Location determination device, location determination system, wireless communication module, and computer program

Abstract

To provide a location determination device, a location determination system, a wireless communication module, and a computer program that can reduce power consumption during standby.SOLUTION: A DK-ECU as a location determination device includes a main controller 11 and a BLE module 12. Based on the fact that a vehicle parks, the main controller 11 goes into power saving mode (power off / sleep). The BLE module 12, on the other hand, maintains a state of being capable of a communication connection with a mobile device 9 while the vehicle is parked. The BLE module 12 periodically performs a CS ranging process, upon establishing a communication connection with the mobile device 9. The CS ranging process calculates distance based on received phase data for each frequency, which is acquired by sequentially transmitting and receiving continuous wave signals of different frequencies to and from the mobile device 9. The BLE module 12 activates the main controller 11 when a first distance calculated in the CS ranging process is less than a predetermined value.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] TECHNICAL FIELD The present disclosure relates to techniques for determining the location of a mobile device relative to a vehicle by wirelessly communicating with the mobile device. [Background technology]

[0002] Patent Document 1 discloses a configuration in which, in an in-vehicle system including one master unit and multiple slave units, the master unit detects the presence of a portable device near the vehicle based on the reception strength of a signal emitted from the portable device and activates the slave units. The master unit and slave units here are communication devices that perform wireless communication with a portable terminal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-171401 A Summary of the Invention [Problem to be solved by the invention]

[0004] According to the configuration disclosed in Patent Document 1, the communication module corresponding to the child device is not activated and remains in a stopped state until the communication module as the parent device detects the mobile device. Therefore, it is expected to have an effect of suppressing power consumption during standby (e.g., while parked). Based on the above configuration, the developers of this disclosure have also considered a configuration in which a target device, which is a specified device, is returned from a power-saving mode to a normal mode (i.e., activated) when the reception strength of a signal from not only the child device but also the mobile device becomes equal to or greater than a specified value.

[0005] However, when the developers verified the operation of a configuration that adopted a communication module that communicates in accordance with Bluetooth (registered trademark) Low Energy (hereinafter also referred to as BLE) as the parent unit, they discovered the following problem. That is, in the above configuration, even if the mobile device is more than 10 m away from the vehicle, the parent unit detects the mobile device and starts the target device. The reason for this is thought to be that the radio waves used in BLE have a frequency of 1 GHz or more, so they tend to travel in a straight line, and the reception strength is prone to variation due to multipath, etc.

[0006] In this configuration, the target device is started when the reception strength of the signal from the portable device reaches a predetermined value or more, so there is a risk that the target device may be started unnecessarily even if it is not actually located near the vehicle. Furthermore, the unnecessary start-up of the target device leads to an increase in power consumption during standby. The target device may be a variety of devices / modules, such as a computer, a communication module, or a circuit module.

[0007] The present disclosure has been made based on the above considerations or points of view, and one of its objectives is to provide a position determination device, a position determination system, a wireless communication module, and a computer program that can reduce power consumption during standby. [Means for solving the problem]

[0008] The position determination device disclosed herein is a position determination device that determines the position of a portable device relative to a vehicle, and is equipped with a first communication unit (12) that performs wireless communication with the portable device in accordance with Bluetooth (registered trademark), and a computer (11) that performs processing related to determining the position of the portable device, the computer having a normal mode and a power saving mode as states, the first communication unit being set to maintain a state in which it can communicate with the portable device even while the computer is in the power saving mode, the first communication unit executes a first ranging process that calculates a first distance, which is the distance from the first communication unit to the portable device, using data related to the reception phase, flight time, or arrival time of a radio signal transmitted from the portable device, and the first communication unit compares the first distance obtained as a result of the first ranging process with a predetermined value, and transitions the computer from the power saving mode to the normal mode based on the comparison result.

[0009] In the above configuration, the condition for returning the computer to the normal mode is that the first distance, which is determined based on a parameter corresponding to the propagation time of the signal, such as the reception phase or arrival time of the wireless signal transmitted from the portable device, becomes less than a predetermined value. Such a first distance has a smaller distance measurement error due to the communication environment than the reception strength. Therefore, according to the above configuration, it is possible to reduce the risk of starting the computer when it is not necessary to start it, such as when the portable device is far from the vehicle. Accordingly, it is possible to reduce power consumption during standby.

[0010] The position determination system included in the present disclosure is a position determination system comprising a first communication unit (12) that performs wireless communication with a portable device compliant with Bluetooth (registered trademark) and a computer (11) that performs processing related to determining the position of the portable device, wherein the computer has a normal mode and a power saving mode as states, and when the computer is in the power saving mode, the first communication unit executes a first ranging process that calculates a first distance, which is the distance from the first communication unit to the portable device, using the reception phase, flight time, or arrival time of a wireless signal transmitted from the portable device, and the first communication unit compares the first distance obtained as a result of the first ranging process with a predetermined value, and returns the computer from the power saving mode to the normal mode based on the comparison result.

[0011] The position determination system has the same configuration as the position determination device described above, and therefore the system also reduces power consumption during standby.

[0012] The wireless communication module included in the present disclosure is a wireless communication module that performs wireless communication with a portable device in accordance with Bluetooth (registered trademark), and includes an antenna (121) for communicating with the portable device, and a communication controller (123) that acquires data related to the reception phase, flight time, or arrival time of a wireless signal transmitted from the portable device based on a signal received by the antenna, and the communication controller maintains a state in which communication with the portable device is possible even while the vehicle is parked based on power from a battery installed in the vehicle, and when the vehicle is parked, performs a first ranging process to calculate a first distance, which is the distance from the vehicle to the portable device, using data related to the reception phase, flight time, or arrival time of the wireless signal, and compares the first distance obtained as a result of the first ranging process with a predetermined value, and outputs a signal to transition a predetermined target device installed in the vehicle from a power saving mode to a normal mode based on the comparison result.

[0013] The wireless communication module also makes it possible to reduce power consumption during standby for the same reasons as the position determination device.

[0014] The computer program included in the present disclosure includes instructions to cause a processor (901) of a portable device (9) equipped with a Bluetooth communication unit (93) for performing wireless communication compliant with Bluetooth (registered trademark) and a UWB communication unit (94) for performing ultra-wideband (UWB) communication to execute the following: establishing a communication connection with the vehicle via Bluetooth based on receiving a signal emitted from a vehicle to which the portable device is previously linked, returning a signal for ranging processing based on receiving a request to start a first ranging processing, which is ranging processing via Bluetooth communication, from the vehicle, and after returning the signal for ranging processing, sequentially transmitting continuous wave signals of different frequencies, activating the UWB communication unit when a request to start a second ranging processing, which is ranging processing via UWB communication, is received from the vehicle, and returning a UWB signal of a predetermined pattern when a UWB signal for ranging is received from the vehicle.

[0015] The computer program is a computer program for causing a normal device to function as a portable device that responds to a position determination device / system. Also, according to the computer program, the portable device can stop the operation of the UWB communication unit when it has not received a request to start the second ranging process from a vehicle, thereby reducing power consumption during standby.

[0016] In addition, the symbols in parentheses in the claims indicate a correspondence with the specific means described in the embodiments described below as one aspect, and do not limit the technical scope of the present disclosure. [Brief description of the drawings]

[0017] [Figure 1] 1 is a diagram showing an overall view of a vehicle electronic key system. [Diagram 2] FIG. 2 is a block diagram showing a configuration of a portable device. [Diagram 3]FIG. 2 is a block diagram showing the configuration of a DK-ECU. [Figure 4] FIG. 2 is a block diagram showing the configuration of a BLE module. [Diagram 5] FIG. 13 is a diagram illustrating a flow of a CS distance measurement process. [Figure 6] FIG. 2 is a functional block diagram of a main controller. [Figure 7] 6 is a flowchart for explaining the operation of the DK-ECU when the main controller is in a power saving mode. [Figure 8] 5 is a flowchart for explaining the operation of the DK-ECU when the main controller is in a normal mode. [Figure 9] 4 is a flowchart for explaining the operation of the DK-ECU in response to a user's approach to the vehicle. [Figure 10] 10 is a flowchart showing another example of the operation of the DK-ECU after the main controller is started up. [Figure 11] 10 is a flowchart showing the operation of a main controller when selecting a UWB module to be used for the next location determination depending on the result of device location determination. [Figure 12] FIG. 13 is a diagram for explaining an example of unnecessary anchors according to device positions. [Figure 13] 13 is a flowchart showing another example of the operation of the BLE controller in a situation where the main controller is in a power saving mode. [Figure 14] 13 is a flowchart showing another example of the operation of the BLE controller in a situation where the main controller is in a power saving mode. [Figure 15] 13 is a flowchart showing another example of the operation of the BLE controller in a situation where the main controller is in a power saving mode. [Figure 16] FIG. 4 is a diagram for explaining the operation of the in-vehicle system and the portable device in a first waiting state. [Figure 17] FIG. 11 is a diagram for explaining the operation of the in-vehicle system and the portable device in a second waiting state. [Figure 18]FIG. 11 is a diagram for explaining the operation of the in-vehicle system and the portable device in a third waiting state. [Figure 19] FIG. 13 is a diagram for explaining the operation of the in-vehicle system and the portable device in a position determination state. [Figure 20] FIG. 13 is a block diagram showing another configuration example of the in-vehicle system. [Figure 21] FIG. 13 is a block diagram showing another configuration example of the in-vehicle system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, an embodiment of a vehicle electronic key system to which the present disclosure is applied will be described with reference to the drawings. The present disclosure is not limited to the following embodiment, and various modified examples described below are also included in the technical scope of the present disclosure. Furthermore, in addition to the following, various modifications can be implemented without departing from the gist of the present disclosure. Various supplements and modified examples can be implemented in appropriate combinations as long as no technical contradictions arise. Components having the same function are given the same reference numerals, and their description may be omitted. In addition, when only a part of the configuration is mentioned, the description given elsewhere can be applied to the other parts.

[0019] <Overall structure> As shown in Fig. 1, the electronic key system for a vehicle according to this embodiment includes an in-vehicle system VS and a portable device 9. The in-vehicle system VS includes a digital key ECU (hereinafter referred to as DK-ECU) 1. ECU is an abbreviation for Electronic Control Unit, which means an electronic control device. DK is an abbreviation for Digital Key.

[0020] The DK-ECU1 is configured to be capable of wireless communication compliant with Bluetooth (registered trademark) Low Energy (hereinafter, referred to as BLE communication) with a portable device 9 carried by a user of the vehicle Hv. In the following, a case will be described in which the DK-ECU1 is configured to act as a master in data communication with the portable device 9, and the portable device 9 is configured to act as a slave. The term "master" can be read as "central" or "scanner." The term "slave" can be read as "peripheral" or "advertiser."

[0021] The DK-ECU1 establishes a communication connection with the portable device 9 by receiving an advertising signal from the portable device 9. The advertising signal is a BLE signal for notifying (i.e. advertising) the presence of the portable device 9 to other devices. The BLE signal is a wireless signal conforming to BLE. The BLE signal may include a code indicating a sender or a destination. The sender or destination may be expressed by a device ID or the like. Of course, as another aspect, the vehicle electronic key system may be configured such that the portable device 9 operates as a master in communication with the DK-ECU1, and the DK-ECU1 acts as a slave. The roles of each device are interchangeable. Furthermore, the functions and configurations of the DK-ECU1 and the portable device 9 may be appropriately changed in accordance with the exchange of roles.

[0022] In the present disclosure, a wireless signal conforming to the BLE standard is referred to as a BLE signal. In addition, among the BLE signals, a signal of an advertisement channel may be referred to as an advertisement signal, and a signal of a data channel may be referred to as a data signal. Of the 40 channels, channels with channel numbers 37 to 39 correspond to advertisement channels. In addition, channels with channel numbers 0 to 36 correspond to data channels. The definitions and specific frequency values ​​of advertisement channels and data channels are determined according to the BLE standard. In addition, in response to changes in the BLE standard, the configuration of the present disclosure may be appropriately modified and implemented so as to conform to the changed standard.

[0023] The in-vehicle system VS and the portable device 9 are configured to be capable of performing UWB communication, which is wireless communication using the UWB-IR (Ultra Wide Band - Impulse Radio) method. That is, the in-vehicle system VS and the portable device 9 are configured to be capable of transmitting and receiving impulse-shaped radio waves (hereinafter, impulse signals) used in UWB communication. The impulse signal used in UWB communication is a signal having a very short pulse width (e.g., 2 ns) and a bandwidth (i.e., ultra-wide bandwidth) of 500 MHz or more (strictly speaking, 499.2 MHz).

[0024] In addition, as specified by IEEE802.15.4z, a plurality of channels can be used in UWB communication. For example, the in-vehicle system VS communicates with the portable device 9 using the fifth channel of UWB communication. Of course, the in-vehicle system VS may be configured to be able to communicate with the portable device 9 using other channels such as the third channel and the ninth channel. The third channel is a channel with a center frequency of 4492 MHz, and the fifth channel is a channel with a center frequency of 6489.6 MHz. The ninth channel is a channel with a center frequency of 7987.2 MHz. IEEE (registered trademark) is an abbreviation for the Institute of Electrical and Electronics Engineers, which means the Institute of Electrical and Electronics Engineers. Each channel corresponds to a frequency band of ±250 MHz from the center frequency. In UWB communication, frequencies such as 3.1 GHz to 4.8 GHz and 6.0 GHz to 10.6 GHz can be used.

