Position determination system and position determination method

Abstract

To provide a technique that can reduce the risk of erroneously determining the position of a portable device.SOLUTION: A smart ECU 2 generates a measurement value by averaging the reception strength of a device signal observed by a plurality of inner anchors in the state where a user device is placed at a predetermined inner set position. The smart ECU 2 determines a correction value based on the difference between the measurement value indicating communication characteristics of a preregistered reference device and a reference value, and stores the correction value in a characteristic data storage unit. The smart ECU 2 corrects the reception strength observed in actual communication using the stored correction value, and determines whether or not a portable device is present in a vehicle.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] TECHNICAL FIELD This disclosure relates to techniques for determining the position of a mobile device relative to a vehicle. [Background technology]

[0002] Patent Document 1 discloses a configuration for determining whether or not a portable unit is inside a vehicle based on whether the reception power (in other words, reception strength) of a signal transmitted from the portable unit at an in-vehicle antenna is equal to or greater than a predetermined value. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-214316 A Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, in-vehicle systems have been developed that allow general-purpose mobile devices such as smartphones to be used as vehicle keys. The in-vehicle systems communicate with the mobile devices via short-range wireless communication (hereinafter, SRWC). SWRC here stands for Bluetooth (registered trademark) Low Energy, Wi-Fi (registered trademark), etc. The in-vehicle systems can determine the location of the mobile device based on the reception strength of the SWRC signal transmitted from the mobile device.

[0005] However, the transmission power and antenna configuration (i.e., directivity) of smartphones may differ depending on the type and model. The mobile device used by a user (hereinafter, user device) may differ from the mobile device (hereinafter, reference device) used by the manufacturer when setting the threshold. In a configuration in which the location of a user device is determined by comparing the reception strength of a signal from the user device with a threshold designed using a reference device, the location may be erroneously determined due to the communication characteristics of each mobile device.

[0006] The present disclosure has been made in light of the above circumstances, and one of its objectives is to provide a technique capable of reducing the risk of erroneously determining the position of a mobile device. [Means for solving the problem]

[0007] The location determination system disclosed herein is an in-vehicle system including a communication device (3) configured to be capable of wireless communication with a portable device used by a user of the vehicle using a predetermined communication method, and a control unit (2) that determines the location of the portable device relative to the vehicle based on the reception strength of a signal received by the communication device from the portable device. The control unit includes a threshold memory unit (M2) in which a threshold for reception strength for determining the location of the portable device, the threshold designed based on the communication characteristics of a predetermined reference device, is registered, and a characteristic data memory unit (M3) for storing data indicating the communication characteristics of the portable device. The control unit is configured to acquire the reception strength from the communication device, generate characteristic data indicating the difference in communication characteristics between the portable device and the reference device based on the reception strength detected when the portable device is placed at a predetermined position, and store the generated characteristic data in the characteristic data storage unit, and determine the location of the portable device based on the characteristic data stored in the characteristic data storage unit, the reception strength detected by the communication device, and the threshold.

[0008] According to the above configuration, the location of the portable device is determined using characteristic data indicating a difference in communication characteristics between the portable device used by the user and a reference device, thereby reducing the risk of erroneous determination of the location due to differences in communication characteristics between the portable devices.

[0009] In addition, a location determination method included in the present disclosure includes acquiring a reception strength of a signal from a portable device from a communication device configured to be capable of performing wireless communication with the portable device using a predetermined communication method, accessing a threshold memory unit (M2) in which a threshold for reception strength for determining the location of the portable device, the threshold designed based on communication characteristics of a predetermined reference device, is registered, and reading the threshold from the threshold memory unit, generating characteristic data indicating the communication characteristics of the portable device based on the reception strength detected when the portable device is placed at a predetermined location, storing the generated characteristic data in a characteristic data memory unit (M3), and determining the location of the portable device based on the characteristic data stored in the characteristic data memory unit, the reception strength detected by the communication device, and the threshold.

[0010] In addition, the symbols in parentheses in the claims indicate a correspondence with the specific means described in the embodiments described below as one aspect, and do not limit the technical scope of the present disclosure. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing an overall view of a vehicle electronic key system. [Diagram 2] FIG. 13 is a diagram showing an example of an anchor mounting position. [Diagram 3] 4 is a flowchart for explaining an outline of the operation of the smart ECU. [Figure 4] 11 is a flowchart for explaining an overview of a position determination process. [Diagram 5] FIG. 2 is a functional block diagram of a smart ECU. [Figure 6] 13 is a flowchart of a position determination related process. [Figure 7] 13 is a flowchart of a characteristic learning process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. The present disclosure is not limited to the following embodiment. The configuration disclosed below may be modified in various ways without departing from the scope of the present disclosure. Various modified examples may be appropriately combined as long as no technical contradiction occurs. The present disclosure also includes a configuration that is not explicitly shown and is formed by combining multiple modified examples. In the following description, the same reference numerals are used for components having the same function, and specific descriptions thereof may be omitted. When only a part of the configuration is mentioned, the description given elsewhere may be applied to the other parts.

[0013] <Overall structure> As shown in FIG. 1, the electronic key system for a vehicle of this embodiment includes an in-vehicle system 1 and a user device 9. The in-vehicle system 1 is a system mounted on the vehicle Hv. The in-vehicle system 1 includes a smart ECU 2. ECU is an abbreviation for Electronic Control Unit, and means an electronic control device. In the following description, the in-vehicle system 1 and the vehicle Hv may be interpreted as interchangeable. The in-vehicle system 1 is a system that determines the position of the user device 9 and controls the locking state of the doors of the vehicle Hv based on the determination result. The in-vehicle system 1 corresponds to a position determination system.

[0014] The user device 9 is a wireless communication terminal (in other words, a portable device) carried by a user. The user device 9 is linked to the smart ECU 2. That is, device information of the user device 9 is registered in the smart ECU 2. The device information includes a device identification number (hereinafter, device ID). The device ID may be a device address or a universally unique identifier (UUID), etc. Device information of multiple user devices 9 may be registered in the smart ECU 2.

[0015] Both the smart ECU 2 and the user device 9 include a short-range communication module. The short-range communication module is a communication module for enabling short-range communication. Here, short-range communication means communication conforming to a predetermined wireless communication standard with a practical communication distance of 5 m to 50 m, and at most about 100 m. The short-range communication may be Bluetooth (registered trademark) Low Energy (hereinafter, Bluetooth LE), Wi-Fi (registered trademark), or the like. In the following description and drawings, the short-range communication may be referred to as SRWC (Short Range Wireless Communication). In addition, in the present disclosure, a signal transmitted and received in the short-range communication may be referred to as a short-range communication signal or an SRWC signal. In particular, the SRWC signal transmitted from the user device 9 is also referred to as a device signal.

[0016] The operation of each part will be described below by taking as an example a case where the short-range communication (i.e., SRWC) is Bluetooth LE. Furthermore, in the following, the user device 9 is set to operate as a peripheral in Bluetooth LE, and the smart ECU 2 to act as a central. The roles of the user device 9 and the smart ECU 2 may be interchanged. SRWC may be communication that can use multiple frequencies (in other words, channels). SRWC may be a communication method that employs channel hopping technology.

[0017] <In-vehicle systems> In addition to the smart ECU 2, the in-vehicle system 1 has other devices such as a plurality of anchors 3, an in-vehicle display 4, an input device 5, and a device detection unit 6. The smart ECU 2 is connected to each of the plurality of anchors 3 with a dedicated communication cable. The smart ECU 2 is connected to the in-vehicle display 4, the input device 5, and the device detection unit 6 via an in-vehicle network. The in-vehicle network is a communication network built in the vehicle Hv. The standard of the in-vehicle network may be any standard such as Controller Area Network (CAN is a registered trademark), Ethernet (registered trademark), or FlexRay (registered trademark). The connection form between the devices may be changed as appropriate.

[0018] The smart ECU 2 is an ECU that determines a device position in cooperation with the anchor 3. As described below, the anchor 3 is a wireless communication module for performing ranging communication with the user device 9. Ranging communication in this disclosure refers to wireless communication for measuring the distance between communication devices based on the time of flight of a signal or phase information of a received signal.

[0019] The smart ECU 2 may have a function of executing vehicle control according to the determined device position. In this disclosure, the device position means the relative position of the user device 9 with respect to the vehicle Hv. Determining the device position corresponds to determining the user's position. The term "device position" may be read as "user position." The smart ECU 2 controls the operation of the anchor 3. The vehicle control here may be switching the locking state of the door (e.g., unlocking), or switching the vehicle power on / off.

[0020] The smart ECU 2 includes a processor 21, a memory 22, a storage 23, a wireless communication module 24, and an in-vehicle communication unit 25. The processor 21 may be a central processing unit (CPU) or a micro processing unit (MPU). The processor 21 corresponds to a control unit. The memory 22 may be a volatile storage medium such as a random access memory (RAM). The memory 22 may be a component for temporarily storing data received from other in-vehicle devices, calculation results of the processor 21, programs, and the like. The storage 23 is a rewritable non-volatile memory. The storage 23 is realized by at least one type of non-transitory tangible storage medium, such as a semiconductor memory, a magnetic medium, and an optical medium. The storage 23 may include multiple types of storage media, such as a read only memory (ROM) and a flash memory.

[0021] The storage 23 may store a device ID and anchor data of the user device 9, and authentication data. The anchor data is data indicating mounting positions of multiple anchors 3 in the vehicle Hv. The authentication data may be data (e.g., a key code) for authenticating the user device 9.

[0022] The storage 23 stores a device response program executed by the processor 21. The device response program may be a program for realizing at least a part of the functions of the smart ECU 2. Execution of the device response program by the processor 21 corresponds to execution of a position determination method.

[0023] The wireless communication module 24 is a short-range communication module built into the smart ECU 2. The wireless communication module 24 includes an antenna for short-range communication, a transmission / reception circuit, and an SRWC controller. The transmission / reception circuit is a circuit that performs signal processing related to modulation and demodulation. The SRWC controller is a microcomputer that executes data processing related to the SRWC.

