In-vehicle device, vehicle control system, and vehicle control method

Abstract

An in-vehicle device (5) is mounted in a vehicle (3) and is capable of wirelessly communicating with a key FOB (19) carried by a user. When the in-vehicle device (5) has transmitted a polling signal to the key FOB (19) and has received a response signal for the polling signal from the key FOB (19), ranging communication is performed for measuring the distance between the in-vehicle device (5) and the key FOB (19). When the ranging communication is performed, the distance between the in-vehicle device (5) and the key FOB (19) is calculated on the basis of the phase difference of the signals transmitted between the in-vehicle device (5) and the key FOB (19). Then, a polling cycle is determined on the basis of this distance.

Description

In-vehicle device, vehicle control system, and vehicle control method CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This international application claims the benefit of Japanese Patent Application No. 2024-112802, filed with the Japan Patent Office on July 12, 2024, the entire disclosure of which is incorporated herein by reference.

[0002] The present disclosure relates to a technology for controlling the operation of a vehicle by performing wireless communication between an in-vehicle device and a portable device.

[0003] Conventionally, digital key systems have been known in which a digital key is mounted on a mobile device such as a smartphone, and wireless communication is established between the digital key and an in-vehicle device to lock and unlock doors, etc. (see, for example, Patent Document 1).

[0004] In recent years, vehicles equipped with digital key systems have been developed that use two types of systems: a system with BLE and UWB functions for communication with mobile devices, and a system with LF and RF functions for conventional key fobs.

[0005] Here, BLE stands for Bluetooth Low Energy (registered trademark). UWB stands for Ultra Wide Band. FOB stands for Free on Board. A key FOB is, for example, a key holder-sized electronic security device. LF stands for Low Frequency, and RF stands for Radio Frequency.

[0006] JP 2015-26988 A

[0007] As a result of detailed investigation by the inventors, the following problems were found in the conventional techniques.

[0008] The slow adoption of UWB-enabled mobile devices and the fact that some users still prefer traditional key fobs make it difficult to transition to a purely digital key system, which is making the system more complex and costly.

[0009] One solution to this problem would be to give the key fob both BLE and UWB functionality, but this would pose the problem of shortening the battery life of the key fob because it would not be able to enter a complete sleep state like an LF chip.

[0010] Furthermore, in order to extend battery life, it is possible to set an appropriate polling period depending on the distance between the in-vehicle device and the key fob. However, with conventional technology, it is not easy to accurately detect the distance between the in-vehicle device and the key fob, and as a result, it is not easy to set an appropriate polling period.

[0011] The present disclosure aims to provide a technology that can extend the battery life of a portable device by accurately detecting the distance between the portable device, such as a key fob, and an in-vehicle device and setting an appropriate polling period.

[0012] a) One aspect of the present disclosure relates to an in-vehicle device (5) that is mounted on a vehicle and is capable of wireless communication with a portable device carried by a user.

[0013] This in-vehicle device includes a communication control unit, a distance calculation unit, and a polling period determination unit.

[0014] The communication control unit is configured to perform ranging communication, which is communication for measuring the distance between the in-vehicle device and the portable device, when a polling signal is sent from the in-vehicle device to the portable device and a response signal to the polling signal is received from the portable device.

[0015] When distance measurement communication is performed, the distance calculation unit is configured to calculate the distance between the in-vehicle device and the portable device based on the phase difference of the signals communicated between the in-vehicle device and the portable device.

[0016] The polling period determination unit is configured to determine a polling period, which is a transmission period of the polling signal, based on the distance calculated by the distance calculation unit.

[0017] With this configuration, the present disclosure can accurately detect the distance between a portable device such as a key fob and an in-vehicle device, and set an appropriate polling period, thereby extending the battery life of the portable device.

[0018] In other words, in the present disclosure, the distance between the in-vehicle device and the portable device is calculated based on the phase difference of the signals communicated between the in-vehicle device and the portable device, so that the distance can be determined with high accuracy. Therefore, the polling period can be set appropriately (e.g., with high accuracy depending on the distance) based on the distance determined in this manner, so that the battery life of the portable device can be extended.

[0019] b) Another aspect of the present disclosure is a vehicle control system including the above-described in-vehicle device and a portable device.

[0020] With this configuration, the present disclosure can accurately detect the distance between a portable device such as a key fob and an in-vehicle device, and set an appropriate polling period, thereby extending the battery life of the portable device.

[0021] c) Yet another aspect of the present disclosure relates to a vehicle control method that enables wireless communication between an in-vehicle device mounted in a vehicle and a portable device carried by a user.

