strength of the second frequency band.

[0142] The first frequency band is a range in which the vehicle exterior communication device 12β operates mainly in the zero-order resonance mode, and refers to a frequency within a certain range around the first frequency. The second frequency band is a range in which the vehicle exterior communication device 12β operates mainly in the ground plate resonance mode, and refers to a frequency within a certain range around the second frequency. In the frequency band used in the system, the first frequency band and the second frequency band are set so that they do not overlap. For example, when the vehicle exterior antenna 121β Fig. 16, it is possible to use 2400 MHz to 2440 MHz as the first frequency band. As an example, the frequencies 2402 MHz to 2438 MHz are set as the first frequency band. If the vehicle exterior antenna 121β has the Fig. 16, it is possible to use the frequencies 2460 MHz to 2500 MHz as the second frequency band. Here, as an example, the frequencies 2460 MHz to 2480 MHz are set as the second frequency band. In addition, the range in which the difference in gain from that of the first frequency in the simulation is within ±3 dB may be defined as the first frequency band. Similarly, the range in which the difference in gain from that of the second frequency in the simulation is within ±3 dB may be referred to as the first frequency band. The respective ranges of the first frequency band and the second frequency band may be appropriately modified according to the operating characteristics of the antenna 121.

[0143] In step S108, the smart ECU 11 and the in-vehicle communication device 12α cooperate with each other to determine whether the communication link with the portable terminal 2 has been terminated. The case where the communication link with the portable terminal 2 has been terminated is, for example, a case where the in-vehicle communication device 12α cannot receive a signal from the portable terminal 2. If the communication with the portable terminal 2 has been terminated, the result of the determination in step S108 is affirmative, and then step S109 is executed. On the other hand, if the communication with the portable terminal 2 is still maintained, the process returns to step S105.

[0144] In step S109, the smart ECU 11 outputs a predetermined control signal to the strength monitoring device and stops monitoring the reception strength of the signal transmitted from the portable terminal 2. For example, the smart ECU 11 may cause the strength monitoring device to enter pause mode. When the process in step S109 is completed, the current flow ends. Positioning process

[0145] The following describes the positioning process performed by the intelligent ECU 11 with reference to the flowchart of Fig. 24. The positioning process is a process for determining the position of the portable terminal 2. The positioning process is performed, for example, in a predetermined positioning cycle in a state where the communication link between the in-vehicle communication device 12α and the portable terminal 2 is established. The positioning cycle is, for example, 200 milliseconds. Needless to say, the positioning cycle may also be 100 milliseconds or 300 milliseconds.

[0146] In step S201, the authentication processing unit F3 executes a process for authenticating the portable terminal 2 in cooperation with the in-vehicle communication device 12α, and then the process proceeds to step S202. Step S201 may be omitted. The authentication process may be appropriately changed according to an authentication time of the portable terminal 2. In step S202, the positioning unit F4 calculates the representation value of the reception strength of the signal in the first frequency band and the representation value of the reception strength of the signal in the second frequency band for each of the strength observation devices based on the reception strengths of each of the strength observation devices stored in the RAM 113. In other words, the representation value of the reception strength of each of the strength observation devices is calculated for each frequency band.

[0147] The representation value for the signal in the first frequency band at the strength observation device is a value representing the reception strength of the signal in the first frequency band within a last predetermined time in the strength observation device. Hereinafter, the representation value of the reception strength of the signal in the first frequency band at each strength observation device is referred to as an individual first strength. The first frequency band for the vehicle-external communication device 12β corresponds to the frequency band operating mainly in the zero-order resonance mode, in other words, the frequency band dominated by the zero-order resonance mode. Therefore, the individual first strength corresponds to the reception strength in the zero-order resonance mode for the vehicle-external communication device 12β.

[0148] According to one example, the single first strength is an average of the respective reception strengths of the signals of the last N times in the first frequency band. Such a single first strength corresponds to a moving average of the reception strengths of the signals in the first frequency band. N may be a natural number of 2 or greater, and is 5 in the present embodiment. In this case, the positioning unit F4 calculates the moving average using the reception strengths of the signals transmitted from the portable terminal 2 in the first frequency band acquired (i.e., sampled) at the last five times. It goes without saying that N may be 10, 20, or the like. According to another mode, N may be 1. The configuration where N=1 corresponds to a configuration where the last reception strength is directly used as the representation value.

[0149] The representative value for the signal in the second frequency band at the strength observation device is a value representing the reception strengths of the signals in the second frequency band within a last predetermined time in the strength observation device. Here, the representative value of the reception strength of the signal in the second frequency band at each strength observation device is referred to as a single second strength. The second frequency band for the vehicle-external communication device 12β corresponds to the frequency band that operates mainly in the ground plate excitation mode, in other words, the frequency band dominated by the ground plate excitation mode. Therefore, the single second strength corresponds to the reception strength in the ground plate excitation mode for the vehicle-external communication device 12β.The individual second strength can be calculated using the same method as used for the individual first strength. In other words, the individual second strength of the strength observer corresponds to an average of the received strengths of the signals in the second frequency band taken from the most recent N samples at the strength observer.

[0150] Hereinafter, the reception strength of the signal in the first frequency band transmitted by the portable terminal 2 may also be referred to as the first frequency reception strength. Similarly, the reception strength of the signal in the second frequency band transmitted by the portable terminal 2 may also be referred to as the second frequency reception strength.

[0151] Specifically, in step S202, the positioning unit F4 calculates, as the single first strength of the in-vehicle communication device 12α, an average of the first frequency reception strengths with the last five reception strengths provided by the in-vehicle communication device 12α as a population. As the single second strength of the in-vehicle communication device 12α, an average of the second frequency reception strengths with the last five reception strengths provided by the in-vehicle communication device 12α is used. In a situation where a plurality of in-vehicle communication devices 12α are provided, an average of the first frequency reception strengths with the last five first frequency reception strengths provided by the in-vehicle communication device 12α as a population is used for each in-vehicle communication device 12α.The same applies to the single second strength. In step S202, the positioning unit F4 also calculates, for the single first strength of the vehicle exterior communication device 12β, an average of the first and second frequency reception strengths using the last five first and second reception strengths provided by the vehicle interior communication device 12β as a population, similarly to the vehicle interior communication device 12α.

[0152] The single first strength of the strength observation device when the number of first reception strengths stored in the RAM 113 is less than N can be calculated by adding, as a missing reception strength representation value, a value corresponding to a lower limit of the reception strength detectable by the on-vehicle communication device 12. The lower limit of the reception strength detectable by the on-vehicle communication device 12 can be determined, for example, by the configuration of the on-vehicle communication device 12. The lower limit can be set to, for example, -60 dBm or the like. The same applies to the single second strength.

[0153] According to the above mode, for example, even if only a part of the strength observation devices included in the on-vehicle system 1 can receive the signal from the portable terminal 2 due to the position of the portable terminal 2, the subsequent process can be performed. For example, even if the right outdoor communication device 12M cannot receive the signal from the portable terminal 2 because the portable terminal 2 is located on the left side of the vehicle Hv, the individual first and second strengths can be calculated for the respective strength observation devices.