[0024] The wireless communication module 24 is supplied with power from the vehicle battery even while the driving power source is set to off. The wireless communication module 24 periodically scans using the power supplied from the vehicle battery and attempts to connect to the user device 9. Scanning is a state in which the SRWC signal can be received. Upon receiving an advertising signal from the user device 9, the wireless communication module 24 transmits a connection request to the user device 9 and communicates with the user device 9. The wireless communication module 24 may be interpreted as an SRWC module that functions as a gateway for the user device 9 to communicate and connect to the vehicle Hv. In the present disclosure, the wireless communication module 24 is also referred to as a gateway module. The wireless communication module 24 may be disposed outside the smart ECU 2.

[0025] The in-vehicle communication unit 25 is a circuit for the processor 21 to communicate with each of the multiple anchors 3. The in-vehicle communication unit 25 may also include a circuit for the processor 21 to communicate with other in-vehicle devices via an in-vehicle network. The in-vehicle communication unit 25 may include a PHY chip or the like that complies with the communication standard of the in-vehicle network.

[0026] The smart ECU 2 performs wireless authentication processing in the SRWC based on the communication connection with the user device 9 using the wireless communication module 24. The wireless authentication processing is processing for authenticating (in other words, verifying) the user device 9 through wireless communication. The authentication may be performed by any method such as a challenge-response method.

[0027] Upon receiving communication connection with the user device 9, the smart ECU 2 causes each anchor 3 to perform distance measurement communication with the user device 9. The smart ECU 2 acquires data indicating the result of the distance measurement communication (hereinafter, distance measurement result data) from each of the multiple anchors 3. The distance measurement result data includes the ID of the user device 9 that performed the distance measurement, data indicating the distance from the anchor 3 to the user device 9, and the reception strength of the device signal. In this disclosure, the value indicating the distance from the anchor 3 to the user device 9, which is determined by the distance measurement communication, may be referred to as a distance measurement value.

[0028] The smart ECU 2 determines whether the user device 9 is located inside the vehicle, in a nearby area, or in a far area based on the distance measurement value and reception strength provided by each anchor 3. The nearby area is an area outside the vehicle that is within a predetermined distance (e.g., 1.5 m) from the vehicle Hv. The far area means an area outside the vehicle that is outside the nearby area. The method of determining the device location will be described in detail later.

[0029] The smart ECU 2 may be configured to calculate device position coordinates by combining distance measurement values ​​provided from multiple anchors 3. The device position coordinates refer to position coordinates where the user device 9 is located in a two-dimensional / three-dimensional coordinate system based on a predetermined position of the vehicle Hv. The calculation of the device position coordinates can be performed by a method similar to three-point positioning or multi-point positioning in the technical fields of GPS and position estimation.

[0030] As described above, each anchor 3 is a device for performing ranging communication with the user device 9. The configuration and function of the anchor 3 may be similar to that of the wireless communication module 24. The anchor 3 is configured to be able to perform SWRC (i.e., Bluetooth LE). The anchor 3 includes an antenna, a transmitting / receiving circuit, and an SRWC controller for SWRC. Based on an instruction from the smart ECU 2, the SRWC controller of the anchor 3 performs ranging communication with the user device 9, generates ranging result data, and transmits (reports) the ranging result data to the smart ECU 2.

[0031] The ranging method using Bluetooth LE may be CS (Channel Sounding) ranging. CS ranging is a method of measuring distance based on the difference in reception phase for each channel obtained by transmitting and receiving CW (Continuous Wave) signals on multiple channels. CS ranging is sometimes called High Accuracy Distance Measurement (HADM) or phase difference ranging. The anchor 3 may be configured to be capable of transmitting and receiving a continuous wave (CW: Continuous Wave) signal of a predetermined waveform as a ranging signal in addition to a modulated signal for data communication. The waveform of the CW signal may be a sine wave or a triangular wave. A specific method of CS ranging will be described later.

[0032] The distance measurement method may be an RTT method that calculates the distance based on a round trip time. In the RTT method, the user device 9 measures the elapsed time from transmitting a poll signal to the anchor 3 to receiving a response signal from the anchor 3 as the RTT. The user device 9 may calculate a distance measurement value from the RTT measured by performing distance measurement communication, and transmit the distance measurement value to the smart ECU 2 by SRWC. The poll signal is a signal that requests the responder to return a response. The response signal may be called an answer signal.

[0033] In the ranging communication of this embodiment, the user device 9 operates as an initiator, and the anchor 3 operates as a responder. An initiator is a device that plays a leading role in ranging communication. The division of roles in ranging communication may be changed as appropriate. A plurality of anchors 3 may individually act as initiators and perform ranging communication with the user device 9.

[0034] The in-vehicle system 1 of the present embodiment may include a plurality of anchors 3. For example, as shown in FIG. 2, the in-vehicle system 1 includes anchors 3a, 3b, 3c, 3p, and 3q. The anchor 3a is an anchor 3 built into an outer door handle for the right front seat. The anchor 3a may be disposed in a right B-pillar, a right side mirror, a right side sill, or the right edge of the roof. The anchor 3a may be rephrased as a right anchor or a first anchor. The anchor 3b is an anchor 3 built into an outer door handle for the left front seat. The anchor 3b may be disposed in a left B-pillar, a left side mirror, a left side sill, or the left edge of the roof. The anchor 3b may be rephrased as a left anchor or a second anchor. The anchor 3c is an anchor 3 disposed in a center part of a rear bumper, a trunk door handle, or an upper end or a lower end of a rear window. The anchor 3c may be rephrased as a rear anchor or a third anchor.

[0035] Anchors 3p and 3q are anchors 3 arranged inside the vehicle. Anchor 3p is arranged forward of anchor 3q inside the vehicle. Anchor 3p may be arranged on the instrument panel, the upper end of the windshield, the center console, or the like. Anchor 3p may be referred to as an interior front anchor or a fourth anchor. Anchor 3q is an anchor 3 arranged rearward of anchor 3p inside the vehicle. Anchor 3q may be arranged in a position closer to the rear, such as the center of the rear seat, the ceiling above the rear seat, or the trunk. Anchor 3q may be referred to as an interior rear anchor or a fifth anchor. The mounting location of the anchor 3 disclosed herein is an example and may be changed as appropriate.

[0036] The anchors 3a to 3c are all attached to the outer surface of the vehicle Hv, and may be referred to as outdoor units or outer anchors. The anchors 3a to 3c correspond to outer communication devices. The anchors 3p and 3q are attached inside the vehicle, and may be referred to as indoor units or inner anchors. The anchors 3p and 3q correspond to inner communication devices. The anchor 3 starts up in response to an instruction from the smart ECU 2 and performs distance measurement communication. The anchor 3 transitions to a power saving state based on an instruction from the smart ECU 2. The power saving state may be a state in which some or all of the functions are stopped in order to reduce power consumption. The wireless communication module 24 may also be used as the anchor 3. The wireless communication module 24 may be interpreted as one of multiple inner anchors.

[0037] The in-vehicle display 4 is a display arranged inside the vehicle. The in-vehicle display 4 displays an image according to an instruction signal input from the smart ECU 2. The in-vehicle display 4 may be a liquid crystal display or an organic EL display. The in-vehicle display 4 may be configured to be capable of displaying a plurality of colors.

[0038] The input device 5 is a device for receiving user instruction operations for the in-vehicle system 1 (mainly the smart ECU 2). The input device 5 may be a touch panel stacked on the in-vehicle display 4. The user device 9 and the in-vehicle system 1 may be configured so that the user device 9 functions as the input device 5. The in-vehicle system 1 may include multiple types of devices as the input device 5.

[0039] The input device 5 outputs an operation signal, which is an electrical signal corresponding to a user's operation, to the smart ECU 2. The operation signal includes information indicating the content of the user's operation. The smart ECU 2 accepts an instruction to register the communication characteristics of the user device 9 via the input device 5. In the present disclosure, a signal indicating that a registration operation for the communication characteristics of the user device 9 has been performed is also referred to as a registration instruction signal. Based on receiving the registration instruction signal, the smart ECU 2 may display a characteristic registration guide image (described later) on the in-vehicle display 4.

[0040] The device detection unit 6 is a device that detects that the user device 9 is placed at a predetermined position (hereinafter, referred to as the inner set position) in the vehicle. The inner set position may be a holder for the user device 9 provided on the center console SC or on the instrument panel.

[0041] The device detection unit 6 may be a device that detects the user device 9 based on a communication connection with the user device 9 using a communication method with a communication distance of 0.1 m or less. The device detection unit 6 may be an NFC (Near Field Communication) module arranged at the inner set position. NFC here means communication with a communication distance of several centimeters to several tens of centimeters. A specific standard of NFC may be ISO / IEC 18092 (NFCIP-1), ISO / IEC 21481 (NFCIP-2), ISO / IEC 14443, or ISO / IEC 18092. When the device detection unit 6 connects with the user device 9 using NFC, the smart ECU 2 may recognize that the user device 9 is placed at the inner set position.

[0042] In another embodiment, the device detection unit 6 may be a wireless charger arranged at the inner set position. When the wireless charger starts supplying power to the user device 9, the smart ECU 2 may recognize that the user device 9 has been placed at a predetermined position in the vehicle. The wireless charging method may be any method such as Qi or AirFuel Inductive / Resonant. Paradoxically, the location in the vehicle where the wireless charger or NFC module is provided may be set to the inner set position.

[0043] Alternatively, the device detection unit 6 may be a device that detects that the user device 9 is placed at a predetermined position inside the vehicle by analyzing video captured by a camera capturing the interior of the vehicle. Such a device detection unit 6 outputs a signal indicating whether the user device 9 is placed at a predetermined position inside the vehicle to the smart ECU 2. Note that the device detection unit 6 is an optional element and may be omitted. The device detection unit 6 may be considered as a type of in-vehicle sensor.

[0044] In addition to the above, various other in-vehicle devices may be directly or indirectly connected to the smart ECU 2. For example, the power supply ECU, the cellular module, and the body-related equipment are connected to the smart ECU 2 so that they can communicate with each other via an in-vehicle network / using a dedicated cable. The power supply ECU is an ECU that controls the on / off of the vehicle power supply. The vehicle power supply is a power supply that is turned on when the vehicle Hv is running. The cellular module is a communication module that implements cellular communication such as 4G or 5G. The body-related equipment includes headlights, door lock motors, and power window motors.

[0045] The smart ECU 2 controls unlocking / locking of the doors based on (i) the presence of the user device 9 in the vicinity area, (ii) the user device 9 has been authenticated, and (iii) a predetermined user action has been performed. The user action for locking / unlocking may be touching the outer door handle or placing a foot over a detection area formed below the door. The smart ECU 2 may be understood as an ECU that provides a passive entry function. The passive entry function is a function that locks / unlocks the vehicle Hv in response to a predetermined user action on the vehicle Hv.