[0022] In this vehicle control method, the in-vehicle device transmits a polling signal to the portable device, and when a response signal to the polling signal is received from the portable device, performs distance measurement communication as communication to measure the distance between the in-vehicle device and the portable device. When performing distance measurement communication, the in-vehicle device calculates the distance between the in-vehicle device and the portable device based on the phase difference of the signals communicated between the in-vehicle device and the portable device, and determines a polling period, which is a transmission period of the polling signal, based on the distance.

[0023] With this configuration, the present disclosure can accurately detect the distance between a portable device such as a key fob and an in-vehicle device, as described above, and set an appropriate polling period, thereby extending the battery life of the portable device.

[0024] In the present disclosure, the phase difference of a signal communicated between an in-vehicle device and a portable device refers to a shift (i.e., change) in the phase of the signal when a signal is transmitted from one to the other at a predetermined frequency between the in-vehicle device and the portable device.

[0025] The above and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.

[0023] FIG. 2A is a block diagram showing the configuration of a key integrated ECU, FIG. 2B is a block diagram showing the configuration of a BLE device, FIG. 2C is a block diagram showing the configuration of a UWB device, and FIG. 2D is a block diagram showing the configuration of a key FOB.

[0024] FIG. 2B is a block diagram showing the configuration of a key FOB.

[0025] FIG. 2C is a block diagram showing the configuration of a UWB device, and FIG. 2D is a block diagram showing the configuration of a key FOB.

[0026] FIG. 7A is a diagram showing the range of each zone, and FIG. 7B is a diagram showing the relationship between the distance between vehicle keys and the polling period.

[0027] FIG. 7B is a diagram showing a method of optimizing the polling period in accordance with human movement.

[0028] FIG. 7C is a diagram showing a method of optimizing the polling period in accordance with human movement using an exponential moving average.

[0029] FIG. 7D is a diagram showing a method of optimizing the polling period in accordance with human movement using two BLE antennas. 11A is an explanatory diagram illustrating an example of optimizing the polling period in accordance with a noise environment, and FIG. 11B is an explanatory diagram illustrating a correction method after three distance measurements. FIG. 11B is a sequence diagram illustrating a method of changing the polling period when a zone is exceeded. FIG. 11C is a sequence diagram illustrating another method of changing the polling period when a zone is exceeded. FIG. 11D is a sequence diagram illustrating yet another method of changing the polling period when a zone is exceeded. FIG. 11E is a sequence diagram illustrating measures when the measured distances differ between the vehicle and the key fob. FIG. 11F is a sequence diagram illustrating a method of determining an initial polling period in a vehicle. FIG. 11G is a sequence diagram illustrating another method of determining an initial polling period in a vehicle. FIG. 11H is a sequence diagram illustrating a method of determining a polling period during pairing. FIG. 11H is a flowchart illustrating a procedure for changing the polling period in accordance with the vehicle-to-key distance in a key fob. FIG. 11H is a flowchart illustrating a procedure for changing the polling period in accordance with the vehicle-to-key distance in a vehicle.24 is a flowchart showing another part of the control of the polling period based on the functionality of each vehicle, which is carried out in the vehicle. FIG. 31A is a flowchart showing another part of the control of the polling period based on the functionality of each vehicle, which is carried out in the vehicle (i.e., a continuation of FIG. 23). FIG. 31B is a flowchart showing another part of the control of the polling period based on the functionality of each vehicle, which is carried out in the vehicle (i.e., a continuation of FIG. 24). FIG. 31C is a flowchart showing another part of the control of the polling period based on the functionality of each vehicle, which is carried out in the vehicle (i.e., a continuation of FIG. 25). FIG. 31B is a flowchart showing another part of the control of the polling period based on the functionality of each vehicle, which is carried out in the vehicle (i.e., a continuation of FIG. 25). FIG. 31C is a flowchart showing the relationship between zones, functions, zone boundary distances, and polling periods. FIG. 31A is a flowchart showing another part of the control of changing the polling period based on the speed of a person in the vehicle, which is carried out in the vehicle (i.e., a continuation of FIG. 28). FIG. 31C is a flowchart showing the control of changing the polling period based on the speed of a person in the key fob. Fig. 32A is an explanatory diagram showing the relationship between the distance between the vehicle keys and the BLE received power on the vehicle side, Fig. 32B is an explanatory diagram showing the relationship between the observation point, the measured distance, the theoretical value of the received power, and the actual measured value of the received power, and Fig. 32C is an explanatory diagram showing the relationship between the distance between the vehicle keys, the BLE output without correction, and the BLE output after correction. Fig. 32B is a flowchart showing the control of optimizing the BLE output in the vehicle. Fig. 32C is a flowchart showing the control of optimizing the BLE output at the key fob.