[0154] In the present embodiment, the average value of the last N reception strengths of the first frequency is used as the single first strength, but the present invention is not limited to the above example. The single first strength may be a median value or a maximum value of the last N reception strengths of the first frequency. The single first strength may be an average value of the reception strengths obtained by removing the maximum value and the minimum value from the last N reception strengths. The single first strength is preferably a value obtained by removing a change component of the current reception strength. The same applies to the single second strength. When the process in step S202 is completed, the process proceeds to step S203.

[0155] In step S203, the positioning unit F4 determines a first indoor device strength representation value Pa1 based on the individual first strengths of the respective in-vehicle communication devices 12α. Since there is only a single in-vehicle communication device 12α according to an example, the single first strength for the one in-vehicle communication device 12α is used as the first indoor device strength representation value Pa1. In step S203, the positioning unit F4 determines a second indoor device strength representation value Pa2 based on the individual second strengths of the respective in-vehicle communication devices 12α in a similar manner to the first indoor device strength representation value Pa1.According to another aspect, in a situation where there are multiple indoor communication devices 12α, the maximum value of the first strength representation values ​​acquired from the respective indoor communication devices 12α may be used as the first indoor device strength representation value Pa1. In a situation where there are multiple indoor communication devices 12α, the first indoor device strength representation value Pa1 may be an average or a median value of the respective first strengths of the vehicle's indoor communication devices 12α. The same applies to the second indoor device strength representation value Pa2. In a situation where the first indoor device strength representation value Pa1 and the second indoor device strength representation value Pa2 do not need to be distinguished from each other, both are referred to as the indoor device strength representation value.

[0156] In step S204, the positioning unit F4 determines a first external device strength representation value Pb1 based on the individual first strengths of the vehicle external communication devices 12β. The positioning unit F4 according to the present embodiment uses the maximum value of the individual first strengths for the respective vehicle external communication devices 12β as the first external device strength representation value Pb1. The maximum value of the individual second strengths for the respective vehicle external communication devices 12β is used as the second external device strength representation value Pb2. When the process in step S204 is completed, the process proceeds to step S205. The external device strength representation value Pb1 may also be an average value or a median value of the individual first strengths acquired from the respective vehicle external communication devices 12β.The same applies to the second external device strength representation value Pb2. In a situation where the first external device strength representation value Pb1 and the second external device strength representation value Pb2 do not need to be distinguished from each other, both are referred to as the external device strength representation value.

[0157] In step S205, the positioning unit F4 determines whether the first outdoor device strength representation value Pb1 is equal to or greater than the operation threshold Prx. The operation threshold Prx is a threshold for determining whether the portable terminal 2 is present in the outdoor operation area Rx outside the vehicle cabin. The operation threshold Prx can be designed based on the minimum value of the first outdoor device strength representation value Pb1 that can be observed when the portable terminal 2 is present in the outdoor operation area Rx.The minimum value of the first outdoor device strength representation value Pb1 observed in a state where the portable terminal 2 is present in the outdoor operation area Rx may be determined based on the result of a test that measures the first outdoor device strength representation value Pb1 at each observation point where the portable terminal 2 is located in the outdoor operation area Rx.

[0158] The operation threshold Prx may preferably be configured as a value obtained by adding a predetermined tolerance to the maximum value of the first outdoor device strength representative value Pb1 that can be observed when the portable terminal 2 is present in the prohibition area. According to setting the operation threshold Prx based on such a technical idea, the situation where the first outdoor device strength representative value Pb1 is equal to or greater than the operation threshold Prx refers to a situation where the portable terminal 2 is present in the outdoor operation area Rx or inside the vehicle cabin. In other words, this means that the portable terminal 2 is at least not present in the prohibition area.

[0159] In the determination process in step S205, if the first outdoor device strength representative value Pb1 is equal to or greater than the operation threshold Prx, the result of the determination in step S205 is affirmative, and then the process proceeds to step S206. On the other hand, if the first outdoor device strength representative value Pb1 is less than the operation threshold Prx, the result of the determination in step S205 is negative, and then step S208 is executed.

[0160] In step S206, it is determined whether the second strength difference ΔP2, which is the value obtained by subtracting the second outdoor device strength representation value Pb2 from the second indoor device strength representation value Pa2, is equal to or greater than a predetermined threshold value (hereinafter referred to as strength difference threshold value Pg). When the portable terminal 2 is present inside the vehicle cabin, the second indoor device strength representation value Pa2 has a high level, and the second outdoor device strength representation value Pb2 has a low level. Therefore, the second strength difference ΔP2 is a relatively large value.When the portable terminal 2 is present below the outdoor operation area Rx, the second indoor device strength representation value Pa2 and the second outdoor device strength representation value Pb2 have a low level, and thus the second strength difference ΔP2 has a relatively small value. When the portable terminal 2 is present above the outdoor operation area Rx, the second outdoor device strength representation value Pb2 has a higher level than the second indoor device strength representation value Pa2, and the second strength difference ΔP2 is anticipated to be a negative value. Therefore, based on whether the second strength difference ΔP2 is equal to or greater than the predetermined strength difference threshold value Pg, it is possible to distinguish whether the portable terminal 2 is present in the outdoor operation area Rx or inside the vehicle cabin.The second strength difference ΔP2 is a threshold value for distinguishing whether the portable terminal 2 is present in the vehicle cabin or in the outdoor operation area Rx, and can be appropriately set based on the results of a simulation or a test. The strength difference threshold value Pg may also be zero. When the second strength difference ΔP2 is equal to or greater than the predetermined strength difference threshold value Pg, the mode according to which it is determined that the portable terminal 2 is present inside the vehicle cabin corresponds to an example according to which it is determined that the portable terminal 2 is inside the vehicle cabin when the second indoor device strength representation value is equal to or greater than the second outdoor device strength representation value.

[0161] If the second strength difference ΔP2 is equal to or greater than the strength difference threshold Pg, the determination result in step S206 is affirmative, and then step S209 is executed. On the other hand, if the second strength difference ΔP2 is smaller than the strength difference threshold Pg, the determination result in step S206 is negative, and then step S207 is executed. In step S207, the positioning unit F4 determines that the portable terminal 2 exists within the outdoor operation area Rx, and then the process is terminated.

[0162] In step S208, the positioning unit F4 determines whether the first indoor device strength representation value Pa1 and / or the second indoor device strength representation value Pa2 is equal to or greater than a predetermined indoor correspondence value Pin. As described above, the indoor correspondence value Pin is a threshold value for determining whether or not the portable terminal 2 is present in the vehicle cabin. The indoor correspondence value Pin can be designed, for example, according to an appropriate test. The indoor correspondence value Pin can be set with reference to, for example, the minimum value of the indoor device representation strength that can be observed when only the portable terminal 2 is present in the vehicle cabin in an unoccupied state.The interior correspondence value Pin can be determined based on the result of a test for measuring the interior device representation values ​​at the respective observation locations within the vehicle cabin in, for example, the unoccupied state. The unoccupied state here refers to a situation where there is no user's luggage or a situation where there are no occupants. In other words, the unoccupied state refers to a situation where there are no objects other than those pre-installed within the vehicle cabin. The interior correspondence value Pin can be interpreted with reference to, for example, the minimum value of the interior device representation strength that can be observed when a position with an average physical size is sitting in the driver's seat.According to the setting of the interior correspondence value Pin based on such a technical idea, the situation that the interior device representation strength is equal to or greater than the interior correspondence value Pin implies that the portable terminal 2 is present inside the vehicle cabin.