[0046] The smart ECU 2 may be divided into multiple ECUs. For example, the smart ECU 2 may be divided into an ECU that determines the device position and an ECU that executes vehicle control such as unlocking. The functional layout within the in-vehicle system 1 may be changed as appropriate.

[0047] <User Device 9> The user device 9 may be a general-purpose information processing terminal equipped with the SRWC function. The user device 9 may be a smartphone or a wearable device. The user device 9 functions as a key to the vehicle Hv by performing wireless authentication using the smart ECU 2 and the SRWC. The user device 9 may be referred to as a portable device, a key device, or the like. The user device 9 may be a dedicated device that functions as a wireless key for the vehicle Hv. The dedicated device may be referred to as a smart key, a key fob, a key card, an access key, or the like.

[0048] The user device 9 of the present embodiment has a rectangular shape with defined left, right, top and bottom directions. The user device 9 has an upper end, a lower end, a left edge and a right edge which correspond to the four sides of the rectangle.

[0049] The user device 9 includes a device display 91, an input device 92, an antenna 93, an RF (radio frequency) core 94, and a controller 95. The antenna 93 and the RF core 94 are electrically connected by a communication line or a conductor pattern. The device display 91, the input device 92, and the RF core 94 are connected to the controller 95 so as to be able to communicate with each other. The user device 9 may include a battery, a power receiving circuit for receiving power from a wireless charger, a communication module for NFC, and the like.

[0050] The device display 91 is a device that displays an image according to a video signal input from the controller 95. The device display 91 may be a liquid crystal display or an organic EL display. The input device 92 is a device for receiving a user's instruction operation on the user device 9. The input device 92 may be a touch panel stacked on the device display 91. The input device 92 outputs an operation signal, which is an electrical signal corresponding to the user's operation, to the controller 95. The operation signal includes information indicating the content of the user's operation on the user device 9.

[0051] The controller 95 may be configured to receive an instruction to register the communication characteristics of the user device 9 in the smart ECU 2 via the input device 92. The controller 95 may be configured to start a process of registering the communication characteristics of the user device 9 (hereinafter, characteristic learning process) in cooperation with the in-vehicle system 1 based on receiving the registration instruction via the input device 92. The controller 95 may transmit an SRWC signal equivalent to a registration instruction signal to the smart ECU 2 based on receiving the registration instruction via the input device 92. The smart ECU 2 may be configured to be able to receive the registration instruction using the input device 92 (user device 9).

[0052] The characteristic learning process may include displaying a characteristic registration guide image on the device display 91 or the in-vehicle display 4, or both. The characteristic registration guide image is an image that shows the user the procedure for registering the communication characteristics of the user device 9 in the smart ECU 2. The characteristic registration guide image includes an image showing the location where the user device 9 should be placed and the posture of the user device 9 when registering the communication characteristics. The characteristic registration guide image may include multiple patterns / images. Hereinafter, the in-vehicle display 4 and the device display 91 will also be collectively referred to as the display. Hereinafter, the display may be interpreted as the in-vehicle display 4 or the device display 91, or both.

[0053] The antenna 93, the RF core 94, and the controller 95 correspond to a configuration for implementing SRWC. The antenna 93, the RF core 94, and the controller 95 may be mounted on a single circuit board. The antenna 93 is an antenna element for transmitting and receiving radio waves in a frequency band (e.g., 2.4 GHz band) used for SRWC.

[0054] The RF core 94 is a circuit module that performs processing related to transmission and reception of radio signals. The RF core 94 may include a modulation circuit, a demodulation circuit, a frequency conversion circuit, an amplifier circuit, a local oscillator, and the like. The RF core 94 is connected to an antenna 93 and a controller 95. The RF core 94 demodulates a signal received by the antenna 93 and provides the demodulated signal to the controller 95. The RF core 94 also modulates transmission data input from the controller 95 and causes the data to be emitted as radio waves from the antenna 93. The RF core 94 may be realized as an IC chip (i.e., a transmission and reception IC).

[0055] Like the anchor 3, the RF core 94 is configured to be able to transmit and receive a CW signal for each channel as a signal for distance measurement. The RF core 94 provides the controller 95 with reception phase information and reception strength for each channel. In this embodiment, the controller 95 generates a distance measurement value based on the reception phase information for each channel, but the functional arrangement in the user device 9 is not limited to this. The RF core 94 may be configured to calculate a distance measurement value based on the reception phase information for each channel.

[0056] The controller 95 is a microcomputer that controls the operation of the entire user device 9. The controller 95 includes a processor E1, a memory E2, a storage E3, and a communication interface E4. The processor E1 may be a CPU. The memory E2 is a volatile storage medium such as a RAM. The storage E3 is a recording device including a non-volatile storage medium such as a flash memory. The storage E3 may include multiple types of storage media such as a ROM (Read Only Memory) and a flash memory. The communication interface E4 is a circuit module that allows the processor E1 to communicate with other components such as the device display 91, the input device 92, the RF core 94, etc.

[0057] A device control program is stored in the storage E3. The device control program is a program including instructions related to device characteristic learning processing. In addition, communication data is stored in the storage E3. The communication data is data for performing wireless communication with the vehicle Hv. The communication data may include parameters received from the smart ECU 2 by pairing, such as the device ID of the smart ECU 2. In addition, the communication data may include an identification number of the vehicle Hv (hereinafter, vehicle ID). The vehicle ID corresponds to identification information of the vehicle / in-vehicle system to be communicated with. The vehicle ID may be referred to as a system ID. The vehicle ID may be a VIN (Vehicle Identification Number). The communication data may include a key code used for wireless authentication with the vehicle Hv.

[0058] The controller 95 is configured to periodically perform advertising using the RF core 94 and the antenna 93. Advertising is a process of transmitting an advertising signal using a predetermined channel. The advertising signal is a wireless signal for notifying other devices of its own presence. When the controller 95 receives a connection request from the vehicle Hv in response to the advertising, the controller 95 establishes a communication connection with the vehicle Hv. The controller 95 can perform an authentication process (i.e., wireless authentication) using the SRWC based on the establishment of a communication connection with the vehicle Hv.

[0059] <Outline of location determination> If the user device 9 is located away from the vehicle Hv (i.e., outside the SRWC area), the smart ECU 2 cannot connect to the user device 9 via SRWC. If the smart ECU 2 is not connected to the user device 9 via SWRC, it sets the anchor 3 to a dormant state and does not perform location determination. If the smart ECU 2 is not connected to the user device 9, it periodically scans to search for the user device 9. If the user device 9 is not connected to the smart ECU 2, it periodically transmits an advertising signal.

[0060] When the user device 9 enters the SRWC area of ​​the vehicle Hv as the user moves, the smart ECU 2 may receive an advertising signal from the user device 9. Upon receiving the advertising signal from the user device 9, the smart ECU 2 transmits a connection request signal to the user device 9. This causes the user device 9 and the smart ECU 2 to transition to a communication connection state (FIG. 3, S11). The communication connection state may be understood as a state in which an SRWC link is established. The connection request signal is a signal that requests a communication connection.

[0061] In the communication connection state, the smart ECU 2 and the user device 9 transmit and receive wireless signals for communication confirmation at a predetermined interval (e.g., a connection interval) and perform encrypted data communication. Accordingly, the smart ECU 2 periodically obtains the reception strength of the device signal from the wireless communication module 24.

[0062] The smart ECU 2 keeps the anchor 3 in the dormant state until the reception strength of the device signal exceeds a predetermined activation strength (S12 NO). In addition, if the communication connection between the user device 9 and the smart ECU 2 is cut off without the reception strength exceeding the activation strength, this flow may be ended.

[0063] When the reception strength of the device signal exceeds a predetermined activation strength (S12 YES), the smart ECU 2 activates all the anchors 3 and causes the anchors 3 to perform distance measurement communication with the user device 9 (S13). After that, the smart ECU 2 periodically executes a position determination process until an end condition is satisfied (S14). The position determination process includes the anchors 3 performing distance measurement communication with the user device 9.

[0064] The activation strength used in step S12 is a threshold value of the reception strength for starting distance measurement communication. The activation strength may be determined based on the reception strength of the SRWC signal transmitted from a predetermined reference device placed at a predetermined position outside the vehicle. For example, the activation strength may be set based on the reception strength observed by the wireless communication module 24 when the reference device is placed at a point 10 m away from the vehicle Hv.

[0065] The reference device means a device used to determine a threshold value for the reception strength for determining the device location. The reference device may be any model of iPhone (registered trademark) or Android (registered trademark) terminal. The reference device may be any model of various user devices 9 generally available on the market. The user device 9 used as the reference device may be selected by a designer. The activation strength may be set based on the reception strength observed when the reference device and the smart ECU 2 are actually communicated as a test.

[0066] The termination condition may be disconnection of the communication connection between the smart ECU 2 and the user device 9. Alternatively, the smart ECU 2 may determine that the termination condition is satisfied when the traveling speed of the vehicle Hv becomes equal to or greater than a predetermined value. When the termination condition is satisfied (YES in S15), the smart ECU 2 transitions all anchors 3 to a pause state and ends the periodic position determination.

[0067] The device location may be determined by using both the distance measurement value and the reception strength as shown in FIG. 4. The reception strength used in the following description may be interpreted as a strength value corrected using characteristic data described later. The location determination process includes determining whether or not the minimum observed distance value obtained as a result of the distance measurement communication exceeds a predetermined proximity determination distance (S21). If the minimum observed distance value obtained as a result of the distance measurement communication exceeds the predetermined proximity determination distance (S21 YES), the smart ECU 2 may determine that the user device 9 is in a distant area (S22).

[0068] The minimum observed distance value means the minimum value of the distance measurement values ​​observed by multiple anchors 3. "Dmin" in FIG. 4 represents the minimum observed distance value. Also, "Dn" represents the proximity determination distance. The proximity determination distance is a parameter that defines the proximity area outside the vehicle. The proximity determination distance may be set to, for example, 1.0 m, 1.5 m, 2 m, etc. The proximity area may be interpreted as an area in which automatic unlocking / locking of the vehicle Hv can be performed. The proximity area may also be referred to as a passive entry area.

