POSITION DETERMINATION DEVICE, POSITION DETERMINATION METHOD AND ELECTRONIC VEHICLE KEY SYSTEM

Abstract

An intelligent ECU transmits audio signals, each containing a transmitter number that identifies the signal source, from audio transmitters and measures the distance to a smart key using a Bluetooth Low Energy (BLE) communication device. The smart key transmits a BLE signal, indicating the audio signal strength of a given transmitter source, to the intelligent ECU at a predetermined time. The intelligent ECU stores a map indicating combinations of distances and audio signal strengths that can be observed when the smart key is within a predetermined area, such as near a vehicle door or inside a vehicle passenger compartment. The intelligent ECU compares the actually observed distance and audio signal strength values ​​with the contents of the map to determine whether the smart key is present in a target area.

Description

Cross-reference to the relevant application

[0001] This application is based on and claims priority from Japanese Patent Application No. 2021-207406 filed on December 21, 2021, the contents of which are hereby incorporated by reference. Technical area

[0002] The present invention relates to techniques for determining a position of a mobile vehicle device carried by a user relative to a vehicle based on a reception condition of a wireless signal transmitted from the mobile vehicle device. State of the art

[0003] Patent Literature 1 discloses an electronic key system for a vehicle that determines the position of a mobile vehicle device relative to the vehicle through communication between an in-vehicle device and the mobile vehicle device using radio waves in the low frequency band (ie, LF band). Specifically, a configuration is disclosed in which an in-vehicle device transmits a response request signal using LF band radio waves from a transmitter disposed in a driver's door and determines that the mobile vehicle device is present in a lock-unlock range based on receiving a response signal to the response request signal.The lock / unlock zone is the area in which the vehicle's onboard system locks or unlocks the vehicle's doors. It is an area outside the vehicle's passenger compartment and within a predetermined distance of the doors. The mobile vehicle device is a dedicated device that serves as a vehicle key and may also be referred to as a key fob, smart key, key card, or similar.

[0004] In an electronic vehicle key system, in a situation where a user is more than a certain distance from the vehicle (for example, 2 meters), it is required, for example, for theft prevention purposes, that automatic door unlocking through wireless communication with the vehicle mobile device is not performed according to a system requirement. For security reasons, the above-mentioned locking / unlocking range is often set to a range within 2 meters of the vehicle, for example, one meter from the doors.

[0005] In many electronic vehicle key systems or vehicle positioning systems, low-frequency radio waves are used to transmit signals from the vehicle to the mobile vehicle device, as the range of wireless signals is easily limited to the vicinity of the vehicle. For example, an antenna for transmitting low-frequency radio waves in the vehicle is adjusted in its transmission power to ensure that the wireless signal reaches only the locking / unlocking range. State of the art literaturePatent literature

[0006] Patent literature 1: JP 5 438 048 B2 Summary of the invention

[0007] In a positioning method using low-frequency signals, a relay attack may be a problem. A relay attack is a method of illegally unlocking a vehicle by relaying an low-frequency signal to a mobile device located away from the vehicle using a repeater, thereby forcing the mobile device to send back a response signal. To address this problem, techniques are considered that measure a distance to the mobile device by having a specific communication device perform distance measurement communication with the mobile device. If the measured distance value is below a determination value, the mobile device is determined to be within the locking-unlocking range.The determination value is a parameter for the measured distance value for determining that a mobile device is present within a predetermined range, such as a locking-unlocking range. The measured distance value is a parameter indicating the measurement result of the distance to the mobile device in the vehicle.

[0008] However, in the configuration under consideration, an erroneous determination may occur depending on the installation position of a communication device that performs distance measurement. The determination value must be set larger to include the lock-unlock range if the communication device is installed at a position offset from the center of the lock-unlock range, for example, on a left C-pillar of the vehicle. However, if the determination value is set larger, areas where the measured distance value is smaller than the determination value, or even outside the lock-unlock range, may increase.As a result, a case may occur where a mobile vehicle device is erroneously determined to be within the lock-unlock range when the mobile vehicle device is actually outside the lock-unlock range.

[0009] The present invention has been made in view of the above problems, and its object is to provide a positioning device, a positioning method, and a vehicle electronic key system capable of reducing a risk of erroneous determination of a position of a vehicle mobile device.

[0010] A positioning device disclosed herein is a positioning device that includes at least one processor, a first communication device for transmitting a signal in a first frequency band, and a second communication device for communicating with a mobile vehicle device using radio waves in a second frequency band different from the first frequency band. The at least one processor acquires first data indicating the reception state at the mobile vehicle device of a signal from the first communication device, acquires second data indicating the distance from the second communication device to the mobile vehicle device, and determines the location of the mobile vehicle device based on the acquired data.

[0011] According to the above configuration, the position of the mobile vehicle device is determined using not only the second data indicating the distance between the second communication device and the mobile vehicle device, but also the first data determined according to the wireless communication conditions using radio waves in a different frequency band. According to this configuration, the amount of information for determining the position of the mobile vehicle device is increased compared to a configuration in which the position is determined using only the second data. As a result, the possibility of erroneous determination of the position of the mobile vehicle device can be reduced.

[0012] A positioning method disclosed herein is a positioning method performed by at least one processor used in conjunction with a first communication device for transmitting a signal in a first frequency band and a second communication device for communicating with a mobile vehicle device using radio waves in a second frequency band different from the first frequency band. The positioning method acquires first data indicating the reception state at the mobile vehicle device of a signal from the first communication device, acquires second data indicating the distance from the second communication device to the mobile vehicle device, and determines the location of the mobile vehicle device based on the acquired data.

[0013] An electronic vehicle key system disclosed herein is an electronic vehicle key system including: a positioning device having at least one processor, a first communication device for transmitting a signal in a first frequency band and a second communication device for wireless communication using radio waves in a second frequency band different from the first frequency band, a mobile vehicle device for receiving the signal from the first communication device and performing wireless communication using the second frequency band, and a mobile terminal for wireless communication using the second frequency band.The mobile vehicle device activates upon receiving a signal in the first frequency band, establishes a wireless communication link with the positioning device using the second frequency band, transmits data indicating the reception strength of the signal in the first frequency band, transmits a code indicating that the device type is the mobile vehicle device, and performs a distance measurement with the second communication device. The mobile terminal performs processing related to the communication link, performs a distance measurement with the second communication device, and transmits a code indicating that the device type is not the mobile vehicle device.The positioning device acquires second data indicating the distance from the second communication device to the communication partner, acquires a signal indicating the device type of the communication partner, determines whether the device type corresponds to the mobile vehicle device, acquires first data indicating the reception state of the mobile vehicle device, and determines the location of the mobile vehicle device based on the acquired data.

[0014] The positioning method and the electronic vehicle key system described above have the same functions as the positioning device and can thus achieve the same effects as the positioning device. Short description of the drawings Fig. 1 is a block diagram illustrating a configuration of an in-vehicle system. Fig. 2 is a block diagram illustrating a configuration of a smart key. Fig. 3 is a block diagram illustrating a configuration of a mobile terminal. Fig. Figure 4 is a diagram showing an example of installation positions of BLE communication devices and LF transmitting devices. Fig. 5 is a block diagram illustrating a configuration of a BLE communication device. Fig. 6 is a functional block of an intelligent ECU. Fig. Figure 7 is a diagram to explain a strength map. Fig. Figure 8 is a schematic diagram showing an example of the strength map. Fig. Figure 9 is a flowchart showing an example of a map generation process. Fig. 10 is a flowchart illustrating an example of a vehicle control process. Fig. 11 is a flowchart showing an example of a positioning process when the communication partner is a smart key. Fig. 12 is a flowchart showing an example of a positioning process when the communication partner is a mobile terminal. Fig. 13 is a diagram for explaining effects of determining a device position using the strength map when the communication partner is the smart key. Fig. 14 is a diagram illustrating a modification of installation positions of BLE communication devices and LF transmitting devices. Fig. 15 is a flowchart illustrating an example of operation of a processor in response to a communication partner. Fig. 16 is a diagram illustrating another modification of installation positions of BLE communication devices and LF transmitting devices. Detailed description

[0015] An embodiment of the present invention will be described below with reference to the drawings. Fig. 1 is a diagram illustrating an example of a schematic configuration of an electronic vehicle key system. As shown in Fig. As shown in Figure 1, the electronic vehicle key system includes an in-vehicle system 1 and a smart key 2. The electronic vehicle key system also includes one or more mobile terminals 3 as optional elements. The in-vehicle system 1 is a system mounted on a vehicle Hv. The smart key 2 is a dedicated device serving as an electronic key for the vehicle Hv. The mobile terminal 3 is a universal information processing terminal carried by a user of the vehicle Hv. Introduction

[0016] For example, in the following description, the vehicle Hv is a vehicle owned by an individual. A user of the vehicle Hv refers to an owner, a family of the owner, or the like. The vehicle Hv can be a company vehicle of a corporate organization or a public vehicle of a public institution. If the vehicle Hv is a company vehicle or a public vehicle, the user can be a person belonging to an organization that manages the vehicle Hv. Furthermore, the vehicle Hv can be a vehicle provided for a vehicle rental service (so-called rental vehicle) or a vehicle provided for a car sharing service (so-called shared vehicle). The vehicle Hv can be a vehicle provided for a passenger transportation service, such as a robotaxi.If the vehicle Hv is a vehicle provided for the above services (hereinafter referred to as a service vehicle), a person who has a contract to use these services and an authority or authorization to temporarily use the vehicle Hv based on a reservation of the services or the like may be a user.

[0017] For example, the vehicle Hv is a vehicle with an internal combustion engine. The vehicle with an internal combustion engine refers to a vehicle that includes only an internal combustion engine as a power source. The vehicle with an internal combustion engine also includes a diesel vehicle. Alternatively, the vehicle Hv may be a vehicle with an electric motor. The vehicle with an electric motor includes a hybrid vehicle and a fuel cell vehicle in addition to an electric vehicle. The electric vehicle is a vehicle that includes only an electric motor as a power source. The hybrid vehicle is a vehicle that includes both an internal combustion engine and an electric motor as power sources. The hybrid vehicle includes a plug-in hybrid vehicle. The vehicle Hv may be a vehicle that has a driver's seat door and may be mounted or arranged on various vehicles capable of traveling on a road, for example, on or near a highway.on a trailer, a tanker or an open car.

[0018] The vehicle Hv here is a vehicle having a driver's seat on a right side. Alternatively, the vehicle Hv may be a vehicle having a driver's seat on the left side. The front-rear, left-right, and up-down directions indicated below are defined based on the vehicle Hv if there is no indication regarding a reference direction (i.e., fundamental). Each of the various flowcharts shown here is only an example, and the number of steps constituting the flowchart and the execution order of the processes may be appropriately changed. Furthermore, the following description may be appropriately modified so that it conforms to the regulations and conventional practice of the region in which the vehicle Hv is used. Overview

[0019] The in-vehicle system 1, the smart key 2, and the mobile terminal 3 are capable of short-range communication. Short-range communication refers to communication in accordance with a predetermined short-range wireless communication standard, according to which a substantially communicable distance is, for example, about 5 m to 30 m, and a maximum communicable distance is about 100 m. A method of short-range communication may be Bluetooth (registered trademark), Wi-Fi (registered trademark), or the like. The Bluetooth standard may be Bluetooth Classic or Bluetooth Low Energy (ie, BLE). A variety of Wi-Fi standards may be used, including IEEE802.11n, IEEE802.11ac, and IEEE802.11ax. IEEE (registered trademark) is an abbreviation for Institute of Electrical and Electronics Engineers and refers to the American Institute of Electrical Engineers.Furthermore, as a communication method between the in-vehicle system 1 and the mobile terminal 3, in other words, as a short-distance communication method, ultra-wideband pulse radio (UWB-IR) using a frequency band of 3 GHz or higher can be used. Short-distance communication is performed using high-frequency radio waves. In the present invention, the high-frequency radio waves are radio waves of 900 MHz or higher, for example, 2.4 GHz. The high-frequency radio waves of the present invention are not limited to radio waves of 1 GHz or higher, and include radio waves in the sub-gigahertz band, such as 920 MHz.