[0163] In the determination process in step S208, if the first indoor device strength representation value Pa1 and / or the second indoor device strength representation value Pa2 is equal to or greater than the indoor corresponding value Pin, the result of the determination in step S208 is affirmative, and then the process proceeds to step S209. On the other hand, if both the first indoor device strength representation value Pa1 and the second indoor device strength representation value Pa2 are smaller than the indoor corresponding value Pin, the result of the determination in step S208 is negative, and then step S210 is executed. In step S209, the positioning unit F4 determines that the portable terminal 2 is present in the vehicle cabin, and then the process flow is ended. In step S210, the positioning unit F4 determines that the portable terminal 2 is present in the outdoor area, and then the process flow is ended.

[0164] The respective determination results in steps S207, S209, and S210 are stored in the RAM 113 as position information of the portable terminal 2, and are referred to by the vehicle control unit F5 or the like. Requirements for the electronic vehicle key system

[0165] In the following, the requirements for the electronic vehicle key system are described in advance to explain the effects of the embodiment. In the electronic vehicle key system, in a situation where a user is present at a predetermined distance (for example, 2 meters) or more from the outer surface of the vehicle (for example, the outer door handle), as shown in Fig. As shown in Figure 25, in order to prevent theft, it is necessary to prevent the automatic door from being unlocked using wireless communication. These requirements are based on the specifications of the Motor Insurance Repair Research Centre, an organization established by the Association of British Insurers. Therefore, the on-board system 1 can determine whether the portable terminal 2 is present within 2 meters of the vehicle Hv. The above-mentioned prohibition range is set as needed.

[0166] The range within 2 meters from the outer surface of the vehicle is one of the indexes. The outer operating range Rx, which is set or specified by a vehicle manufacturer, is often set or limited to a smaller range for increased security. The outer operating range Rx is often set to 0.7 meters from the vehicle Hv. In other words, under the premise that the electronic vehicle key system can at least determine with increased accuracy whether the portable terminal 2 is present within 2 meters of the vehicle Hv, it is also necessary for the electronic vehicle key system to determine whether the portable terminal 2 is present within the outer operating range Rx. In addition, the accuracy of determining whether the portable terminal 2 is present in the vehicle cabin or not is also an important requirement for the electronic vehicle key system.

[0167] In the vehicle electronic key system, the vehicle exterior communication device 12β may be configured to generate a significant difference in the reception strength of a signal from the portable terminal 2 according to whether the portable terminal 2 is present in the outdoor operation area Rx or in the prohibition area. In the vehicle electronic key system, the vehicle exterior communication device 12β may preferably be configured to generate a significant difference in the reception strength of a signal from the portable terminal 2 according to whether the portable terminal 2 is present inside the vehicle cabin. The general reference plane for the outdoor operation area and the prohibition area is the side surface portion of the vehicle.The reference plane, in other words, the plane considered as the side surface portion for the outer operating area or the prohibition area when evaluating the positioning accuracy, can be a plane perpendicular to the vehicle width direction, passing through, for example, the outer door handle. The area between the outer operating area Rx and the prohibition area corresponds to a buffer area (in other words, a gray zone).

[0168] According to the structure and installation of the vehicle exterior communication device 12β described in the present embodiment, the main beam is not directed toward the exterior of the cabin when the vehicle exterior communication device 12β is operated in the zero-order resonance mode. The linearly polarized wave with the perpendicular vibration direction of the electric field is radiated in both directions parallel to the side surface portion of the vehicle in the zero-order resonance mode. According to such radiation characteristics as described in Fig. 20, it is possible to set almost the entire three-dimensional space within 0.7 meters from the center pillar 42B as the strong electric field area, and it is possible to prevent the prohibition area from becoming the strong electric field area. The vehicle exterior communication device 12β may be configured to generate a significant difference in the reception strength of a signal from the portable terminal 2 depending on whether the portable terminal 2 is present within the exterior operation area Rx or within the prohibition area. Although not shown, the strong electric field area may be formed along the vehicle front-rear direction from the vicinity of the front seat door to the vicinity of the rear seat door.Therefore, it is possible to determine the position of the portable terminal 2 with improved accuracy by using the reception strength of the signal received from the portable terminal 2 by the vehicle exterior communication device 12β. Since the portable terminal 2 is unlikely to be present in an area near the road surface within 0.1 meters of the road surface or in an area where the height from the road surface is 2 meters or greater, these areas can be excluded from the outdoor operating area Rx.

[0169] In the vehicle exterior communication device 12β according to the present embodiment, the linearly polarized wave whose electric vibration direction is parallel to the side surface portion of the vehicle is radiated in a direction perpendicular to the side surface portion, in other words, toward the cabin exterior, at the time of operation in the ground plate excitation mode. According to such a configuration, based on the relationship between the directivity and the polarization, the interior of the vehicle cabin becomes the region of a weak electric field in the ground plate excitation mode. Therefore, it is possible to determine whether the portable terminal 2 is present inside the vehicle cabin based on the reception strength of the vehicle exterior communication device 12β operating in the ground plate excitation mode and the vehicle interior strength representative value.

[0170] According to the configuration of the present embodiment, compared to the comparative configuration, it is possible to uniformly set the strong electric field area in the outdoor operation area Rx. Since an elliptical radial characteristic is present in which the direction along the ground plate 51 is the longitudinal direction as a whole, according to the configuration in which the ground plate 51 is installed in a position parallel to the side surface portion, it is possible to form a communication area having the vehicle front-rear direction as the longitudinal direction and the strong electric field area. The vehicle outdoor communication device 12β can be configured to generate a significant difference in the reception strength of a signal from the portable terminal 2 according to whether the portable terminal 2 is present within the outdoor operation area Rx or within the prohibition area.Therefore, it is possible to determine the position of the portable terminal 2 with improved accuracy by using the reception strength of the signal received by the portable terminal 2 at the vehicle exterior communication device 12β. The antenna 121 included in the vehicle exterior communication device 12β is formed as a plate with a thickness of several millimeters. Therefore, it is possible to reduce the likelihood of the antenna 121 protruding from the side surface portion.