[0026] Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings.

[0027] [1. First Embodiment] In the first embodiment, a technology for controlling the operation of a vehicle by wirelessly communicating between a device mounted on a vehicle (i.e., an in-vehicle device) and a portable device carried by a person (e.g., a portable terminal such as a key fob or a smartphone) will be described.

[0028] 1, a vehicle control system 1 according to the first embodiment is a system including an in-vehicle device 5 mounted on a vehicle (i.e., a car) 3, and a portable device 7. In the following description, an automobile will be taken as an example of the vehicle 3.

[0029] The in-vehicle device 5 includes a key integrated ECU 11, a plurality of UWB devices 13, a first BLE device 15a, a second BLE device 15b, etc. When the first BLE device 15a and the second BLE device 15b are not distinguished from each other, they may be simply referred to as BLE devices 15. ECU stands for Electronic Control Unit. BLE stands for Bluetooth Low Energy (registered trademark).

[0030] The key integrated ECU 11, the plurality of UWB devices 13, the first BLE device 15a, and the second BLE device 15b are wired together via a wired LAN 16 such as CAN (registered trademark). CAN is an abbreviation for Controller Area Network.

[0031] The portable device 7 is a well-known information terminal, such as a smartphone 17, and a key FOB 19. The key FOB 19 is a small (e.g., key holder sized) electronic security device incorporating an authentication protocol or mechanism. FOB stands for Free on Board.

[0032] As will be described later, the smartphone 17 and the key fob 19 can communicate with the in-vehicle device 5 via BLE (i.e., BLE communication) and UWB radio wave (i.e., UWB communication), where UWB stands for Ultra Wide Band.

[0033] As is well known, UWB stands for ultra-wideband radio waves. UWB communication is a wireless communication method that uses an ultra-wideband frequency bandwidth. As is well known, the UWB band includes a wide frequency band of 3.1 to 10.6 GHz, for example.

[0034] [1-2. Configuration of Each Part] Each component will be described below.

[0035] <Key Integrated ECU> The key integrated ECU 11 is an electronic control device that realizes the functions of a digital key by wirelessly communicating with a portable device 7 (e.g., a smartphone 17 or a key fob 19) that has the functions of a digital key and is carried by the driver or the like of the vehicle 3.

[0036] The key integrated ECU 11 also has passive entry and passive start functions (i.e., PEPS functions), which allow the vehicle 3 doors to be unlocked without pressing a button on the remote control (i.e., key fob 19) and the vehicle engine to be started without a physical key.

[0037] As shown in FIG. 2 , the key integrated ECU 11 includes a key integrated control unit 21 , a storage unit 23 , and a communication unit 25 .

[0038] The key integrated control unit 21 is a device that performs various calculation processes related to the operation of the key integrated ECU 11, and is mainly composed of a well-known microcomputer (hereinafter referred to as "microcomputer") having a CPU 21a, RAM 21b, ROM 21c, etc.

[0039] The various functions of the key integrated control unit 21 are realized by the CPU 21a executing a program stored in a non-transitory physical recording medium. In this example, the ROM 21c, for example, corresponds to the non-transitory physical recording medium storing the program. Furthermore, by executing this program, a method corresponding to the program is performed.

[0040] The number of microcomputers constituting the key integrated control unit 21 may be one or more. Furthermore, the method of realizing the various functions of the key integrated control unit 21 is not limited to software, and some or all of the elements may be realized using one or more pieces of hardware. For example, when the functions are realized by electronic circuits that are hardware, the electronic circuits may be realized by digital circuits including multiple logic circuits, analog circuits, or a combination of these.

[0041] The storage unit 23 may be a flash memory or an EEPROM that can rewrite various data.

[0042] The communication unit 25 is a communication device that can communicate with each UWB device 13, each BLE device 15, etc. via the wired LAN 16.

[0043] <BLE Device> The BLE device 15 is a device capable of various types of communication by BLE using a well-known BLE antenna (not shown). Note that a device equipped with a well-known integrated circuit for BLE (i.e., a BLE IC) can be used as the BLE device 15.

[0044] As shown in FIG. 2 , the BLE device 15 includes a BLE control unit 27 , a storage unit 29 , and a communication unit 31 .