[0069] On the other hand, if the minimum distance measurement value (Dmin) is equal to or less than the proximity judgment distance (Dn), the smart ECU2 judges whether the maximum inner intensity value exceeds a predetermined indoor judgment value (S23). The maximum inner intensity value here means the maximum value of the reception intensity observed at the inner anchor. "PinMax" in the figure represents the maximum inner intensity value. Also, Pin in the figure represents the indoor judgment intensity.

[0070] If the minimum observation distance is equal to or less than the vicinity determination distance and the maximum inner intensity does not exceed the predetermined interior determination intensity (S23 NO), the smart ECU2 may determine that the device location is in the vicinity area (S24). On the other hand, if the minimum observation distance is equal to or less than the vicinity determination distance and the maximum inner intensity exceeds the predetermined interior determination intensity (S23 YES), the smart ECU2 may determine that the device location is inside the vehicle (S24).

[0071] The indoor determination strength is a threshold value related to the reception strength for determining that the user device 9 is inside the vehicle. The indoor determination strength may be determined based on the reception strength at the inner anchor for the SRWC signal transmitted from a reference device arranged at an inner set position inside the vehicle. The indoor determination strength may be set in advance by a test using the reference device.

[0072] Of course, the method of determining the device position shown in Fig. 4, in other words, the method of determination described above, is an example and is not limited thereto. The condition for determining that the user device 9 is inside the vehicle (hereinafter, the inside-vehicle determination condition) may include that the inside / outside intensity, which is the value obtained by subtracting the outside intensity maximum value from the inside intensity maximum value, is equal to or greater than a predetermined intensity difference threshold value (e.g., 10 dB). The outside intensity maximum value here means the maximum value of the reception intensity observed at multiple outside anchors. The inside-vehicle determination condition may also include that the inside distance minimum value, which is the minimum value of the distance measurement values ​​at the inside-vehicle anchors, is less than a predetermined indoor determination distance (e.g., 1.0 m).

[0073] The conditions for determining that the device position is within the vicinity area (hereinafter, the vicinity determination conditions) may also be changed as appropriate. The vicinity determination conditions may include that the outer strength maximum value is equal to or greater than a predetermined vicinity determination strength. The vicinity determination strength may be set based on the results of a reception strength observation test using a reference device.

[0074] The above-mentioned various parameters for determining the device position (hereinafter, referred to as position determination parameters) may be registered in the storage 23 of the smart ECU 2. The position determination parameters include some or all of the activation intensity, the indoor determination intensity, the intensity difference threshold, the proximity determination intensity, the proximity determination distance, and the indoor determination distance.

[0075] <Issues regarding location accuracy> Mobile devices that can be user devices 9, such as smartphones, tablets, and wearable devices, can be manufactured by multiple manufacturers. The strength and directivity of the SRWC signal transmitted by the user device 9 can vary depending on the manufacturer and model. This is because the antenna configuration and transmission power settings vary depending on the manufacturer and model.

[0076] Furthermore, even if the user devices 9 are of the same model, the communication characteristics may differ due to manufacturing errors. The communication characteristics here may be interpreted as directivity or transmission characteristics. Furthermore, the communication characteristics of the user device 9 may be affected by attachments such as covers. In this way, the communication characteristics may differ for each user device 9. In a configuration in which the actual reception strength of a signal from the user device 9 is compared with a threshold value designed based on a reference device to determine the device position, the device position may be erroneously determined. For this reason, the smart ECU 2 of this embodiment is provided with a mechanism for learning the difference in communication characteristics between the user device 9 and the reference device and using the learning result for position determination.

[0077] <Smart ECU functions> As shown in FIG. 5, the smart ECU 2 has functional blocks including an intensity acquisition unit F1, a characteristic learning unit F2, a correction unit F3, a position determination unit F4, and a distance measurement unit F5. Some or all of these functional blocks may be realized by the processor 21 executing a device control program. The smart ECU 2 has a reference value storage unit M1, a threshold storage unit M2, and a characteristic data storage unit M3. These storage units may be realized using a storage area provided in the storage E3. The reference value storage unit M1, the threshold storage unit M2, and the characteristic data storage unit M3 may be implemented in the same storage medium, or some of them may be implemented in different storage media. The smart ECU 2 corresponds to a control unit.

[0078] The reference value storage unit M1 is a storage medium / area in which data indicating the communication characteristics of the reference device is stored. The data indicating the communication characteristics of the reference device includes data of the reception strength observed at the inner anchor when the reference device is present inside the vehicle. The data indicating the communication characteristics of the reference device includes data of the reception strength observed at the outer anchor when the reference device is in the vicinity area.

[0079] In this embodiment, the data indicating the communication characteristics of the reference device includes an inner reference value and an outer reference value. The inner reference value may be an average value of the reception strength of the SRWC signal from the reference device observed by multiple inner anchors when the reference device is placed at the inner set position. In another example, the inner reference value may be the reception strength of the SRWC signal from the reference device detected by a specific anchor 3 when the reference device is placed at the inner set position. The specific anchor 3 may be, for example, anchor 3p or wireless communication module 24.

[0080] The outer reference value may be the maximum value of the reception strength of the SRWC signal from the reference device observed by the multiple outer anchors when the reference device is placed at a predetermined outer set position. The outer set position is a predetermined measurement position outside the vehicle. The outer set position may be a point 1.5 m away to the right from the outer door handle for the right front seat. In another embodiment, the outer set position may be a location 0.1 m away from the outer door handle for the right front seat or the lower end of the side window. The reception strength used to determine the outer reference value may be the reception strength of the direct wave (hereinafter, direct wave strength). The direct wave means the SRWC signal transmitted from the portable device and reaching the anchor 3 without being reflected by other objects. Basically, the reflected wave has a longer propagation path than the direct wave. Therefore, the direct wave is received by the anchor 3 earlier than the reflected wave. The anchor 3 may report the strength of the device signal received first in one ranging communication to the processor 21 as the strength of the direct wave. Note that the anchor 3 may receive a signal in which the reflected wave is superimposed on the direct wave over time. The anchor 3 may extract a direct wave from the received signal and obtain its reception strength by digital signal processing such as the MUSIC method or the ESPRIT method. The direct wave may be called a first path.

[0081] In another example, the outer reference value may be the reception strength of the SRWC signal from the reference device detected by a specific outer anchor when the reference device is placed at the outer set position. The specific outer anchor may be anchor 3 (i.e., anchor 3a) located closest to the outer set position.

[0082] In addition to the inner reference value and the outer reference value, the reference value storage unit M1 may store a gateway reference value. The gateway reference value is the reception strength of a signal from a reference device detected by the wireless communication module 24 when the reference device is placed in the outer set position. The gateway reference value may be understood as a parameter on which the activation strength is based. The various reference values ​​correspond to assumed values ​​of the reception strength of a signal transmitted from the reference device.

[0083] The threshold memory unit M2 is a storage medium / area in which parameters for position determination, such as activation strength, indoor determination strength, etc. The parameters for position determination related to reception strength may be set based on an inner reference value or an outer reference value.

[0084] The characteristic data storage unit M3 is a storage medium / area in which data indicating the difference in communication characteristics between the user device 9 and a reference device is stored. The difference in communication characteristics may be interpreted as a difference in signal strength (in other words, reception strength). The data indicating the difference in communication characteristics may be a correction value γ. When the reception strength of the SRWC signal from the reference device observed under the same conditions (hereinafter, reference value) is α and the reception strength of the device signal (observed value) is β, the correction value γ may be β-α.

[0085] The characteristic data storage unit M3 stores, for example, an inner correction value γ1, which is a value for correcting the reception strength observed at the inner anchor. The inner correction value γ1 may be a value obtained by subtracting a reference value α1 from the measured value β1. The reference value α1 may be an inner reference value. The measured value β1 may be an average value of the reception strengths detected at multiple inner anchors when the user device 9 is placed at the inner set position. The measured value β1 may be the reception strength of a device signal detected by a specific anchor 3. The inner correction value γ1 corresponds to a correction value assuming that the user device 9 is inside a vehicle.

[0086] In addition to the inner correction value γ1, an outer correction value γ2 may be registered in the characteristic data storage unit M3. This is a value for correcting the reception strength observed at the outer anchor. The outer correction value γ2 is a correction value assuming that the user device 9 is outside the vehicle. The outer correction value γ2 may be a value obtained by subtracting a reference value α2 from the measurement value β2. The reference value α2 may be an outer reference value. The measurement value β2 may be the maximum value of the direct wave strength detected at multiple outer anchors when the user device 9 is placed at the outer set position. The reference value α2 and the measurement value β2 may be the direct wave strength observed at a specific outer anchor when the reference device and the user device 9 are placed at the outer set position. The specific outer anchor may be the anchor 3 (i.e., anchor 3a) located closest to the outer set position.

[0087] A gateway correction value may be registered in the characteristic data storage unit M3. The gateway correction value may be a value obtained by subtracting a gateway reference value from a device signal detected by the wireless communication module 24 when the user device 9 is placed in the outer set position. The gateway correction value may be used to correct the reception strength or activation strength used in the judgment of step S12. The data stored in the characteristic data storage unit M3 is updated by the characteristic learning unit F2. A data set indicating the communication characteristics of one user device 9 is also referred to as characteristic data hereinafter. The characteristic data may be understood as data including various correction values ​​such as an inner correction value. The characteristic data may be rephrased as correction data or difference data. The various correction values ​​and the calculation methods thereof described above are examples. The types of correction values ​​generated by the smart ECU 2 and the calculation methods thereof may be changed as appropriate.

[0088] The strength acquisition unit F1 is configured to acquire data indicating the reception strength of the device signal from the wireless communication module 24 and the anchor 3. The reception strength data acquired by the strength acquisition unit F1 is temporarily stored in the memory E2. The reception strength data stored in the memory E2 is referred to by the characteristic learning unit F2, the correction unit F3, and the position determination unit F4.

[0089] The characteristic learning unit F2 is configured to generate characteristic data of the user device 9 and store it in the characteristic data storage unit M3. The characteristic learning unit F2 acquires characteristic data such as an inner correction value by executing a characteristic learning process described later. The characteristic data may be stored in association with the device ID of the user device 9. The characteristic learning unit F2 may be configured to be able to store characteristic data of multiple user devices 9 in the characteristic data storage unit M3. The device characteristic data for each user device 9 may be distinguished using a device ID or the like.