[0171] Although an embodiment of the vehicle communication device of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various modifications described below are included in the technical scope of the present invention. In addition to the following, various changes are possible within the scope of the present invention. Various modifications described below can be implemented in combination as needed within the scope of technical consistency of the invention. Elements having the same functions as those of elements described in the above embodiment are denoted by the same reference numerals and will not be described repeatedly.When only a part of the configuration is described, reference may be made to the above embodiment with respect to the other parts of the configuration. First modification

[0172] According to the above vehicle external communication device 12β, when the portable terminal 2 is located below the outdoor operating area or inside the vehicle cabin, a significant difference is generated in the reception strength of the signal transmitted from the portable terminal 2 between the zero-order resonance mode operation and the ground plate excitation mode operation. When the portable terminal 2 is located below the outdoor operating area or inside the vehicle cabin, the reception strength during the ground plate excitation mode deteriorates significantly (for example, by 5 dB or more) compared to the reception strength during the zero-order resonance mode.Therefore, by comparing the reception strength in the zero-order resonance mode and the reception strength in the ground plate excitation mode, it is possible to detect whether or not the portable terminal is present in the upper half of the outdoor operating range Rx. Accordingly, it is possible to identify that the portable terminal is not present inside the vehicle cabin. For example, when the reception strength in the zero-order resonance mode and the reception strength in the ground plate excitation mode are equal to or greater than a threshold value, it is determined that the portable terminal 2 is present above the outdoor operating range, in other words, that the portable terminal 2 is not present inside the vehicle cabin.When the reception strength in the zero-order resonance mode is greater than the predetermined threshold and the reception strength in the ground plate excitation mode is equal to or less than the predetermined threshold, it can be determined that the portable terminal 2 is present below the outdoor operating area or inside the vehicle cabin. The above-mentioned single first strength or the first outdoor device strength representative value can be used as the reception strength in the zero-order resonance mode. The above-mentioned single second strength or the second outdoor device strength representative value can be used as the reception strength in the ground plate excitation mode. Second modification

[0173] The second modification is a modification of the positioning algorithm. The above embodiment describes an aspect in which the positioning unit F4 determines whether the portable terminal 2 is present inside the vehicle cabin based on whether the interior device representation value is equal to or greater than the interior correspondence value Pin. However, the determination algorithm is not limited to this. A variety of algorithms can be used as the algorithm for determining whether the portable terminal 2 is present inside the vehicle cabin.

[0174] The positioning unit F4 may determine that the portable terminal 2 is present inside the vehicle cabin, for example, based on the condition that the indoor device representation strength is equal to or greater than the indoor corresponding value Pin and the second outdoor device strength representation value Pb2 is smaller than the outdoor corresponding value Pout. The outdoor corresponding value Pout described here is a threshold value for determining that the portable terminal 2 is present outside the vehicle cabin and is a parameter different from the operation threshold Prx. The outdoor corresponding value Pout may be set to a value for adding a predetermined tolerance (for example, -3 dBm) to the maximum value of the second outdoor device strength representation value Pb2 that can be observed in a situation where the portable terminal 2 is present inside the vehicle cabin.The maximum value of the second external device strength representative value Pb observed when the portable terminal 2 is present inside the vehicle cabin can be designed based on simulation or testing. Since the external equivalent value Pout is set to be equal to or greater than the maximum value of the second external device strength representative value Pb2 observed when the portable terminal 2 is present inside the vehicle cabin, the situation where the second external device strength representative value Pb2 is equal to or greater than the external equivalent value Pout suggests that the portable terminal 2 is present outside the vehicle cabin.

[0175] The positioning unit F4 may determine that the portable terminal 2 is present outside the vehicle cabin based on the condition that the indoor device representation strength is equal to or greater than the outdoor corresponding value Pout and the first outdoor device strength representation value Pb1 is equal to or greater than the outdoor corresponding value Pout. The outdoor corresponding value Pout may be set to the minimum value of the second outdoor device strength representation value Pb2 observed in a situation where the portable terminal 2 is present within a leakage area, with the indoor communication device 12α formed outside the vehicle cabin. The leakage area is an area outside the vehicle cabin where the second indoor device strength representation value Pa2 is equal to or greater than the indoor corresponding value Pin.The area that may be a leakage area is mainly located in the vicinity of the window section 43. The proximity of the window section 43 refers to an area within a few centimeters to a few tens of centimeters from a window frame.

[0176] The positioning unit F4 can determine whether the portable terminal 2 is present inside the vehicle cabin by using the interior device representation strength, a high-level threshold, and a low-level threshold. The high-level threshold is a threshold for determining whether the portable terminal 2 is present inside the vehicle cabin. The high-level threshold is set to a value greater than the low-level threshold. The high-level threshold can be designed, for example, based on the interior device representation strength in a situation where the portable terminal 2 is present inside the vehicle cabin (specifically, in the vicinity of the driver's seat) as a reference, which is determined, for example, by a test.The high-level threshold may be set, based on a result of the above test, to a value sufficiently greater than the indoor device representation strength observed in a situation where the portable terminal 2 is present in the prohibition area. For example, the high-level threshold may be set to a minimum value of the indoor device representation strength observed when the portable terminal 2 is present inside the vehicle cabin. The low-level threshold is a threshold for determining whether the portable terminal 2 is present outside the vehicle cabin. It may be advantageous if the low-level threshold is set to a value 10 dBm or more lower than the high-level threshold.In the above configuration, in a situation where the indoor device representation strength becomes equal to or greater than the high-level threshold, the positioning unit F4 determines that the portable terminal 2 is present inside the vehicle cabin until the indoor device representation strength becomes less than the low-level threshold. In a situation where the indoor device representation strength becomes less than the low-level threshold, the positioning unit F4 may determine that the portable terminal 2 is present outside the vehicle cabin until the indoor device representation strength becomes equal to or greater than the high-level threshold. A variety of determination algorithms can be used to determine whether the portable terminal 2 is present inside the vehicle cabin and also to determine whether the portable terminal 2 is present in the outdoor operation area Rx.

[0177] Even if the positioning of the portable terminal 2 is divided into multiple phases, for example, it is first determined whether the portable terminal is present inside the vehicle cabin. Then, for example, only in a situation where it is determined that the mobile terminal 2 is present outside the vehicle cabin, is it determined whether the portable terminal 2 is present in the outdoor operating area Rx. In other words, if the absence of the portable terminal inside the vehicle cabin is confirmed by the predetermined algorithm, another algorithm determines whether the portable terminal is present in the outdoor operating area.Therefore, it is possible to reduce the probability of erroneous determination that the portable terminal is present inside the cabin regardless of whether the portable terminal is present in the outdoor operation area, since the radio wave of the outdoor communication device 12β easily circulates inside the vehicle cabin. Third modification

[0178] The third modification is a modification of the configuration of the vehicle external communication device. As shown in Fig. 26, the vehicle exterior communication device 12β may include a master grounding plate 58 as a metal plate larger than the grounding plate 51 to be arranged on the inner bottom surface portion of the housing 6 made of resin. As shown in (B) in Fig. 26, the master grounding plate 58 may be disposed on the outer bottom surface portion of the casing 6 of the vehicle exterior communication device 12β. The casing 6 and the master grounding plate 58 may be integrally formed. The bottom portion of the casing 6 may be made of metal. In this case, a casing bottom portion 61 made of metal corresponds to the master grounding plate 58. In addition, the vehicle metal body may be used as the master grounding plate 58. If the sealing material 7 maintains a solid state within the assumed operating temperature, the casing top plate portion 63 and / or the casing bottom portion 61 may be omitted. The casing 6 may be formed into a flat box shape in which the top surface or the bottom surface is formed as an opening.The opening surface of the housing 6 can be brought into contact with a member to which the housing 6 is attached, for example the B-pillar 42B or the inner door panel.