[0025] A variety of modulation methods can be used for UWB communication, including on-off keying (OOK), pulse position modulation (PPM), and pulse width modulation (PWM). The on-off modulation method expresses information (e.g., 0 and 1) by the presence / absence of an impulse signal. The pulse position modulation method modulates at the position where a pulse is generated. The pulse width modulation method expresses information by the pulse width. As an example, UWB communication between the in-vehicle system VS and the portable device 9 is performed by the OOK method. Data transmission by UWB communication is achieved by using multiple impulse signals. Hereinafter, the data signal exchanged in UWB communication is referred to as a UWB signal. Since the UWB signal includes multiple impulses, it can also be called a pulse sequence signal.

[0026] <About Mobile Device 9> The portable device 9 is a portable and general-purpose information processing terminal equipped with a BLE communication function. As the portable device 9, various communication terminals such as a smartphone and a wearable device can be adopted. A wearable device is a device that is worn on the user's body and can be of various shapes such as a wristband type, a watch type, a finger ring type, a glasses type, and an earphone type. The portable device 9 can also be called a user device, a key device, or the like.

[0027] The portable device 9 may be a smart key, which is a dedicated device as an electronic key for the vehicle Hv. The smart key is a device that is transferred to the owner together with the vehicle Hv when the vehicle Hv is purchased. The smart key can be understood as one of the accessories of the vehicle Hv. The smart key can adopt various shapes, such as a flat rectangular parallelepiped type, a flat ellipsoid type (so-called fob type), and a card type. The smart key can be called a vehicle portable device, a key fob, a key card, an access key, etc.

[0028] As shown in FIG. 2, the mobile device 9 includes a device control unit 90, a display 91, a touch panel 92, a BLE module 93, and a UWB module 94.

[0029] The device control unit 90 is a module that controls the overall operation of the portable device 9. The device control unit 90 is configured as a computer including, for example, a device processor 901, a memory 902, a storage 903, an input / output circuit 904, and the like. The device processor 901 is, for example, a CPU (Central Processing Unit). The memory 902 is a volatile storage medium such as a RAM (Random Access Memory). The storage 903 is configured to include a non-volatile storage medium such as a flash memory.

[0030] The storage 903 may store a device ID and a key code used in wireless authentication processing with the DK-ECU1. The key code may also be called an encryption key, etc. The storage 903 may have installed therein a digital key app that is application software for causing the portable device 9 to function as a vehicle key. The digital key app is an app for implementing secure communication with the DK-ECU1 and responding to inquiries / requests from the DK-ECU1. In this disclosure, the application software may be simply referred to as an app.

[0031] The display 91 is, for example, a liquid crystal display or an organic EL display. The display 91 displays an image in response to an input signal from the device control unit 90. The touch panel 92 is a capacitive touch panel and is layered on the display 91. The touch panel 92 is an input device provided in the portable device 9. The touch panel 92 and the display 91 correspond to an interface for the user to input a password for logging in to the digital key app into the portable device 9 and for pairing the portable device 9 with the DK-ECU1.

[0032] The BLE module 93 is a communication module for performing BLE communication. The BLE module 93 includes a reception strength detection unit that is a functional unit that measures the reception strength of a received signal. The measurement value of the reception strength itself may be called RSSI (Received Signal Strength Indicator / Indication). In addition to the received data, the BLE module 93 transmits data indicating the measured reception strength together with transmission source information to the device control unit 90.

[0033] The BLE module 93 is configured to be capable of transmitting and receiving a continuous wave (CW) signal of a predetermined waveform as a signal for CS (Channel Sounding) ranging, which will be described later, in addition to a modulated signal for data communication. The CW signal may be a sine wave or a triangular wave. The BLE module 93 may have a similar configuration to the BLE module 12 included in the in-vehicle system VS. The BLE module 93 may be configured in whole or in part as described for the BLE module 12. The BLE module 93 corresponds to a Bluetooth communication unit.

[0034] The UWB module 94 is a communication module for performing UWB communication. The UWB module 94 outputs received data to the device control unit 90. The UWB module 94 also transmits a UWB signal corresponding to the transmission data based on an instruction from the device control unit 90. The UWB module 94 may transmit a single impulse signal as a UWB signal for distance measurement based on an instruction from the device control unit 90. The operation of the UWB module 94 is controlled by the device control unit 90. The UWB module 94 corresponds to a UWB communication unit.

[0035] The device control unit 90 causes the BLE module 93 to transmit an advertising signal at a predetermined transmission interval. Furthermore, based on the BLE module 93 receiving a connection request from the DK-ECU1, the device control unit 90 performs a communication connection process with the DK-ECU1. When the device control unit 90 receives a BLE signal transmitted from the vehicle Hv, the device control unit 90 returns a response signal corresponding to the received signal. Based on the establishment of a communication connection with the DK-ECU1, the device control unit 90 may perform an authentication process by wireless communication (hereinafter, wireless authentication process). The wireless authentication process may be performed, for example, by a challenge-response method. When the device control unit 90 receives a challenge code from the DK-ECU1, the device control unit 90 may generate a response code using a key code and return the response code to the DK-ECU1.

[0036] The device control unit 90 executes communication for distance measurement based on a request from the DK-ECU 1. For example, the portable device 9 causes the BLE module 93 to transmit a CW signal of a specified channel based on a request from the DK-ECU 1. The interaction between the portable device 9 and the DK-ECU 1 (actually, the DK-ECU 1) will be described separately later.

[0037] Furthermore, when the portable device 9 receives a UWB signal transmitted from the in-vehicle system VS, it returns a response signal corresponding to the received signal. For example, when the portable device 9 receives a UWB signal as a search signal, it returns a UWB signal modulated with a code including its own device ID to the in-vehicle system VS as a response signal. The search signal is a signal for the in-vehicle system VS to search for the portable device 9, and is a type of signal that requests the portable device 9 to return a response signal. The UWB signals transmitted by the portable device 9 and the in-vehicle system VS may include a code indicating the source or destination.

[0038] The device control unit 90 maintains the standby state for the BLE module 93 even when it is not connected for communication with the DK-ECU1. The standby state is a state in which an advertising signal is periodically transmitted at a predetermined advertising interval. The standby state corresponds to a state in which an advertising state in which an advertising signal is being transmitted and a standby state in which an advertising signal is not being transmitted are repeated.

[0039] On the other hand, when a BLE link with the DK-ECU1 is not established, the device control unit 90 stops the UWB module 94. When a BLE link with the DK-ECU1 is established, the device control unit 90 starts the UWB module 94. This configuration reduces power consumption during standby.

[0040] The device control unit 90 may be configured to start the UWB module 94 on the condition that a UWB ranging start request is received from the DK-ECU1 via BLE after the BLE communication connection with the DK-ECU1 is established. The UWB ranging start request is a BLE signal requesting the start of UWB ranging processing. The UWB module 94 often consumes more power than the BLE module 93. Therefore, by reducing the time during which the UWB module 94 is activated, further power saving effects can be expected.

[0041] <About the in-vehicle system> As shown in FIG. 3, the in-vehicle system VS includes a DK-ECU1, a plurality of UWB modules 2, a body ECU3, an action sensor 4, and an actuator 5. The DK-ECU1 is individually connected to each of the plurality of UWB modules 2 by a cable. The DK-ECU1 is also connected to the body ECU3 via a dedicated communication cable or an in-vehicle network so that they can communicate with each other. The in-vehicle network is a communication network built in the vehicle Hv. As a standard for the in-vehicle network, various standards such as Controller Area Network (CAN: registered trademark), Ethernet (registered trademark), and FlexRay (registered trademark) can be adopted. The body ECU3 is connected to the action sensor 4 and the actuator 5. Of course, the connection form between the devices disclosed here is only an example and can be changed as appropriate.

[0042] The DK-ECU1 is an ECU that determines a device position in cooperation with the UWB module 2. In this disclosure, the device position means the relative position of the portable device 9 with respect to the vehicle Hv. For example, the DK-ECU1 determines whether the portable device 9 is present inside the vehicle based on the communication status between the multiple UWB modules 2 and the portable device 9. The DK-ECU1 corresponds to a position determination device. Since the portable device 9 corresponds to a user, determining the device position corresponds to determining the user's position.

[0043] The DK-ECU1 is disposed in the vehicle interior, for example, in the instrument panel. The DK-ECU1 may be attached to an overhead console, a right or left C-pillar, under the driver's seat, etc. The C-pillar refers to the third pillar from the front among the pillars provided on the vehicle Hv.

[0044] As shown in Fig. 3, the DK-ECU1 includes a main controller 11, a BLE module 12, an input / output circuit 13, and a power supply circuit 14. The main controller 11 is a computer that executes various processes related to determining the device position. The main controller 11 includes a main processor 111, a memory 112, and a storage 113. The main processor 111 is, for example, a CPU. The main processor 111 can be called an ECU processor or the like. The memory 112 is a volatile storage medium, for example, a RAM.

[0045] The storage 113 includes a non-volatile storage medium such as a flash memory. The storage 113 stores a device location determination program executed by the main processor 111. Execution of the device location determination program by the main processor 111 corresponds to execution of a location determination method corresponding to the device location determination program. The storage 113 also stores a device ID of the portable device 9. The storage 113 also stores data indicating the mounting position of each UWB module 2 in the vehicle Hv.

[0046] The main controller 11 has a normal mode and a power saving mode as power states, or in other words, operation modes (or in other words, states). The normal mode refers to a state in which power is supplied to the main controller 11 and various processes such as position determination can be executed. The power saving mode is, for example, a so-called power-off state in which the power supply to the main controller 11 is completely cut off.

[0047] The power saving mode may be a sleep mode or a hibernation mode. The sleep mode refers to a state in which the supply of power to the main processor 111 is stopped with the data being worked on, in other words, the execution state of the program, stored in a volatile memory such as a RAM. The hibernation state refers to a state in which the supply of power to the main processor 111 and the memory 112 is stopped with the execution state of the program stored in a writable non-volatile memory such as a flash memory. The power saving mode may be called a stop mode, since it is a state in which operation is stopped in one aspect.

[0048] The power saving mode may be an operation mode that is activated intermittently, for example, once every 10 seconds, 1 minute, or 10 minutes, and communicates with the body ECU 3 and an external server. Furthermore, the power saving mode may be a state in which functions are limited compared to the normal mode, in other words, an operation mode in which only some functions can be executed. For example, the power saving mode may be a state in which the position determination function is stopped while the authentication function by the backup means is maintained. The backup means refers to, for example, transponder communication or NFC (Near Field Communication). The main controller 11 corresponds to a computer. Details of the main controller 11 will be described separately later.

[0049] The BLE module 12 is a communication module for performing BLE communication. Like the BLE module 93 included in the mobile device 9, the BLE module 12 is configured to be capable of transmitting and receiving a CW signal for each channel as a signal for CS ranging in addition to a modulated signal for data communication. The BLE module 12 is supplied with power from the vehicle battery even while the driving power source is set to off. The BLE module 12 is in a standby state constantly or intermittently using the power supplied from the vehicle battery even while the vehicle Hv is parked.

[0050] The BLE module 12 periodically scans and attempts to connect to the portable device 9 even while the main controller 11 is in the power saving mode. The BLE module 12 executes a CS ranging process, which will be described later, based on the communication connection with the portable device 9. In this manner, the BLE module that maintains a state in which it can receive signals from the portable device 9 even while the main controller 11 is in the power saving mode is referred to as a gateway module in this disclosure. The gateway module can also be interpreted as a BLE module that plays a role in activating the main controller 11 based on the communication status with the portable device 9. The communication status here mainly refers to the device distance and reception strength obtained as a CS ranging result. The device distance is the distance from a communication module mounted on the vehicle Hv, such as the BLE module 12 or the UWB module 2, to the portable device 9. The gateway module can also be interpreted as a BLE module that communicates and connects to the portable device 9. Details of the BLE module 12 will be described separately below. The BLE module 12 corresponds to a wireless communication module and a first communication unit.

[0051] The input / output circuit 13 is a circuit module that enables the DK-ECU 1 to communicate with other devices such as the body ECU 3. The input / output circuit 13 may include analog circuit elements, ICs, and PHY chips that comply with the communication standards of in-vehicle networks. The input / output circuit may include a chip set that converts logical signals into actual electrical signals in interfaces such as CAN, Ethernet (registered trademark), and UART.

[0052] The power supply circuit 14 is a circuit module that supplies power to each of the main controller 11, the BLE module 12, and the input / output circuit 13. The power supply circuit 14 converts a voltage (e.g., a battery voltage) input from a power cable into a voltage suitable for the operation of each of the main controller 11, the BLE module 12, and the input / output circuit 13, and outputs the voltage to each part.

[0053] The power supply circuit 14 may have a function of switching the power supply of the DK-ECU1 from an off state to an on state based on a predetermined start-up signal being input from the BLE module 12. The power off state of the DK-ECU1 corresponds to a state in which power supply to components other than the power supply circuit 14 and the BLE module 12 is stopped. The power on state of the DK-ECU1 corresponds to a state in which the main controller 11 is operating in normal mode. The main controller 11 cooperates with the power supply circuit 14 to transition to a power saving mode based on the driving power being set from on to off.

[0054] The UWB module 2 is a communication module for performing UWB communication. Like the UWB module 94 included in the portable device 9, the UWB module 2 is configured to be able to transmit and receive UWB signals. The UWB module 2 is a communication device used to determine the position of the portable device 9, and is also called an anchor or a reference station. The UWB module 2 corresponds to a second communication unit.

[0055] The UWB module 2 includes an antenna for UWB communication, a transmission / reception circuit, a UWB controller, etc. The transmission / reception circuit is a circuit that performs signal processing related to modulation and demodulation. The UWB controller is a microcomputer that controls the operation of the UWB module 2 and generates UWB ranging data, which will be described next.