[0045] The BLE control unit 27 is a device that performs various calculation processes related to the operation of the BLE device 15, and is mainly composed of a well-known microcomputer having a CPU 27a, a RAM 27b, a ROM 27c, etc.

[0046] The various functions of the BLE control unit 27 are realized by the CPU 27a executing a program stored in a non-transient physical recording medium. Note that the BLE control unit 27 is basically the same as the key integrated control unit 21, and therefore a description thereof will be omitted.

[0047] The storage unit 29 may be a flash memory or an EEPROM that can rewrite various data.

[0048] The communication unit 31 is a communication device capable of performing communication such as data communication by BLE using a well-known BLE antenna (not shown). Note that communication is not limited to BLE, and communication by Bluetooth (registered trademark) is also possible.

[0049] The communication unit 31 can also perform BLE-CS communication, which is a well-known channel sounding communication using Bluetooth Low Energy, to measure the distance to a communication partner (for example, the smartphone 17 or the key fob 19). Note that CS is an abbreviation for Channel Sounding.

[0050] The distance measurement method using BLE-CS communication is publicly known, so it will be explained briefly. For example, an initiator transmits a CW signal at a certain frequency f0, measures the phase θ0 of the signal received by the reflector, then shifts the frequency and transmits a CW signal at frequency f1, and similarly measures the phase θ1 of the signal received by the reflector. Then, the distance x between the initiator and the reflector can be calculated from the phase difference (θ0 - θ1) of the received signals (i.e., signals of different frequencies) using a predetermined calculation formula (i.e., formula (1) below). Note that C is the speed of light.

[0051] x = (θ0 - θ1) × C / 2π(f0 - f1) (1) Normally, distance can be determined with high accuracy through two-way communication with the communication partner, but as is well known, phase measurement, and therefore distance measurement, is also possible through one-way communication.

[0052] <UWB Device> The UWB device 13, under the control of the key integrated ECU 11, is capable of communicating with the smartphone 17 and the key fob 19 that have UWB communication capabilities through communication (i.e., UWB communication) using UWB radio waves (i.e., UWB radio waves).

[0053] As shown in FIG. 2C, the UWB device 13 includes a UWB control unit 33 , a storage unit 35 , and a communication unit 37 .

[0054] The UWB control unit 33 is a device that performs various calculation processes related to the operation of the UWB device 13, and is mainly composed of a microcomputer having a known CPU 33a, RAM 33b, ROM 33c, and the like.

[0055] The various functions of the UWB control unit 33 are realized by the CPU 33a executing a program stored in a non-transient physical recording medium. Note that the UWB control unit 33 is basically the same as the key integrated control unit 21, and therefore a description thereof will be omitted.

[0056] The storage unit 35 may be a flash memory or an EEPROM that can rewrite various data.

[0057] The communication unit 37 is a communication device capable of communicating with the key integrated ECU 11 via the wired LAN 16. The communication unit 37 is also capable of UWB communication using a UWB antenna (not shown). For example, UWB communication between the UWB device 13 and the smartphone 17 or key fob 19 can measure the distance between the UWB device 13 and the smartphone 17 or key fob 19. Note that distance measurement using UWB communication is sometimes referred to as ranging communication.

[0058] <Key FOB> The key fob 19 is a device (for example, a key holder type device) that can communicate with the in-vehicle device 5 via BLE communication or UWB communication.

[0059] As shown in FIG. 2D, the key fob 19 includes a key fob control unit 39, a storage unit 41, a communication unit 43, and an operation unit 45.

[0060] The key fob control unit 39 is a device that performs various calculation processes related to the operation of the key fob 19, and is mainly composed of a microcomputer having a known CPU 39a, RAM 39b, ROM 39c, etc.

[0061] The various functions of the key fob control unit 39 are realized by the CPU 39a executing a program stored in a non-transient physical recording medium. The key fob control unit 39 is basically the same as the key integrated control unit 21, so a description thereof will be omitted.

[0062] The storage unit 41 may be a flash memory or an EEPROM that can rewrite various data.

[0063] The communication unit 43 is a communication device capable of BLE communication with the BLE device 15 using a BLE antenna (not shown). Note that communication is not limited to BLE, and Bluetooth communication is also possible. The communication unit 43 is also capable of BLE-CS communication in order to measure the distance to the communication partner (for example, the BLE device 15). Furthermore, the communication unit 43 is capable of UWB communication with the UWB device 13 using a UWB antenna (not shown).

[0064] The operation unit 45 is a switch that can be manually operated by a driver or the like to lock or unlock the doors, for example.