[0020] Hereinafter, the operation of the respective parts will be described, using a case where the on-vehicle system 1, the smart key 2, and the mobile terminal 3 each perform wireless communication according to the BLE standard (hereinafter referred to as BLE communication) as a short-range communication, as an example. In the present invention, a wireless signal transmitted and received in BLE communication is also referred to as a BLE signal. The BLE signal transmitted from the smart key 2 or the mobile terminal 3 to the on-vehicle system 1 includes a device ID (i.e., identification) as information indicating a transmission source.

[0021] A case will be described where the on-vehicle system 1 is designated as a master of communication with the mobile terminal 3, and the mobile terminal 3 is designated as a slave. According to another aspect, the mobile terminal 3 may be designated as the master in communication with the on-vehicle system 1.

[0022] The in-vehicle system 1 and the smart key 2 are capable of wireless communication using radio waves in the AF band, such as 125 kHz or 134 kHz. That is, the in-vehicle system 1 is configured to transmit an AF signal having a predetermined frequency in the AF band, and the smart key 2 is configured to receive the AF signal. In this example, the AF band refers to a frequency band of 300 kHz or less and includes a frequency of 20 kHz to 30 kHz or so. The smart key 2 returns response data corresponding to the received AF signal to the in-vehicle system 1 via BLE communication.

[0023] The smart key 2 and the mobile terminal 3 are devices that hold key information for using the vehicle Hv, and serve as an electronic key for the vehicle Hv using the key information. The key information is data used in an authentication process described later. The key information is data for confirming that the person attempting to access the vehicle Hv is the user, that is, a validity of the person attempting to access the vehicle Hv. The key information may be referred to as an authentication key, encryption key, or key code. The key information may be, for example, a character string (value) encrypted into a predetermined hash function by inputting a password set by the user.The key information can be generated based on a device ID. In the present invention, the smart key 2 and the mobile terminal 3 are collectively referred to as the key device Kd. The following description of the key device Kd can be replaced with that of the smart key 2 or the mobile terminal 3.

[0024] The key information may be different for each key device Kd. In the on-vehicle system 1, key information for each key device Kd is stored and registered in association with a device ID. The key device Kd may be distinguished by a key ID assigned by the vehicle Hv in the order of registration, instead of by the device ID. The device ID is expressed in a length of approximately 48 bits or 128 bits, whereas the key ID may be expressed in a few bytes, for example, 1 byte. Smart Key 2

[0025] The smart key 2 is a dedicated device for the user to operate the vehicle Hv. The smart key 2 is a device provided to the owner together with the vehicle Hv upon purchase of the vehicle Hv. The smart key 2 is essentially the property of the owner. The smart key 2 can be considered an accessory of the vehicle Hv. The smart key 2 can have various shapes, such as a flat rectangular parallelepiped shape, a flat elliptical shape (so-called fob type), or a card shape. The smart key 2 can be referred to as a mobile vehicle device, key fob, key card, access key, or the like.

[0026] As it is in Fig. 2, the smart key 2 includes a key control unit 20, an operation unit 21, an LF reception unit 22, a BLE communication unit 23, and an internal battery 24.

[0027] The operation unit 21 is an element for receiving a user operation of the smart key 2. The operation unit 21 may be a push button switch or the like. The operation unit 21 may include a plurality of switches. For example, the operation unit 21 may include a lock switch, which is a switch for locking the doors of the vehicle Hv, and an unlock switch, which is a switch for unlocking the doors of the vehicle Hv. The smart key 2 wirelessly transmits a remote control signal corresponding to a switch operated by a user to a smart ECU 4 to create a so-called remote keyless entry system configured to perform control such as locking or unlocking vehicle doors.

[0028] The AF receiving unit 22 receives an AF signal. The AF receiving unit 22 may use an antenna for receiving the AF signal or a circuit (so-called demodulation circuit) for demodulating the received signal. The AF receiving unit 22 extracts data contained in the received signal by performing predetermined processing such as analog-to-digital conversion, demodulation, and decoding of the signal received by the antenna. The extracted data is provided to the key control unit 20. The AF receiving unit 22 outputs, in addition to the received data, data indicating a reception strength of the AF signal transmitted from the on-vehicle system 1 to the key control unit 20. A signal indicating the reception strength or its measured value may also be referred to as a received signal strength indicator (i.e., RSSI).In the present invention, the reception strength of the LF signal detected by the smart key 2 is also referred to as LF strength or LF_RSSI.

[0029] The BLE communication unit 23 is a communication module for BLE. The BLE communication unit 23 operates under the control of the key control unit 20. An operating state of the BLE communication unit 23 is switched, for example, by the key control unit 20. The BLE communication unit 23 has an active state in which it is capable of transmitting and receiving announcement signals and the like, and an inactive state in which it is unable to transmit and receive BLE signals. The inactive state may be a power-free state. The internal battery 24 is a power source that supplies electrical power for operations of the smart key 2. The internal battery 24 is a primary battery such as a lithium battery.

[0030] The key control unit 20 includes a microcontroller having a central processing unit (i.e., CPU) 201 and a memory 202. The key control unit 20 can be implemented using an integrated circuit (i.e., IC) or a field-programmable gate array (i.e., FPGA). The memory 202 stores information related to a key. The information related to a key includes key information and the vehicle ID associated with the smart key 2.

[0031] The key control unit 20 is activated when the LF receiving unit 22 receives a wake-up signal with a strength equal to or greater than a predetermined threshold, and causes the entire smart key 2 to transition from the sleep mode to the active mode. The active mode is an operation mode in which BLE communication is possible and corresponds to an operation mode in which the BLE communication unit 23 is placed in an active state. The sleep mode is an operation mode in which power consumption is reduced by restricting the functions that can be executed compared to the active mode. The sleep mode corresponds to an operation mode in which the BLE communication unit 23 is placed in an inactive state.

[0032] Furthermore, the key control unit 20 is capable of transitioning from the sleep mode to the active mode when the operation unit 21 is operated, as compared to when the wake-up signal is received. That is, the key control unit 20 activates the BLE communication unit 23 when triggered by receiving the wake-up signal or a user operation of the operation unit 21. In the active mode, when a state in which no communication link with the on-vehicle system 1 is detected continuously continues for a given period of time, and when a state in which the operation unit 21 is not operated continuously continues for a given period of time, the key control unit 20 puts the smart key 2 into the sleep mode.

[0033] In the active mode, the key control unit 20 acquires information indicating a communication connection state with the on-vehicle system 1 and received data from the on-vehicle system 1 from the BLE communication unit 23. When the BLE communication unit 23 receives a challenge code, the key control unit 20 generates a response code using the key information stored in the memory 202 and causes the BLE communication unit 23 to transmit the response code. The key control unit 20 also causes the BLE communication unit 23 to transmit a control signal corresponding to an operation content of the operation unit 21 when it is operated.

[0034] The key control unit 20 stores the NF_RSSI for a specific period of time in association with information indicating the signal source (e.g., a transmitter number) when the NF receiving unit 22 receives the wake-up signal. Furthermore, the key control unit 20 causes the BLE communication unit 23 to transmit an NF strength report to the on-board system 1 based on a request from the on-board system 1 or spontaneously (periodically). The NF strength report is a BLE signal containing data indicating the NF_RSSI for each source. The NF_RSSI for each transmission source corresponds to initial data.

[0035] Even in the in-vehicle system 1 configured to allow the mobile terminal 3 to be used as an electronic key, as disclosed here, it is considered that the smart key 2 is sold or distributed as an accessory of the vehicle, as proof of ownership, or as a physical master key. It is also assumed that some users may choose, based on their preferences, to continue using the smart key 2 as a vehicle key rather than the mobile terminal 3. In other words, the in-vehicle system 1 must be able to communicate with both the smart key 2 and the mobile terminal 3. Mobile device 3

[0036] The mobile terminal 3 is a portable and universal information processing terminal that has a BLE communication function. Various communication terminals, such as a smartphone or a wearable device, can be used as the mobile terminal 3. The wearable device is a device worn and used on the user's body and can take various forms, such as a bracelet, a wristwatch, a ring, glasses, or a headset.

[0037] As it is in Fig. 3, the mobile terminal 3 includes a BLE communication unit 31 and a device control unit 32. The BLE communication unit 31 is a communication module for performing BLE communication. The device control unit 32 performs various arithmetic processes. The device control unit 32 is configured as a computer including, for example, a processor 33, a random access memory (i.e., RAM) 34, and a memory 35. A digital key application, which is an application for causing the mobile terminal 3 to serve as an electronic key for the vehicle Hv, is installed in the memory 35. In addition, the memory 35 stores the key information. Similar to the key control unit 20, the device control unit 32 also performs processes related to communication connection and authentication with the on-vehicle system 1. That is,, the device control unit 32 cooperates with the BLE communication unit 31 to periodically send out announcement signals and return response codes. Configuration of the vehicle's own system 1

[0038] The configuration and operation of the vehicle's system 1 are described below. As described in Fig. 1, the on-vehicle system 1 includes a smart ECU 4, a door knob 5, a start button 6, a BLE communication device 7, and an LF transmitting device 8. The on-vehicle system 1 also includes a power supply ECU 11, a body ECU 12, a display 13, and an input device 14. “ECU” is used as an abbreviation for electronic control unit and indicates any type of electronic control device.

[0039] The intelligent ECU 4 is connected to the door button 5, the start button 6, and the BLE communication device 7 via associated signal lines. The intelligent ECU 5 is connected to the power supply ECU 11, the body ECU 12, and the like via an in-vehicle network Nw, so that they can communicate with each other. The in-vehicle network Nw is a communication network constructed in the vehicle Hv. A standard of the in-vehicle network Nw can be any standard. The connection mode of the in-vehicle network Nw Fig. 1 is an example, and a specific connection mode of the devices may be appropriately changed.

[0040] The smart ECU 4 is an ECU that determines a device position relative to the vehicle Hv in cooperation with the BLE communication device 7 or the like and performs vehicle control according to the device position determination result. The device position of the present invention means a position of the key device Kd. Since the key device Kd is carried by the user, determining the device position is equivalent to determining the user location. The smart ECU 4 corresponds to a position determination device. The smart ECU 4 is arranged in a dashboard. The smart ECU 4 may be mounted on an interior side surface of a right or left C-pillar. The C-pillar refers to the third pillar from the front among the pillars of the vehicle Hv.

[0041] The intelligent ECU 4 is implemented using a computer. That is, the intelligent ECU 4 includes a processor 41, a RAM 42, a memory 43, an input / output (I / O) module 44, and a bus line connecting these components.

[0042] The processor 41 is hardware (in other words, an arithmetic core) for arithmetic processing, which is combined with the RAM 42. The processor 41 is, for example, a CPU. The processor 41 executes various types of processing for implementing a function of each functional unit described later by accessing the RAM 42. The RAM 42 is a volatile storage medium. The memory 43 includes a non-volatile storage medium such as a flash memory. The memory 43 stores a control program executed by the processor 41. The execution of the control program by the processor 41 corresponds to the execution of the position determination process according to the control program. The input-output module 44 is a circuit module for communicating with another device.