[0056] The UWB module 2 performs UWB ranging processing based on an instruction from the DK-ECU 1. The UWB ranging processing is processing for measuring the device distance based on the propagation time (in other words, flight time) of radio waves from the UWB module 2 to the portable device 9. The UWB ranging processing includes a step of transmitting a UWB signal of a predetermined pattern toward the portable device 9, and a step of receiving a UWB signal as a response signal from the portable device 9. In the UWB ranging processing, the UWB signal exchanged between the UWB module 2 and the portable device 9 may be a single impulse signal, or may be a pulse sequence signal in which a plurality of impulse signals are arranged in a predetermined pattern. The UWB ranging processing corresponds to a second ranging processing.

[0057] The UWB controller measures a round trip time (RTT), which is the time elapsed from transmitting a UWB signal to receiving a response signal from the portable device 9, and calculates the device distance based on the RTT. The RTT corresponds to the round trip flight time of the UWB signal. The RTT takes a value according to the distance from the UWB module 2 to the portable device 9. The UWB controller of this embodiment calculates the device distance by multiplying half of the value obtained by subtracting a predetermined correction value from the RTT by the propagation time of the radio wave. The correction value here is a parameter for offsetting the response processing time in the portable device 9 and the delay time in the UWB module 2. A specific value of the correction value can be designed as appropriate. The correction value may be 0.

[0058] In the present disclosure, the device distance calculated by the UWB ranging process is referred to as the second distance. The second distance may also be referred to as the UWB ranging value. Data indicating the second distance is the UWB ranging data. If no response is obtained from the portable device 9 in the UWB ranging process, the UWB module 2 adopts a value indicating that the measurement was not possible or a sufficiently large predetermined value as the second distance. The UWB module 2 transmits the generated UWB ranging data to the DK-ECU1. Since the flight time corresponds to the distance, calculating the RTT substantially corresponds to calculating the distance from the UWB module 2 to the portable device 9. Therefore, the process of calculating the RTT and providing it to the DK-ECU1 is also included in the concept of the UWB ranging process (second ranging process). The process of converting the RTT into the distance may be performed by the main controller 11.

[0059] The UWB module 2 may generate location-related data indicating a location / area where the portable device 9 may be located, based on the second distance and its own installation position. The UWB module 2 may transmit the location-related data to the DK-ECU 1 instead of or together with the UWB ranging data.

[0060] The in-vehicle system VS includes an in-vehicle anchor 2A, a right anchor 2B, a left anchor 2C, and a rear anchor 2D as UWB modules 2. The in-vehicle anchor 2A is a UWB module 2 arranged in the vehicle cabin. The in-vehicle anchor 2A is arranged, for example, on the instrument panel, the upper end of the windshield, or the center of the ceiling part of the vehicle. The in-vehicle anchor 2A may be accommodated inside the housing of the DK-ECU1. The right anchor 2B, the left anchor 2C, and the rear anchor 2D are all UWB modules 2 arranged on the outer surface of the vehicle Hv. The right anchor 2B is built into the outer door handle for the right front seat. The right front seat is a seat located to the right of the center console among the front seats. When the handle is provided on the right side of the instrument panel, the right front seat corresponds to the driver's seat. The right anchor 2B may be arranged on the right B pillar, the right side mirror, or the right side sill. The right anchor 2B can be called a right outdoor unit. The right anchor 2B corresponds to the right communication unit.

[0061] The left anchor 2C is built into the outer door handle for the left front seat. The left anchor 2C may be arranged on the left B-pillar, the left side mirror, or the left side sill. The left anchor 2C can be called the left outdoor unit. The left anchor 2C corresponds to the left communication unit. The rear anchor 2D is arranged near the rear bumper or the trunk door. The rear anchor 2D can be called the rear outdoor unit. The right anchor 2B, the left anchor 2C, and the rear anchor 2D can be called outdoor units or outer anchors. The configuration and performance of each UWB module 2 may be substantially the same.

[0062] Each UWB module 2 operates according to instructions from the DK-ECU1. Each UWB module 2 starts up based on instructions from the DK-ECU1 and performs UWB ranging processing. The state in which the UWB module 2 is capable of communication can be called an active state or a wake state. The UWB module 2 that has performed UWB ranging processing stops operating spontaneously or based on instructions from the DK-ECU1. The state in which the operation is stopped may be a power-off state or a state in which only some functions are active. The state in which the operation is stopped may be called a sleep state or an invalid state. Each UWB module 2 may be configured to spontaneously attempt UWB ranging processing at a predetermined interval. A configuration including the DK-ECU1 and the UWB module 2 corresponds to a position determination system.

[0063] The body ECU 3 is an ECU that detects a user's operation (action) on the vehicle Hv based on an input signal from the action sensor 4, and operates the actuator 5 in response to the detected user's operation. The action sensor 4 here is a sensor for detecting a user's action on the vehicle Hv. The action can also be called an operation or an instruction. Examples of actions on the vehicle Hv include a locking operation, an unlocking operation, taking a seat, pressing a start switch, and depressing a brake pedal. The action sensor 4 includes, for example, a door sensor provided on an outer door handle, a start switch, a brake pedal sensor, and a seating sensor. The unlocking operation is a user operation for unlocking the vehicle Hv. The locking operation is an operation for locking the vehicle Hv. The DK-ECU 1 can detect a touch operation on a door sensor as an unlocking operation / locking operation.

[0064] The door sensor is a sensor for detecting a user operation for unlocking and locking the doors of the vehicle Hv. The door sensor may be a touch sensor or a push switch. The start switch is a push switch that the user uses to turn on / off the power source for driving. The start switch may also be called a power switch.

[0065] The actuator 5 is, for example, a lock motor, a headlight, a welcome lamp, etc. The lock motor is a motor that switches between locking and unlocking the door. The welcome lamp is an in-vehicle lighting device that illuminates the road surface near the door. The welcome lamp is disposed on the side mirror, the side sill, the lower end of the door panel, etc.

[0066] When the body ECU 3 detects a predetermined determination event that requires the position of the portable device 9 to be determined, such as an unlocking operation, the body ECU 3 transmits an event occurrence notification signal to the DK-ECU 1. The DK-ECU 1 may return from the power saving mode to the normal mode (i.e., start up) based on the input of the event occurrence notification signal from the body ECU 3, and execute control and processing related to determining the device position. Note that the DK-ECU 1 may be provided with a function for detecting a determination event.

[0067] In addition to the body ECU 3 and UWB module 2 described above, various in-vehicle devices can be directly or indirectly connected to the DK-ECU 1. For example, the DK-ECU 1 is connected to a power supply ECU, a cellular module, an NFC module, etc., so that they can communicate with each other via an in-vehicle network or using dedicated cables. The power supply ECU is an ECU that controls the on / off of a power supply for running mounted on the vehicle Hv. The power supply for running is a power supply for running the vehicle Hv, and refers to the ignition power supply when the vehicle Hv is an engine vehicle. When the vehicle Hv is an electric vehicle, the power supply for running refers to the system main relay.

[0068] The cellular module is a communication module that performs cellular communication such as 4G and 5G. The NFC module is a communication module for performing Near Field Communication. NFC refers to communication with a communicable distance of about several cm to 10 cm. The vehicle Hv may be equipped with a plurality of NFC modules. The NFC module may be used as a tool for pairing the mobile device 9 and the DK-ECU1. The pairing here includes so-called bonding that stores keys exchanged between devices.

[0069] <Configuration and Function of BLE Module> Here, the configuration and function of the BLE module 12 will be described. As shown in FIGS. 3 and 4, the BLE module 12 includes an antenna 121, an RF core 122, and a BLE controller 123.

[0070] The antenna 121 is an antenna element for transmitting and receiving radio waves in the frequency band used for BLE communication, that is, the 2.4 GHz band. The 2.4 GHz band can be understood as a frequency band including a plurality of channels (0 to 39Ch) used for BLE communication. The antenna 121 is electrically connected to the RF core 122. A channel can also be referred to as a frequency. Among the plurality of channels assigned to BLE, the channels actually used for communication (in other words, the used frequency / used channel) change over time by frequency hopping or by an instruction from the BLE controller.

[0071] The RF core 122 is a circuit module that performs signal processing related to transmission and reception of wireless signals. The RF core 122 may include a modulation circuit, a demodulation circuit, a frequency conversion circuit, an amplifier circuit, a local oscillator, and the like. The RF core 122 also includes an input / output terminal for outputting a signal to the antenna 121 and receiving a signal from the antenna 121. The RF core 122 is connected to the BLE controller so as to be able to communicate with each other. The RF core 122 demodulates a signal received by the antenna 121 and provides the signal to the BLE controller 123. The RF core 122 also modulates transmission data input from the BLE controller 123 and causes the data to be emitted as radio waves from the antenna 121. The RF core 122 may be realized as an IC chip (i.e., a transmission / reception IC). The BLE controller 123 corresponds to a communication controller.

[0072] The RF core 122 is configured to be capable of transmitting and receiving a CW signal for each channel as a function for CS ranging in addition to a modulated signal for data communication. The RF core 122 also includes a reception strength detection unit E1 and a reception phase detection unit E2. The reception strength detection unit E1 is a functional unit that measures the reception strength of a received signal. The reception strength detection unit E1 outputs data indicating the detected reception strength to the BLE controller 123.

[0073] The reception phase detection unit E2 is a circuit that detects the reception phase, which is the phase angle of the reception signal relative to the output signal of the local oscillator, when a CW signal is received. The phase angle of the reception signal relative to the output signal of the local oscillator corresponds to the reception phase. In other words, the reception phase can be interpreted as the output value of an arctangent whose input value is, for example, the ratio of the Q (Quadrature-Phase) component to the I (In-Phase) component of the reception signal. The magnitude of the I component corresponds to the strength of the in-phase component of the reception signal. The magnitude of the Q component corresponds to the strength of the quadrature component of the reception signal. The I component is obtained by multiplying the reception signal by the carrier wave output by the local oscillator. The Q component is obtained by multiplying the reception signal by a phase-shifted signal that shifts the phase of the output signal of the local oscillator by 90°. The phase-shifted signal can be obtained by passing the output signal of the local oscillator through a phase shift circuit, which is a circuit that shifts the phase by 90°.

[0074] The local oscillator is a circuit that generates a sine wave or cosine wave of a carrier frequency, and is realized using, for example, a voltage-controlled oscillator (VCO). The reception phase may be determined based on an IQ signal whose frequency has been reduced to the baseband. The detected reception phase information is used to calculate the device distance.

[0075] The RF core 122 provides the BLE controller 123 with the detection value of the reception phase of the CW signal in association with information indicating the frequency in use (e.g., a channel number). The RF core 122 detects the transmission and reception phase of the CW signal as part of the ranging process every time the frequency in use is switched. In other words, the BLE controller 123 is provided with data indicating the reception phase for each frequency.

[0076] The BLE controller 123 is a microcomputer that controls the RF core 122. The BLE controller 123 includes a processor 124, a memory 125, a storage 126, and an input / output circuit 127. "I / O" in FIG. 4 represents a circuit for input / output, that is, an input / output circuit. The BLE controller 123 plays a role in controlling the transfer of data with the DK-ECU1. Specifically, the BLE controller 123 provides the DK-ECU1 with the received data input from the RF core 122 sequentially or based on a request from the DK-ECU1. The BLE controller 123 also outputs the transmission data input from the DK-ECU1 to the RF core 122.

[0077] The BLE controller 123 includes a CS ranging unit F1, a reception strength acquisition unit F2, a start-up unit F3, and a report processing unit F4. The CS ranging unit F1, the reception strength acquisition unit F2, the start-up unit F3, and the report processing unit F4 may each be a software module or a hardware module. The following descriptions of the CS ranging unit F1, the reception strength acquisition unit F2, the start-up unit F3, and the report processing unit F4 can be replaced with the BLE module 12 or the BLE controller 123 as appropriate.

[0078] The CS ranging unit F1 is a functional unit that executes CS ranging. The CS ranging here refers to a process of generating distance data indicating a device distance based on a distance-related value, which is a parameter indicating the length of a propagation path of a wireless signal to the portable device 9. The CS ranging includes a process of performing two-way or one-way communication with the portable device 9 to acquire the distance-related value. The CS ranging can also be called High Accuracy Distance Measurement (HADM) or phase difference ranging. In the present disclosure, a series of processes including communication for CS ranging may also be referred to as CS ranging processing. The CS ranging processing corresponds to a first ranging processing.

[0079] The distance-related value may be a parameter that takes a value according to the propagation time of a wireless signal, in other words, the flight time. For example, the reception phase of a signal transmitted from the portable device 9 corresponds to the distance-related value. The distance-related value may be the arrival time of a wireless signal transmitted from the portable device 9. The arrival time of a wireless signal may alternatively be the RTT. These distance-related values ​​are parameters different from the reception strength. In the present embodiment, the CS ranging unit F1 acquires the reception phase for each frequency as a CS ranging process, and calculates the device distance based on the reception phase. The reception phase is the phase difference between the CW signal transmitted by the portable device 9 and the CW signal received by the BLE module 12. The reception phase can be called the transmission / reception phase difference, the single frequency phase difference, or the first-order phase difference.

[0080] The CS ranging unit F1 acquires the reception phase for each frequency, for example, by a one-way method. The one-way method is a method in which the reception phase of the CW signal transmitted from the portable device 9 is directly adopted as a calculation material for the phase difference between frequencies, on the premise that the initial phase of the CW signal for each frequency transmitted from the portable device 9 is constant. The reception phase (in other words, the single frequency phase difference) used as a calculation material for the phase difference between frequencies can also be acquired by a passive two-way method, an active two-way method, or the like. The passive two-way method and the active two-way method will be described later as a supplementary explanation.