[0090] The correction unit F3 is configured to correct the reception strength acquired by the strength acquisition unit F1 using characteristic data stored in the characteristic data storage unit M3. The correction unit F3 corrects the reception strength observed at the inner anchor with an inner correction value. For example, when the reception strength detected at the inner anchor is ρ1, the correction unit F3 corrects the reception strength by ρ1-γ1. For convenience, the reception strength after correction is also called the corrected strength. ρ1 may be the maximum inner strength value. The correction unit F3 may be configured to correct each of the reception strengths observed at multiple inner anchors.

[0091] The correction unit F3 may correct the reception strength observed at the outer anchor with an outer correction value. For example, when the reception strength detected at the outer anchor is ρ2, the correction unit F3 corrects the reception strength by ρ2-γ2. ρ2 may be the outer strength maximum value. The correction unit F3 may be configured to correct each of the reception strengths observed at the multiple outer anchors.

[0092] The correction unit F3 may use the gateway correction value to correct the reception strength used for judging the activation of the anchor 3. The reception strength used for judging the activation of the anchor 3 is the reception strength at the wireless communication module 24. In the present disclosure, the reception strength of the device signal detected at the wireless communication module 24 is also referred to as the gateway strength. The corrected gateway strength may be a value obtained by subtracting the gateway correction value from the gateway strength.

[0093] The location determination unit F4 is configured to determine the device location based on the corrected reception strength and the distance measurement value. The distance measurement unit F5 is configured to control distance measurement communication between the anchor 3 and the user device 9. The distance measurement unit F5 activates the anchor 3 based on the fact that the uncorrected gateway strength exceeds the activation strength, and causes the anchor 3 to perform distance measurement communication with the user device 9.

[0094] <Example of mobile device operation> Here, the operation of the smart ECU 2 will be described with reference to the flowcharts shown in Figures 6 and 7. The flow shown in Figure 6 corresponds to a flow in which a characteristic learning process and a reception strength correction process are incorporated into the position determination process described with reference to Figures 3 and 4. The series of processes shown in Figure 6 can be called position determination related processes. The position determination related processes may include steps S101 to S111 as shown in Figure 6. The processor 21 in the following flow description may be replaced with the smart ECU 2, the strength acquisition unit F1, the characteristic learning unit F2, the correction unit F3, the position determination unit F4, or the distance measurement unit F5.

[0095] The flow shown in FIG. 6 may be started when the wireless communication module 24 receives an advertising signal from the user device 9. Step S101 is a step of transmitting a connection request signal to the user device 9 and establishing a communication connection with the user device 9. Step S102 is a step of the processor 21 determining whether or not characteristic data of the user device 9 to which the smart ECU 2 is connected in communication is stored in the characteristic data storage unit M3. The case where the characteristic data of the user device 9 is not stored in the characteristic data storage unit M3 may be, for example, a case where the position determination process is performed for the first time after pairing between the smart ECU 2 and the user device 9. The case where the characteristic data is not stored may also be a case where the user uses a vehicle that the user has never used for the first time in a car sharing service or the like.

[0096] If the characteristic data of the user device 9 is not stored in the characteristic data storage unit M3, a negative judgment is made in step S102 and the process proceeds to step S103. On the other hand, if the characteristic data of the user device 9 is stored in the characteristic data storage unit M3, a positive judgment is made in step S102 and the process proceeds to step S106. Note that even if a certain period of time has passed since the previous characteristic learning process was performed, a positive judgment is made in step S102 and steps S103 to S105 may be performed.

[0097] Step S103 is a step in which the processor 21 executes an intention confirmation process. The intention confirmation process is a process of inquiring of the user as to whether or not to register the characteristic data of the user device 9 in the smart ECU 2 (i.e., the vehicle Hv). The intention confirmation process may include displaying on the display an image (hereinafter, intention confirmation screen) including a message inquiring as to whether or not to register the characteristic data in the vehicle Hv. The processor 21 acquires the result of the intention confirmation process, i.e., the user's answer indicating whether or not to register the characteristic data in the vehicle, via the input device 5, 92. The input device 5, 92 transmits an answer signal indicating that the characteristic data is to be registered in the vehicle to the processor 21 based on the user's operation. The answer signal corresponds to a registration instruction signal.

[0098] If the processor 21 receives a registration instruction signal (S103 YES), the processor 21 executes step S104. On the other hand, if the processor 21 does not receive a registration instruction signal as a result of the intention confirmation process (S103 NO), the processor 21 advances the process to step S106.

[0099] Step S105 is a step of executing a characteristic learning process. The characteristic learning process includes steps S201 to S208 as shown in FIG. 7. In the present disclosure, steps S201 to S206 are also referred to as a strength measurement process. The strength measurement process may include multiple in-vehicle anchors simultaneously / sequentially measuring the reception strength of device signals for each frequency. The strength measurement process may include an inner strength measurement process and an outer strength measurement process. The inner strength measurement process is a process of measuring the reception strength of a device signal when the user device 9 is placed in an inner set position. The outer strength measurement process is a process of measuring the reception strength of a device signal when the user device 9 is placed outside the vehicle (e.g., in an outer set position).

[0100] Step S201 is a step of displaying a characteristic registration guide image on the display. The characteristic registration guide image may include an image indicating that the user device 9 is placed in an initial set position. The initial set position means a position to which the user device 9 should be initially set among a plurality of set positions preset in the smart ECU 2. In this embodiment, the initial set position is an inner set position. In another embodiment, the initial set position may be an outer set position.

[0101] The characteristic registration guide image may include a set completion button. The set completion button is a button for inputting to the smart ECU 2 that the user device 9 has been placed in the specified set position. Step S201 may include outputting a voice message guiding the user to place the user device 9 in the inner set position. After step S201 is executed, the process proceeds to step S202. The set position in which the processor 21 requests the user to place the user device 9 using a voice or image is also referred to as a specified position in the present disclosure.

[0102] Step S202 is a step in which the processor 21 confirms that the user device 9 has been placed at the designated position. The designated position here may be interpreted as the inner set position. The fact that the user device 9 has been placed at the designated position may be confirmed based on a user operation on the input devices 92 and 5. The processor 21 may determine that the user device 9 has been placed at the designated position based on the user pressing the set completion button. The processor 21 may determine whether or not the user device 9 has been placed at the designated set position based on the distance measurement values ​​observed at the multiple anchors 3. When the position of the user device 9 estimated from the distance measurement values ​​is deviated from the designated set position, the processor 21 may display an image on the display requesting that the position of the user device 9 be adjusted. In addition, the processor 21 may confirm that the user device 9 has been placed at the inner set position based on a signal from the device detection unit 6.

[0103] If the processor 21 can confirm that the user device 9 has been placed at the designated position (S203 YES), the processor 21 proceeds to step S204. If the processor 21 cannot confirm that the user device 9 has been placed at the designated position (S203 NO), the processor 21 may redisplay the characteristic registration guide image. If the processor 21 cannot confirm that the user device 9 has been placed at the designated position even after a certain time has elapsed since displaying the characteristic registration guide image, the processor 21 may interrupt the characteristic learning process and execute step S106.

[0104] Step S204 is a step of performing test communication. The test communication may be communication for each anchor 3 to observe the reception strength of the device signal. The test communication may be communication for each anchor 3 to eavesdrop (sniffer) on the communication between the wireless communication module 24 and the user device 9. The test communication may be a plurality of anchors 3 individually performing SRWC with the user device 9. The test communication may include the anchor 3 detecting the reception strength of each channel by switching the channels in sequence. The test communication may also be ranging communication between the user device 9 and the anchor 3. When the test communication is completed, the process proceeds to step S205.

[0105] Step S205 is a step in which the processor 21 collects communication results from the anchors 3. For example, the processor 21 may receive the reception strength for each channel as the communication result from each anchor 3. The communication result may include a distance measurement value. The communication result is associated with data indicating the measurement conditions and stored in the memory 22. The measurement conditions indicate the position of the user device 9 when the test communication was performed. The measurement conditions may include the attitude of the user device 9 when the test communication was performed. Hereinafter, the attitude of the user device 9 may also be referred to as the device attitude. When step S205 is completed, the process proceeds to step S206.

[0106] Step S206 is a step of determining whether the intensity measurement process has been completed under all planned measurement conditions. The characteristic learning process may include a step of causing multiple anchors 3 to detect the reception intensity of the device signal under multiple measurement conditions in which the positions or orientations of the user device 9 are different.

[0107] If the intensity measurement process has not been completed under all measurement conditions (NO in S206), the process returns to step S201, and the processor 21 may display a characteristic registration guide image for executing the intensity measurement process under unmeasured conditions. For example, if the inner intensity measurement process has been completed and the outer intensity measurement process has not been completed, the processor 21 may change the designated position to the outer set position and then perform steps S201 to S205.

[0108] The strength measurement process at the outer set position may include observing the reception strength when the user device 9 is placed at the outer set position in different postures. For example, the characteristic learning process may include collecting the reception strength when the user device 9 is placed at the outer set position in the first to fifth postures. The first posture may be a posture in which the screen of the user device 9 is horizontal and the upper end is directed toward the vehicle Hv. The second posture may be a posture in which the screen of the user device 9 is horizontal and the lower end is directed toward the vehicle Hv. The third posture may be a posture in which the screen of the user device 9 is horizontal and the left edge is directed toward the vehicle Hv. The fourth posture may be a posture in which the screen of the user device 9 is horizontal and the right edge is directed toward the vehicle Hv. The fifth posture may be a posture in which the screen or the back of the user device 9 is directed toward the vehicle Hv. The above first to fifth postures applied in the outer strength measurement process may be called outer first to fifth postures. Each posture may be different from each other. In addition, the combination of device postures in which test communication should be performed in the outer strength measurement process may be only the first to fourth postures, or may be only the first and fifth postures. The combination of device postures in which test communication should be performed may be designed as appropriate.

[0109] Furthermore, the outer set position is not limited to one location. A first outer set position and a second outer set position may be set in the smart ECU 2. The first outer set position may be within 0.1 m from the center of the driver's side window. The second outer set position may be 1.5 m away from the driver's outer door handle to the side. The processor 21 may perform the strength measurement process in the order of the inner set position, the first outer set position, and the second outer set position.

[0110] The orientation of the user device 9 in the first outer set position may be an orientation in which the screen faces the interior of the vehicle. The measurement orientation in the first outer set position may be one pattern or multiple patterns. The measurement orientation in the second outer set position may be five patterns of the above-mentioned first to fifth orientations, or may be four patterns of the first to fourth orientations.