[0043] The device ID of each key device Kd is registered in the memory 43. The memory 43 stores communication device setting data indicating an installation position of each BLE communication device 7 in the vehicle Hv. The installation position of each BLE communication device 7 can be expressed, for example, as a point in a vehicle coordinate system, which is a two-dimensional coordinate system that has the position of the vehicle Hv as the center and is parallel to both a width direction and a front-rear direction of the vehicle Hv. An X-axis constituting the vehicle coordinate system can be set parallel to the vehicle width direction, and a Y-axis can be set parallel to the front-rear direction of the vehicle.For example, any position such as the center of a vehicle body or the installation position of the intelligent ECU 4 can be used as the center of the coordinate system. Of course, the vehicle coordinate system may be a three-dimensional coordinate system including a Z-axis parallel to the up-down direction of the vehicle. The details of the intelligent ECU 4 will be described later.

[0044] The doorknob 5 is a switch for the user to unlock and lock a door of the vehicle Hv. The doorknob 5 is arranged on an exterior door handle arranged on a respective door. The exterior door handle is a gripping element arranged on an exterior surface of the door for opening and closing the door. When the doorknob 5 is pressed by the user, it outputs an electrical signal to the smart ECU 4 indicating this fact. A touch sensor may be used as a configuration for receiving at least one unlocking instruction or a locking instruction from the user. The touch sensor may be arranged on the exterior door handle instead of the doorknob 5 or together with the doorknob 5.

[0045] The start button 6 is a push button switch for the user to turn a driving power source on / off. The driving power source is a power source for driving the vehicle Hv. The driving power source can also be referred to as an ignition power source if the vehicle is an internal combustion engine vehicle. The driving power source indicates a system main relay if the vehicle Hv is an electric vehicle or a hybrid vehicle. The start button 6 corresponds to a switch for starting a power source (for example, an internal combustion engine). When the start button 6 is pressed by the user, the start button 6 outputs an electrical signal indicating this fact to the intelligent ECU 4.

[0046] The BLE communication device 7 is a communication module for performing wireless communication with the key device Kd according to the BLE standard. At least one BLE communication device 7 is arranged in the vehicle Hv. According to one example, the on-vehicle system 1 of the present embodiment includes only a single BLE communication device 7, as shown in Fig. 4. The BLE communication device 7 is arranged, for example, on the inside surface of the left C-pillar. The location where the BLE communication device 7 is mounted is not limited to the C-pillar, but may be a B-pillar, a dashboard, a center console, an interior ceiling, an upper end of a windshield, or the like. The B-pillar refers to the second pillar from the front among the pillars of the vehicle Hv. The B-pillar may also be referred to as a center pillar. The BLE communication device 7 is connected to the smart ECU 4 via a dedicated communication line or the in-vehicle network Nw so that it can communicate with the smart ECU 4. According to another embodiment, the BLE communication device 7 may be built into the smart ECU 4. Furthermore, the BLE communication device 7 may be distributed at multiple locations in the vehicle Hv.The BLE communication device 7p corresponds to a second communication device.

[0047] The AF transmitting device 8 is a device that transmits an AF signal based on an instruction from the smart ECU 4. The AF transmitting device 8 transmits a wake-up signal based on an input signal from the smart ECU 4. The wake-up signal is an AF signal for transitioning the smart key 2 to the active mode. The AF transmitting device 8 includes an AF transmitting antenna and an AF transmitting circuit. The AF transmitting circuit is a circuit that performs predetermined signal processing such as digital-to-analog conversion, frequency conversion, or modulation. The AF transmitting device can be arranged in the smart ECU 4.

[0048] The on-vehicle system 1 of the present embodiment includes AF transmitters 8a, 8b, 8c, 8p, and 8q. The AF transmitter 8a among the AF transmitters is arranged on the outside door handle for a driver's seat. The AF transmitter 8b among the AF transmitters is arranged on the outside door handle for a passenger's seat. The AF transmitter 8c among the AF transmitters is arranged near a trunk lid. The AF transmitter 8p and the AF transmitter 8q among the AF transmitters are arranged within the vehicle passenger compartment. The AF transmitter 8p is arranged at a center of the instrument panel in the vehicle width direction or at a front portion of the driver's seat, so that the front seats are arranged in a main communication area. The LF transmitter device 8q is arranged near a seat surface or a foot area of ​​a rear seat.Each LF transmitter 8 has an assigned predetermined transmitter number. The transmitter number corresponds to information indicating a source of the LF signal. The LF transmitter 8 corresponds to a first communication device.

[0049] The power supply ECU 11 is an ECU that controls the on and off states of the driving power source mounted on the vehicle Hv. For example, the power supply ECU 11 switches the driving power source from off to on based on a command signal from the intelligent ECU 4. The power supply ECU 11 starts the internal combustion engine based on the command signal from the intelligent ECU 4 when the vehicle Hv is an internal combustion engine vehicle.

[0050] The body ECU 12 is an ECU that controls body system actuators based on a request from the smart ECU 4 or the user. The body ECU 12 is communicatively connected to various body system actuators and various body system sensors. The body system actuator is, for example, a door lock motor that forms a locking mechanism of each door. A body system sensor 192 includes a safety switch or the like arranged on each door. The safety switch is a sensor for detecting opening and closing of the door. The body ECU 12 locks or unlocks each door by outputting a predetermined control signal to a door lock motor arranged on each door of the vehicle Hv, for example, based on a request.Prompt from the intelligent ECU 4.

[0051] The display 13 is, for example, a liquid crystal display or an organic electroluminescence display. The display 13 displays an image according to an input signal from the intelligent ECU 4. The display 13 is arranged, for example, in a central area of ​​the dashboard in the vehicle width direction or a front area of ​​the driver's seat. The display 13 corresponds to an in-vehicle display.

[0052] The input device 14 is a device for receiving a user's instruction operation regarding the smart ECU 4. The input device 14 may be a touch panel (touch-sensitive surface) arranged on the display 13. The input device 14 may be a mechanical switch arranged, for example, on the instrument panel. The input device 14 outputs, as an operation signal, an electrical signal corresponding to an operation performed by the user on the smart ECU 4. The operation signal output from the input device 14 indicates an operation content of the user. The display 13 and the input device 14 correspond to an interface for an operator at a dealer or a manufacturer for registering strength card data, as described later, in the smart ECU 4.The display 13 and the input device 14 are collectively referred to as the vehicle's HMI. "HMI" is an abbreviation for human-machine interface. Configuration of the BLE communication device

[0053] As it is in Fig. As shown in Figure 5, each BLE communication device 7 includes an antenna 71, a transceiver 72, and a communication microcomputer 73. The antenna 71 is a metal body for transmitting and receiving radio waves in a frequency band used for BLE communication, e.g., a 2.4 GHz band. The antenna 71 is electrically connected to the transceiver 72. The antenna 71 may be an array antenna formed by arranging multiple antenna elements side by side. The 2.4 GHz band corresponds to a second frequency band. The 2.4 GHz band may refer to 2402 MHz to 2480 MHz (or 2495 MHz).

[0054] The transceiver 72 demodulates a signal received by the antenna 71 and provides the demodulated signal to the communication microcomputer 73. The transceiver 72 modulates a signal received from the intelligent ECU 4 via the communication microcomputer 73, outputs the modulated signal to the antenna 71, and radiates the modulated signal as radio waves. The transceiver 72 is connected to the communication microcomputer 73 so that they can communicate with each other. The transceiver 72 includes a reception strength detection unit 721 and a distance measurement processor 722 in addition to a modulator-demodulator circuit. The reception strength detection unit 721 sequentially detects the strength of signals received by the antenna 71. The reception strength detected by the reception strength detection unit 721 is stored together with the device ID indicating a transmission source.Indicates the transmission source of the received signal, and outputs frequency information of the received signal to the communication microcomputer 73. In the present invention, the reception strength of a BLE signal is also referred to as BLE_RSSI.

[0055] The distance measurement processor 722 performs distance measurement communication with the communication partner, thereby generating a distance correspondence value that indirectly indicates the distance from the BLE communication device 7 to the communication partner. The distance correspondence value is a parameter that indicates a travel time of a signal transmitted from the key device Kd until the signal is received by the BLE communication device 7. The distance correspondence value is a parameter that is different from the reception strength. More specifically, the distance correspondence value is a round-trip time (RTT) or a two-frequency phase difference. Distance measurement communication may also be referred to as communication for measuring RTT or two-frequency phase difference. The distance correspondence value indicates the signal travel time (ToF) for one path or one round trip and may therefore also be referred to as a value related to ToF.The distance corresponding value such as RTT and two-frequency phase difference correspond to the measurement distance value and second data.

[0056] The RTT is measured as the time from when a response request signal is sent to a communication partner until a response signal is received from the communication partner. The distance measurement processor 722 may use, as the RTT, a value obtained by applying a predetermined correction process, such as subtracting a presumed value of a response processing time generated by the key device Kd or a presumed value of a delay time that may be generated by the BLE communication device 7, from the elapsed time between the actual transmission and reception of the signal.

[0057] The two-frequency phase difference is a parameter specified by the BLE communication device 7 and the key device Kd that receives and transmits a CW (continuous wave) signal, and is a difference between a transmission and reception phase difference observed at respective two frequencies. The transmission and reception phase difference at a specific frequency corresponds to a phase difference between the CW signal of a target frequency transmitted to a target and the CW signal of the target frequency returned from the target.

[0058] The transmission and reception phase difference may also be simply referred to as a phase angle. The transmission and reception phase difference may be an average value or a total value of the phase differences between the transmission signal and the reception signal detected by each device when the BLE communication device 7 and the key device Kd exchange (transmit and receive) CW signals with each other. The distance measurement processor 722 may use a reception phase of the CW signal transmitted from the key device Kd without change as the transmission and reception phase difference, assuming that initial phases or local oscillators among the devices are synchronized. The initial phase or local oscillator synchronization among the devices can be achieved, for example, by transmitting a predetermined synchronization signal.The transmit and receive phase difference for each frequency, which is a source of the two-frequency phase difference, can be treated as a kind of measured distance value. The two-frequency phase difference corresponds to a shift in the transmit and receive phase difference due to a change in frequency.

[0059] Based on instructions from the smart ECU 4, the BLE communication device 7 performs distance measurement communication with the smart key 2 or the mobile terminal 3, generates a distance correspondence value, and reports it to the processor 41. In a preferred embodiment of the present embodiment, the distance measurement processor 722 calculates both the RTT and the two-frequency phase difference. The distance measurement processor 722 calculates the two-frequency phase difference for each combination of frequencies used in the BLE communication. The distance correspondence value can be generated or calculated by the communication microcomputer 73 or the smart ECU 4.The distance measurement processor 722 can identify the transmission and reception phase difference for each frequency, and the intelligent ECU 4 can calculate the two-frequency phase difference for each communication frequency based on the transmission and reception phase difference for each frequency. The functional allocation between the BLE communication device 7 and the intelligent ECU 4 can be changed as needed.

[0060] The communication microcomputer 73 is a microcontroller that controls data exchange with the smart ECU 4. The communication microcomputer 73 is implemented using a CPU, a RAM, a read-only memory (ROM), and the like. The communication microcomputer 73 provides reception data received by the transceiver 72 to the smart ECU 4 sequentially or based on a request from the smart ECU 4. Furthermore, the communication microcomputer 73 outputs data regarding the reception condition of signals from the key device Kd and distance correspondence values ​​to the smart ECU 4 either in response to a request from the smart ECU 4 or spontaneously.