[0081] 5 is a flowchart showing an example of a CS ranging process, and includes steps S101 to S111. The CS ranging process includes a preparation phase for adjusting the implementation conditions of ranging, a collection phase for collecting reception phases by actually transmitting and receiving CW signals, and a calculation phase for calculating distances based on the collected reception phases for each frequency. In the present disclosure, wireless communication for acquiring distance-related values, such as transmitting and receiving CW signals, is also referred to as ranging communication.

[0082] Step S101 is a step in which the BLE module 12 transmits a CS ranging start request to the mobile device 9. The CS ranging start request is a BLE signal requesting to start CS ranging. The CS ranging start request may be transmitted using a data channel. The mobile device 9 returns a positive response signal (so-called Ack) to the BLE module 12 based on receiving the CS ranging start request (S102).

[0083] The BLE controller 123 transmits a ranging setting notification signal based on receiving an Ack in response to a CS ranging start request from the mobile device 9 (S103). The ranging setting notification signal is a BLE signal indicating specifications related to the implementation of communication for CS ranging. The specifications related to the implementation of ranging communication include an initial phase setting value, a hopping interval, a channel transition amount, and an initial frequency. The initial phase setting value is basically set to 0. The hopping interval indicates a time for switching a frequency, in other words, a time for maintaining one frequency. The hopping interval may be the same as a connection interval used in data communication. The channel transition amount is a parameter indicating an amount of change in a channel at the time of channel switching. The channel transition amount may be the same value as a hop increment during data communication. In other words, the channel transition amount in CS ranging may be determined by the hop increment. The initial frequency is the frequency of a CW signal to be transmitted first in a series of ranging communications. The initial frequency can be determined randomly. The frequency information can be expressed by, for example, a channel number.

[0084] Upon receiving the ranging setting notification signal, the portable device 9 returns an Ack to the BLE module 12 (S104). Upon receiving the Ack from the portable device 9, the BLE module 12 transitions to a state in which it can receive a signal of the initial frequency (S105). The state in which it can receive a wireless signal can also be called a receiving state or a scanning state.

[0085] The mobile device 9 starts transmitting a CW signal at the initial frequency when a predetermined time has elapsed since returning the Ack (S106). The transmission of the CW signal can be stopped, for example, when a certain time has elapsed since the start. The CW transmission time, which is the time for which the CW signal is continuously transmitted, may be set shorter than the hopping interval. Note that the mobile device 9 may start transmitting a CW signal based on receiving a CW transmission request from the BLE module 12 after receiving the ranging setting notification signal. The CW transmission request is a BLE signal that requests the transmission of a CW signal.

[0086] When the BLE module 12 receives the CW signal from the mobile device 9, it detects the reception phase and stores the reception phase data together with frequency information (e.g., channel number) in the memory 125 (S107). The BLE module 12 and the mobile device 9 automatically switch the operating frequency at the hopping interval previously agreed upon in step S103 (S108). The frequency after the change can be uniquely determined from the frequency before the change and the previously agreed upon channel transition amount. For example, the channel to be used after the change can be a channel number obtained by adding a hop increment setting value to the channel number before the change.

[0087] When the mobile device 9 switches the channel in use, it transmits a CW signal of the new channel in use (S109). When the BLE module 12 switches the channel in use, it also transitions to a state in which it can receive a signal of the new channel in use. Then, the BLE module 12 observes the reception phase at the frequency after the switching (S110).

[0088] The BLE module 12 and the portable device 9 repeat steps S108 to S110 until they collect the reception phases for all channels (0 to 36Ch) that can be used for data communication. The BLE module 12 and the portable device 9 may end the repetitive process at the timing when they have collected a predetermined required number of reception phases for each channel. The required number here may be the same as the number of data channels, or may be smaller than that. A configuration in which the required number is set to 37 corresponds to a configuration in which reception phases for all channels are collected. The greater the number of channels for which reception phases are collected, the higher the ranging accuracy described below can be. On the other hand, the time and power consumption required for ranging communication may increase. The required number may be 3, 4, 5, 8, 10, 16, etc. The required number may be set to any value from 2 to 37. Of course, if the number of data channels is 37 or more, the required number may be a value of 37 or more.

[0089] The BLE module 12 transmits a ranging end notification signal to the mobile device 9 at the timing when the necessary number of reception phases for each frequency have been collected (S111). The ranging end notification signal is a data signal for notifying the end of ranging communication. Upon receiving the ranging end notification signal, the mobile device 9 transitions to a normal data communication mode. The normal data communication mode corresponds to a state in which predetermined data such as voice data can be transmitted and received. The transmission and reception of the ranging end notification signal is an optional element and may be omitted. Upon receiving the ranging end notification signal, the mobile device 9 may return an Ack to the BLE module 12.

[0090] After the CS ranging unit F1 has completed collection of the reception phase for each frequency, it calculates a phase change coefficient (α) in step S111. The phase change coefficient is a parameter that indicates the degree to which the reception phase changes in response to a change in frequency. The phase change coefficient can also be called the degree of phase change, the amount of phase shift, or the correlation coefficient between phase and frequency.

[0091] The phase change coefficient is calculated based on the reception phase observed at two arbitrary frequencies, for example, a first frequency and a second frequency. If the difference frequency between the first frequency and the second frequency is Δf, the inter-frequency phase difference between the reception phases observed at the first frequency and the second frequency is Δφ, and the phase change coefficient is α, then there is a relationship of α=Δφ / Δf. Note that the inter-frequency phase difference (Δφ) is the difference between the reception phases observed at two different frequencies. The inter-frequency phase difference can be called the two-frequency phase difference or the quadratic phase difference. The inter-frequency phase difference corresponds to the amount of phase angle displacement caused by a change in the frequency used.

[0092] The CS ranging unit F1 of this embodiment calculates a regression line showing the relationship between the frequency and the reception phase based on the reception phase for each frequency, and adopts the slope of the regression line as the phase change coefficient. This is because the slope of the regression line indicates the amount of change in the reception phase relative to the amount of change in the frequency. The regression line and its slope can be calculated by various methods, such as the least squares method. If the regression line is expressed as y=a·x+b, the coefficient a of x corresponds to the slope of the regression line. In other words, the CS ranging unit F1 can calculate the coefficient (a) as the phase change coefficient (α). According to this configuration, it is possible to calculate the phase change coefficient based on the inter-frequency phase difference and the differential frequency for each combination of multiple frequencies. In the above formula, "x" is a variable corresponding to the frequency, and "y" is a variable corresponding to the reception phase. The regression line can also be called an approximation line.

[0093] The CS ranging unit F1 may provisionally calculate a first regression line based on all observed reception phase data, and may recalculate a second regression line after excluding values ​​(so-called outliers) whose distance from the provisionally calculated first regression line is equal to or greater than a predetermined value. In this case, the CS ranging unit F1 may adopt the slope of the second regression line as the phase change coefficient. In this way, the phase change coefficient used in distance calculation may be determined based on a regression line whose population is data excluding outliers. This configuration may improve the accuracy of the inter-frequency phase difference, and therefore the ranging accuracy.

[0094] The CS ranging unit F1 may calculate the inter-frequency phase difference (Δφ), the differential frequency (Δf), and the phase change coefficient for each combination of frequencies for which the reception phase can be observed. The CS ranging unit F1 may use the average or median of the phase difference change coefficients for each combination of frequencies as the phase difference change coefficient to be used for distance calculation.

[0095] Step S112 is a step in which the CS ranging unit F1 calculates the device distance (D) using a phase difference change coefficient generated based on received phase information at multiple frequencies. If the device distance is D, there is a relationship between the differential frequency Δf and the phase difference between frequencies (Δφ) as follows: D∝C·Δφ / (2π·Δf)=C·α / 2π. The parameter "C" in the above equation indicates the propagation speed of radio waves (3×10^8m / sec). The CS ranging unit F1 calculates the device distance based on this equation. For example, the CS ranging unit F1 calculates the device distance using Equation 1: D=k·C·α / 2π. The parameter k in Equation 1 is a design value and is set to 1.0 or 0.5. The value of k can be determined depending on whether the transmission and reception phase difference is calculated as a phase change coefficient for one way or a round trip. The CS ranging unit F1 stores the calculated device distance data in the memory 125. In this disclosure, the communication distance calculated by the BLE module 12 in the CS ranging process is referred to as the first distance. The first distance can also be referred to as a CS ranging value.

[0096] In another embodiment, the CS ranging unit F1 may calculate a tentative value (d) of the device distance using Δf and Δφ for each frequency combination, and use the average or median of the calculated values ​​as the device distance for the antenna in use. The tentative value (d) of the device distance for a certain frequency combination may be calculated using d=k·C·Δφ / (2π·Δf), etc.

[0097] Among the series of processes shown in Fig. 5, the steps executed by the BLE module 12 are executed in cooperation with the CS ranging unit F1 and the RF core 122. In the above, as an example, the BLE module 12 determines and notifies the implementation conditions for CS ranging, but this is not limiting. The portable device 9, instead of the BLE module 12, may determine the specifications for implementing ranging communication and transmit a ranging setting notification signal. Also, the execution subject of each step may be interchangeable. The above sequence may be executed by the portable device 9 acting as the main subject (in other words, the master).

[0098] The reception strength acquisition unit F2 is configured to acquire data indicating the reception strength of a signal from the mobile device 9 for each frequency from the RF core 122. While the BLE module 12 is communicatively connected to the mobile device 9, the BLE module 12 periodically transmits and receives a data signal for communication check with the mobile device 9. The reception strength acquisition unit F2 acquires reception strength data when the data signal for communication check is received. Note that communication for communication check may be performed at a connection interval. Communication for communication check may also be performed every time channel hopping is performed. The connection interval corresponds to the first interval.

[0099] The signal used to detect the reception strength is not limited to a data signal for communication confirmation. It may be a normal data signal or an advertising signal. In the following, the reception strength refers to the reception strength of a signal transmitted from the mobile device 9 unless otherwise noted.

[0100] The activation unit F3 is a software / hardware module that activates the main controller 11 based on the fact that the first distance calculated in the CS distance measurement process is less than a predetermined value (hereinafter also referred to as the activation distance). For example, the activation unit F3 transmits an activation signal to the main controller 11 based on the fact that the state in which the first distance is less than the activation distance continues for a predetermined time or a predetermined number of times. The activation signal is a signal for activating the main controller 11.

[0101] Here, startup refers to switching from the power saving mode to the normal mode. Startup can be rephrased as recovery, enablement, activation, wake-up, etc. Startup of the main controller 11 may be achieved in cooperation with the power supply circuit 14. For example, the startup unit F3 may output a control signal for starting the main controller 11 to the power supply circuit 14, and the power supply circuit 14 may start the main controller 11 upon receiving the control signal. Note that transition from the normal mode to the power saving mode can be rephrased as sleep, shutdown, etc. The state in the power saving mode can also be called a sleep state.

[0102] The activation distance can be set to, for example, 2.5 m, 3.0 m, 5.0 m, 6.0 m, etc. The smaller the activation distance is set to, the less frequently the main controller 11 is activated, and the more power consumption can be suppressed. On the other hand, the smaller the activation distance is set to, the later the timing at which the system activates in response to the approach of the user. Therefore, when the user is running towards the system, the system may not be activated in time, which may impair user convenience.

[0103] The report processing unit F4 transmits reception strength data indicating the reception strength acquired by the reception strength acquisition unit F2 and first distance data indicating the first distance calculated by the CS distance measurement unit F1 to the main controller 11. The transmission of various data may be performed periodically while the main controller 11 is operating in the normal mode. The report processing unit F4 may transmit various data based on a request from the main controller 11.

[0104] The BLE module 12 periodically performs the CS ranging process while the main controller 11 is in the power saving mode and is communicatively connected to the mobile device 9. On the other hand, after the main controller 11 returns to the normal mode, the BLE module 12 stops performing the periodic CS ranging process. Of course, the BLE module 12 may continue the periodic CS ranging process even after the main controller 11 returns to the normal mode. The BLE module 12 may be configured to perform the CS ranging process only when a determination event occurs while the main controller 11 is in the normal mode.

[0105] <Main controller functions> The main controller 11 includes, as functional blocks, a communication control unit G1 and a position determination unit G2 as shown in FIG. 6. Each functional block is enabled in the normal mode. The communication control unit G1 is a software / hardware module that controls the operation of each of the BLE module 12 and the UWB module 2. For example, when the communication control unit G1 detects the occurrence of a determination event, in other words, a predetermined user action, it causes the BLE module 12 to perform CS ranging processing. The occurrence of a determination event may be detected by the body ECU 3 as described above, or may be detected by the main controller 11 based on signals input from various sensors and ECUs.

[0106] The communication system control unit G1 also performs a cyclic measurement process, which is a process for causing each of the multiple UWB modules 2 to perform UWB ranging in turn. The communication system control unit G1 periodically performs the cyclic measurement process, for example, while operating in normal mode. The communication system control unit G1 may dynamically change the cyclic measurement interval, which is the interval at which the cyclic measurement process is performed, depending on the value of the device distance observed within a fixed time period and the state of the vehicle Hv. The communication system control unit G1 may perform the cyclic measurement process based on the detection of the occurrence of a determination event.

[0107] The position determination unit G2 determines the device position based on the second distance for each UWB module 2 obtained as a result of the patrol measurement process. The device position is the position of the portable device 9 relative to the vehicle Hv. The device position can be expressed by a plurality of areas / zones that are set in advance in the vehicle Hv, such as inside the vehicle, a nearby area, an intermediate area, and a distant area. The inside of the vehicle is the inside of the vehicle. The inside of the vehicle can include the inside of the trunk. The inside of the vehicle may be divided into the inside of the vehicle and the inside of the trunk.