[0111] When the intensity measurement process is completed under all conditions (YES in S206), the process proceeds to step S207. In step S207, the processor 21 generates characteristic data based on the reception intensity data collected in the above process. As described above, the processor 21 generates various correction values ​​based on the difference between the reference value α and the measured value β observed under the same conditions.

[0112] The measured value β1 used to calculate the inner correction value may be the average value of the reception strength for each channel detected by multiple inner anchors when the user device 9 is placed in the inner set position. In this disclosure, the average value of the reception strength for each channel is also referred to as the intensity average value at multiple frequencies or the frequency average value. If there are three inner anchors and reception strength is observed in 10 channels, β1 may be the average value of 30 reception strength samples. The reference value α2 and the measured value β2 used to calculate the outer correction value may be the maximum value of the direct wave strength for each channel and each outer anchor.

[0113] The above steps S201 to S205 may be designed to collect data for generating a desired correction value. Step S206 may be a step of performing a predetermined calculation process on the reception intensity data collected in steps S201 to S205 so as to generate a desired correction value according to a method for determining the device position. The calculation process may include removing outliers, calculating an average value, subtracting, etc.

[0114] When the generation of the characteristic data is completed, the process proceeds to step S207. Step S207 is a step for storing the characteristic data generated in step S206 in the characteristic data storage unit M3.

[0115] When the above characteristic learning process is completed, the process proceeds to step S106 in Fig. 6. Note that the set position for which the intensity measurement process is performed in the characteristic learning process may be only the inner set position or the outer set position. The combination of locations for placing the user device 9 may be changed as appropriate depending on the correction value to be generated. The correction value to be generated in the characteristic learning process may be configured to be selectable by the user in the intention confirmation process.

[0116] Step S106 is a step in which the processor 21 monitors the gateway strength. Step S106 corresponds to step S12 described above. When the characteristic data is stored in the characteristic data storage unit M3, step S106 may include the processor 21 correcting the reception strength (gateway strength) detected by the wireless communication module 24 with a gateway correction value. The gateway strength compared with the startup strength may be the corrected gateway strength. The processor 21 executes step S107 based on the corrected gateway strength being equal to or greater than the startup strength. Note that when the characteristic data is stored in the characteristic data storage unit M3, the gateway strength compared with the startup strength may be an uncorrected value.

[0117] Step S107 is a step of executing communication for position determination. The communication for position determination may be distance measurement communication between each anchor 3 and the user device 9. Step S107 may include activating the anchor 3. Step S107 may include the smart ECU 2 exchanging distance measurement communication settings with the user device 9 via SRWC. The distance measurement communication settings refer to the execution interval of the distance measurement communication, etc. As described later, step S107 is executed periodically until a predetermined end condition is satisfied. The processor 21 executes step S108 every time it executes step S107.

[0118] Step S108 is a step in which the processor 21 acquires the results of the ranging communication, such as the reception strength and the distance measurement value, from each anchor 3. When step S108 is completed, the process proceeds to step S109. Step S109 is a step in which the collected reception strength is corrected with characteristic data. Step S109 may include correcting the reception strength observed at the outer anchor with an outer correction value. Step S109 may also include correcting the reception strength observed at the inner anchor with an inner correction value. Step S109 may include correcting the outer strength maximum value and the inner strength maximum value.

[0119] When step S109 is completed, the process proceeds to step S110. Step S110 is a step for determining the device position using the corrected inner intensity maximum value and the corrected outer intensity maximum value. The outline of step S110 may be explained with reference to FIG. 4. When step S110 is completed, the process proceeds to step S111. If no characteristic data is registered at the time step S110 is executed, the processor 21 may perform position determination using the uncorrected reception intensity. Cases where no characteristic data is registered at the time step S110 is executed include cases where the characteristic registration process has failed and cases where a registration instruction signal has not been received as a result of the intention confirmation process (S103 NO), etc.

[0120] Step S111 is a step for determining whether or not the termination condition is satisfied. Step S111 corresponds to S15. If the termination condition is satisfied, the processor 21 puts the anchor 3 to sleep. The processor 21 repeatedly executes steps S107 to S111 until the termination condition is satisfied.

[0121] The processor 21 may execute a process according to a user action based on the latest determination result of the device location. For example, when the processor 21 detects an unlocking operation by the user while the device location is determined to be in the nearby area, the processor 21 unlocks the door. When a function for executing vehicle control is provided in an ECU other than the smart ECU 2, the smart ECU 2 may periodically transmit data including the determination result of the device location and the device ID / user information to the other ECU.

[0122] <Effects> The smart ECU 2 generates characteristic data indicating a difference in communication characteristics between the user device 9 used by the user and a reference device by communicating with the actual user device 9. The smart ECU 2 determines the device position using the reception strength of the device signal corrected using the characteristic data. This reduces the risk of erroneous determination of the device position due to a difference in communication characteristics between the user device 9 and the reference device.

[0123] The inner correction value is calculated based on the average value of the reception strength observed at multiple in-vehicle anchors. Based on the results of tests, the developers of the present disclosure have found that since the inside of a vehicle is a multipath environment, the posture of the user device 9 is unlikely to affect the average value of the reception strength at multiple anchors 3. According to a configuration in which the correction value is determined based on the average value of the reception strength observed at multiple in-vehicle anchors, the effect of the device posture on the correction value can be reduced.

[0124] Furthermore, if the frequency differs, the propagation path may differ. The degree of influence of the reflected wave may differ for each frequency. By using a configuration in which the correction value is generated based on the reception strength at multiple frequencies, the correction value can be set to a more appropriate value.

[0125] In addition, when the user uses the vehicle Hv for the first time, or when the characteristic data of the user device 9 is not registered in the smart ECU 2, the smart ECU 2 automatically executes an intention confirmation process. When a response instructing the start of characteristic learning process is received as a result of the intention confirmation process, the smart ECU 2 instructs the user on the operation procedure by displaying a characteristic registration guide image, etc. This configuration enables the user to easily register communication characteristics without confusion.

[0126] <Modification> The processor 21 may be configured to execute the intention confirmation process when a certain period (e.g., half a year or one year) has elapsed since the characteristic data was registered. An expiration date may be set for the characteristic data. The processor 21 may be configured to automatically delete expired characteristic data. The processor 21 may be configured to execute the intention confirmation process when the inside / outside determination has failed a certain number of times (e.g., once or twice). The failure of the inside / outside determination may be input by the user via the input device 5, 92. The processor 21 may also determine that the inside / outside determination has failed when a start operation is performed a certain number of times within a certain time period while the device position is determined to be outside the vehicle (e.g., in a nearby area). The start operation is an operation for turning on the vehicle power supply. The start operation may be an operation of pressing a start switch (power switch) while depressing the brake pedal.

[0127] The measurement value β1 used to calculate the inner correction value may be a value obtained by subtracting a nearby measurement value from the inner measurement value. The inner measurement value here may be an average value of the reception strength observed at the vehicle anchor when the user device 9 is placed at the inner set position. The nearby measurement value may be an average value of the reception strength observed at the vehicle anchor when the user device 9 is placed at the first outer set position. The average value may be an average value of the strength at multiple frequencies. When the measurement value β1 is a value obtained by subtracting a nearby measurement value from the inner measurement value, the reference value α1 may also be a value calculated under the same conditions. In other words, the reference value α1 may also be a value obtained by subtracting a nearby measurement value from the inner measurement value observed using a reference device.

[0128] Although the above describes a pattern in which the reception strength is corrected using characteristic data, the object of correction may not be the reception strength, but may be thresholds such as the activation strength, the indoor determination strength, the strength difference threshold, and the proximity determination strength. The processor 21 may determine the device position by comparing the threshold corrected using the characteristic data with the actual reception strength.

[0129] The processor 21 may have a function of receiving attitude-related data, which is data indicating the device attitude, from the user device 9, and determining whether the user device 9 is in a designated attitude. The attitude-related data may be data including some or all of the detection results of the magnetic sensor, the acceleration sensor, and the gyro sensor. When the processor 21 detects that the user device 9 is not in a designated attitude based on the received attitude-related data, the processor 21 may execute a process for displaying an image on the display requesting that the device attitude be adjusted.

[0130] The processor 21 may execute the intensity measurement process for determining the inside correction value when there is no passenger in the vehicle and all the doors are closed. Closing the doors creates a multipath environment inside the vehicle, which is expected to reduce the effect of the device posture. In addition, the device signal may be attenuated by the human body. By making the vehicle empty, the effect of the human body on the inside correction value can be reduced. In view of the above circumstances, the processor 21 may request the user to get out of the vehicle and close all the doors after placing the user device 9 in the inside set position. The request may be notified to the user by using a screen display or a voice message.

[0131] The processor 21 may determine that all the doors are closed from an output signal of an in-vehicle sensor (e.g., a courtesy switch). When the processor 21 detects that some of the doors are open from the output signal of the in-vehicle sensor in the inside strength measurement process, the processor 21 may display an image on the in-vehicle display 4 requesting that all the doors be closed.

[0132] The processor 21 may detect whether or not there is an occupant inside the vehicle from an output signal of an in-vehicle sensor such as a seating sensor or an in-vehicle camera. When the processor 21 detects that there is an occupant inside the vehicle from the output signal of the in-vehicle sensor in the inside strength measurement process, the processor 21 may execute a process of outputting an image / audio requesting the occupant to get out of the vehicle.

[0133] In the outer intensity measurement process, the processor 21 may request the user to hold the user device 9 in his / her hand so that the user device 9 is positioned between the vehicle Hv and the user. This positional relationship can reduce the risk of the device signal being attenuated by the human body. In addition, the user's body can play a role in blocking reflected waves from walls and the like. In the outer intensity measurement process, the processor 21 may instruct the user to stand facing the vehicle Hv and hold the user device 9 in a predetermined posture. In the outer intensity measurement process, by requesting the user to stand facing the vehicle Hv, it is expected that the reflected waves can be suppressed while the intensity of the direct waves is increased. The instruction / request to the user may be implemented by image display or audio output.