[0065] [1-3. Functional Configuration (First Configuration Example)] Next, the configuration and functions related to the key fob 19 of the vehicle control system 1 will be described.

[0066] As shown in Fig. 3, the vehicle control system 1 includes the key integrated ECU 11, the UWB device 13, and the BLE device 15, which are connected by a wired LAN 16 (e.g., CAN). In Figs. 3 and 4, signals are transmitted in the directions indicated by the solid and dashed arrows. In each figure, SPI stands for Serial Peripheral Interface, a well-known data transmission standard. INT is an interrupt terminal that stands for Interrupt.

[0067] <Key Integrated ECU> The key integrated ECU 11 includes a key integrated control unit 21 and a CAN driver 51. Functionally, the key integrated control unit 21 includes a door lock SW input unit 53, an SSSW input unit 55, a UWB drive request unit 57, and a position measurement unit 59. Note that SW means a switch.

[0068] The door lock SW input unit 53 receives a signal from the door lock SW. The SSSW input unit 55 receives a signal from a start / stop SW (i.e., SSSW) that instructs the driving or stopping of an engine, etc. The UWB drive request unit 57 requests the UWB device 13 to measure the distance between the UWB device 13 and the key fob 19. The position measurement unit 59 measures the position of the key fob 19 based on the distance information obtained from the UWB device 13.

[0069] <UWB Device> The UWB device 13 includes a UWB device 61 and a CAN driver 63. Functionally, the UWB device 61 includes a UWB transmitter 65, a UWB receiver 69, and a distance measurement unit 67. Note that the term "device" here refers to a configuration that processes the operations of the blocks shown in the drawings (the same applies hereinafter).

[0070] The UWB transmitter 65 transmits a signal by UWB radio waves (i.e., a UWB signal) to the UWB receiver 111 of the key FOB 19 for distance measurement communication. The UWB receiver 69 receives the UWB signal for distance measurement communication transmitted from the UWB transmitter 115 of the key FOB 19. The distance measurement unit 67 measures the distance between the UWB device 13 and the key FOB 19 based on the UWB signal received by the UWB receiver 69. The measured distance is transmitted to the position measurement unit 59.

[0071] <BLE Apparatus> The BLE apparatus 15 includes a BLE device 71 and a CAN driver 73. The BLE device 71 functionally includes a polling cycle correction unit 75, a polling cycle unit 77, a message generation unit 79, a BLE transmission unit 81, a BLE reception unit 83, a message authentication unit 85, a distance measurement unit 87, and a UWB drive request unit 89.

[0072] Here, polling refers to a device making an inquiry to another device at regular intervals (i.e., requesting a response to the inquiry), and the polling period refers to the period at which the polling is performed.

[0073] The polling cycle correction unit 75 corrects the polling cycle. The polling cycle unit 77 stores the set polling cycle. The message generation unit 79 generates a message to be transmitted to the key FOB 19. The BLE transmission unit 81 transmits information such as the generated message to the BLE reception unit 97 of the key FOB 19 via BLE communication. The BLE reception unit 83 receives information such as a message transmitted from the BLE transmission unit 107 of the key FOB 19. The message authentication unit 85 authenticates the received message. The distance measurement unit 87 measures the distance between the BLE device 15 and the key FOB 19 via BLE-CS communication between the BLE device 15 and the key FOB 19 (i.e., between the BLE transmission unit 81 and the BLE reception unit 97, and between the BLE transmission unit 107 and the BLE reception unit 83). The UWB drive request unit 89 requests the UWB device 13 to drive the UWB device 13 (i.e., to perform distance measurement communication by UWB).

[0074] The signals transmitted and received between the BLE device 15 and the key FOB 19 include BLE communication signals for data communication, etc., and BLE-CS communication signals for measuring the distance between the BLE device 15 and the key FOB 19, and these signals are transmitted and received at different times to avoid interference.

[0075] <Key FOB> The key FOB 19 includes a BLE device 91, an acceleration sensor 93, and a UWB device 95. The BLE device 91 functionally includes a BLE receiving unit 97, a message authenticating unit 99, a distance measuring unit 101, a message generating unit 103, a polling period unit 105, a BLE transmitting unit 107, and a power state managing unit 109.