[0061] The BLE communication device 7 can calculate the arrival direction of a signal from the key device Kd and output the arrival direction of the signal to the smart ECU 4 as information indicating the reception condition of the signal from the key device Kd. The arrival direction of a signal can be estimated using various methods, such as the MUSIC method or the ESPRIT method. The reception strength, phase, and arrival direction can also be referred to as reception signal characteristics. Functions of the intelligent ECU 4

[0062] The following describes the functions and operations of the intelligent ECU 4. The intelligent ECU 4 provides functions corresponding to various function blocks, which are Fig. 6 by executing a program stored in the memory 43. That is, the smart ECU 4 includes a vehicle information acquisition device F1, a communication controller F2, a positioning device F3, an authentication processor F4, and a vehicle controller F5 as functional units. The communication controller F2 includes an LF controller F21 and a BLE controller F22 as sub-functional units.

[0063] The smart ECU 4 also includes a key information storage unit M1 and a strength map storage unit M2. The key information storage unit M1 and the strength map storage unit M2 are implemented using a portion of a storage area of ​​the memory 43. The key information storage unit M1 and / or the strength map storage unit M2 may be implemented using a non-volatile storage medium that is physically independent of the memory 43. The key information storage unit M1 and the strength map storage unit M2 allow the processor 41 to write to, read from, and delete data therein.

[0064] The key information storage unit M1 is a storage medium for storing information regarding the key device Kd used as an electronic key of the vehicle Hv. In the key information storage unit M1, key information for each key device Kd is stored in association with a key ID, a device ID, a user ID, and the like. The user ID is an identifier for identifying a respective user among multiple users and is set for each user. The device type indicates whether it is a smart key 2 or a mobile terminal 3.If the vehicle Hv is a company vehicle, the smart ECU 4 may acquire the device information corresponding to a user making a reservation in advance from a digital key server that issues the key information, and store the device information in the key information storage unit M1. The key information for each user or device may be stored in association with information such as an expiration date, authorization, and seat position.

[0065] The strength map storage unit M2 is a storage medium that stores a strength map containing the NF_RSSI for each measurement point from among measurement points set at a predetermined interval at least within the lock-unlock range EA. The strength map will be described in more detail later.

[0066] The vehicle information acquisition unit F1 acquires various types of vehicle information indicating a state of the vehicle Hv and a user's operation with respect to the vehicle Hv from sensors, ECUs, switches, and the like mounted on the vehicle Hv. The vehicle information includes a state (on / off) of the driving power source, an opening and closing state of each door, a locking and unlocking state of each door, a pressing state of the door knob 5 and the start button 6, a gear position, and the like. An output value of a brake sensor detecting an operation amount or force of the brake pedal and a signal indicating an operation state of a parking brake may correspond to or constitute the vehicle information.Obtaining the electrical signals from the doorknob 5 and the start button 6 corresponds to detecting user operations with respect to these buttons. According to one aspect, the vehicle information acquisition unit F1 corresponds to a configuration that detects a user operation with respect to the vehicle Hv, for example, pressing the doorknob 5, opening or closing the door, or pressing the start button 6.

[0067] The vehicle information acquisition unit F1 acquires a current state of the vehicle Hv based on the various types of information described above. The vehicle information acquisition unit F1 determines that the vehicle Hv is parked when the driving power source is turned off and all doors are locked. A condition for determining that the vehicle Hv is parked can be appropriately designed, and various determination conditions can be used. The "acquisition" of the present invention includes generating, detecting, and / or determining by internal arithmetic based on data or the like received from another device and / or a sensor. This is because the functional arrangement in the system can be changed as needed.

[0068] The communication controller F2 is configured to control the operation of the BLE communication device 7 and the LF transmitter 8. A configuration for controlling the LF device 8 corresponds to the LF controller F21, and a configuration for controlling the BLE communication device 7 corresponds to the BLE controller F22.

[0069] The communication controller F2, together with the LF controller F21, causes the LF transmitting devices 8 to transmit wake-up signals in sequence at predetermined ringing intervals while the vehicle Hv is parked. The wake-up signals contain at least one transmitter number as transmission source information. The ringing interval is set to 200 milliseconds, for example. When the communication controller F2 detects a user operation of an operating element arranged on the vehicle Hv, such as the doorknob 5, the start button 6, the brake pedal, etc., it can transmit the wake-up signal from the LF transmitting device 8 corresponding to the operated element. The communication controller F2 can cause the LF transmitting device 8b to transmit the wake-up signal in response to a pressing of the doorknob 5 arranged on the left door.In the present invention, transmission of the wake-up signal based on detection of user operation of the doorknob 5, the start button 6, etc. is also referred to as trigger transmission. The communication controller F2 can stop / cancel the transmission of the LF signal when connected to the smart key 2 via BLE communication.

[0070] The communication controller F2, with the BLE controller F22, performs data communication with the key device Kd using the BLE communication device 7. The communication controller F2 generates data addressed to the key device Kd in the connection communication and outputs the data to the BLE communication device 7. Accordingly, the communication controller F2 causes the signal corresponding to the desired data to be transmitted as radio waves. The communication controller F2 receives data from the key device Kd received by the BLE communication device 7. In the present embodiment, according to a preferred mode, the data communication between the smart ECU 4 and the key device Kd is encrypted.

[0071] The communication controller F2 detects that the user is near the vehicle Hv based on receiving a BLE signal transmitted from the key device Kd. That is, the BLE communication device 7 detects the key device Kd present in the vicinity of the vehicle using a passive scanning method. The in-vehicle system 1 can search for the key device Kd using an active scanning method that involves transmitting a scanning request. The two types of scanning methods can be used depending on the scene. The passive scanning method can be used in a standby scene during parking, and the active scanning method can be used when a predetermined comparison event occurs, such as pressing the door knob 5.

[0072] The communication controller F2 acquires the device ID of the key device Kd in communication connection from the BLE communication device 7. The smart ECU 4 specifies the user present in the vicinity of the vehicle Hv based on the received device ID. The communication controller F2 determines whether the device type of the communication partner corresponds to the smart key 2 based on the device ID.

[0073] The communication controller F2 acquires the reception condition of the signal from the key device Kd and the distance correspondence value from the BLE communication device 7. The communication controller F2 acquires the reception strength and the transmission and reception phase difference for each frequency as data indicating the reception condition of the signal from the key device Kd. The communication controller F2 also provides data indicating the reception condition and the distance correspondence value of the signal from the key device Kd in each BLE communication device 7 to other functional and circuit modules, such as the position determination device F3.

[0074] The position determining device F3 is configured to determine a position of the key device Kd relative to the vehicle Hv based on the distance correspondence value observed by the BLE communication device 7. The position determining device F3 determines whether the key device Kd is located in the lock-unlock area EA, an inside door area, or another area based on the state of communication with the key device Kd.

[0075] The lock-unlock area EA is an area for the on-vehicle system 1 to execute predetermined vehicle control, such as locking or unlocking a door, based on the presence of the key device Kd in the area. The lock-unlock area EA is a type of cabin exterior working area and may also be referred to as a passive access area. An area within a predetermined working distance to an exterior door handle, each of which is located on a driver's door, a front passenger door, and the trunk lid, may be set as the lock-unlock area EA. The working distance, which defines a size of the lock-unlock area EA, is, for example, 1.5 meters. Of course, the working distance may be 1 meter or 0.7 meters. The working distance is set to less than 2 meters for safety reasons.In the present invention, a region on the right side in the lock-unlock range EA is also referred to as a right-side region EA_A, a region on the left side in the lock-unlock range EA is also referred to as a left-side region EA_B, and a region on the rear side in the lock-unlock range EA is also referred to as a rear region EA_C.

[0076] The interior area corresponds to an area within the vehicle passenger compartment. The interior area can be divided into a start-permit area and a start-prohibited area, which are determined based on the driver's seat. The start-permit area is an area for the on-vehicle system 1 to perform vehicle control of switching the driving power source from off to on based on the presence of the key device Kd in the area. The start-permit area is a part of the vehicle passenger compartment that is within 0.5 m of, for example, the gear lever or the start button 6. The start-prohibited area is a part of the vehicle passenger compartment that is not the start-permit area. The interior area can be divided into a front seat area and a rear seat area. The start-permit area can also be referred to as a passive start area.

[0077] The other area is an area outside the vehicle passenger compartment, corresponding to the outside of the locking / unlocking area EA. The other area can be divided into a far area and an intermediate area. The far area is an area 6 m or more away from the vehicle Hv. The intermediate area is within 6 m of the vehicle Hv and is an area outside the vehicle passenger compartment and is not the locking / unlocking area EA.

[0078] The position determining device F3 considers the key device Kd, which is not communicatively connected, to be located in the other area. If the position determining device F3 determines that the communicatively connected key device Kd is not present in the indoor area or the lock-unlock area EA, it determines that the key device Kd is present in another area. The lock-unlock area EA and the indoor area correspond to a target area. Furthermore, the target area of ​​the present invention can be either the lock-unlock area EA or the indoor area.

[0079] When determining the device location, the positioning device F3 applies different positioning algorithms depending on whether the communication partner is a smart key 2 or a mobile terminal 3. When the communication partner is the smart key 2, the positioning device F3 determines the position of the smart key 2 using both the distance correspondence value and the NF_RSSI, as described separately below. On the other hand, when the communication partner is a mobile terminal 3, the positioning device F3 makes a determination based on the distance correspondence value and the BLE_RSSI without using the NF_RSSI.

[0080] Note that the position determination device F3 may have a function for calculating a device distance, which is the distance from the BLE communication device 7 to the communication partner, based on the observed distance correspondence value as a sub-function related to the device position determination. The device distance corresponds to a parameter obtained by converting the two-frequency phase difference or the RTT into a distance dimension. The device distance is a one-way distance. Alternatively, the device distance may be a round-trip distance. The BLE communication device 7 may have a function for converting the distance correspondence value into a device distance. The device distance calculated based on the distance correspondence value can also be regarded as a type of measured distance value.A positioning method of the smart key 2 will be described separately later.

[0081] The authentication processor F4 cooperates with the BLE communication device 7 to perform a process for confirming or authenticating that a communication partner is the key device Kd. The communication for authentication is encrypted. The authentication process itself can be performed using various methods, such as a challenge-response method. The authentication processor F4 sends a predetermined or randomly generated challenge code to the key device Kd. The challenge code includes a verification code generated by a predetermined procedure using key information corresponding to a device ID or a key ID of the communication partner.Then, a response code returned from the communication partner is compared with the verification code, and based on the fact that the response code and the verification code match, it is determined that the authentication is successful. Such an authentication process is accompanied by a process of comparing the response code generated by the key device Kd based on the key information with the verification code held or dynamically generated by the smart ECU 4. Successful authentication of the key device Kd corresponds to a determination that the person accessing the vehicle Hv is an authorized user.

[0082] A time at which the authentication processor F4 performs the authentication process may, for example, be a time at which the communication link between the BLE communication device 7 and the key device Kd is established. The authentication processor F4 may be configured to perform the authentication process in a predetermined cycle while the BLE communication device 7 and the key device Kd are connected by communication. The communication for the authentication process may be performed using a predetermined user operation with respect to the vehicle Hv as a trigger, for example, when the start button 6 is pressed by the user or the door is opened or closed.

[0083] The vehicle controller F5 is configured to execute vehicle control according to the position of the key device Kd (in other words, the user) and a state of the vehicle Hv in cooperation with the body ECU 12 under the condition that the authentication of the key device Kd by the authentication processor F4 is successful. The vehicle controller F5 unlocks the door in cooperation with the body ECU 12 when the position determining device F3 determines that the key device Kd is present in the lock-unlock area EA and detects that the door knob 5 is pressed by the user. The vehicle controller F5 switches the driving power source from off to on in cooperation with the power supply ECU 11 when the position determining device F3 determines that the key device Kd is present in the vehicle passenger compartment and detects that the start button 6 is pressed by the user.