[0134] The strength measurement process at the inner set position may include observing the reception strength when the user device 9 is placed at the inner set position in different orientations. For example, the strength measurement process at the inner set position may be performed in a pattern in which the user device 9 is placed in a first inner orientation and a pattern in which the user device 9 is placed in a second inner orientation. The first inner orientation may be an orientation in which the screen of the user device 9 is facing upward. The second inner orientation may be an orientation in which the screen of the user device 9 is facing downward.

[0135] Furthermore, the number of inner set positions is not limited to one. A first inner set position and a second inner set position may be set in the smart ECU 2. When the first inner set position is on the center console, the second inner set position may be in the center of the rear seat, or the like. The second inner set position may be in the trunk.

[0136] As described above, the processor 21 may calculate the correction value by averaging the reception strength measured under a plurality of measurement conditions in which the physical states (positions / postures) of the user device 9 are different. With this configuration, the accuracy of the correction value can be improved.

[0137] In the above, the outer correction value is determined based on the reception strength observed at the outer anchor when the user device 9 is placed at a predetermined position outside the vehicle (for example, the second outer set position), but this is not limiting. The outer correction value may be determined based on the reception strength observed when the user device 9 is present at any location outside the vehicle. However, the reception strength may attenuate depending on the distance between the communication devices. If the device position is not specified in the outer strength measurement process due to such circumstances, the processor 21 may correct the reception strength based on the distance measurement value. The processor 21 may determine the outer correction value based on the reception strength at the outer anchor corrected based on the distance measurement value.

[0138] In the above, the inner correction value is determined based on the reception strength observed at the inner anchor when the user device 9 is placed at a predetermined position (e.g., the inner set position) in the vehicle, but the present invention is not limited to this. The inner correction value may be determined based on the reception strength observed when the user device 9 is located at any position in the vehicle.

[0139] The smart ECU2 (i.e., the processor 21) may be configured to transmit a characteristic report to a predetermined server via cellular communication based on the execution of the characteristic learning process. The characteristic report is a data set including characteristic data of the user device 9. The characteristic report may include, in addition to the characteristic data, vehicle model information of the vehicle Hv and model information of the user device 9. The server may be a server managed by a vehicle manufacturer or an entity providing a car sharing service. The server may be referred to as a center. Note that the user device 9 may transmit the characteristic report instead of the processor 21. The user device 9 may be configured to acquire the characteristic data from the smart ECU2 via SRWC.

[0140] The server may statistically generate correction values according to the combination of vehicle type and model based on the characteristic reports received from multiple smart ECUs 2 or user devices 9, and distribute them to the user devices 9. For example, the server may generate various correction values for the combination by averaging the characteristic data shown in the multiple characteristic reports in the same combination of vehicle type and model. According to such a configuration, the accuracy of the correction values can be improved. Further, according to the configuration in which the server generates and distributes the correction values as described above, it may be possible to register characteristic data even in the user devices 9 / smart ECUs 2 in which the characteristic learning process has not been implemented. Furthermore, when the server is a server for a car-sharing service, the server may pre-distribute correction values suitable for the combination of the user device 9 and the service car to the vehicle reserved by the user. According to the system, the position determination accuracy can be improved even in a vehicle that the user uses for the first time. As a result, the convenience of the user may be enhanced.

[0141] <CS ranging> Here, CS ranging will be supplemented. The CS ranging process includes a step of collecting the received phase for each channel, a step of calculating the phase change coefficient from the received phase for each channel, and a step of calculating data indicating the distance (that is, the ranging value) from the phase change coefficient.

[0142] The received phase for each channel may be collected by the anchor 3 and the user device 9 transmitting and receiving CW signals while switching the channels in order. The anchor 3 and the user device 9 may collect the received phases in all channels available in SRWC, or may collect the received phases in a predetermined number (for example, 10) of channels.

[0143] The phase change coefficient is a parameter indicating the degree to which the reception phase changes according to the change in frequency. The phase change coefficient can also be called the phase change degree, the phase shift amount, or the correlation coefficient between phase and frequency. The anchor 3 may calculate a regression line indicating the relationship between the frequency and the reception phase based on the reception phase for each channel, and may adopt the slope of the regression line as the phase change coefficient. This is because the slope of the regression line indicates the amount of change in the reception phase relative to the amount of shift in the frequency. The regression line and its slope can be calculated by various methods, such as the least squares method. The anchor 3 may calculate the phase difference, the differential frequency, and the phase change degree for each combination of frequencies for which the reception phase can be observed. The anchor 3 may adopt the average value or median value of the phase change degree for each combination of frequencies as the phase difference change coefficient. The phase difference is the difference between the reception phases observed at two frequencies. The differential frequency is the difference between the two frequencies, and the phase change degree is the value obtained by dividing the phase difference by the differential phase difference. The phase change coefficient corresponds to a parameter obtained by averaging the phase change degrees in multiple combinations of frequencies. The phase change degree and the phase change coefficient correspond to the amount of phase angle displacement caused by a change in the frequency used.

[0144] Calculating the distance measurement value from the phase change coefficient may be performed using the following relational expressions. There is a relationship of D∝C·Δφ / (2π·Δf) between the device distance (D), the differential frequency (Δf), and the phase difference (Δφ). There is a relationship of α=Δφ / Δf between the phase change coefficient (α), the differential frequency (Δf), and the phase difference (Δφ). From the above relations, the anchor 3 can calculate the device distance using D=k·C·α / 2π. The parameter "C" in the formula indicates the propagation speed of radio waves (3×10^8 m / sec). The parameter "k" is a design value and is set to 1.0 or 0.5. When D is the one-way distance, k=0.5 may be set. When D is the round-trip distance, k=1 may be set.

[0145] The anchors 3 may individually transmit and receive CW signals to and from the user device 9 to detect the reception phase for each channel, or may collect the reception phase for each channel by utilizing a sniffer (sniffing) technique. Sniffing / sniffing is a technique in which the anchors 3 eavesdrop on the communication between the user device 9 and the gateway module using channel information provided by the gateway module. The gateway module is one of the SRWC modules mounted on the vehicle Hv that is responsible for bidirectional communication with the user device 9. The gateway module may be a wireless communication module 24. The channel information is information indicating a channel used for data communication between the gateway module and the user device 9. The channel information may be a specific channel number, or may be a parameter (so-called hop increment) indicating a transition rule of the channel in use. The channel information preferably includes a currently used channel number and a hop increment.

[0146] In short-distance communication such as Bluetooth LE, frequency hopping is performed after communication connection, so that normally only the gateway module connected to the communication can capture the data signal from the user device 9. In contrast, according to the sniffing technology, channel information is deployed to each anchor 3, so that the anchor 3 can also capture the data signal from the user device 9. This is because the anchor 3 can recognize which channel out of many channels available in a short distance can be received to receive the signal from the user device 9 by referring to the channel information. As a result, the anchor 3 can detect the reception strength, reception phase, reception time, etc. of the signal from the user device 9 without communication connection. Therefore, according to the configuration to which the sniffing technology is applied, there is an advantage that multiple SRWC modules can calculate the distance measurement value and detect the reception strength in parallel. Although this supplement has been described as a mode in which the anchor 3 calculates the distance measurement value, the processor 21 may collect reception phase information for each channel from the anchor 3 and calculate the distance measurement value.

[0147] <Communication method> The method of data communication between the user device 9 and the smart ECU 2 is not limited to Bluetooth LE, and may be Bluetooth Classic, Wi-Fi (registered trademark), EnOcean (registered trademark), Zigbee (registered trademark), etc. The wireless protocol used for data communication (communication connection) may be referred to as a first wireless protocol, and the wireless protocol used for ranging communication may be referred to as a second wireless protocol.

[0148] The ranging communication may be performed using a communication method other than Bluetooth LE. For example, the anchor 3 may be configured to be able to perform the ranging communication by UWB communication. The UWB communication is wireless communication of the UWB-IR (Ultra-Wide Band - Impulse Radio) method. The anchor 3 and the user device 9 may be configured to be able to transmit and receive impulse-shaped radio waves (hereinafter, impulse signals) used in the UWB communication. The impulse signal used in the UWB communication may be a signal having a very short pulse width (e.g., 2 ns) and a bandwidth (i.e., ultra-wide bandwidth) of 500 MHz (strictly speaking, 499.2 MHz) or more. The UWB signal in the following description may be interpreted as a signal exchanged in the UWB communication.

[0149] <Additional remarks (1)> The present disclosure also includes the following technical ideas. In addition, a method, a program, and a computer-readable recording medium storing a program corresponding to the following technical ideas are also included in the scope of the present disclosure.

[0150] [Technical thought 1] a communication device (3) configured to be capable of wireless communication with a portable device used by a user of the vehicle in a predetermined communication method; a control unit (2) that determines a position of the portable device relative to the vehicle based on a reception strength of a signal from the portable device received by the communication device, The control unit is a threshold value storage unit (M2) in which a threshold value for the reception strength for determining the position of the mobile device, the threshold value being designed based on communication characteristics of a predetermined reference device, is registered; A characteristic data storage unit (M3) for storing data indicating communication characteristics of the portable device, The control unit is acquiring the reception strength from the communication device; generating characteristic data indicating a difference in communication characteristics between the portable device and the reference device based on the reception intensity detected when the portable device is placed at a predetermined position, and storing the generated characteristic data in the characteristic data storage unit; and determining a location of the mobile device based on the characteristic data stored in the characteristic data storage unit, the reception strength detected by the communication device, and the threshold value. The above-mentioned predetermined position does not indicate a pinpoint location, but may be a predetermined area having a diameter of about 0.5 m. The above-mentioned predetermined position may be inside or outside the vehicle. The above-mentioned threshold value may be a starting intensity or a threshold value used for inside / outside determination such as an interior determination intensity.

[0151] [Technical thought 2] The communication device is an inner communication device (3p, 3q) that is a communication device arranged inside the vehicle, the predetermined position is a predetermined position inside the vehicle, The communication method is a communication method capable of using a plurality of frequencies, The control unit is obtaining the reception strength at a plurality of the frequencies from the inside communication device; Calculating an average value of the reception strength for each of the frequencies; The position determination system according to technical idea 1 is configured to perform the steps of: generating the characteristic data based on the average value.

[0152] [Technical thought 3] The control unit is acquiring a reception strength for each of the frequencies in a situation where the portable device is placed at the predetermined position in a first attitude; acquiring a reception strength for each of the frequencies in a situation where the portable device is placed at the predetermined position in a second attitude different from the first attitude; generating the characteristic data based on an average of the reception strength for each frequency acquired when the portable device is placed at the specified position in the first attitude and the reception strength for each frequency acquired when the portable device is placed at the specified position in the second attitude.