[0108] The vicinity area refers to an area outside the vehicle where the distance from the vehicle Hv is less than a predetermined vicinity determination value. The vicinity determination value is a parameter that defines the vicinity area outside the vehicle. The vicinity determination value is set to, for example, 1.0 m, 1.5 m, 2 m, etc. The vicinity area can be interpreted as an area where automatic unlocking / locking of the vehicle Hv can be performed. The vicinity area may also be referred to as a passive entry area.

[0109] The far area refers to an area where the distance from the vehicle Hv is equal to or greater than a predetermined far judgment value. The far judgment value is a parameter for judging that the portable device 9 is not present around the vehicle Hv. The far judgment value is set to, for example, 5.0 m, 6.0 m, 10 m, or 12 m. The intermediate area refers to an area intermediate between the far area and the near area. The intermediate area may be a so-called welcome area in which a predetermined welcome control, such as turning on the exterior lights, is executed upon entry of the portable device 9 into the area. The intermediate area may be an area in which a predetermined control that is not executed when the portable device 9 is present far outside the vehicle is executed / started, such as authentication by wireless communication with the portable device 9, tracking of the device position, and shortening of the position judgment period. The intermediate area may also be called a standby area, a surrounding area, or the like. In addition, the intermediate area may be an area in which a user can use a function to remotely park / leave the vehicle Hv.

[0110] The above-mentioned near area, middle area, and far area are subdivisions of the outside-vehicle area. The position determination unit G2 may simply determine whether the mobile device 9 is present inside the vehicle. Further, the position determination unit G2 may determine not only the distance from the vehicle Hv to the mobile device 9 but also the direction in which the device is present. The direction in which the device is present is the direction in which the mobile device 9 is present as viewed from the vehicle Hv / the in-vehicle anchor. The direction in which the device is present can be expressed as right, left, rear, front, etc. The near area may be divided into a right area, a left area, and a rear area, respectively. The right area refers to a range outside the vehicle that is less than the near determination value from the right door handle or the right B-pillar. The left area and the rear area can also be defined based on specific parts of the vehicle Hv. The middle area may also be subdivided into front, rear, left, and right in the same way as the near area.

[0111] As described above, the position determination unit G2 of the present embodiment determines the staying area, which is the area where the mobile device 9 is present. As another aspect, instead of / along with the determination of the staying area, the position determination unit G2 may calculate the device position coordinates. The device position coordinates refer to the position coordinates where the mobile device 9 is present in a two-dimensional / three-dimensional coordinate system based on a predetermined position of the vehicle Hv. The calculation of the device position coordinates can be carried out by a method similar to three-point positioning or multi-point positioning in the technical field of GPS or position estimation.

[0112] The main controller 11 transmits device position data, which is data indicating the determination result of the device position, to a predetermined ECU such as the body ECU 3. While in the normal mode, the main controller 11 may periodically generate device position data. Further, the main controller 11 may perform a patrol measurement process in response to the occurrence of a determination event and generate device position data.

[0113] <Operating Example of DK-ECU> While the main controller 11 is in the power saving mode, the BLE module 12 periodically performs an activation determination process as shown in FIG. 7 (S11). The activation determination process is a process for determining whether or not an activation condition of the main controller 11 is satisfied. The activation condition includes that the first distance is less than the activation distance. Therefore, the activation determination process includes a CS ranging process. The activation condition may include that the reception strength from the portable device 9 observed by the BLE module 12 is equal to or greater than a predetermined intensity threshold. In this case, the activation determination process may include a process of measuring the reception strength of an advertising signal or a data signal from the portable device 9. The activation condition may include various items related to the communication state with the portable device 9. The items related to the communication state include reception strength, device distance, degree of variation in reception strength within a certain time, whether or not communication connection is possible, and SN ratio. The activation determination process may be appropriately designed to include a process for collecting values / data for each item constituting the activation condition.

[0114] When the start-up condition is satisfied (S12 YES), the BLE module 12 transmits a start-up signal to the main controller 11 to return to the normal mode (S13). When various data related to the communication state with the mobile device 9 collected in the start-up determination process does not satisfy the start-up condition (S12 NO), the BLE module 12 re-executes the start-up determination process after a predetermined waiting time has elapsed. The start-up determination process may be performed every time an advertisement / data signal is received from the mobile device 9. The start-up determination process may be performed in parallel with processes such as communication connection and data communication.

[0115] During the normal mode, the main controller 11 periodically performs a stop determination process (S21) as shown in Fig. 8. The stop determination process may be triggered by a user operation to turn off the power supply for driving, a door lock operation, or the like.

[0116] The stop determination process is a process for determining whether or not the stop condition of the main controller 11 is satisfied. The stop condition includes that the vehicle Hv is locked with the running power source turned off. The stop condition may include that the smallest value of the multiple second distances collected in the patrol measurement process is equal to or greater than a predetermined stopping distance. The stopping distance may be set to 10 m, 15 m, or the like. The stop condition may also include that a state in which the reception strength is less than a predetermined stopping strength continues for a predetermined period of time. The stop condition may also include various items related to the communication state with the portable device 9. The stop determination process may be appropriately designed to include a sequence for collecting values / data for each item constituting the start condition.

[0117] When the stop condition is satisfied (S22 YES), the main controller 11 performs a predetermined stop preparation process and then transitions to the power saving mode (S23). The stop preparation process may include, for example, storing the current vehicle state in the storage 113 and notifying the BLE module 12 that the mode will soon transition to the power saving mode. When the various data related to the communication state with the portable device 9 collected in the stop determination process does not satisfy the stop condition (S22 NO), the main controller 11 performs the stop determination process after a predetermined waiting time has elapsed.

[0118] FIG. 9 is a flowchart showing a more specific operation example of the DK-ECU1 in a scene where a user approaches a parked vehicle Hv. The flowchart shown in FIG. 9 shows a flow from when the main controller 11 returns from the power saving mode to the normal mode until the position determination process is performed. For convenience, a series of processes related to the startup of the main controller 11 and the position determination is referred to as a user approach reaction process. As shown in FIG. 9, the user approach reaction process may include steps S201 to S210. At the time when step S201 is performed, the main controller 11 is in the power saving mode. In addition, the portable device 9 is sufficiently far away from the vehicle Hv, and the portable device 9 and the BLE module 12 are not connected to each other.

[0119] Step S201 is a step in which the BLE controller 123 determines whether or not a communication connection with the mobile device 9 has been established. If a communication connection with the mobile device 9 has been established (S201 YES), the BLE controller 123 starts periodic execution of CS ranging (S202). The periodic execution of CS ranging can be continued until, for example, the communication connection with the mobile device 9 is disconnected or the main controller 11 is started up.

[0120] Step S203 is a step for determining whether or not the device distance obtained by CS ranging (i.e., the first distance) is less than the activation distance. Step S203 is performed every time CS ranging is performed. "D1" in FIG. 9 indicates the first distance. "ThD1" indicates the activation distance. The first distance used for comparison with the activation distance, in other words, for determining whether or not to activate the main controller 11, may be the most recently calculated value.

[0121] If the first distance is less than the activation distance (S203 YES), the BLE controller 123 as the activation unit F3 activates the main controller 11 (S204). The BLE controller 123 stops the periodic execution of the CS ranging process based on the activation of the main controller 11 (S205). Steps S201 to S203 correspond to the activation determination process described above.

[0122] The first distance used to determine whether to activate main controller 11 may be the average or median of the first distances observed within a fixed time period, that is, the moving average / moving median. A configuration in which main controller 11 is activated based on the moving average / median of the first distances being equal to or greater than the activation threshold value can further reduce the risk of activating main controller 11 unnecessarily.

[0123] When the main controller 11 is started, it transitions each UWB module 2 to a communication-enabled state (S206). Then, the main controller 11 starts periodic execution of a tour measurement process (S207). The periodic execution of the tour measurement process can be continued until, for example, the power source for driving the vehicle Hv is turned on or the communication connection with the portable device 9 is terminated.

[0124] Prior to the execution of the patrol measurement process, the main controller 11 may transmit a UWB ranging start request to the portable device 9 by BLE. This enables the portable device 9 to activate the UWB module 94 and respond to a UWB signal from the vehicle Hv. The transmission of the UWB ranging start request is an optional element and may be omitted. For example, in a configuration in which the portable device 9 always activates the UWB module 94, the transmission of the UWB ranging start request can be omitted. The contents of the advance preparation processes for various ranging processes can be changed according to the configuration of the portable device 9.

[0125] Step S208 is a step in which main controller 11 collects, as a result of the cyclic measurement process, second distance data from each of the multiple UWB modules 2. When the collection of the second distance data is completed, main controller 11 executes step S209.

[0126] Step S209 is a step in which the main controller 11 determines the device location based on the second distances observed by the multiple UWB modules 2. Various algorithms can be adopted as the device location determination algorithm. For example, the main controller 11 determines that the device location is inside the vehicle when the second distance observed by the in-vehicle anchor 2A is less than a predetermined indoor determination value. The indoor determination value can be set to, for example, 1 m. Also, the main controller 11 may determine that the device location is outside the vehicle when the second distance observed by the in-vehicle anchor 2A is equal to or greater than a predetermined value.

[0127] In a state where the main controller 11 determines that the portable device 9 is present outside the vehicle, if there is an outdoor unit observing a second distance less than the proximity determination value, the main controller 11 may determine that the device location is a nearby area. If there is no outdoor unit with a second distance less than the proximity determination value and there is an outdoor unit observing a second distance less than the far determination value, the main controller 11 may determine that the device location is a middle area. If there is no outdoor unit observing a second distance less than the far determination value, the main controller 11 may determine that the device location is a far area. If the UWB module 2 observing the smallest second distance is the left anchor 2C, the main controller 11 may determine that the portable device 9 is present on the left side of the vehicle.

[0128] As described above, the main controller 11 may calculate the device position coordinates by combining the second distances of the multiple UWB modules 2. In a configuration in which the UWB modules 2 report position-related data to the DK-ECU 1, the main controller 11 may determine the device position by combining the position-related data reported from each UWB module 2. The device position may also be determined using the reception strength of a signal from the portable device 9 observed by the BLE module 12 and the UWB module 2. For example, when the reception strength at the interior anchor 2A is greater than the maximum reception strength observed at the outdoor unit by a predetermined value or more, and the second distance observed at the interior anchor 2A is within a predetermined value (e.g., 2 m), the device position may be determined to be inside the vehicle.

[0129] When the main controller 11 completes the determination of the device position, it transmits device position data indicating the determination result to the body ECU 3. Based on the device position data provided by the DK-ECU 1, the body ECU 3 can execute predetermined control such as unlocking / locking the vehicle Hv and turning on the power.

[0130] In the above, the control pattern in which the BLE module 12 stops performing periodic CS ranging after the main controller 11 is started has been described, but the operation of the DK-ECU1 is not limited to this. The DK-ECU1 may continue performing periodic CS ranging even after the main controller 11 is started. FIG. 10 is a flowchart for explaining the operation of the DK-ECU1 in this control pattern, and shows a sequence following step S204 in FIG. 9. Step S301 shown in FIG. 10 is a process after the main controller 11 is started, in which the main controller 11 starts each UWB module 2. Step S302 is a step in which the main controller 11 starts performing periodic cyclic measurement process.

[0131] Step S303 is a step in which the BLE module 12 performs CS ranging at a timing when UWB ranging is not being performed by the UWB module 2. The BLE module 12 can acquire the timing when UWB ranging is not being performed by the UWB module 2 from the main controller 11. Note that after the main controller 11 is started, the BLE module 12 may be configured to perform CS ranging processing based on an instruction from the main controller 11. Step S303 can be performed at a predetermined interval.

[0132] Step S304 is a step in which the main controller 11 acquires second distances from the multiple UWB modules 2 and acquires the first distance from the BLE module 12. Step S305 is a step in which the main controller 11 as the position determination unit G2 determines the device position based on the first distance data and the multiple second distance data. Step S306 is a step in which the main controller 11 transmits the determination result of the device position to the body ECU 3, similar to step S210.

[0133] According to the above-described configuration in which the first distance is used in addition to the second distance to determine the device position, it is expected that the accuracy of determining the position can be improved.

[0134] <Additional information on UWB modules used for cyclic measurement processing> Although the configuration in which the cyclic measurement process is performed using all the UWB modules 2 has been described above, it is not necessary to use all the UWB modules 2. For example, the main controller 11 may be configured to classify the multiple UWB modules 2 into unnecessary anchors and useful anchors based on the previous device position determination result, and not use the unnecessary anchors in the cyclic measurement process. The unnecessary anchors are UWB modules 2 that do not perform UWB ranging process in the cyclic measurement process, in other words, UWB modules 2 that are not operated. The unnecessary anchors can be called invalid anchors. The useful anchors are UWB modules 2 that perform UWB ranging process in the cyclic measurement process. The UWB modules 2 other than the unnecessary anchors correspond to useful anchors. The useful anchors can be called valid anchors.

[0135] Fig. 11 is a flowchart showing an example of the operation of the main controller 11 corresponding to this technical idea, and includes steps S401 to S403. The flowchart shown in Fig. 11 can be executed in response to the completion of the determination process of the device position in the previous patrol measurement process or the like.

[0136] Step S401 is a step in which the main controller 11 refers to the previous determination result of the device location. Step S402 is a step in which the main controller 11 classifies each UWB module 2 into an unnecessary anchor or a useful anchor based on the device location information read in step S401.