[0084] Furthermore, the smart ECU 4 registers, deletes, or locks or deactivates the key device Kd based on an input signal from the input device 14. The processor 41 registers or deletes the key device Kd based on a user operation. When registering a key device, the smart ECU 4 acquires the type of the device to be newly registered through an operation signal input from the input device 14. The type information of the key device Kd acquired by the smart ECU 4 is stored in the key information unit M1 in association with the key information. The smart key 2 can be registered as a key device Kd at a dealer or the like.

[0085] The intelligent ECU 4 described above can perform a map generation process, a vehicle control process, a positioning process, and the like as described below. Strength card

[0086] The strength map stored in the strength map storage unit M2 indicates the NF_RSSI for each relative measurement point determined using the vehicle HV as a reference. The measurement points are arranged in a three-dimensional grid at predetermined intervals within a range of 2 m from the vehicle Hv. The measurement points may be arranged at intervals of, for example, 5 cm or 10 cm in a front-to-rear direction and a left-to-right direction, as shown in Fig. 7. The arrangement pitch or arrangement interval D of the measurement points can be a different value, for example, 20 cm. The measurement points can also be arranged at predetermined intervals in an up-down direction. The measurement points can also be set only within the lock-unlock area EA or the vehicle passenger compartment. The strength map storage unit M2 can store data in which an NF_RSSI is mapped to each point in the lock-unlock area EA or in the vehicle passenger compartment.

[0087] For example, in the present embodiment, the strength map includes a data set of observable device distances and LF strength ranges for each measurement point, as shown in Fig. 8. Each measurement point is identified by a measurement number or by coordinates. Device distance data for a specific point need not be a pinpoint, but may be a specific range, such as an observed value of ±0.1 m, taking distance measurement errors into account. The LF strength range data for a specific measurement point indicates a range of the LF RSSI observed at the smart key 2 when the smart key 2 is present at the measurement point. The LF strength range data is created for each LF transmitting device 8 that is a transmission source.

[0088] The LF strength range data for each transmission source for the lock-unlock area EA and the indoor area may also be referred to as strength condition data, which indicates the LF RSSI conditions that allow system operation for a respective device spacing. The strength map corresponds to the determination data. The strength map storage unit M2 corresponds to a determination data storage unit. Alternatively, the strength map may be a data set indicating the correspondence between distance correspondence values ​​such as the RTT or the two-frequency phase difference and the LF strength range for each source, instead of or parallel to the device spacing.

[0089] If the strength map contains data from types of areas, the strength map may contain information indicating the type of area to which the corresponding point belongs. The area type can be expressed by a number. "1 B" in Fig. For example, 8 indicates the left-side area EA_B. In addition, the right-side area EA_A can be expressed as "1B," the rear area EA_C can be expressed as "1C," the interior area can be expressed as "2," and other areas can be expressed as "0." According to a configuration in which the strength map includes area type information for each measurement point, it is possible to quickly identify which area the identified device position lies in.

[0090] The point number “100001” in Fig. 8 indicates the measuring point k, which is Fig. 7. The word “ANT” in Fig. 8 is an abbreviation for antenna, and in the present invention, this refers to an AF transmitter or an AF antenna. The word "ANT.A" indicates the AF transmitter 8a, and "ANT.P" indicates the AF transmitter 8p. Fig. 8, the word "<-80" in the second row of the "ANT.A" column indicates that the reception strength of the AF signal emitted by the AF transmitter 8a is less than -80 dBm. The word "-10<" in the second row of the "ANT.B" column indicates that the reception strength of the AF signal emitted by the AF transmitter 8b is greater than -10 dBm. The word "-50±5" indicates that the observable NF_RSSI is within the range of -45 dBm to -55 dBm. Map generation process

[0091] Here, the map generation process performed by the intelligent ECU 4 in cooperation with the intelligent key 2 is described with reference to the Fig. 9. The card generation process is a process for generating a strength card and storing it in the strength card storage unit M2. The card generation process can be started when an employee of a merchant, company, or the like performs a predetermined registration start operation with the input device 14. The card generation process includes, for example, steps S101 to S107.

[0092] Step S101 is a step for determining whether the smart key 2 is located at a given measurement point. The processor 41 detects that the smart key 2 has been located at any measurement point based on an operation signal input from the input device 14 indicating that the placement of the smart key 2 has been completed. If the processor 41 detects that the smart key 2 has been located, the processor 41 executes step S102.

[0093] Step S102 is a step for obtaining information about the measurement point to be registered, such as coordinates and the measurement point number. The processor 41 also obtains information about the measurement points based on the operation of the operator / user of the input device 14. Once the information about the measurement point is obtained, the processor 41 executes step S103.

[0094] Step S103 is a step for measuring the NF_RSSI. Step S103 includes causing each NF transmission device 8 to transmit an NF signal (e.g., a wake-up signal), and the smart key 2 measures the NF_RSSI for each transmission source. Step S103 also includes obtaining an observed value of the NF_RSSI for each transmission source from the smart key 2 through BLE communication. After establishing a BLE communication link with the smart ECU 4, the smart key 2 can spontaneously report the NF_RSSI observation value for each transmission source or can report the NF_RSSI observation value based on receiving a transmission request from the smart ECU 4.

[0095] In step S103, the processor 41 generates low-frequency strength range data for each transmission source at the measurement points. The low-frequency RSSI measurement for each transmission source may be performed multiple times. The processor 41 may generate the low-frequency strength range data for each transmission source by performing statistical processing (e.g., averaging) on ​​the results of multiple measurements. When the generation of the low-frequency strength range data for each transmission source is complete, the processor 41 executes step S104.

[0096] In step S104, the BLE communication device 7 performs distance measurement communication to obtain the distance from the BLE communication device 7 to the measurement point. The processor 41 obtains the device distance based on the RTT and the two-frequency phase difference obtained by the BLE communication device 7 performing the distance measurement communication. The distance value obtained here is a value obtained during actual communication. A propagation path of a wireless signal may be longer than a straight-line distance due to round-trip.By using the distance value observed by actually performing communication, rather than a simple straight-line distance from the installation position of the BLE communication device 7 to the target measurement point, as the distance information to be combined with the LF strength range data, it is possible to reduce the risk of misjudging the device position. When the registration of the distance information is completed, the processor 41 executes step S105.

[0097] In step S105, the low-frequency strength area data for each transmission source observed in step S103 and the observed device distance value obtained in step S104 are temporarily stored in the RAM 42 in association with the number / coordinates of the measurement points. The processor 41 also sets the area type value based on the number / coordinates of the measurement points. When the association of each piece of data for the measurement point to be registered is complete, the processor 41 executes step S106.

[0098] Step S106 is a step for determining whether any measurement point for which the NF RSSI or the like has not yet been measured remains. If there is any remaining unmeasured point, the process from step S101 is executed for each unmeasured point. On the other hand, if distance information and NF strength range data have been obtained for all measurement points, the process proceeds to step S107, and a record in which the data for each measurement point is packed is registered in the strength map storage unit M2 as strength map data, and then the process is terminated.

[0099] The map generation process can be performed for each vehicle Hv or can be performed only for a specific vehicle. The strength map storage unit M2 of a specific vehicle Hv can store strength map data generated in another vehicle. Common strength map data can be stored in intelligent ECUs 4 used in the same vehicle model. Vehicle control process

[0100] The following describes the vehicle control process performed by the intelligent ECU 4 with reference to the Fig. 10. The vehicle control process is a process for performing vehicle control such as unlocking or locking the doors and turning on or off the driving power source depending on the position of the smart key 2 or the mobile terminal 3. The vehicle control process is executed at a predetermined cycle, for example, every 200 milliseconds, while the driving power source is turned off. The vehicle control process may be executed in response to a trigger such as detection of a user operation with respect to the vehicle Hv, e.g., pressing the door knob 5, pressing the start button 6, opening or closing a door, or pressing the brake pedal. The vehicle control process includes, for example, steps S201 to S211.

[0101] Step S201 is a step for causing the LF transmitting devices 8 to transmit a respective wake-up signal in a predetermined order. When step S201 is completed, the processor 41 executes step S202.

[0102] Step S202 is a step for searching for (so-called scanning) the key device Kd. If the scanning in step S202 does not detect the key device Kd (S203: no), the process from step S204 is omitted, and the process is terminated. If the key device Kd is found as a result of the scanning in step S202, the processor 41 executes step S204.

[0103] Step S204 is a step for causing the BLE communication device 7 to establish a communication link with the key device Kd detected by the scanning in step S202. A communication link is established by sending a connection request and exchanging a response thereto. The processor 41 identifies the communication partner based on the source information included in the announcement signal or the like. The detailed sequence from the scanning to the establishment of a communication link and the start of encrypted communication can be performed according to the BLE standard. When the communication link with the key device Kd is completed, the processor 41 executes step S205.

[0104] Step S205 is a step for executing communication to authenticate the wireless communication partner. The processor 41 performs the authentication process for the key device Kd using the challenge code and the key information of the communication partner stored in the key information storage unit M1. If the authentication is successful (S206: yes), the processor 41 executes step S207. On the other hand, if the wireless authentication fails (S206: no), the process is terminated.

[0105] Step S207 is a step for determining whether the communication partner is a smart key 2. The processor 41 determines whether the communication partner is a smart key 2 by comparing the device ID of the communication partner with the device type information for each device ID stored in the key information storage unit M1. According to another aspect, the processor 41 can determine whether the communication partner is a smart key 2 by acquiring a device type code or an included function code, as described later, from the communication partner via BLE communication. If it is determined that the communication partner is a smart key 2 (S207: yes), the processor 41 executes step S208. If it is determined that the communication partner is not a smart key 2 (S207: no), the processor 41 executes step S209.

[0106] Step S208 is a step for performing a smart key positioning process. The smart key positioning process will be described separately later. By executing the smart key positioning process, the processor 41 determines whether the smart key 2 as the communication partner is located in the lock-unlock area EA, the interior area, or another area. When step S208 is completed, the processor 41 executes step S210.

[0107] Step S209 is a step for performing a mobile terminal positioning process. The mobile terminal positioning process is described separately below. By executing the mobile terminal positioning process, the processor 41 determines whether the mobile terminal 3 as the communication partner is located in the lock-unlock area EA, the indoor area, or another area. When step S209 is completed, the processor 41 executes step S210.

[0108] In step S210, based on the result of the process in step S208 or S209, it is determined whether the key device Kd as the communication partner exists within an operation area. The operation area refers to an area where vehicle control such as unlocking can be performed. Specifically, the lock-unlock area EA and the interior area correspond to the operation area. Other areas are not included in the operation area. If a welcome area, which is an outdoor area where an external lighting device is turned on when a user approaches, is set in the smart ECU 4, the welcome area can also be included in the operation area.If a remote parking area, which is an outdoor area where the vehicle Hv can be semi-automatically parked by remote control, is set in the intelligent ECU 4, the remote parking area can also be included in the operating area. The welcome area and the remote parking area are set within 6 m of the vehicle Hv.

[0109] If the processor 41 determines that the key device Kd is present within the operating range (S210: yes), the processor 41 performs vehicle control according to the device position (S211). On the other hand, if the processor 41 does not determine that the key device Kd is present within the operating range (S210: no), the process is terminated.