[0179] The above embodiment describes that the in-vehicle communication device 12 integrally includes the antenna 121 and an electronic component such as the transceiver 122, in other words, it is an in-circuit antenna. However, this is not limited to this. The transceiver 122 and the communication microcomputer 123 may be housed in a casing different from that of the antenna 121. The in-vehicle communication device 12α and the out-vehicle communication device 12β may have the same configurations or different configurations. Among the out-vehicle communication devices 12β, the rear out-vehicle communication device 12N may have a configuration different from that of other side communication devices such as the left out-vehicle communication device 12L.

[0180] The housing top plate section 63 can be as in Fig. 27 may be omitted. The case bottom portion 61 may be omitted in the case 6. When either the case top plate portion 63 or the case bottom portion 61 of the case 6 is omitted, the sealing material 7 may preferably be realized using a resin that maintains its strength in the range assumed to be the temperature of the environment in which the vehicle exterior communication device 12β is used (hereinafter referred to as the operating temperature range). The operating temperature range may be, for example, -30°C to 100°C. Fourth modification

[0181] The fourth modification is a modification of the installation position of the vehicle exterior communication device. The installation position and attitude of the vehicle exterior communication device 12β as a side communication device are not limited to the above example. The vehicle exterior communication device 12β can be installed at any position on the exterior surface portion of the vehicle, such as the upper end of the A-pillar 42A, the C-pillar 42C, the upper end portion of the door panel, or inside or near the exterior door handle 44. For example, the vehicle exterior communication device 12β can be installed in a position such that the X-axis direction is along the longitudinal direction and the Y-axis is along the vehicle height direction inside the exterior door handle 44.In addition, the vehicle exterior communication device 12β, as a side communication device, may also be installed in a position such that the grounding plate 51 is located along the side surface of the vehicle at a portion of the door module 45 serving as the window frame of the side window. However, it may be advantageous if the vehicle exterior communication device 12β is installed in a position such that a flat metal body (hereinafter referred to as the vehicle metal portion 4) included in the vehicle faces the grounding plate 51. According to the mode in which the vehicle exterior communication device 12β is installed on the outer side surface of the vehicle metal portion 4, the vehicle metal portion 4 serves as the master grounding plate 58 for the grounding plate 51, and thus the operation of the vehicle exterior communication device 12β can be made stable.For example, in a situation where the left exterior communication device 12L is installed within the door module 45, which is a combination of the inner door panel and the outer door panel, it may be advantageous for the outer door panel to be made of resin and the inner door panel to be made of metal. The inner door panel, which is made of metal, can serve as the master grounding plate 58 for the vehicle exterior communication device 12β. In a situation where the inner door panel is made of resin, the left exterior communication device 12L can be installed at a portion within the door module 45 that overlaps with a metal frame, such as the B-pillar 42B. This also applies to the right exterior communication device 12M. The installation position can be modified for the rear exterior communication device 12N.It may also be advantageous if the rear external communication device 12N is located near the flat vehicle metal portion 4 or contacts the flat vehicle metal portion 4. Fifth modification

[0182] The configuration of the antenna 121 of the vehicle exterior communication device 12β, in other words, the vehicle exterior antenna 121β, is not limited to the configuration described above. As shown in Fig. As shown in FIG. 28, the short-circuit portion 54 included in the vehicle exterior antenna 121β may be arranged at a position deviated from the center of the opposing conductive plate 53 by a predetermined amount (hereinafter, a short-circuit portion offset amount ΔSb) in the Y-axis direction. According to this configuration, the symmetry of the current distribution on the opposing conductive plate 53 is broken, and linearly polarized waves parallel to the Y-axis direction are radiated from the opposing conductive plate 53. Specific examples will be described below.

[0183] In the configuration where the short-circuit portion 54 is arranged in the center of the opposite conduction plate 53, the current flowing through the opposite conduction plate 53 is symmetrical to a center of the short-circuit portion 54, as shown in Fig. 29. Therefore, when viewed from the connection point of the opposite conducting plate 53 (hereinafter, the short-circuit point) between the short-circuit portion 54 and the opposite conducting plate 53, the radio waves generated by the current flowing in a certain direction are canceled out by the radio waves generated by the current flowing in the opposite direction.

[0184] On the other hand, in the configuration in which the short-circuit portion 54 is arranged at a position deviated by a predetermined amount in the Y-axis direction from the center of the opposing conduction plate 53, the symmetry of the distribution of the current flowing through the opposing conduction plate 53 is as shown in (A) in Fig. 30. As shown in (B) in Fig. Therefore, as shown in Fig. 30, the radio waves radiated by the current component in the Y-axis direction are not canceled. That is, in the configuration where the short-circuit portion 54 is arranged at a position deviated by a predetermined amount in the Y-axis direction from the center of the opposing conductive plate 53, the linearly polarized waves in which the electric field vibrates in the direction parallel to the Y-axis (hereinafter referred to as the Y-axis parallel direction) are radiated upward from the opposing conductive plate 53. Since the symmetry of the current component in the X-axis direction is maintained, the linearly polarized waves in which the electric field oscillates in the X-axis direction cancel each other out. That is, the linearly polarized wave whose electric field oscillates in the X-axis direction is not radiated from the opposing conductive plate 53.

[0185] The polarization of the ground plate in the horizontal direction of the ground plate is formed by the parallel resonance of the capacitance formed between the opposing conductive plate 53 and the ground plate 51 and the inductance provided by the short-circuit portion 54. That is, according to the above configuration, the X-axis parallel polarization and the Y-axis parallel polarization can be radiated simultaneously in the direction perpendicular to the ground plate. The radiation of the X-axis parallel polarization in the direction perpendicular to the ground plate is provided by the asymmetry portion 511 of the ground plate 51. The radiation of the Y-axis parallel polarization in the direction perpendicular to the ground plate is provided by the offset arrangement of the short-circuit portion 54 in the Y-axis direction.

[0186] When the vehicle exterior antenna 121β is used in the zero-order resonance mode, the Y-axis parallel polarization provided by the offset arrangement of the short-circuit portion 54 is radiated in a direction perpendicular to the ground plate (the direction toward the cabin exterior as viewed from the vehicle Hv). In other words, the area that cannot be covered only by the wave polarized perpendicular to the ground plate radiated from the edge portion of the opposite conducting plate 53 is covered by the Y-axis parallel polarization. As a result, according to the zero-order resonance mode, it is possible to uniformly adjust the entire area of ​​the outdoor operating region Rx to the strong electric field area, as shown in Fig. 31. The dotted lines in Fig. The contour lines shown in Figure 31 represent points equal to the minimum electric field strength value Rx in the outdoor operation area. The above-mentioned operation threshold Prx is set to the electric field strength of the contour line. According to the above-described configuration, the probability of erroneously determining that the portable terminal 2 is present inside the vehicle cabin can be reduced even when the portable terminal 2 is present in the prohibition area.

[0187] The direction of deviation of the short-circuit portion 54 from the center of the opposing conductive plate 53 (hereinafter referred to as the short-circuit portion offset) may be a direction orthogonal to the conductive plate offset direction. It is possible to radiate two types of linearly polarized waves whose electric field vibration directions are orthogonal to each other as linearly polarized waves radiated in the direction perpendicular to the ground plate.