[0153] [Technical thought 4] The communication device includes a plurality of inner communication devices (3p, 3q) arranged in the vehicle; The control unit is acquiring the reception strength for each of the frequencies detected by each of the inside communication units while the portable device is placed at the predetermined position; The position determination system described in Technical Idea 2 or 3 is configured to carry out the steps of: generating the characteristic data based on the average value of the reception strength for each of the frequencies detected by each of the multiple inside communication devices.

[0154] [Technical thought 5] The communication device is an inner communication device (3p, 3q) that is a communication device arranged inside the vehicle, the predetermined position is a predetermined position inside the vehicle, The control unit is Based on signals from on-board sensors, it determines whether there are passengers in the vehicle, A position determination system described in any one of technical ideas 1 to 4, configured to cause the communication device to perform wireless communication to generate the characteristic data when it is determined that there are no occupants in the vehicle.

[0155] [Technical Thought 6] The communication device is an inner communication device (3p, 3q) that is a communication device arranged inside the vehicle, the predetermined position is a predetermined position inside the vehicle, The control unit is determining whether all doors of the vehicle are closed based on signals from an on-board sensor; determining whether the portable device is placed at the predetermined position based on a signal from an in-vehicle sensor, an input device installed in the vehicle, the portable device, or the communication device; A position determination system described in any one of technical ideas 1 to 5, configured to cause the communication device to perform wireless communication to generate the characteristic data when it is determined that all of the doors are closed and the portable device is placed at the specified position.

[0156] [Technical Thought 7] A position determination system described in any one of technical ideas 1 to 6, wherein the characteristic data is data indicating the difference between an expected value of the receiving strength of the signal transmitted from the reference device and the receiving strength of the signal transmitted from the mobile device.

[0157] [Technical Thought 8] The communication device includes an outer communication device (3a) that is a communication device disposed on an outer surface of the vehicle, the predetermined position is a predetermined position outside the vehicle, The control unit is A position determination system as described in any one of Technical Ideas 1 to 7, configured to generate the characteristic data based on the reception strength of a signal corresponding to a direct wave, among the reception strengths detected when the system is placed at the specified position.

[0158] [Technical Thought 9] The control unit is acquiring the reception intensity of the direct wave in a situation where the portable device is placed at the predetermined position in a different posture; The position determination system according to Technical Idea 8, wherein the position determination system is configured to execute the steps of: generating the characteristic data based on the maximum value of the reception strength for each of the postures.

[0159] [Technical Thought 10] the communication unit includes a plurality of exterior communication units disposed on an exterior surface of the vehicle; The control unit is acquiring the reception strength of the direct wave detected by each of the plurality of outside communication devices while the portable device is placed at the predetermined position; A position determination system as described in Technical Idea 8 or 9, which is configured to carry out the steps of: generating the characteristic data based on the maximum value of the receiving strength of the direct wave detected by each of the multiple outer communication devices.

[0160] [Technical Thought 11] The control unit is causing the outside communication device to perform distance measurement communication, which is wireless communication for measuring a distance between the outside communication device and the portable device; obtaining, from the outside communication device or the portable device, a distance measurement value indicating a distance from the outside communication device to the portable device as a result of the distance measurement communication; correcting the reception intensity based on the distance measurement value and the characteristic data; and generating the characteristic data using the corrected reception strength.

[0161] <Additional remarks (2)> The various flowcharts shown in this disclosure are merely examples, and the number of steps constituting the flowcharts and the order of execution of the processes can be changed as appropriate. The controls shown in each flowchart may be combined / executed in parallel to the extent that there is no contradiction. Expressions such as acquisition, determination, detection, generation, and calculation may be used interchangeably. When a certain device acquires certain data, it also includes the device generating the data based on a signal input from another device / sensor.

[0162] The apparatus, system, and methods described herein may be realized by a dedicated computer comprising a processor programmed to execute one or more functions embodied in a computer program. The apparatus and methods described herein may be realized by a dedicated hardware logic circuit. The apparatus and methods described herein may be realized by one or more dedicated computers configured by a combination of a processor that executes a computer program and one or more hardware logic circuits. The processor may be any computing core, such as a CPU, an MPU, a GPU, or a DFP (Data Flow Processor). The processor of the present disclosure may be understood as a device that executes a predetermined process based on an input signal and generates and outputs a signal / data different from the input signal. Some or all of the functions of the smart ECU may be realized by any of a system-on-chip (SoC), an integrated circuit (IC), and a field-programmable gate array (FPGA).

[0163] The computer program includes instructions to be executed by a computer. The computer program may be stored in a computer-readable non-transitive tangible storage medium. The storage medium for the computer program may be a variety of media, such as a hard-disk drive (HDD), a solid-state drive (SSD), or a flash memory. [Explanation of symbols]

[0164] 1 Vehicle-mounted system, 2 Smart ECU (control unit), 3 Anchor (communication device), 3a Outer communication device, 3b Outer communication device, 3c Outer communication device, 3p Inner communication device, 3q Inner communication device, 24 Wireless communication module, M1 Reference value storage unit, M2 Threshold value storage unit, M3 Characteristics data storage unit

Claims

1. A communication device (3) configured to be capable of wireless communication with a portable device used by a user of the vehicle in a predetermined communication method; a control unit (2) that determines a position of the portable device relative to the vehicle based on a reception strength of a signal from the portable device received by the communication device, The control unit is a threshold value storage unit (M2) in which a threshold value for the reception strength for determining the position of the mobile device, the threshold value being designed based on communication characteristics of a predetermined reference device, is registered; a characteristic data storage unit (M3) for storing data indicating communication characteristics of the portable device; The control unit is acquiring the reception strength from the communication device; generating characteristic data indicating a difference in communication characteristics between the portable device and the reference device based on the reception intensity detected when the portable device is placed at a predetermined position, and storing the generated characteristic data in the characteristic data storage unit; and determining a location of the mobile device based on the characteristic data stored in the characteristic data storage unit, the reception strength detected by the communication device, and the threshold value.

2. The communication device is an inner communication device (3p, 3q) that is a communication device arranged inside the vehicle, the predetermined position is a predetermined position inside the vehicle, The communication method is a communication method capable of using a plurality of frequencies, The control unit is obtaining the reception strength at a plurality of the frequencies from the inside communication device; Calculating an average value of the reception strength for each of the frequencies; and generating said characteristic data based on said average value.

3. The control unit is acquiring a reception strength for each of the frequencies in a situation where the portable device is placed at the predetermined position in a first attitude; acquiring a reception strength for each of the frequencies in a situation where the portable device is placed at the predetermined position in a second attitude different from the first attitude; 3. The position determination system of claim 2, further comprising: a receiving strength for each frequency acquired when the mobile device is placed at the specified position in the first attitude; and a receiving strength for each frequency acquired when the mobile device is placed at the specified position in the second attitude.

4. The communication device includes a plurality of inner communication devices (3p, 3q) arranged in the vehicle; The control unit is acquiring the reception strength for each of the frequencies detected by each of the inside communication units while the portable device is placed at the predetermined position; 3. The position determination system of claim 2, further comprising: a first communication unit configured to receive the first and second signals from the first and second communication units;

5. The communication device is an inner communication device (3p, 3q) that is a communication device arranged inside the vehicle, the predetermined position is a predetermined position inside the vehicle, The control unit is Based on signals from on-board sensors, it determines whether there are passengers in the vehicle, The position determination system according to claim 1 , further configured to cause the communication device to perform wireless communication for generating the characteristic data when it is determined that no occupant is present in the vehicle.

6. The communication device is an inner communication device (3p, 3q) that is a communication device arranged inside the vehicle, the predetermined position is a predetermined position inside the vehicle, The control unit is determining whether all doors of the vehicle are closed based on signals from an on-board sensor; determining whether the portable device is placed at the predetermined position based on a signal from an in-vehicle sensor, an input device installed in the vehicle, the portable device, or the communication device; 2. The position determination system of claim 1, further configured to cause the communicator to perform wireless communication to generate the characteristic data when it is determined that all of the doors are closed and the portable device is located at the predetermined location.

7. The position determination system according to claim 1 , wherein the characteristic data is data indicating a difference between an expected value of a reception strength of a signal transmitted from the reference device and the reception strength of a signal transmitted from the mobile device.

8. The communication device includes an outer communication device (3 a) that is a communication device disposed on an outer surface of the vehicle, the predetermined position is a predetermined position outside the vehicle, The control unit is 2. The position determination system according to claim 1, configured to generate the characteristic data based on the reception strength of a signal corresponding to a direct wave, among the reception strengths detected when the system is placed at the specified position.

9. The control unit is acquiring the reception intensity of the direct wave in a situation where the portable device is placed at the predetermined position in a different posture; The position determination system according to claim 8 , further comprising: a step of: generating the characteristic data based on a maximum value of the reception strength for each of the attitudes.

10. the communication unit includes a plurality of exterior communication units disposed on an exterior surface of the vehicle; The control unit is acquiring the reception strength of the direct wave detected by each of the plurality of outside communication devices while the portable device is placed at the predetermined position; The position determination system according to claim 8, further configured to generate the characteristic data based on a maximum value of the reception strength of the direct wave detected by each of the plurality of outer communication devices.

11. The control unit is causing the outside communication device to perform distance measurement communication, which is wireless communication for measuring a distance between the outside communication device and the portable device; obtaining, from the outside communication device or the portable device, a distance measurement value indicating a distance from the outside communication device to the portable device as a result of the distance measurement communication; correcting the reception intensity based on the distance measurement value and the characteristic data; and generating said characteristic data using said corrected received strength.

12. acquiring a reception strength of a signal from a portable device from a communication device configured to be able to perform wireless communication with the portable device in a predetermined communication method; accessing a threshold storage unit (M2) in which a threshold for the reception strength for determining the position of the mobile device, the threshold designed based on a communication characteristic of a predetermined reference device, is registered, and reading out the threshold from the threshold storage unit; generating characteristic data indicating communication characteristics of the portable device based on the received signal strength detected when the portable device is placed in a predetermined position; storing the generated characteristic data in a characteristic data storage unit (M3); determining a location of the mobile device based on the characteristic data stored in the characteristic data storage unit, the reception strength detected by the communication device, and the threshold value.

Images