[0110] Note that step S211 may be a step for entering a standby state in which vehicle control may be executed in response to a user operation regarding a predetermined operation item, instead of performing vehicle control such as unlocking. The standby state corresponds to a state in which the vehicle waits for a user operation regarding an operation item such as the doorknob 5 according to the content of the vehicle control. When the processor 41 detects a specific user operation in the standby state, the processor 41 immediately executes vehicle control according to the operation item or device position. Positioning process for smart keys

[0111] This describes the positioning process when the communication partner is identified as intelligent key 2. The intelligent key positioning process includes the Fig. 11 shown steps S301 to S307. The Fig. 11 is used as step S208 of the Fig. 10 executed.

[0112] Step S301 is a step of receiving an LF strength report, consisting of a record or message indicating the LF RSSI for each transmission source, from the smart key 2. The LF strength report itself is sent and received via BLE communication. The LF RSSI for each transmission source reported here is a strength observation value for the wake-up signal transmitted in step S201. According to another aspect, step S301 may include a step of transmitting an LF signal for LF strength measurement from each LF transmission device 8. In this case, step S301 corresponds to a step of obtaining an observed value of the received strength of the LF signal transmitted from each LF transmission device 8 for LF strength measurement. When the reception of the LF strength report is completed, the processor 41 executes step S302.

[0113] Step S302 is a step for performing the distance measurement process similar to step S104. That is, the processor 41 acquires the RTT and the two-frequency phase difference by having the BLE communication device 7 perform the distance measurement communication. The processor 41 also generates, as the device distance, an RTT measurement distance value, which is a distance value calculated based on the observed RTT, and a phase difference measurement distance value, which is a distance value calculated based on the observed two-frequency phase difference.

[0114] In Fig. 11, the word "D_rtt" indicates the RTT measurement distance value, and the word "D_Δϕ" indicates the phase difference measurement distance value. The combination of frequencies for distance measurement, which are the frequencies used to calculate the two-frequency phase difference, can be set in advance or determined dynamically. The frequency for distance measurement can be an advertising frequency or a data communication frequency. In BLE communication, frequency hopping is performed after a connection is established. The processor 41 can obtain the transmission and reception phase difference at the current frequency each time the frequency is changed. The current frequency is the frequency currently in use. The processor 41 can select a combination of frequencies for distance measurement at which the difference frequency Δf, i.e.The difference between the frequencies is equal to or greater than 10 MHz and less than 70 MHz to perform a phase difference distance measurement. The processor 41 can calculate the phase difference measurement distance value for a combination of multiple frequencies. A phase difference measurement distance value can be calculated for each combination of frequencies from a population of four or more frequencies, and a final phase difference measurement distance value can be determined by combining them. When the distance measurement process is completed in step S302, the processor 41 executes step S303.

[0115] Step S303 is a step for determining whether the RTT measurement distance value (D_rtt) is less than a predetermined value. Here, the predetermined value is set to 6 m, 10 m, 15 m, or the like. If the RTT measurement distance value is less than the predetermined value, the processor 41 executes step S304. On the other hand, if the RTT measurement distance value is equal to or greater than the predetermined value, the processor 41 executes step S307. The RTT measurement distance value is proportional to the RTT. Step S303 corresponds to a step for determining whether the observed RTT value is less than a predetermined value.

[0116] Because the signals exchanged in BLE communication are longer than the pulse signals used in UWB-IR, the RTT observable in BLE communication is less accurate than the RTT observable in UWB communication. Furthermore, the accuracy of the distance using RTT in BLE communication is not as high as that of the distance using the two-frequency phase difference. The RTT measurement distance value in BLE communication may contain an error of approximately several meters. The threshold value used in step S303 is preferably set to approximately 1 to 2 m larger than the expected maximum distance, which is the distance from the installation position of the BLE communication device 7 to a farthest point of the lock-unlock range EA.Step S303 corresponds to a primary filter that discriminates whether the smart key 2 may be present in the lock-unlock area EA or in the vehicle passenger compartment based on the RTT measurement distance value.

[0117] In step S304, it is determined whether the phase difference measurement distance value (D_Δϕ) is less than a predetermined value. Here, the predetermined value can be set to an expected maximum distance, for example, 5 m. Step S304 corresponds to a secondary filter that distinguishes, based on the phase difference measurement distance value, whether the smart key 2 is likely present in the lock-unlock area EA or the interior area. If the phase difference measurement distance value is less than the predetermined value, the processor 41 executes step S305. On the other hand, if the phase difference measurement distance value is equal to or greater than the predetermined value, the processor 41 executes step S307.

[0118] Step S305 is a step of referring to the strength map and acquiring data of the measurement point corresponding to the device distance acquired in the above process. If there are multiple measurement points corresponding to the device distance, data for all of these points is extracted. Step S305 corresponds to a step of acquiring data of a measurement point associated with the observed device distance from the strength map data using the device distance as a search key. The measurement point data includes LF strength range data for each LF antenna. From the RTT measurement distance value and the phase difference measurement distance value, the processor 41 uses the phase difference measurement distance value as the device distance. According to another aspect, the processor 41 may use the RTT measurement distance value as the device distance.The processor 41 may also use as the device distance an average or a weighted average of the RTT measurement distance value and the phase difference measurement distance value.

[0119] In step S306, the location of the smart key 2 is determined based on the currently observed device distance, a combination of the NF_RSSI for each transmission source, and the strength map. Specifically, the processor 41 compares the NF_RSSI observation values ​​for each source obtained in step S301 with the NF strength range data for each measurement point read in step S305 and determines whether there is a measurement point that matches the combination of observation values.

[0120] If there is no measurement point or record in the strength map that matches the current observation result, the device location is determined to be unknown. If a measurement point that matches the current observation result exists in the strength map, it is determined that the smart key 2 exists at that measurement point. If there is no measurement point in the strength map that matches the current observation result, the measurement point that is most similar to the current observation result can be determined as the device position. If there are multiple measurement points in the strength map that match the current observation result, the measurement point that is most similar to the current observation result can be determined as the device position.

[0121] The processor 41 determines whether the smart key 2 is located in the lock-unlock area EA, the indoor area, or another area based on the coordinates or area type associated with the device position determined in the strength map by the above process. Furthermore, determining whether the smart key 2 is present in the lock-unlock area EA based on the reception conditions of the signal from the smart key 2 corresponds to determining whether the reception conditions of the signal from the smart key 2 satisfy specific conditions for considering or assuming that the smart key 2 is present in the lock-unlock area EA. The same may apply to determining other areas, such as the indoor area. The same may apply to the mobile terminal 3.

[0122] Step S307 is a step for determining that the device location is in the other area. Step S307 may be a step for determining that the device location is unknown. If the processor 41 determines that the device location is unknown, it may further be assumed that the key device Kd is located in another area. The determination result of the device location may be managed, for example, by an area flag. Here, according to an example, when the location of the smart key 2 is determined to be in the other area or unknown, the area flag is set to 0. In addition, a state in which the smart key 2 is determined to be present in the lock-unlock area EA is represented by an area flag = 1, and a state in which the smart key 2 is determined to be present in the indoor area may be determined by an area flag = 2.The area flag corresponds to a parameter that indicates the result of determining the area to which the smart key 2 belongs—in other words, the result of determining the device location. The area flag can also be referred to as an area code. The values ​​of the flags (codes) indicating the various determination results can be changed as needed. Positioning process for mobile devices

[0123] The mobile device positioning process includes the Fig. 12 shown steps S401 to S402. The Fig. The flowchart shown in Fig. 12 is used as step S209 of the Fig. 10 executed.

[0124] Step S401 is a step for performing the distance measurement process similar to step S302. By executing step S302, the processor 41 obtains the RTT measurement distance value and the phase difference measurement distance value for at least one combination of frequencies and determines the device distance based thereon. Furthermore, the processor 41 obtains the reception strength (BLE_RSSI) of the signal from the mobile terminal 3 from the BLE communication device 7.

[0125] Step S402 is a step for determining the device position based on the combination of the reception strength and the device distance obtained in step S401. The processor 41 determines that the device is present in the interior when the BLE RSSI is equal to or greater than a predetermined first strength threshold and the device distance is less than a first distance. The first distance may be set to a value such as 0.5 m added to the distance from the left C-pillar to the steering wheel where the BLE communication device 7 is mounted.

[0126] Furthermore, the processor 41 determines that the device is located in the left area EA_B if the BLE_RSSI is less than a predetermined second strength threshold and the device distance is less than a second distance. The second strength threshold may be set to a value that is smaller than the first strength threshold by a predetermined amount, considering that the BLE communication device 7 is located on the inside of the C-pillar. The second distance may be set to a value such as the distance from the left C-pillar to the outside door handle for the left front seat plus a predetermined value, such as 0.5 m.Furthermore, the processor 41 determines that the device is located in the right area EA_A or the rear area EA_C when the BLE_RSSI is less than a third strength threshold and the device distance is greater than a third distance and less than a fourth distance. The third strength threshold may be set to a value equal to or less than the second strength threshold, taking into account the presence of an obstacle such as a right door between the left C-pillar and the right area EA_A. The third distance is set to a value obtained by subtracting a predetermined value (for example, 0.5 m) from the distance from the left C-pillar to the right B-pillar.The fourth distance is set to the value obtained by adding a predetermined value (for example, 0.5 m) to the distance from the left C-pillar to the outside door handle for the right front seat. Furthermore, it is preferable for the processor 41 to be configured not to unlock the door even if the doorknob 5 for the left front seat is pressed when it is determined that the mobile terminal 3 is present in the right area EA_A or the rear area EA_C.

[0127] In addition, the processor 41 determines that the mobile terminal 3 is located in another area when the combination of the observed BLE_RSSI and the device distance does not satisfy the conditions for determining that the mobile terminal 3 is located in the lock-unlock area EA or the indoor area. Effects

[0128] Forming a suitable lock-unlock area EA based solely on a device distance is difficult when the on-vehicle system 1 is equipped with only a single BLE communication device 7, and the BLE communication device 7 is positioned on the left or right side of the vehicle center, for example, on the left C-pillar. Setting the area within 2 m of the BLE communication device 7 (left C-pillar) as the lock-unlock area EA may result in a reduction or disappearance of the area serving as the right-side area EA_A. This may potentially reduce the convenience for users attempting to enter the vehicle from the right side.If the convenience of users attempting to enter from the right side were ensured by setting the area within 4 m of the BLE communication device 7 as the lock-unlock area EA, the area on the left side of the vehicle considered as the lock-unlock area EA would become larger, which might reduce safety.

[0129] To address such a problem, the processor 41, configured as described above, determines the device position by combining the reception strength of the AF signal for each transmission source with the device distance. This allows the processor 41 to accurately determine whether the smart key 2 is present in the lock-unlock area EA or the interior area.

[0130] Specific examples are the following: A first point k1 and a second point k2, which are Fig. 13 are both points that are 3 meters away from the BLE communication device 7. The first point k1 is located in the right-side area, whereas the second point k2 is a point belonging to the other area on the left side of the vehicle. Since the first point k1 and the second point k2 are both the same distance from the BLE communication device 7, the device distances observed by the distance measurement communication are approximately equal. Therefore, the first point k1 and the second point k2 cannot be distinguished from each other based on the device distance alone.

[0131] However, since the relative positions of the first point k1 and the second point k2 with respect to the LF transmitting devices 8 are different, the LF strength of each transmission source observed by the smart key 2 may be significantly different. At the first point k1, the LF RSSI for the LF transmitting device 8a may be large, and the LF RSSI for the LF transmitting device 8b may be small. On the other hand, at the second point k2, the LF RSSI for the LF transmitting device 8a may be small, and the LF RSSI for the LF transmitting device 8b may be large. Therefore, by combining the device distance with the reception strength of the LF signal, the risk of erroneously determining that the smart key 2 is present in the lock-unlock area EA when it is actually not present can be reduced.