[0076] The BLE receiving unit 97 receives information such as a message transmitted from the BLE transmitting unit 81 of the BLE device 15 via BLE communication. The message authenticating unit 99 authenticates the received message. The distance measuring unit 101 measures the distance between the BLE device 15 and the key FOB 19 via BLE-CS communication between the BLE device 15 and the key FOB 19. The message generating unit 79 generates a message to be transmitted to the key FOB 19 (e.g., distance information measured by the distance measuring unit 101). The BLE transmitting unit 107 transmits information such as a message generated by the message generating unit 103 to the BLE receiving unit 83 of the key FOB 19 based on the polling period obtained from the polling period unit 77. The polling period unit 77 stores the set polling period (e.g., the polling period received by the BLE receiving unit 97). The power supply state management unit 109 manages the state (for example, the state of power such as voltage) of the battery BT that supplies power to the key fob 19 .

[0077] The UWB device 95 functionally comprises a UWB receiving section 111 , a distance measuring section 113 , and a UWB transmitting section 115 .

[0078] The UWB receiver 111 receives a UWB signal for ranging communication transmitted from the UWB transmitter 65 of the UWB device 13. The distance measurement unit 113 measures the distance between the UWB device 13 and the key FOB 19 based on the UWB signal received by the UWB receiver 111. The UWB transmitter 115 transmits a UWB signal for ranging communication to the UWB receiver 69 of the UWB device 13.

[0079] [1-4. Functional Configuration (Second Configuration Example)] Next, a description will be given of the configuration and functions related to the key fob 19 in another configuration example (i.e., a second configuration example) of the vehicle control system 1. In this example, the integrated device 12, in which the BLE device 15 is built into the key integrated ECU 11, is mounted on, for example, the ceiling of the vehicle interior.

[0080] 4, the vehicle control system 1 includes an integrated device 12, a UWB device 13, a key fob 19, etc. The integrated device 12 includes a key integrated control unit 21, a BLE device 71, and a CAN driver 51. The key integrated ECU 11 and the UWB device 13 are connected via a wired LAN 16 (e.g., a CAN).

[0081] In this second configuration example, the configuration of the UWB device 13 and the configuration of the key FOB 19 are the same as those in the first configuration example, and therefore a description thereof will be omitted.

[0082] In the second configuration example, the key integrated control unit 21 and the BLE device 71 are similar to those in the first configuration example, but since the key integrated control unit 21 and the BLE device 71 are arranged in the integrated device 12, data is transmitted and received between the key integrated control unit 21 and the BLE device 71 in accordance with the SPI data transmission standard. In addition, the integrated device 12 and the UWB device 13 communicate with each other via the CAN through the CAN drivers 51 and 63.

[0083] [1-5. Overall System Configuration] <First Configuration Example> Next, the overall system configuration corresponding to the first configuration example will be described.

[0084] 5, in the first configuration example, the key integrated ECU 11, the first BLE device 15a, the second BLE device 15b, and the multiple UWB devices 13 are connected as a wired LAN, for example, via a CAN FD1, to a vehicle computer 121 that controls the overall operation of the vehicle 3. CAN FD stands for CAN with Flexible Data Rate.

[0085] Of these, when the smartphone 17 functions as the master, the first BLE device 15a functions as a slave controlled by the master, and conversely, when the key fob 19 functions as the slave, the first BLE device 15a functions as the master.

[0086] In addition, the vehicle computer 121 is connected via a wired LAN, for example, CAN FD2 or Ethernet (registered trademark), to a zone controller 123 that controls the area (i.e., zone) in front of the right side of the vehicle 3, a zone controller 125 that controls the zone in front of the left side of the vehicle 3, a zone controller 127 that controls the zone in the rear of the vehicle 3, a wireless power charger 129, a door handle 131, and a kick sensor 133.

[0087] The zone controller 123 controls the load on the right front portion of the vehicle 3. For example, it can control door locking / unlocking, power sliding doors, welcome lights, engine start, etc.

[0088] The zone controller 125 controls the load on the front left portion of the vehicle 3. For example, it can control the locking / unlocking of doors, the power sliding door, the welcome light, and the like.

[0089] The zone controller 127 controls the load on the rear portion of the vehicle 3. For example, it can control the locking / unlocking of doors, the power back door, the welcome light, and the like.

[0090] The wireless power charger 129 can perform control of Qi power reception, control of NFC (for example, backup control and registration control), etc. NFC is an abbreviation for Near Field Communication, which means short-distance wireless communication.

[0091] The door handle 131 is connected to an NFC device, a lock sensor that detects whether the door is locked, and an unlock sensor that detects whether the door is unlocked.

[0092] <Second Configuration Example> Next, the configuration of the entire system corresponding to the second configuration example will be described.

[0093] As shown in FIG. 6, the second configuration example has almost the same configuration as the first configuration example except for some parts, so it will be explained briefly.