[0137] For example, when the main controller 11 determines that the portable device 9 is present in the left area of ​​the vehicle Hv as shown in Fig. 12, it sets the right anchor 2B as an unnecessary anchor. When the main controller 11 determines that the portable device 9 is present on the right side of the vehicle Hv, it sets the left anchor 2C as an unnecessary anchor. In this way, the main controller 11 may set the outer anchor located on the opposite side to the device presence direction as an unnecessary anchor.

[0138] When the main controller 11 determines that the portable device 9 is outside the vehicle, the main controller 11 may set the interior anchor 2A as an interior anchor as an unnecessary anchor until the door / window is opened. When the main controller 11 determines that the portable device 9 is inside the vehicle, the main controller 11 may set the right anchor 2B, the left anchor 2C, and the rear anchor 2D as exterior anchors as unnecessary anchors until the door / window is opened.

[0139] Data indicating the correspondence between the device position / device presence direction and the unnecessary anchors may be stored in advance in the storage 113 in the form of a data table, a program, or the like. The main controller 11 can dynamically change the settings of the unnecessary anchors according to the device position / device presence direction based on the preregistered data / program.

[0140] In one aspect, the main controller 11 can be understood as a computer that stops the UWB module 2 installed in an unwanted zone determined according to the device location. The unwanted zone corresponds to the outer surface of the vehicle on the opposite side to the device location. When the portable device 9 is inside the vehicle, the outer surface of the vehicle can correspond to the unwanted zone. When the portable device 9 is outside the vehicle, the interior of the vehicle can correspond to the unwanted zone.

[0141] If there is a UWB module 2 that has been set as an unnecessary anchor, the main controller 11 stops the operation of that UWB module 2 (S403). The setting of the unnecessary anchor may be updated for each circular search process. Also, the setting of the unnecessary anchor may be reset every time the circular search process is performed a predetermined number of times (e.g., three times). A configuration in which the setting of the unnecessary anchor is reset every predetermined number of times can reduce the risk of erroneously determining the device position by continuously disabling some UWB modules 2.

[0142] <Startup determination process> 13, the BLE controller 123 may be configured to start regular CS ranging when the reception strength is equal to or greater than a predetermined value after the BLE controller 123 has established a communication connection with the portable device 9. In other words, the BLE controller 123 may be configured to execute the CS ranging process on the condition that the BLE controller 123 has established a communication connection with the portable device 9 and the reception strength is equal to or greater than a predetermined value.

[0143] Fig. 13 is a flowchart showing an example of control corresponding to this technical idea, and includes steps S501 to S506. The flowchart shown in Fig. 13 can be implemented as an alternative process to steps S201 to S204 in Fig. 9. That is, step S501 can be executed periodically while the main controller 11 is in the power saving mode.

[0144] 13 is a step in which the BLE controller 123 determines whether or not a communication connection with the mobile device 9 has been established. If a communication connection has been established (S501 YES), periodic data communication with the mobile device 9 and measurement of the reception strength are started (S502). Periodic data communication with the mobile device 9 may be continued while the communication connection is maintained. If the communication connection with the mobile device 9 is terminated, the process is repeated from step S501. As another aspect, the periodic communication may be transmission and reception of an advertising signal.

[0145] Step S503 is a step of judging whether or not the reception strength of a data signal transmitted from the portable device 9 as periodic data communication is equal to a predetermined strength threshold. Step S503 is performed every time periodic communication is executed. "RSSI" in FIG. 13 indicates the observed value of the reception strength of the signal from the portable device 9. "ThRSSI" indicates the strength threshold. The strength threshold is set to a value according to the reception strength observed in a situation where the device distance is a predetermined value (e.g., 10 m). The ideal environment refers to a situation where no obstacle exists between the portable device 9 and the BLE module 12. The strength threshold can be set by testing or simulation.

[0146] The reception strength used for the comparison with the strength threshold in step S503, in other words, for determining whether or not to perform CS ranging, may be the most recently observed value. Also, the reception strength used for determining whether or not to perform CS ranging may be the average or median of the reception strength observed within a fixed period of time, that is, the moving average / moving median. This configuration can reduce the risk of performing CS ranging processing unnecessarily.

[0147] If the reception strength is equal to or greater than the strength threshold (S503 YES), the BLE controller 123 starts periodic execution of CS ranging (S504). Step S505 is a step of determining whether or not the latest first distance obtained by the CS ranging process is less than the activation distance. The determination of step S505 is performed every time the CS ranging process is executed.

[0148] If the first distance is less than the activation distance (S505 YES), the BLE controller 123 activates the main controller 11 (S506). The subsequent processing may be similar to steps S205 to S210 in Fig. 9 or steps S301 to S306 in Fig. 10. Steps S501 to S505 also correspond to an example of the above-mentioned activation determination processing.

[0149] According to the above configuration, it is possible to reduce the risk of performing CS ranging processing in a situation where the reception strength is low, that is, in a scene where the distance between the portable device 9 and the vehicle Hv is likely to still be far away. Naturally, reducing the frequency of performing CS ranging processing leads to a reduction in power consumption. According to the above configuration, it is possible to further reduce power consumption. Note that the intensity threshold can also be considered as a parameter for starting CS ranging in one aspect.

[0150] Furthermore, as shown in Fig. 14, the BLE controller 123 may be configured to perform CS ranging processing under the condition that the BLE controller 123 is already connected to the mobile device 9 for communication and that the variation in reception strength is less than a predetermined value. "δ" in Fig. 14 indicates the degree of variation in reception strength. "Thδ" in Fig. 14 indicates a threshold value for the degree of variation in reception strength. The degree of variation in reception strength can be expressed by variance in statistics. Of course, the degree of variation in reception strength may be expressed by standard deviation or the difference between the maximum value and the minimum value.

[0151] 14 are similar to the above-mentioned steps S501 to S502 and steps S504 to S506, and therefore detailed description thereof will be omitted. Step S603 is a step for determining whether the degree of variation in reception strength observed within a fixed period of time is less than a predetermined threshold. If the degree of variation in reception strength is less than the predetermined threshold (S603 YES), the BLE controller 123 starts regular execution of CS ranging processing. In other words, the BLE controller 123 may be configured not to start regular execution of CS ranging processing when the degree of variation in reception strength is equal to or greater than the threshold.

[0152] In general, when there is an object between the portable device 9 and the vehicle Hv that blocks radio waves, such as a wall, the degree of variation in the reception strength is greater than when there is no wall. Paradoxically, a large degree of variation in the reception signal suggests that the portable device 9 may be present inside a building such as a house or an office. Naturally, when the portable device 9 as a key for the vehicle Hv is present inside a building, the vehicle Hv is less likely to be used by a user. Therefore, the need to execute the CS ranging process itself is also low. According to the configuration to which the control flow shown in FIG. 14 is applied, the risk of executing the CS ranging process can be reduced in a scene in which the portable device 9 is present inside a building. Accordingly, the power consumption during standby can be further reduced. The standby state here corresponds to a state in which the vehicle Hv is parked. In addition, by reducing the frequency of execution of unnecessary CS ranging processes, the risk of the main controller 11 and the UWB module 2 being unnecessarily activated can also be reduced.

[0153] Of course, the technical ideas described with reference to Fig. 13 and Fig. 14 can be implemented in combination. For example, the BLE controller 123 may be configured to perform CS ranging processing under the conditions that the BLE controller 123 is already connected for communication with the mobile device 9, the reception strength is equal to or greater than a predetermined value, and the variation in the reception strength is less than a predetermined value. This configuration can further reduce malfunctions and power consumption of the system.

[0154] In addition, although the above describes an example of operation on the assumption that the BLE module 12 is communicatively connected to the mobile device 9, the communicative connection between the BLE module 12 and the mobile device 9 is not essential. As shown in FIG. 15, the BLE module 12 may successively detect the reception strength of a BLE signal, such as an advertising signal, periodically transmitted from the mobile device 9, and execute the CS ranging process when the reception strength becomes equal to or greater than the intensity threshold. Steps S701 to S704 shown in FIG. 15 correspond to the above-mentioned steps S503 to S506. The flowchart shown in FIG. 15 may be started when the main controller 11 changes from the normal mode to the power saving mode. Note that step S701 is executed at a predetermined interval while the main controller 11 is in the power saving mode. The first interval may be an advertising interval.

[0155] <Interaction between mobile devices and in-vehicle systems> Here, the interaction between the mobile device 9 and the in-vehicle system VS for each state of the in-vehicle system VS will be described. When the BLE module 12 starts the CS ranging process on the condition that the reception strength is equal to or greater than a predetermined value, the in-vehicle system VS can take a first waiting state, a second waiting state, a third waiting state, or a position determination state as a status according to the device position.

[0156] The first waiting state is a state in which there is no communication connection with the portable device 9. The first waiting state corresponds to a situation in which the portable device 9 is outside the communication range of the BLE module 12, in other words, a situation in which the portable device 9 is sufficiently far away from the vehicle Hv. The first waiting state can be called a connection waiting state.

[0157] In the first waiting state, the mobile device 9 transmits an advertising signal at an interval that is a predetermined advertising interval plus a random time (so-called advertising delay) as shown in Fig. 16. Also, the BLE module 12 enters a reception waiting state at a predetermined scan interval and searches for a signal from the mobile device 9. The size of the scan window, which corresponds to the length of time for which the reception waiting state is maintained, may be designed as appropriate.

[0158] The lengths of the scan interval and the advertising interval can also be set to various values. The values ​​of the various intervals are preferably set to values ​​that allow a quick connection when the user approaches the vehicle Hv. The advertising interval can be set to a value between 20 milliseconds and 400 milliseconds, such as 37.5 milliseconds, 50 milliseconds, 80 milliseconds, or 100 milliseconds. Of course, the advertising interval may be set to a value exceeding 400 milliseconds within a range that complies with the BLE standard. The advertising interval may be set to a value shorter than the scan interval.

[0159] The second waiting state is a state in which the mobile device 9 and the BLE module 12 are connected for communication and the reception strength is less than the strength threshold. The second waiting state can be called a strength determination state. In the second waiting state, the BLE module 12 does not perform CS ranging communication. In the second waiting state, as shown in FIG. 17, the mobile device 9 and the BLE module 12 periodically perform data communication at a predetermined connection interval. The communication contents may be various, such as a communication confirmation. The connection interval may be set to a value from 7.5 milliseconds to 200 milliseconds, such as 30 milliseconds or 40 milliseconds. The connection interval may also be set to a value exceeding 200 milliseconds within a range conforming to the BLE standard.

[0160] The third waiting state corresponds to a state in which the mobile device 9 and the BLE module 12 are connected for communication, the reception strength is less than the strength threshold, and the device distance is equal to or greater than the activation distance. In the third waiting state, the mobile device 9 and the BLE module 12 periodically perform data communication at a predetermined connection interval, and also periodically perform communication for CS ranging. The third waiting state can be called a distance determination state.

[0161] The CS ranging interval, which is the interval at which the BLE module 12 executes CS ranging communication, can be set to, for example, twice or three times the connection interval. It is preferable that the CS ranging interval is set longer than the connection interval as shown in FIG. 18. By making the CS ranging interval longer than the execution interval of periodic data communication, it is possible to expect an effect of further suppressing power consumption. The CS ranging interval corresponds to the second interval. Note that "CS-Ranging Interval" in FIG. 18 indicates the CS ranging interval. In one CS ranging communication, CW signals can be transmitted and received at multiple frequencies. One CS ranging communication may be a communication in which a CW signal is transmitted and received at one frequency. The time for one CS ranging communication can be adjusted by the length of the CW signal (tone).

[0162] In the first, second, and third waiting states, the main controller 11 and the UWB module 2 maintain a sleep state. Note that, as described with reference to Fig. 9, in a configuration in which reception strength information is not used to determine the activation of the main controller 11, etc., the second waiting state is omitted, and a transition can be made from the first waiting state (connection waiting state) to the third waiting state (distance determination state).

[0163] The position determination state is a state in which the main controller 11 periodically performs patrol measurement processing. The position determination state corresponds to a state in which the portable device 9 is present within an activation distance from the vehicle Hv (actually, the BLE module 12). In the position determination state, the main controller 11 and the UWB module 2 are activated. In the position determination state, the in-vehicle system VS periodically performs data communication by BLE and ranging communication by UWB with the portable device 9. The position determination state can be rephrased as a system operation state.

[0164] The UWB ranging interval, which is an interval at which the main controller 11 causes the UWB module 2 to execute UWB ranging communication, can be set to, for example, three or four times the connection interval. The UWB ranging interval is preferably set longer than the connection interval as shown in FIG. 19. By lengthening the UWB ranging interval, it is expected that the effect of further suppressing power consumption can be achieved. Note that "UWB-Ranging Interval" in FIG. 19 indicates the UWB ranging interval. One UWB ranging communication can include UWB ranging communication in multiple UWB modules 2. In other words, one UWB ranging communication shown in FIG. 19 may be communication corresponding to a cyclic measurement process. The UWB ranging interval can also be referred to as a cyclic measurement interval. The UWB ranging interval can be set to a value between 150 milliseconds and 400 milliseconds, such as 180 milliseconds or 280 milliseconds. The UWB ranging interval may be longer than the CS ranging interval. Also, the UWB ranging interval may be the same as or shorter than the CS ranging interval.

[0165] <Summary of the embodiment> The 2.4 GHz band signal used in BLE is easily affected by reflectors and human bodies. Therefore, even if the distance is constant, the reception strength is likely to vary depending on how the user holds the portable device 9 and the surrounding environment. The developers of the present disclosure have considered a comparative configuration in which the first distance is not used and the main controller 11 and the like are activated when the reception strength reaches a predetermined value or more. The threshold value for the reception strength in the comparative configuration is set to a value corresponding to the reception strength observed in a situation in which the device distance is 5.5 m in an ideal environment. The description of the main controller 11 and the like means, for example, the main controller 11 and the UWB module 2.