[0132] In addition, the processor 41 changes the algorithm used to determine the device location depending on whether the communication partner is a smart key 2 or not. According to this configuration, an appropriate positioning algorithm can be used according to the functions installed in the communication partner, so the same effects of improving the accuracy of positioning and avoiding unnecessary processing in the processor 41 are expected to be achieved. Note that a change in the determination algorithm corresponds to a change in the number, combinations, and parameters of communication devices used for determination.

[0133] Furthermore, if the communication partner is a mobile terminal 3 with which LF communication is not possible, the processor 41 performs positioning using only the distance measurement result from a single BLE communication device 7, but also using the BLE_RSSI. This configuration can improve the accuracy of the determination compared to a configuration in which positioning is performed based only on the device distance.

[0134] While an embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment. Various modifications described below are included within the technical scope of the present invention. Apart from the modifications described below, the present invention can be implemented by various changes without departing from the scope of the present invention. Various additions and / or modifications described below can be implemented in combination, where appropriate, within the range that does not result in technical inconsistency. The elements having the same functions as those described above have the same reference numerals, and the description of these same elements will not be repeated.If only part of the configuration is mentioned, reference can be made to the above description for the remaining parts. Additional information on distance measurement methods using two-frequency phase difference

[0135] The value of the two-frequency phase difference undergoes rotation with a difference wavelength λd, which corresponds to the difference frequency Δf. The processor 41 cannot normally distinguish between Δϕ and Δϕ + 2π × N (N is an integer) when the two-frequency phase difference is equal to Δϕ. Therefore, in general, a distance measurement method using a two-frequency phase difference can only be used in a range where the two-frequency phase difference does not exceed 2π or 360° (i.e., one period). In addition, the difference wavelength λd is a parameter determined by 2π / Δf. Therefore, the measurement range based on the two-frequency phase difference may vary depending on the combination of frequencies.

[0136] For example, if a first frequency f1 = 2402 MHz and a second frequency f2 = 2480 MHz, the difference frequency Δf is equal to 78 MHz, and the difference wavelength λd is equal to 3.85 m. Therefore, the measurement range for the above frequency combination is equal to 3.85 meters for the round-trip distance and approximately 1.93 meters for the one-way distance. With the above frequency combination, the processor 41 cannot distinguish between a case where the device distance is equal to 0.5 meters and a case where the device distance is equal to 0.5 + 1.93 = 2.43 meters.

[0137] The processor 41 can select a combination of frequencies to provide a desired measurement range. If the distance at which a BLE communication link can occur is assumed to be 20 meters, the processor 41 can perform a phase difference distance measurement using a combination of frequencies that results in a one-way measurement range of 20 meters or more. According to this configuration, an erroneous determination of the device position due to periodicity of the phase difference can be reduced. As described above, the processor 41 can determine the device distance by combining phase difference measurement distance values ​​for frequency combinations. According to this configuration, the accuracy of the position determination can be improved while the restrictions on the frequencies used for distance measurement are relaxed.

[0138] Furthermore, the processor 41 can estimate the value of the period number N described above using an RTT-based measurement distance value. In other words, it is possible to estimate whether the two-frequency phase difference corresponds to any one of N = 0, 1, 2, 3, ... based on the RTT measurement distance value. The processor 41 can determine the phase difference measurement distance value based on the estimated value of the number of periods (N). According to this configuration, phase difference distance measurement may be possible even in a range exceeding the difference wavelength. As described above, the RTT measurement distance value can be used to determine the number of periods (N) in the phase difference distance measurement. Additional information of the BLE communication device placement

[0139] The vehicle's own system 1 can be equipped with several BLE communication devices 7. The vehicle's own system 1 can Fig. 14. The BLE communication device 7x is installed in the smart ECU 4. The BLE communication device 7a is arranged on the outer surface of the right side of the vehicle Hv, and the BLE communication device 7b is arranged on the outer surface of the left side of the vehicle Hv. The BLE communication devices 7a, 7b are arranged on the outer surface of the B-pillar or on the outside door handle. The BLE communication device 7c is arranged at an arbitrary location at the rear end of the vehicle, for example, in a trunk lid or in a rear bumper. The BLE communication device 7p is arranged at an arbitrary location in the vehicle passenger compartment, for example, on a dashboard or a center console.

[0140] The B-pillar arranged in the vehicle Hv may be divided into a door-side B-pillar arranged in a door module and a vehicle body-side B-pillar serving as a pillar or frame including a roof portion of a vehicle body. The door-side B-pillar corresponds to a portion of a front door or rear door that contacts a vehicle body-side pillar. The BLE communication devices 7a, 7b may be arranged in a portion of the door-side B-pillar adjacent to a side window, for example, in a resin portion above a lower end of the side window.

[0141] Furthermore, the in-vehicle system 1 may be equipped with a BLE communication device 7 arranged on the inside of the driver's door, a BLE communication device 7 arranged on the inside of the left B-pillar, and a BLE communication device 7 arranged in the trunk. The BLE communication device 7 may be mounted in the vehicle passenger compartment at a position at least 0.1 meters below a lower edge of the side window. The in-vehicle system 1 may include a BLE communication device 7 arranged on a ceiling of the vehicle passenger compartment.

[0142] The BLE communication device 7x is used for data communication with the key device Kd. In the present invention, the communication device used for data communication with the key device Kd is also referred to as a gateway communication device. The BLE communication device 7 (gateway communication device) used for data communication with the key device Kd may also be referred to as a representative device, a central device, or a data communication device. The BLE communication device 7 as a gateway communication device can be used not only for data communication but also for monitoring the RTT and the transmission and reception phase difference.

[0143] The processor 41 uses the BLE communication device 7 other than the BLE communication device 7x as a communication device for determining the device position. The BLE communication device 7 for position determination is also referred to as a distance measuring device in the present invention. The distance measuring device corresponds to a communication device for observing the RTT, the transmission and reception phase difference, and the reception strength. According to one aspect, the distance measuring device may correspond to a communication device that does not exchange data with the key device Kd. In the example shown in Fig. As shown in Figure 14, the BLE communication devices 7a, 7b, 7c, 7p correspond to the distance measuring devices. The distance measuring device may also be referred to as an observation device or a satellite communication device. Alternatively, the smart ECU 4 may cause each of the BLE communication devices 7 to perform data communication with the key device Kd.

[0144] If the on-vehicle system 1 includes multiple BLE communication devices 7, the processor 41 first performs authentication and identification of the communication partner using the BLE communication device 7x as a gateway communication device. If the processor 41 determines that the communication partner is a smart key 2 ( Fig. 15, S501: yes), it determines the device location based on a combination of observed values ​​such as the RTT at the BLE communication device 7x and the NF_RSSI for each transmission source (S502). If the on-vehicle system 1 includes multiple BLE communication devices 7, the processor 41 may also cause a different BLE communication device 7 to perform distance measurement communication with the smart key 2 instead of the BLE communication device 7x.

[0145] On the other hand, if the processor 41 determines that the communication partner is not a smart key 2 (S501: no), it activates the BLE communication device 7 as a distance measuring device (S503). Then, the device position is determined based on the device distances and the reception strengths from the BLE communication devices 7 (S504). In this way, the processor 41 can change the number and type of communication devices used to determine the device location depending on whether the communication partner is a smart key 2. The distance measuring device can be placed in an inactive state to save power until the gateway communication device is connected to the key device Kd.

[0146] According to the above configuration, when the communication partner is a smart key 2, there is no need to operate multiple distance measuring devices, so the processor 41 can reduce the frequency of activating the BLE communication device 7. Furthermore, when the communication partner is a mobile terminal 3, the measured distance values / reception strengths of multiple BLE communication devices 7 are used to determine the device position, making it possible to improve the accuracy of estimating the position of the mobile terminal 3 compared to the above-described embodiment. Furthermore, according to an exemplary operation, the mobile terminal 3 performs distance measuring communication with multiple BLE communication devices 7, whereas the smart key 2 performs distance measuring communication only with the gateway communication device.In other words, the number of BLE communication devices 7 with which the smart key 2 communicates during a single positioning operation is smaller than the number of mobile terminals 3. The frequency of transmitting distance measurement signals from the smart key 2 is lower compared to the mobile terminal 3. Therefore, according to the above configuration, the power consumption in the smart key 2 can be reduced compared to the mobile terminal 3.

[0147] The process flow that Fig. 15 may be performed in parallel with, in combination with, or instead of the various processes described above. A specific processing content of step S502 may include processing for determining the device position using an LF strength map similar to the flowchart of Fig. 11. In step S504, it is determined that a mobile terminal 3 exists in an area corresponding to a communication device whose distance from the mobile terminal 3 is less than a predetermined value. The processor 41 determines that the mobile terminal 3 exists in the indoor area when the device distance based on the BLE communication device 7p is within 0.6 meters. Furthermore, the processor 41 determines that the mobile terminal 3 exists in the right area EA_A when the device distance based on the BLE communication device 7a is within 0.6 meters. The processor 41 may determine that the device location is in the other area when there is no BLE communication device 7 whose distance from the mobile terminal 3 is less than a predetermined value. Additional information on LF transmitter placement

[0148] The arrangement number and arrangement mode of the LF transmitter 8 described above are only examples and can be changed as appropriate. The LF transmitters 8a, 8b can be arranged on outer surfaces of the B-pillar and the C-pillar. Furthermore, the LF transmitter 8 arranged in the interior area can also be a single LF transmitter 8p, as shown in Fig. 16. The number of LF transmitters 8 arranged within the vehicle may be three or more. The on-board system 1 may include an LF transmitter 8b arranged in the trunk. First modification

[0149] The smart key 2 and the mobile terminal 3 may transmit the device type code in response to a request from the on-vehicle system 1. The device type code is a code indicating the type of device, for example, whether it is a smart key 2. In response to the request from the on-vehicle system 1, the smart key 2 may transmit a BLE signal in which a bit string indicating that the smart key 2 is a smart key 2 is arranged in a data field in which a device type code is placed. The processor 41 may use the device type code instead of the device ID to determine whether the communication partner is a smart key 2.

[0150] The smart key 2 and the mobile terminal 3 may transmit, instead of the device type code or in addition to the device type code, an included function code indicating a variation of the communication function they have in response to the request from the on-vehicle system 1. The smart key 2 may be configured to transmit, in response to the request from the on-vehicle system 1, a BLE signal in which a bit string indicating that the smart key 2 has an LF reception function is placed in a data field in which a function code is placed. The processor 41 may use the provided function code instead of the device ID to determine whether the communication partner is a smart key 2. Furthermore, the processor 41 may switch the positioning algorithm depending on whether the communication partner has an LF reception function.The processor 41 may determine the location using a strength map when the communication partner has the LF receiving function, but may determine the device location using a method that does not use the strength map when the communication partner does not have the LF receiving function. Second modification

[0151] The smart ECU 4 may be configured to delete or invalidate the information of the smart key 2 from the key information storage unit M1 through a user operation. Only the mobile terminal 3 may be registered as the key device Kd in the key information storage unit M1.

[0152] Although, as described above, the mobile terminal 3 is configured to be used as the key device Kd, the present invention is not limited thereto. The smart ECU 4 may be configured such that only the smart key 2 can be used as the key device Kd. In this case, the smart ECU 4 may be configured to terminate the process flow when a smart key 2 cannot be found. More specifically, the processor 41 may be configured to execute a positioning process (S208) for the smart key when the authentication of the communication partner is successful ( Fig. 10, p.206: yes). Further modification

[0153] The smart key 2 is generally configured to be powered by a primary battery. Considering this aspect, when the communication partner is a smart key 2, the power consumption of the communication partner can be further reduced than when the communication partner is a mobile terminal 3. This is because primary batteries are not rechargeable. Considering this aspect, when the communication partner is a smart key 2, the processor 41 can reduce the frequency of distance measurement communication (for example, to less than half) compared to when the communication partner is a mobile terminal 3.