[0188] The short-circuit portion 54 may be formed in a central region of the opposing conduction plate 53. The short-circuit offset amount ΔSb may preferably be set equal to or less than 0.04λ to maintain omnidirectional directivity in the horizontal direction of the ground plate. It may be advantageous if the short-circuit offset amount ΔSb is equal to or less than 0.02λ (=2.5 mm), for example, 0.004λ (=0.5 mm), 0.008λ (=1.0 mm), 0.012λ (=1.5 mm), etc. By changing the short-circuit offset amount ΔSb, the radiation gain of the Y-axis parallel polarization in the direction perpendicular to the ground plate can be adjusted. The operating frequency does not change even if the short-circuit offset amount ΔSb is changed. If the position of the feed point 531 is fixed, the voltage standing wave ratio (VSWR) can fluctuate according to the short-circuit offset size ΔSb.Here, since the feed point 531 can be set to any position, the VSWR at the first frequency band can be reduced to a practical level (e.g., 3 or less) by providing the power supply point 31 at a position corresponding to the short-circuit offset amount ΔSb. That is, the reverse loss can be reduced to a desired allowable level by adjusting the position of the feed point 531 according to the position of the short-circuit portion 54. Sixth modification

[0189] The sixth modification is a modification of the antenna structure. The vehicle exterior antenna 121β may have the configuration described in JP 2016-15688 A. As described in Fig. As shown in Figure 32, by setting the length of the opposing conductive plate 53 in the X-axis direction to 0.5λ2 and providing the feeding point 531 on the symmetry axis parallel to the X-axis, the antenna 121 can also be operated as a patch antenna at the second frequency. Such a zero-order resonant antenna is referred to in this specification, for example, as a zero-order resonant half-wave antenna. In the zero-order resonant half-wave antenna, the feeding point 531 can also serve as a feeding point in the zero-order resonant mode.

[0190] The opposing conductive plate 53 of this modification may have a set of diagonal cutouts configured as degeneration separators. According to this configuration, circularly polarized waves can be radiated, and the influence of the position of the portable terminal 2 can be mitigated. In the above example, the X-axis corresponds to the first axis of symmetry. The direction in which the electrical length of the opposing conductive plate is set to 0.5λ2 may be the Y-axis direction. That is, the first axis of symmetry may also be the Y-axis.

[0191] The antenna 121 includes a mode operating as the zero-order resonant antenna, in other words, the zero-order resonant mode, and a mode operating as a patch antenna (hereinafter referred to as the patch antenna mode). The patch antenna forms a main beam in a direction perpendicular to the ground plate, in other words, the Z-axis direction. The vibration direction of the electric field is parallel to the ground plate 51, that is, the X-axis here. Therefore, the patch antenna mode corresponds to the second mode. A filter or the like can be used to separate the reception signal of the zero-order resonant mode input from the feed point 531 (in other words, the signal in the first frequency band) from the reception signal of the patch antenna mode (in other words, the signal in the second frequency band). Seventh modification

[0192] In the ground plane extensional resonance antenna, the symmetry holding section 512 and the asymmetry section 511 may be physically separated, as shown in Fig. 33, and the electrical connection state between the two sections can be switchable using a switch 513. The distance between the symmetry holding section 512 and the asymmetry section 511 can be set, for example, based on simulations, to a value that does not cause electromagnetic coupling in the first frequency band. The switch 513 is arranged at the edge portion of the ground plate 51. The symmetry holding section 512 corresponds to a plate-shaped conductive element arranged concentrically with the opposing conductive plate 53, which has a rectangular shape. The asymmetry section 511 corresponds to a plate-shaped conductive element arranged at a lateral side of the symmetry holding section 512.When switch 513 is off, the vehicle exterior antenna 121β operates only in the zero-order resonant mode because the asymmetry section 511 is electrically isolated. When switch 513 is on, the vehicle exterior antenna 121β operates in both the zero-order resonant mode and the ground plate excitation mode.

[0193] The gain ratio between the zero-order resonant mode and the ground plate excitation mode in a situation where switch 513 is turned on can be modified by adjusting the asymmetry section width W and the distance between the back surface metal (here, B-pillar 42B) and the ground plate. In other words, it is possible to operate substantially only the ground plate excitation mode by adjusting the above parameters when switch 513 is turned on. According to one example, in a situation where switch 513 is turned on, antenna 121 operates substantially only in the ground plate excitation mode because the gain in the zero-order resonant mode is sufficiently smaller than the gain in the ground plate excitation mode.For example, the asymmetry section width W can preferably be set to an integer multiple of λ / 4, such as λ / 4 or λ / 2. According to such a setting, the gain of the ground plate excitation mode can be increased. According to the above configuration, it is possible to control the operation mode of the vehicle-external communication device 12β by turning the switch 513 on and off. In other words, by turning the switch 513 on and off, it is possible to control the vehicle-external communication device 12β between the zero-order resonance mode and the ground plate excitation mode.

[0194] As it is in Fig. As shown in Figure 34, the intelligent ECU 11 of this modification includes an operation mode instruction unit F6 for intentionally changing the operation mode of the vehicle external communication device 12β. Each vehicle external communication device 12β includes an operation mode switching unit 125. Fig. 34, the illustration of the configuration already described in the previous embodiment is omitted.

[0195] The operation mode instruction unit F6 collectively controls the operation mode of each vehicle exterior communication device 12β, essentially the operation mode of the vehicle exterior antenna 121β. For example, the operation mode instruction unit F6 instructs each vehicle exterior communication device 12β to perform operation in the ground plate excitation mode to determine whether the portable terminal 2 is inside the vehicle cabin. For example, the operation mode instruction unit F6 instructs each vehicle exterior communication device 12β to perform operation in the zero-order resonance mode to determine whether the portable terminal 2 is present in the exterior operation area Rx.

[0196] The operation mode switching unit 125 switches the operation mode of the vehicle exterior antenna 121β based on the instruction from the smart ECU 11. For example, the operation mode switching unit 125 turns on the switch 513 in a situation where the smart ECU 11 issues an instruction to operate in the ground plate excitation mode. The operation mode switching unit 125 turns off the switch 513 in a situation where the smart ECU 11 issues an instruction to operate in the zero-order resonance mode.

[0197] It is possible to operate the vehicle exterior communication device 12β in an operation mode corresponding to the determination target of the positioning unit F4. The feature of switching the operation mode of the vehicle exterior communication device 12β is substantially the same as the feature of switching the operation mode of the vehicle exterior antenna 121β. The feature of switching the operation mode of the vehicle exterior antenna 121β corresponds to the feature of switching the directivity and polarization plane of the vehicle exterior antenna 121β. In other words, the feature of switching the operation mode of the vehicle exterior antenna 121β corresponds to the feature of switching the polarization and reception direction of the vehicle exterior communication device 12β, which is a reception target.