[0166] When the system was tested in the above comparative configuration, the main controller 11 and the like were activated when the user held the portable device 9 in his / her hand, even when the device distance was 10 m. Also, when the user had the portable device 9 in his / her back pocket, the main controller 11 and the like were not activated until the device distance was 2.4 m. Thus, the comparative configuration has a variation in the area in which the main controller 11 and the like are activated. If the main controller 11 is activated even when the portable device 9 is away from the vehicle, this leads to an increase in dark current. Also, a configuration in which the main controller 11 is activated only after the portable device 9 approaches the vicinity of the vehicle Hv may impair user convenience.

[0167] In contrast to such a comparative configuration, in the above configuration, it is determined whether or not to start the main controller 11 based on the first distance determined based on the propagation time of a signal from the portable device 9, not on the reception strength. The first distance determined according to the propagation time of a signal has a smaller distance measurement error due to the communication environment than the reception strength. In other words, the variation in the distance measurement from the vehicle Hv to the portable device 9 is reduced. According to such a configuration of the present embodiment, it is possible to reduce the risk of unnecessarily starting the main controller 11 even though the portable device 9 is not actually near the vehicle Hv. Furthermore, it is possible to reduce the current consumption during standby. Furthermore, according to the configuration of the present embodiment, it is possible to reduce the variation in the area in which the main controller 11 and the like are started, so that the system operation can be stabilized. Furthermore, it is possible to reduce the risk of confusing the user due to a malfunction or delay in the operation of the system.

[0168] In the above configuration, the UWB module 2 is also activated after the main controller 11 is activated. In other words, the UWB module 2 is also stopped while the main controller 11 is in the power saving mode. The UWB module 2 can also maintain a stopped state until the first distance becomes less than the activation distance. This can reduce the activation frequency of the UWB module 2, thereby further reducing power consumption. The above configuration can also be interpreted as a configuration in which the UWB module 2 is transitioned to a communication-enabled state based on the first distance observed by the BLE module 12 becoming less than a predetermined value.

[0169] In the above, the BLE module 12 indirectly activates the UWB module 2, but the present invention is not limited to this. The BLE module 12 may transmit an activation signal to the UWB module 2 when the CS ranging result falls short of the activation distance. The activation order of the main controller 11 and the UWB module 2 may be reversed. For example, the BLE module 12 may activate some or all of the UWB modules 2 when the CS ranging result falls short of the activation distance. Then, the UWB module 2 or the BLE module 12 may activate the main controller 11 when the ranging result of at least one UWB module 2 is less than a predetermined value.

[0170] After the main controller 11 is started, the main controller 11 may cooperate with the body ECU 3 to execute welcome control such as turning on welcome lights and operating an air conditioner. This configuration corresponds to a system in which the main controller 11 executes welcome control based on the first distance measured by the BLE module 12 through CS ranging becoming less than the activation distance. As described above, the first distance determined by CS ranging represents the device distance more accurately than the reception strength. Therefore, according to the configuration in which the welcome control is executed based on the first distance becoming less than a predetermined value, the risk of executing well control unnecessarily can be reduced compared to the configuration in which the welcome control is executed based on the reception strength becoming equal to or greater than a predetermined value. Various devices such as the main controller 11 and a UWB module can be the target device. The target device may be the body ECU 3 or the like.

[0171] <System configuration variation (1)> In the above embodiment, the BLE module 12 is disposed inside the housing of the DK-ECU1, but the present invention is not limited thereto. As shown in Fig. 20, the BLE module 12 may be disposed outside the housing of the DK-ECU1. The BLE module 12 disposed outside the housing operates to activate the DK-ECU1 when the CS ranging result falls below the activation distance. The body ECU 3 and the like are omitted from Fig. 20.

[0172] <System configuration variation (2)> The in-vehicle system VS may include a distance measurement module 12β as a BLE module in addition to the gateway module 12α. As described above, the gateway module 12α is a BLE module that communicates with the portable device 9 even while the main controller 11 is in a power saving mode and wakes up the main controller 11 based on the CS distance measurement result. The gateway module 12α has a configuration equivalent to the BLE module 12 described above. "BLE-GW" in FIG. 21 indicates a module that functions as the gateway module 12α among the in-vehicle modules that perform BLE communication. "GW" is an abbreviation for gateway. The expression "gateway module" can be replaced with "representative module" or "BLE-GW module". In FIG. 21, the body ECU 3 and the like are omitted from the illustration.

[0173] The ranging module 12β is a BLE module that functions as an anchor. The ranging module 12β performs CS ranging processing based on an instruction from the main controller 11. "BLE-CS" in FIG. 21 indicates that the ranging module is a module for CS ranging among the in-vehicle BLE modules. The expression "ranging module" can be replaced with "BLE-CS module", "BLE anchor", "CS anchor", etc. The ranging module 12β may be, for example, a BLE module dedicated to ranging. The ranging module 12β may be a BLE module used only for ranging and reception strength measurement. Furthermore, the ranging module 12β may temporarily perform data communication with the portable device 9 while having a primary role of ranging.

[0174] The ranging module 12β stops operating while the main controller 11 is in the power saving mode. As another embodiment, the ranging module 12β may be configured to be activated intermittently and perform CS ranging processing even while the main controller 11 is in the power saving mode. For example, the ranging module 12β may be activated at the timing when the gateway module 12α performs CS ranging processing, and may eavesdrop (sniff) on the CW signal transmitted from the portable device 9 and detect the reception phase for each frequency.

[0175] Sniffing / sniffing is a technique in which a BLE module other than the gateway module 12α uses channel information provided by the gateway module 12α to eavesdrop on communication between the mobile device 9 and the gateway module 12α. The channel information is information indicating a channel used for data communication between the gateway module 12α and the mobile device 9 (hereinafter, channel information). The channel information may be a specific channel number, or a parameter indicating a transition rule of the channel in use (so-called hop increment). It is preferable that the channel information includes a currently used channel number and a hop increment. The channel information may be deployed to each ranging module 12β via the main controller 11. Also, the channel information may be deployed to each ranging module 12β directly from the gateway module 12α, in other words, without going through the main controller 11. The BLE module other than the gateway module 12α refers to the ranging module 12β.

[0176] In BLE, frequency hopping is performed after communication connection, so normally only the gateway module 12α connected to communication can capture the data signal from the mobile device 9. In contrast, according to the sniffing technology, channel information is deployed to each ranging module 12β, so that the ranging module 12β can also capture the data signal from the mobile device 9. This is because the ranging module 12β can recognize which channel out of many channels available in BLE can be received to receive the signal from the mobile device 9 by referring to the channel information. As a result, the ranging module 12β can detect the reception strength, reception phase, reception time, etc. of the signal from the mobile device 9 without communication connection. Therefore, according to the configuration to which the sniffing technology is applied, there is an advantage that multiple BLE modules can perform CS ranging processing in parallel.

[0177] In the present disclosure, the BLE module disposed inside the housing of the DK-ECU1 is referred to as an internal module, and the BLE module provided outside the housing is referred to as an external module. In FIG. 21, the internal module functions as the gateway module 12α, but this is not limiting. As described above, the gateway module 12α may be an external module.

[0178] FIG. 21 shows a configuration in which multiple external modules as distance measurement modules 12β are connected to the DK-ECU1. The multiple distance measurement modules 12β can be distributed and arranged on the right side, left side, rear end, and part or all of the front end of the vehicle Hv. Possible locations for BLE modules on the side of the vehicle include B-pillars, C-pillars, side mirrors, door handles, side sills, and roof edges. Possible locations for BLE modules at the rear end of the vehicle include inside the rear bumper, near the license plate, the upper / lower end of the rear glass, and trunk door handles. Possible locations for BLE modules at the front end of the vehicle include inside the front bumper, the front grille, and the upper / lower end of the windshield. Of course, the in-vehicle system VS may have only one distance measurement module 12β.

[0179] When the in-vehicle system VS includes multiple ranging modules 12β, the position determination unit G2 may determine the device position using the CS ranging results from the multiple ranging modules 12β. In other words, the multiple UWB modules 2 may be omitted. The second communication unit may be the ranging module 12β. The position determination unit G2 may determine the device position using the CS ranging results from the multiple ranging modules 12β and the UWB ranging results from the multiple UWB modules.

[0180] Furthermore, the location determination unit G2 may specify a rough device location or a device presence direction using the CS ranging results of the multiple ranging modules 12β, and set unnecessary anchors based on the specified results. With this configuration, it is possible to reduce the number of UWB modules 2 that operate after the main controller 11 is started.

[0181] <Additional information on how to obtain single frequency phase difference> The BLE module 12 may obtain a single frequency phase difference for each frequency by the active 2-way system or the passive 2-way system, and use the single frequency phase difference to calculate the inter-frequency phase difference. Here, an overview of the active 2-way system and the passive 2-way system will be described.

[0182] The active two-way system is a system in which an initiator and a reflector transmit and receive CW signals to each other, detect the phase difference between the transmitted signal and the received signal, and use these two phase differences to determine the single-frequency phase difference. The active two-way system includes a process in which the initiator and the reflector transmit and receive CW signals to each other, and a process in which the reflector transmits the observed received phase (θr) to the initiator.

[0183] An initiator is a device that starts communication, in other words, a device that requests a response. A reflector is a device that returns a response. In the above embodiment, the BLE module 12 corresponds to the initiator, and the portable device 9 corresponds to the reflector.

[0184] If the initial phase of the initiator is δi, the initial phase of the reflector is δr, the single frequency phase difference that should be observed according to the one-way distance between the initiator and the reflector is φ, and the target frequency is f, then there is a relationship of θr=φ+δi-δr and θi=φ-δi+δr. Based on this relational expression, the average value of θi and θr is the single frequency phase difference (φ) in which the initial phase components of the initiator and the reflector are offset. The active two-way method corresponds to a method of calculating the average value of the reception phase at the initiator and the reception phase at the reflector as the single frequency phase difference. Note that since the phase difference due to one-way propagation is assumed here, the average value of θi and θr is the single frequency phase difference. As another aspect, when the phase difference due to round-trip propagation is assumed as the single frequency phase difference, the single frequency phase difference can be calculated by θi+θr.

[0185] The passive two-way method is also a method in which the initiator and the reflector transmit and receive CW signals to and from each other. The difference from the active two-way method is that the reflector transmits the received phase of the CW signal sent from the initiator by reflecting it to the initial phase of the transmitted signal. For example, when the received phase in the reflector is θr, a CW signal expressed by z(t)=A·exp{-i(ωt+θr+2πn)} is transmitted. A represents the amplitude. ω is the angular frequency corresponding to the target frequency (f) and has the relationship ω=2πf. n is a natural number and corresponds to the interval from when the reflector receives the CW signal to when it transmits the CW signal. According to this method, the received phase observed by the initiator does not include the initial phase component of the reflector. The received phase observed by the initiator is the same value as when receiving a CW signal reflected by a reflector such as a wall and returned. As a result, the initiator can calculate the single-frequency phase difference without obtaining the received phase from the reflector. According to the passive two-way method, compared with the active two-way method, it has the advantage that the reflector does not need to transmit a received phase message. As described above, the single-frequency phase difference and thus the inter-frequency phase difference can be executed in various ways.

[0186] <Modified Example of CS Ranging> The BLE controller 123 may calculate the first distance using the RTT instead of or in combination with the inter-frequency phase difference. The RTT measured by the BLE controller 123 is the time from when a predetermined BLE signal requesting a response is transmitted until a response signal from the portable device 9 is received. The RTT also corresponds to a distance-related value. Transmitting and receiving signals for measuring the RTT also corresponds to an example of CS ranging communication. Calculating the phase change coefficient or the RTT is substantially equivalent to calculating the device distance. Therefore, the process of generating data indicating the device distance, such as the phase change coefficient or the RTT, based on the phase, flight time, or arrival time of the signal received from the portable device 9 is also included in the concept of the first ranging process. Calculating the distance also includes generating data indirectly indicating the distance.

[0187] <Applicable subjects of this disclosure> The above embodiment is applicable to various vehicles that run on roads. That is, the present disclosure can be installed in various vehicles that can run on roads, such as two-wheeled vehicles, three-wheeled vehicles, etc., in addition to four-wheeled vehicles. Motorized bicycles can also be included in two-wheeled vehicles.

[0188] The in-vehicle system VS may be configured such that a plurality of in-vehicle BLE modules operate as masters of the mobile device 9 by using a multipoint technique. Also, a plurality of in-vehicle BLE modules may be configured to operate as slaves of the mobile device 9.

[0189] The communication method between the BLE module 12 and the mobile device 9 is not limited to BLE, and may be Bluetooth Classic, etc. Wireless communication conforming to Bluetooth includes both BLE communication and communication conforming to Bluetooth Classic.

[0190] The communication standard used for distance measurement communication after the main controller 11 is started is not limited to BLE or UWB, and may be Wi-Fi (registered trademark), EnOcean (registered trademark), Zigbee (registered trademark), etc. In other words, the second communication unit may be a communication module conforming to Wi-Fi or the like.