[0094] Specifically, in the second configuration example, the integrated device 12, the first BLE device 15a, the second BLE device 15b, and a plurality of UWB devices 13 are connected to the vehicle computer 121 via, for example, a CAN FD1.

[0095] Among these, the integrated device 12 functions as a slave when the smartphone 17 functions as a master, and conversely, functions as a master when the key fob 19 functions as a slave.

[0096] The vehicle computer 121 is also connected to the zone controllers 123 to 127, a wireless power charger 129, a door handle 131, and a kick sensor 133 via, for example, a CAN FD2 or Ethernet.

[0097] [1-6. Main Control Portions] Next, the main control portions in the first embodiment will be described.

[0098] 7A, in the first embodiment, a plurality of zones are set to indicate how far the key fob 19 is from the vehicle 3. The position of the vehicle 3 may be the center of gravity of the vehicle 3 or the outer periphery of the vehicle 3 in a plan view.

[0099] In the following description, the distance between the vehicle 3 and the key FOB 19 may be simply referred to as the vehicle-key distance. In practice, the distance between the key FOB 19 and the BLE device 15 and the distance between the key FOB 19 and the UWB device 13 are measured, but because the positions of the BLE device 15 and the UWB device 13 are fixed, the distance from the center of gravity of the vehicle 3 to the key FOB 19, for example, can be calculated from the measured distances.

[0100] For example, the zone between 0m and 5m from vehicle 3 is the entry zone ZA, the zone between 5m and 10m from vehicle 3 is the welcome zone ZB, the zone between 10m and 15m from vehicle 3 is the approach zone ZC, the zone between 20m and 30m from vehicle 3 is the middle zone ZD, the zone between 30m and 40m from vehicle 3 is the welcome zone ZE, and the zone more than 40m from vehicle 3 is the advertiser zone ZF.

[0101] Note that if the distance values ​​of adjacent zones overlap (for example, 5 m overlaps between 0 m to 5 m and 5 m to 10 m), the upper limit value of the zone closer to the vehicle 3 may be set to less than this (for example, less than 5 m). Alternatively, the upper limit value of the zone closer to the vehicle 3 may be set to a value equal to or less than this (for example, 5 m or less). The same applies hereinafter unless otherwise specified.

[0102] The priority of each zone is as follows: entry zone ZA is priority 5, welcome zone ZB is priority 4, approach zone ZC is priority 3, middle zone ZD is priority 2, and welcome zone ZE and advertiser zone ZF are priority 1.

[0103] The higher the priority number, the higher the priority. For example, when performing a certain control, the higher the priority of the zone, the more priority the control can be carried out. Also, as will be described later, after a connection is established (i.e., after communication is established), the higher the priority, the shorter the polling period is set.

[0104] 7B, the polling period becomes longer as the distance of the key fob 19 from the vehicle 3 increases. Note that the unit of period [ms] here indicates milliseconds.

[0105] For example, the polling period is set to 100 ms in the entry zone ZA, 250 ms in the welcome zone ZB, 500 ms in the approach zone ZC, 100 ms in the middle zone ZD, and 300 ms in the welcome zone ZE.

[0106] [1-7. Polling Period Determination Method] Next, various methods for determining the polling period will be described.

[0107] <First Determination Method> This first determination method is a method for optimizing the polling period in accordance with the movement (i.e., speed) of the person carrying the key fob 19 .

[0108] As shown in Figure 8, consider the case where a person moves from outside the entry zone ZA into the entry zone ZA. The locations where communication between the vehicle 3 and the key fob 19 occurs are designated as points P1 and P2, in order of furthest from the vehicle 3. The distance between the vehicle keys at point P1 is designated as D1 [m] and the timestamp is designated as T1 [s], while the distance between the vehicle keys at point P2 is designated as D2 [m] and the timestamp is designated as T2 [s]. Note that a timestamp is a time stamp indicating time information. Note that [s] indicates seconds.

[0109] In such a situation, the speed V [m / s] of the user based on the observation results can be calculated using the following formula (2).

[0110] V = (D2 - D1) / (T2 - T1) (2) Here, if the user's speed assumed when building the system is V0 [m / s], the difference between this and the actual speed, ΔV [m / s], is given by the following formula (3).

[0111] ΔV=V−V0 (3) If ΔV is not 0, the polling period is corrected as follows: If ΔV is 0, no correction is made.

[0112] The initial value of the polling period of the entry zone ZA is set to T0_entry [ms], and the optimized polling period is set to Topt_entry [ms].