[0198] The technical idea disclosed in this modification can also be applied to a vehicle exterior antenna 121β configured as the zero-order resonant half-wave antenna described in the sixth modification. For example, as shown in Fig. As shown in Fig. 35, a zero-order resonance feeding point 531a and a patch antenna feeding point 531b can be provided separately for the opposite conductor plate 53 of the zero-order resonant half-wave antenna. By appropriately using the two feeding points 531a and 531b, the operation mode of the antenna 121 can be appropriately used. The operation mode instruction unit F6 jointly controls, via the operation mode switching unit 125, the determination of which of the feeding points 531 is used. The feeding point 531a corresponds to a first feeding point, and the feeding point 531b corresponds to a second feeding point.

[0199] In the zero-order resonant half-wave antenna, the antenna 121 and the transceiver 122 may be connected to each other via a matching circuit 59 for adjusting an internal inductance or an electrostatic capacitance, as shown in Fig. 36. In the above configuration, it is possible to change the operating mode by adjusting the internal inductance or the electrostatic capacitance of the adjustment circuit 59. The Fig. The example shown in Fig. 36 shows a configuration of changing the resonance frequency of the antenna 121 by adjusting the electrostatic capacitance of a variable capacitor 591. As the variable capacitor 591, for example, an element in which the electrostatic capacitance is changed by modifying a voltage level applied to a predetermined input terminal can be used as a variable capacitor. The specific configuration of the adjustment circuit 59 for modifying the internal inductance or the electrostatic capacitance can be appropriately modified and is not limited to the configuration shown in Fig.36. In a configuration where the matching circuit 59 includes a variable coil, the resonance frequency of the antenna 121 can be changed by adjusting the inductance of the variable coil. The inductance or electrostatic capacitance of the matching circuit 59 can be jointly controlled by the operation mode instruction unit F6. The variable capacitor 591 and / or the variable coil correspond to a variable impedance element. Eighth modification

[0200] The eighth modification is a modification of the index of the distance between the portable terminal 2 and the in-vehicle communication device 12. In the above embodiment, it is described that the presence of the portable terminal 2 is determined based on the reception strength of the signal received by the portable terminal with reference to the index of the distance from the respective in-vehicle communication devices 12 to the portable terminal 2. However, it is not limited to this example. As an index of the distance from the respective in-vehicle communication devices 12 to the portable terminal 2, a one-way / round-trip propagation time of the wireless signal from the in-vehicle communication device 12 to the portable terminal 2 can be used.In other words, the position determination unit F4 can also determine the position of the portable terminal 2 by using the one-way / round-trip propagation time of the wireless signal from the on-vehicle communication device 12 to the portable terminal 2. The propagation time of the wireless signal can be measured by receiving the signal from the portable terminal 2. In other words, the configuration in which the position of the portable terminal 2 is determined by using the one-way / round-trip propagation time of the wireless signal from the on-vehicle communication device 12 to the portable terminal 2 also corresponds to the configuration in which the position of the portable terminal 2 is determined based on the reception status of the signal from the portable terminal 2. Ninth modification

[0201] The ninth modification is a modification of the communication method with the portable terminal 2. In the above embodiment, it is described that the portable terminal 2 and the on-vehicle communication device 12 perform bidirectional wireless communication according to the Bluetooth standard; however, the communication method between the portable terminal 2 and the on-vehicle communication device 12 is not limited to this example. The portable terminal 2 and the on-vehicle system 1 may be configured to perform wireless communication using a pulse signal used in ultra-wideband (UWB) communication. In other words, the on-vehicle communication device 12 may be a communication module that performs UWB communication.The pulse signals used in UWB communication are signals with extremely short pulse widths (e.g., 2 ns) and bandwidths of 500 MHz or more (i.e., ultra-wide bandwidths). Examples of frequency bands (hereinafter referred to as UWB bands) that can be used for UWB communication include 3.1 GHz to 16 GHz, 3.4 GHz to 4.8 GHz, 7.25 GHz to 16 GHz, and 22 GHz to 29 GHz.

[0202] The standard for the portable terminal 2 and the in-vehicle system 1 to perform wireless communication and the frequency of the radio wave used for wireless communication (hereinafter referred to as radio wave used in the system) can be appropriately selected. Tenth modification

[0203] The tenth modification is a modification of the material of the vehicle body. In the above embodiments, the vehicle positioning system according to the present invention is applied to the vehicle Hv having a metal body. However, the vehicle suitable as an application target of the vehicle positioning system is not limited to a vehicle having a metal body. For example, the various body panels constituting the body of the vehicle Hv may be made of carbon-based resin filled with a sufficient amount of carbon to attenuate the propagation of radio waves by 5 dB or more. A vehicle having the above-described body is also suitable as an application target of the vehicle positioning system. The body of the vehicle Hv may be made of general resin that does not contain carbon.It may be advantageous if the vehicle exterior communication device 12β has a configuration for blocking radio waves on the rear side, and the vehicle exterior communication device 12β is installed at a position where the radio waves are not blocked on the lateral side and the upper side.

[0204] The control and method therefor described herein may be implemented by an associated computer forming a processor programmed to perform one or more functions specified by computer programs. The apparatus and method therefor described herein may also be implemented by a special-purpose hardware logic circuit. Furthermore, the apparatus and method therefor described herein may also be implemented by one or more associated computers formed by combining a processor for executing computer programs and one or more hardware logic circuits. The computer programs may be stored as computer-executable instructions in a tangible, non-transitory computer-readable medium.

[0205] Here, for example, the controller is the smart ECU 11. The processes or functions provided by the smart ECU 11 may be provided by software stored in a tangible storage device and a computer that executes the software, by software only, by hardware only, or by a combination of the software and hardware. Some or all of the functions of the smart ECU 11 may be implemented in hardware. A configuration in which a certain function is implemented in hardware includes a configuration in which the function is implemented using one or more ICs or the like. In the above embodiment, the smart ECU 11 is executed using the CPU. However, the configuration of the smart ECU 11 is not limited to this.The smart ECU 11 can be implemented using an MPU (microprocessor unit), a GPU (graphics processing unit), or a DFP (data flow processor) instead of the CPU 111. Furthermore, the smart ECU 11 can be achieved by combining various processors such as the CPU 111, the MPU, the GPU, and the DFP. Furthermore, for example, some functions to be provided by the smart ECU 11 can be implemented using an FPGA (field-programmable gate array), an ASIC (application-specific integrated circuit), or the like.