[0191] <Additional remarks (1)> The present disclosure also includes the following technical ideas. [Technical thought 1] 1. A position determination device for determining a position of a mobile device relative to a vehicle, comprising: a first communication unit (12) that performs wireless communication with the portable device in accordance with Bluetooth (registered trademark); A computer (11) that performs processing related to determining the location of the portable device, The computer has a normal mode and a power saving mode as states, the first communication unit is configured to maintain a state in which communication with the portable device is possible even while the computer is in the power saving mode; the first communication unit executes a first distance measurement process to calculate a first distance from the first communication unit to the portable device using data related to a reception phase, a flight time, or an arrival time of a wireless signal transmitted from the portable device; The first communication unit is a position determination device that compares the first distance obtained as a result of the first ranging process with a predetermined value, and transitions the computer from the power saving mode to the normal mode based on the comparison result. [Technical thought 2] The position determination device according to Technical Idea 1 is used in connection with a second communication unit (2) that is disposed in the vehicle and is capable of wireless communication with the portable device, The computer includes: activating the second communication unit based on a return from the power saving mode to the normal mode; causing the second communication unit to perform a second distance measurement process for calculating a second distance, which is a distance from the second communication unit to the portable device, using data related to a reception phase, a flight time, or an arrival time of a wireless signal transmitted from the portable device; and determining a position of the mobile device based on the second distance determined based on a result of the second ranging process. [Technical thought 3] The second communication unit is a communication module that performs ultra-wideband (UWB) communication, The second distance measurement process includes measuring a flight time of the wireless signal by transmitting and receiving an impulse signal used in UWB communication with the portable device, and calculating the second distance based on the measured flight time, The position determination device described in technical idea 2, wherein the second communication unit performs the second ranging process based on instructions from the computer. [Technical thought 4] The computer includes: causing the first communication unit to continue the first distance measurement process even after the mode is switched to the normal mode; The position determination device according to Technical Idea 2 or 3, which determines the position of the mobile device based on the first distance and the second distance. [Technical thought 5] A position determination device according to any one of Technical Concepts 2 to 4, which is used in connection with a plurality of the second communication units, The computer includes: acquiring the second distances from each of the second communication units; determining a location of the portable device based on the second distance for each of the second communication units; and stopping operation of some of the second communication units in accordance with the determined location of the portable device. [Technical Thought 6] The second communication units include a right communication unit (2B) arranged on the right side of the vehicle and a left communication unit (2C) arranged on the left side of the vehicle, The computer includes: When the position of the portable device is determined to be on the right side of the vehicle, the operation of the left side communication unit is stopped, The position determination device according to technical idea 5, wherein when the position of the portable device is determined to be on the left side of the vehicle, the operation of the right-side communication unit is stopped. [Technical Thought 7] The first communication unit is receiving a signal from the portable device periodically at a first interval and acquiring a reception strength of the received signal; The position determination device according to any one of Technical Ideas 1 to 6, wherein the first distance measurement process is executed when the observed value of the reception strength is equal to or greater than a predetermined strength threshold. [Technical Thought 8] the first communication unit compares the observed value of the reception strength with a predetermined threshold, and periodically executes the first distance measurement process at a second interval based on a result of the comparison; The position determination device according to Technical Idea 7, wherein the second interval is set longer than the first interval. [Technical Thought 9] The first communication unit is When the computer is in the power saving mode and has not established a communication connection with the portable device, intermittently transmitting or scanning a signal to establish a communication connection with the portable device; A position determination device according to Technical Idea 7 or 8, which starts receiving or transmitting periodic data signals based on the establishment of a communication connection with the mobile device. [Technical Thought 10] The first communication unit is storing the observed value of the reception strength in a memory; The position determination device according to any one of Technical Ideas 7 to 9, wherein the first distance measurement process is performed on condition that the degree of variation in the reception strength within a certain period of time is less than a predetermined value. [Technical Thought 11] A position determination device described in any one of technical ideas 2 to 10, wherein the computer stops the first ranging process by the first communication unit based on starting up the second communication unit. <Additional remarks (2)> The various flowcharts shown in this disclosure are merely examples, and the number of steps constituting the flowcharts and the order of execution of the processes can be changed as appropriate. The descriptions of wireless signals / BLE signals / data / messages / packets / frames / packages / data sets / information in this disclosure may be read as interchangeable.

[0192] The apparatus, system, and method thereof described in the present disclosure may be realized by a dedicated computer having a processor programmed to execute one or more functions embodied in a computer program. The apparatus and method described in the present disclosure may be realized by a dedicated hardware logic circuit. The apparatus and method described in the present disclosure may be realized by one or more dedicated computers configured by a combination of a processor that executes a computer program and one or more hardware logic circuits. For example, some or all of the functions of the BLE controller 123 may be realized as hardware. The embodiment in which a certain function is realized as hardware includes an embodiment in which it is realized using one or more ICs. The processor (computation core) may be a CPU, an MPU, a GPU, a DFP (Data Flow Processor), or the like. Some or all of the functions of the BLE controller 123 may be realized using any of a system-on-chip (SoC), an IC (Integrated Circuit), and an FPGA (Field-Programmable Gate Array). The concept of an IC also includes an ASIC (Application Specific Integrated Circuit). The computer program may be stored in a computer-readable non-transitive tangible storage medium as instructions executed by a computer. A hard-disk drive (HDD), a solid-state drive (SSD), a flash memory, or the like may be used as the program storage medium. The scope of the present disclosure also includes a program for causing a computer to function as the BLE controller 123 or the main controller 11, and a non-transitive tangible storage medium such as a semiconductor memory on which the program is stored. [Explanation of symbols]

[0193] 1 DK-ECU, 2 UWB module (second communication unit), 2B right anchor (right communication unit), 2C left anchor (left communication unit), 9 mobile device, 11 main controller (computer), 12 BLE module (first communication unit), 93 BLE module (Bluetooth communication unit), 94 UWB module (UWB communication unit), 121 antenna, 123 BLE controller (communication controller), 901 device processor (processor), 903 storage

Claims

1. 1. A position determination device for determining a position of a mobile device relative to a vehicle, comprising: A first communication unit (12) that performs wireless communication with the portable device in accordance with Bluetooth (registered trademark); A computer (11) that performs processing related to determining the location of the mobile device, The first communication unit is configured to be capable of transmitting and receiving a modulated signal for data communication and a continuous wave signal for distance measurement, The computer has a normal mode and a power saving mode as states, the first communication unit is configured to maintain a state in which communication with the portable device is possible even while the computer is in the power saving mode; the first communication unit executes a first distance measurement process to calculate a first distance from the first communication unit to the portable device using data related to a reception phase of the continuous wave signal transmitted from the portable device; The first communication unit is a position determination device that compares the first distance obtained as a result of the first ranging process with a predetermined value, and transitions the computer from the power saving mode to the normal mode based on the comparison result.

2. 2. The position determination device according to claim 1, wherein the position determination device is used in connection with a second communication unit (2) that is arranged in the vehicle and is capable of wireless communication with the portable device, The computer includes: activating the second communication unit based on a return from the power saving mode to the normal mode; causing the second communication unit to perform a second distance measurement process for calculating a second distance, which is a distance from the second communication unit to the portable device, using data related to a reception phase, a flight time, or an arrival time of a wireless signal transmitted from the portable device; and determining a position of the mobile device based on the second distance determined based on a result of the second ranging process.

3. The second communication unit is a communication module that performs ultra-wideband (UWB) communication, The second distance measurement process includes measuring a flight time of the wireless signal by transmitting and receiving an impulse signal used in UWB communication with the portable device, and calculating the second distance based on the measured flight time, The position determination device according to claim 2 , wherein the second communication unit performs the second distance measurement process based on an instruction from the computer.

4. The computer includes: causing the first communication unit to continue the first distance measurement process even after the mode is switched to the normal mode; The position determination apparatus according to claim 2 or 3, further comprising a step of determining a position of the mobile device based on the first distance and the second distance.

5. The position determination device according to claim 2 , which is used in connection with a plurality of the second communication units, The computer includes: acquiring the second distances from each of the second communication units; determining a location of the portable device based on the second distance for each of the second communication units; and stopping operation of some of the second communication units in accordance with the determined location of the portable device.

6. The second communication units include a right communication unit (2B) arranged on a right side of the vehicle and a left communication unit (2C) arranged on a left side of the vehicle, The computer includes: When the position of the portable device is determined to be on the right side of the vehicle, the operation of the left side communication unit is stopped, The position determination device according to claim 5 , wherein when the position of the portable device is determined to be on the left side of the vehicle, operation of the right side communication unit is stopped.

7. The first communication unit is receiving a signal from the portable device periodically at a first interval and acquiring a reception strength of the received signal; The position determination device according to claim 1 , wherein the first distance measurement process is executed when the observed value of the reception strength is equal to or greater than a predetermined strength threshold.

8. the first communication unit compares the observed value of the reception strength with a predetermined threshold, and periodically executes the first distance measurement process at a second interval based on a result of the comparison, The position determination device according to claim 7 , wherein the second interval is set to be longer than the first interval.

9. The first communication unit is When the computer is in the power saving mode and has not established a communication connection with the portable device, intermittently transmitting or scanning a signal to establish a communication connection with the portable device; The position determining apparatus of claim 7 , which begins receiving or transmitting a periodic data signal upon establishing a communication connection with the mobile device.

10. The first communication unit is storing the observed value of the reception strength in a memory; The position determination device according to claim 7 , wherein the first distance measurement process is performed on the condition that a degree of variation in the reception strength within a certain period of time is less than a predetermined value.

11. The position determination device according to claim 2 , wherein the computer stops the first distance measurement process by the first communication unit upon activation of the second communication unit.

12. 1. A position determination device for determining a position of a mobile device relative to a vehicle, comprising: A first communication unit (12) that performs wireless communication with the portable device in accordance with Bluetooth (registered trademark); A computer (11) that performs processing related to determining the location of the mobile device, The computer has a normal mode and a power saving mode as states, the first communication unit is configured to maintain a state in which communication with the portable device is possible even while the computer is in the power saving mode; The first communication unit is receiving a signal from the portable device periodically at a first interval and acquiring a reception strength of the received signal; When the observed value of the reception strength is equal to or greater than a predetermined strength threshold, a first distance measurement process is executed periodically at a second interval to calculate a first distance, which is a distance from the first communication unit to the portable device, using data related to a reception phase, a flight time, or an arrival time of the wireless signal transmitted from the portable device; the first distance obtained as a result of the first distance measurement process is compared with a predetermined value, and the computer is transitioned from the power saving mode to the normal mode based on the comparison result; The second interval is set to be longer than the first interval.

13. A first communication unit (12) that performs wireless communication with the portable device in accordance with Bluetooth (registered trademark); A location determination system comprising: a computer (11) that performs processing related to location determination of the mobile device, The first communication unit is configured to be capable of transmitting and receiving a modulated signal for data communication and a continuous wave signal for distance measurement, the computer has a normal mode and a power saving mode as states; the first communication unit executes a first distance measurement process to calculate a first distance from the first communication unit to the portable device using data related to a reception phase of the continuous wave signal transmitted from the portable device when the computer is in the power saving mode; A position determination system in which the first communication unit compares the first distance obtained as a result of the first ranging process with a predetermined value, and returns the computer from a power saving mode to a normal mode based on the comparison result.

14. The position determination system according to claim 13, further comprising a plurality of second communication units (2) capable of wireless communication with the mobile device, the second communication units (2) being arranged at different positions on the vehicle, The computer includes: activating the second communication unit based on a return from the power saving mode to the normal mode; instructing the second communication unit to perform a second distance measurement process for calculating a second distance from the second communication unit to the portable device using data related to a reception phase, a flight time, or an arrival time of a wireless signal transmitted from the portable device; The second communication unit is performing the second distance measurement process based on an instruction from the computer; and generating location-related data indicating a location where the portable device is located based on the second distance determined based on a result of the second ranging process; and transmitting the generated location related data to the computer. The computer determines a location of the mobile device by aggregating the location-related data received from a plurality of the second communication units.

15. A wireless communication module for performing wireless communication with a mobile device in accordance with Bluetooth (registered trademark), an antenna (121) for communicating with said mobile device; a circuit module (122) connected to the antenna and configured to transmit and receive modulated signals for data communication and continuous wave signals for distance measurement to and from the mobile device; a communication controller (123) for acquiring data relating to a reception phase of the continuous wave signal transmitted from the portable device using the antenna and the circuit module; The communication controller maintaining a state in which communication with the portable device is possible while the vehicle is parked based on power from a battery installed in the vehicle; When the vehicle is parked, executing a first distance measurement process to calculate a first distance from the vehicle itself to the portable device using data related to the reception phase of the continuous wave signal; A wireless communication module that compares the first distance obtained as a result of the first ranging process with a predetermined value, and outputs a signal to transition a predetermined target device installed in the vehicle from a power saving mode to a normal mode based on the comparison result.

16. A processor (901) provided in a portable device (9) including a Bluetooth communication unit (93) for performing wireless communication conforming to Bluetooth (registered trademark) and a UWB communication unit (94) for performing ultra-wideband (UWB) communication, Establishing a Bluetooth communication connection with a pre-linked vehicle based on receiving a signal emitted from the vehicle; While being communicatively connected to the vehicle via Bluetooth, a modulated signal is transmitted to the vehicle periodically at a predetermined first interval, thereby causing the vehicle to periodically monitor a reception strength of the modulated signal; returning a signal for a first distance measurement process, which is a distance measurement process via Bluetooth communication, based on a request to start the first distance measurement process from the vehicle; after returning the signal for the distance measurement process, periodically execute a process of sequentially transmitting continuous wave signals having different frequencies at a second interval longer than the first interval; when receiving a request to start a second distance measurement process, which is a distance measurement process by UWB communication, from the vehicle, starting the UWB communication unit; When a UWB signal for distance measurement is received from the vehicle, a UWB signal of a predetermined pattern is returned.

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