[0154] Furthermore, processor 41 does not necessarily need to obtain both the RTT and the transmit and receive phase difference. Processor 41 may determine the device spacing based solely on the RTT. Furthermore, processor 41 may calculate the device spacing based solely on the two-frequency phase difference without using the RTT.

[0155] The functions of the intelligent ECU 4 may be divided into a positioning ECU, which is provided for determining the device position, and a vehicle control ECU, which is provided for coordinating the execution of vehicle control according to the positioning result. In this case, the positioning ECU transmits data indicating the positioning result of the key device Kd as the communication partner to the vehicle control ECU. The data can be received by the vehicle control ECU via the in-vehicle network Nw. The body ECU 12 and the power supply ECU 11 correspond to an example of a vehicle control ECU.

[0156] Alternatively, the second frequency band may be the 5.2 GHz band from 5150 MHz to 5250 MHz or the 5.6 GHz band from 5470 MHz to 5730 MHz. The first frequency band may be any frequency band lower than the second frequency band, and a specific range thereof may be changed as needed.

[0157] The smart ECU 4 and the smart key 2 may be configured to calculate the RTT and / or the transmission and reception phase difference using the LF signal. The first data may be data regarding parameters related to the time of flight (ToF) of a wireless signal, such as the reception strength, the RTT, the transmission and reception phase difference, or the two-frequency phase difference. The first data and the second data may be data about parameters whose values ​​change depending on the distances from the LF transmitter device 8 and the BLE communication device 7 to the smart key 2. The first frequency band is not limited to the LF frequency band but may be a frequency band of 900 MHz or higher. The term "device distance" in the above description may be appropriately replaced with a distance corresponding value, an RTT measurement distance value, a phase difference measurement distance value, or the like.The device distance, distance equivalent value, RTT measurement distance value and phase difference measurement distance value correspond to the measured distance value. Supplementary note (1)

[0158] The present invention also includes the following configurations. Technical Idea 1

[0159] A control program contains instructions for causing at least one processor of a mobile terminal (3), which is a universal information processing terminal capable of wireless communication with a vehicle-mounted positioning device, to carry out processing relating to a communication link with the positioning device, and when a communication link with the positioning device is established, to send and receive a signal for distance measurement periodically or upon request from the positioning device, and upon establishment of a communication link with the positioning device, to send a code indicating that the mobile terminal is not a mobile vehicle device.

[0160] The above control program is a control program for the mobile terminal 3, and the mobile terminal 3, operating according to the above control program, sends a signal indicating the device type to the smart ECU 4. According to this configuration, the smart ECU 4 can determine whether the communication partner is a smart key 2 or not, and this has the advantage of being able to apply a determination method according to the type of the communication partner. Supplementary note (2)

[0161] The apparatus, system, and method described herein may be implemented by an associated computer configured by a processor programmed to perform one or more functions by executing a computer program. The apparatus and method described herein may be implemented using dedicated hardware logic circuitry. Furthermore, the apparatus and method described herein may be implemented by one or more dedicated computers including a combination of a processor executing a computer program and one or more hardware logic circuits. Some or all of the functions provided by processor 41 may, for example, be implemented in hardware.A configuration in which a specific function is implemented by hardware includes a configuration in which the function is implemented using one or more ICs or the like. A CPU, an MPU, a GPU, a DFP (Data Flow Processor), or the like can be used as the processor (arithmetic core). Some or all of the functions of the processor 41 can be implemented using a system-on-chip (SoC), an FPGA, an ASIC, or the like. FPGA is an abbreviation for field-programmable gate array. ASIC is an abbreviation for application-specific integrated circuit. Furthermore, the computer program can be stored in a computer-readable non-volatile tangible storage medium as instructions to be executed by the computer. An HDD (hard disk), an SSD (solid state drive), a flash memory, or the like can be used as the program storage medium. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 5 438 048 B2

[0006]

Claims

[1] Position determining device comprising at least one processor, wherein the at least one processor is used in conjunction with at least one first communication device (8) designed to transmit a signal in a first frequency band and at least one second communication device (7) designed to communicate with a mobile vehicle device carried by a user of the vehicle using radio waves in a second frequency band different from the first frequency band, wherein the at least one processor is configured to cause the position determining device to: obtaining first data indicating a reception state at the mobile vehicle device of a signal transmitted by the first communication device; obtaining second data indicating a distance from the second communication device to the mobile vehicle device, the second data being determined by causing the second communication device to communicate with the mobile vehicle device; and determines a location of the mobile vehicle device based on the first data and the second data. [2] Position determining device according to claim 1, wherein the positioning device is used in conjunction with a plurality of first communication devices, the position determining device further includes a determination data storage unit (M2) which stores determination data, the determination data is a data set that associates, for each of the first communication devices, the first data and the second data that can be observed when the mobile vehicle device is present within a predetermined target area, and the at least one processor is configured to cause the position determining device to determine whether the mobile vehicle device is located within the target area by comparing actually observed first data and the second data with the determination data. [3] Position determining device according to claim 2, wherein the at least one second communication device is designed to communicate with a mobile terminal which is a universal information processing terminal in addition to the communication with the mobile vehicle device, the mobile device is used as an electronic key for the vehicle, the at least one processor is designed to cause the position determining device obtaining a signal indicating a device type from a communication partner in cooperation with the second communication device; based on the signal obtained from the communication partner, determines whether the device type of the communication partner corresponds to the mobile vehicle device; and changes an algorithm for determining a position of the communication partner depending on whether the device type of the communication partner is the mobile vehicle device. [4] Position determining device according to claim 3, wherein the at least one processor is designed to cause the position determining device determines the location of the communication partner using the determination data if the device type of the communication partner is the mobile vehicle device; and determines the location of the communication partner without using the destination data if the communication partner is the mobile device. [5] The positioning device according to any one of claims 1 to 4, wherein the first data is data indicating a reception strength of a wireless signal in the first frequency band observed by the mobile vehicle device. [6] Position determining device according to one of claims 1 to 5, wherein the at least one processor is designed to cause the position determining device Data indicating a round trip time, which is a time from sending a response request signal to the mobile vehicle device to receiving a response signal from the mobile vehicle device, is acquired as the second data; and determines that the mobile vehicle device is not present in a predetermined target area when the round trip time is equal to or greater than a predetermined value. [7] Position determining device according to one of claims 1 to 5, wherein the at least one processor is designed to cause the position determining device Data indicating a transmission and reception phase difference for each of frequencies obtained by transmitting and receiving continuous wave signals at the frequencies in the second frequency band is acquired as the second data; obtains a phase difference measurement distance value indicating a distance from the second communication device to the mobile vehicle device based on the transmission and reception phase difference for each frequency; and determines that the mobile vehicle device is not present in a predetermined target area when the phase difference measurement distance value is equal to or greater than a predetermined value. [8] Position determining device according to one of claims 1 to 5, wherein the at least one processor is designed to cause the position determining device Acquires data indicating a round trip time, which is a time from sending a response request signal to the mobile vehicle device to receiving a response signal from the mobile vehicle device, as the second data; Data indicating a transmission and reception phase difference for each of frequencies obtained by transmitting and receiving continuous wave signals at the frequencies in the second frequency band is acquired as the second data; obtains a phase difference measurement distance value indicating a distance from the second communication device to the mobile vehicle device based on the transmission and reception phase difference for each frequency; and determines that the mobile vehicle device is not present in a predetermined target area when the round trip time is equal to or greater than a predetermined value or when the phase difference measurement distance value is equal to or greater than a predetermined value and the round trip time is less than the predetermined value. [9] The positioning device according to claim 8, wherein the at least one processor is configured to cause the positioning device to perform a positioning process of the mobile vehicle device using the first data when the round trip time is less than the predetermined value and the phase difference measurement distance value is less than the predetermined value. [10] Position determining device according to one of claims 1 to 9, wherein the at least one processor is designed to cause the position determining device causes the first communication device to transmit a wireless signal for initiating communication with the second communication device to the mobile vehicle device periodically or in response to an input of a signal indicating that a predetermined operating element disposed in the vehicle has been operated; causes the second communication device to perform a distance measurement communication in response to an establishment of a communication connection between the mobile vehicle device and the second communication device, and the second data is obtained as a result of the distance measurement communication. [11] A positioning device according to any one of claims 1 to 10, wherein the first frequency band is a lower frequency band than the second frequency band. [12] Position determining device according to one of claims 1 to 11, wherein the first frequency band is the whole band from 20 kHz to 300 kHz or a part thereof, and the second frequency band is a 2.4 GHz band. [13] The positioning device according to any one of claims 1 to 12, wherein the at least one processor is configured to cause the positioning device to perform predetermined vehicle control corresponding to the position of the mobile vehicle device based on a result of a determination of the position of the mobile vehicle device. [14] A positioning device according to any one of claims 1 to 13, wherein the at least one processor is configured to cause the positioning device to transmit data indicating a result of a determination of a position of the mobile vehicle device to another device mounted in the vehicle. [15] A positioning method performed by at least one processor used in conjunction with at least one first communication device (8) configured to transmit a signal in a first frequency band and at least one second communication device (7) configured to communicate with a mobile vehicle device carried by a user of the vehicle using radio waves in a second frequency band different from the first frequency band, the positioning method comprising: Obtaining first data from the mobile vehicle device indicating a reception state at the mobile vehicle device of a signal transmitted by the first communication device; Obtaining second data indicating a distance of the second communication device to the mobile vehicle device, wherein the second data is determined by causing the second communication device to communicate with the mobile vehicle device; and Determining a location of the mobile vehicle device based on the first data and the second data. [16] Electronic vehicle key system comprising: a position determining device (4) including at least one processor (41) used in conjunction with at least one first communication device (8) configured to transmit a signal in a first frequency band and at least one second communication device (7) configured to perform wireless communication using radio waves in a second frequency band different from the first frequency band; a mobile vehicle device (2) which is a dedicated device for a user to operate a vehicle and which is designed to receive a signal transmitted from the first communication device and to perform the wireless communication using the second frequency band; and a mobile terminal (3) which is a universal information processing terminal and is designed to perform the wireless communication using the second frequency band, wherein the mobile vehicle device is designed to be activated based on reception of a signal in the first frequency band and then to initiate a wireless communication link with the positioning device using the radio waves in the second frequency band; transmitting data indicating a reception strength of a signal in the first frequency band through the wireless communication using the second frequency band; transmit a code indicating that a device type is the mobile vehicle device based on establishing a communication link with the positioning device; and to send and receive a distance measurement signal with the second communication device when a communication connection with the position determining device has been established, the mobile device is designed perform processing relating to a communication connection with the positioning device using the radio waves in the second frequency band; to transmit and receive a distance measurement signal with the second communication device when a communication link has been established with the position-determining device; and transmit a code indicating that a device type is not the mobile vehicle device based on establishing a communication link with the positioning device, the positioning device is designed obtain second data indicating a distance from the second communication device to a communication partner, the second data being determined by causing the second communication device to perform predetermined distance measurement communication; obtain a signal indicating the device type from the communication partner using the second communication device; determine, based on the signal obtained from the communication partner, whether the device type of the communication partner corresponds to the mobile vehicle device; to acquire first data of the mobile vehicle device as the communication partner, the first data indicating a reception state of the mobile vehicle device with respect to a signal transmitted from the first communication device when the device type of the communication partner is the mobile vehicle device; and determine a location of the mobile vehicle device based on the first data and the second data when the device type of the communication partner is the mobile vehicle device.

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