Claims

[1] A positioning system for a vehicle for performing wireless communication with a portable terminal carried by a user of the vehicle by using a radio wave of 1 GHz or higher to determine a position of the portable terminal with respect to the vehicle, the positioning system comprising: a vehicle external communication device (12β, 12L, 12M, 12N) configured to be arranged on an outer surface portion of the vehicle, which is a side surface portion of the vehicle and / or a rear surface portion of the vehicle, and including an antenna (121) configured to receive a wireless signal transmitted from the portable terminal; and a position determination unit (F4) configured to determine the position of the portable terminal based on a reception status of the wireless signal received by the vehicle external communication device from the portable terminal, wherein the vehicle external communication device includes an operation mode having a first mode and a second mode, wherein, in the first mode of the operation mode, a linearly polarized wave whose electric field vibration direction is perpendicular to the outer surface portion is radiated in a direction parallel to the outer surface portion to which the vehicle external communication device is attached, wherein in the second mode of the operating mode, a linearly polarized wave is radiated whose electric field vibration direction is parallel to the outer surface portion, and wherein the positioning unit is further designed based on the reception status of the wireless signal received by the vehicle exterior communication device from the portable terminal in the first mode of the operation mode, determine whether the portable terminal is present in an outdoor operation area, which is an area outside a vehicle cabin within a predetermined operation distance from the vehicle; and determine whether the portable terminal is present inside the vehicle cabin based on the reception status of the wireless signal received by the vehicle exterior communication device from the portable terminal in the second mode of the operation mode. [2] The positioning system according to claim 1, wherein the antenna of the vehicle exterior communication device is further configured to radiate, in the second mode of the operation mode, a linearly polarized wave whose electric field vibration direction is parallel to the outer surface portion in a direction perpendicular to the outer surface portion to which the vehicle exterior communication device is mounted. [3] Locating system according to claim 1 or 2, wherein the vehicle external communication device is further configured to operate at a predetermined first frequency belonging to a frequency band used in wireless communication with the portable terminal in the first mode of the operation mode, wherein the vehicle external communication device is further configured to operate at a predetermined second frequency as a frequency belonging to the frequency band used in wireless communication with the portable terminal in the second mode of the operation mode, and wherein the predetermined second frequency is different from the predetermined first frequency. [4] Location system according to claim 3, where the antenna contains: a grounding plate (51) made of a conductor having a flat plate shape; an opposing conductor plate (53) made of another conductor having a flat plate shape, which has a feed point (531) electrically connected to a feed line and is designed to be arranged at a predetermined distance from the ground plate; and a short-circuit section (54) designed to be arranged in a central region of the opposite conducting plate and to electrically connect the opposite conducting plate and the grounding plate, wherein the grounding plate is designed to be arranged asymmetrically with respect to the opposite conducting plate, wherein the antenna is further configured to generate a parallel resonance at the predetermined first frequency by using an electrostatic capacitance between the opposing conduction plate and the ground plate and an inductance in the short-circuit portion, and wherein the vehicle exterior communication device is further configured to be mounted on the exterior surface portion in a position such that the ground plate faces the exterior surface portion. [5] Location system according to claim 4, where the antenna ground plate contains: a symmetry holding portion (512) having a rectangular shape, wherein the symmetry holding portion is designed to be arranged concentrically with the opposite conduction plate, and an asymmetry section (511) designed to be arranged on a transverse side of the symmetry holding section, wherein the symmetry holding section and the asymmetry section are connected to each other via a switch (513), and wherein the vehicle external communication device is further configured to operate in the first mode under a condition that the switch is turned off, and to operate in the second mode under a condition in which the switch is turned off. [6] The locating system according to claim 4 or 5, wherein the short-circuit portion in the antenna is further configured to be arranged at a position deviated from a center of the opposing lead plate by a predetermined distance. [7] Location system according to claim 3, where the antenna contains: a grounding plate (51) made of a conductor having a flat plate shape; an opposing conductor plate (53) made of another conductor having a flat plate shape, which has a feed point (531) electrically connected to a feed line and is designed to be arranged at a predetermined distance from the ground plate; and a short-circuit section (54) designed to be arranged in a central region of the opposite line plate and to electrically connect the opposite line plate and the ground plate, wherein the opposite conducting plate is designed linearly symmetrically with respect to respective two straight lines which are orthogonal to each other, wherein an electrical length of the opposing conductive plate in a direction parallel to a first axis of symmetry, which is one of the two straight lines contained in the opposing conductive plate, is half a wavelength of the radio wave at the predetermined second frequency, wherein the feed point is arranged on a straight line parallel to the first axis of symmetry through a center of the opposite conduction plate, wherein the antenna is designed to generate a parallel resonance at the predetermined first frequency by using an electrostatic capacitance between the opposite conduction plate and the ground plate and an inductance in the short-circuit portion, and wherein the vehicle exterior communication device is further configured to be mounted on the exterior surface portion in a position such that the ground plate faces the exterior surface portion. [8] Locating system according to claim 7, wherein the antenna in the vehicle external communication device is connected to a transceiver (122) via a variable impedance element (591) designed to change at least one of an electrostatic capacitance and an inductance, The tracking system also comprises: an operating mode switching unit (125) configured to change the operating mode of the vehicle external communication device by changing at least the electrostatic capacitance or the inductance of the variable impedance element, and wherein the positioning unit is further designed to operate the vehicle outdoor communication device in the first mode in cooperation with the operation mode switching unit based on a condition that the positioning unit determines whether or not the portable terminal is present in the outdoor operation area; and operate the vehicle exterior communication device in the second mode in cooperation with the operation mode switching unit based on a condition that the positioning unit determines whether or not the portable terminal is present in the vehicle cabin. [9] Locating system according to claim 7, wherein the opposite line plate has a first feed point for transmitting and receiving a signal at the predetermined first frequency and a second feed point which is the feed point for transmitting and receiving a signal at the predetermined second frequency, wherein the second feed point is arranged on a straight line parallel to the first axis of symmetry through the center of the opposite conduction plate, and wherein the vehicle external communication device is further designed determining whether or not the portable terminal is present in the outdoor operating area by using a reception strength of the wireless signal from the portable terminal acquired by the first feeding point; and determining whether or not the portable terminal is present in the vehicle cabin by using a reception strength of the wireless signal from the portable terminal acquired through the second feeding point. [10] A location system according to any one of claims 3 to 9, further comprising: an in-vehicle communication device (12α) designed to be arranged within the vehicle cabin of the vehicle, and further designed to receive the wireless signal and detect a reception strength of the wireless signal received by the in-vehicle communication device, wherein the vehicle external communication device further includes a strength detector (124) configured to detect a reception strength of the wireless signal received by the antenna, and wherein the positioning unit is further designed determining that the portable terminal is present in the outdoor operating area based on a condition that the reception strength of the wireless signal at the predetermined first frequency detected by the vehicle outdoor communication device is equal to or greater than a predetermined operating threshold; and determining that the portable terminal is present in the vehicle cabin based on a condition that the reception strength of the wireless signal at the predetermined second frequency detected by the in-vehicle communication device is greater than the reception strength of the wireless signal at the predetermined second frequency detected by the out-vehicle communication device by a predetermined threshold or more. [11] A location system according to any one of claims 3 to 10, further comprising: an in-vehicle communication device (12α) designed to be arranged within the vehicle cabin of the vehicle, and further designed to receive the wireless signal and detect a reception strength of the wireless signal received by the in-vehicle communication device, wherein the vehicle external communication device further includes a strength detector (124) configured to detect a reception strength of the wireless signal received by the antenna, wherein the positioning unit is further designed determining that the portable terminal is present in the outdoor operating area based on a condition that the reception strength of the wireless signal at the predetermined first frequency detected by the vehicle outdoor communication device is equal to or greater than a predetermined operating threshold; and determining that the portable terminal is present within the vehicle cabin based on a condition that the reception strength of the wireless signal at the predetermined second frequency detected by the in-vehicle communication device is equal to or greater than a predetermined indoor correspondence value. [12] A positioning system according to any one of claims 1 to 11, wherein the vehicle exterior communication device is further configured to be arranged on a window frame portion of a side window of the vehicle.

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