[0113] The distance traveled in the default (i.e., initial setting value) polling period is set as D, and the following equation (4) is set.

[0114] V0×T0_entry=D (4) Furthermore, to maintain functionality, the following formula (5) is set so that the same amount of progress as the default is made.

[0115] V × Topt_entry = D (5) Using the above equations (4) and (5), the optimized polling period Topt_entry is calculated from the following equation (6).

[0116] Topt_entry = (V0 / V) × T0_entry (6) The next communication will be performed after Topt_entry. Note that the difference between the two timestamps and the polling period are almost the same, but this is incorporated into the calculation to match the observer's perspective.

[0117] Although the entry zone ZA is given as an example here, correction may be made continuously from a zone farther away from the vehicle 3 .

[0118] <Second Determination Method> This second determination method is a method for optimizing the polling period in accordance with the movement of the person carrying the key fob 19, and is a method for optimizing after measuring the distance multiple times.

[0119] As shown in Figure 9, consider the case where a person moves from outside the entry zone ZA into the entry zone ZA. The locations where communication between the vehicle 3 and the key fob 19 occurs are assumed to be points P1, P2, P3, and P4, in order of furthest from the vehicle 3. The distance between the vehicle keys at point P1 is assumed to be D1 [m] and the timestamp is T1 [s], the distance between the vehicle keys at point P2 is assumed to be D2 [m] and the timestamp is T2 [s], the distance between the vehicle keys at point P3 is assumed to be D3 [m] and the timestamp is T3 [s], and the distance between the vehicle keys at point P4 is assumed to be D4 [m] and the timestamp is T4 [s].

[0120] In this situation, the user's speed V21 [m / s] from point P1 to point P2, the user's speed V32 [m / s] from point P2 to point P3, and the user's speed V43 [m / s] from point P3 to point P4 based on the observation results can be calculated using the following equations (7) to (9), respectively.

[0121] V21 = (D2 - D1) / (T2 - T1) (7) V32 = (D3 - D2) / (T3 - T2) (8) V43 = (D4 - D3) / (T4 - T3) (9) Next, using the following formulas (10) to (12), an exponential moving average is taken to find the sequential average speeds EMA21 [m / s], EMA32 [m / s], and EMA43 [m / s]. This reduces the variation in speed. Note that α is a smoothing coefficient, and V0 is the user speed assumed when building the system.

[0122] EMA21 = α × V21 + (1 - α) × V0 (10) EMA32 = α × V32 + (1 - α) × EMA21 (11) EMA43 = α × V43 + (1 - α) × EMA32 (12) Then, as in the first determination method, if ΔV is not 0, the polling period is corrected as follows.

[0123] The initial value of the polling period of the entry zone ZA is set to T0_entry [ms], and the optimized polling period is set to Topt_entry [ms].

[0124] The distance traveled in the default polling period is set as D, and the following equation (13) is set.

[0125] V0×T0_entry=D (13) Furthermore, to maintain functionality, the following equation (14) is set to advance by the same amount as the default.

[0126] EMA43×Topt_entry=D (14) Using the above equations (13) and (14), the optimized polling period Topt_entry is calculated from the following equation (15).

[0127] Topt_entry=(V0 / EMA43)×T0_entry (15) The next communication is performed after Topt_entry. Also, although the entry zone ZA is given as an example here, correction may be made continuously from a zone farther away from the vehicle 3.

[0128] <Third Determination Method> This third determination method is a method for optimizing the polling period in accordance with the movement of the person carrying the key fob 19. In other words, this method uses BLE antennas A and B of the BLE device 13 in two locations. The two BLE antennas A and B are arranged in staggered positions, as shown in FIG. 10 . Furthermore, in this third determination direction, only components approaching the vehicle 3 are extracted.

[0129] More specifically, consider the case where a person moves from outside the entry zone ZA into the entry zone ZA, as shown in Figure 10. The point at which the vehicle 3 and the key fob 19 communicate for the first time is defined as point P1, and the point at which the vehicle 3 communicates for the second time is defined as point P2. The timestamp at point P1 is defined as T1 [s], and the timestamp at point P2 is defined as T2 [s]. Furthermore, the speed of the user moving from point P1 to point P2 is defined as V [m / s], and the speed of the user in a direction perpendicular to the vehicle 3 (i.e., the direction from the user toward vehicle 3 in the shortest distance) is defined as Vx [m / s].

[0130] As shown in the figure, in the vertical coordinate system of XY, when considering the front-to-rear direction (i.e., Y-axis direction) and left-to-right direction (i.e., X-axis direction) of the vehicle 3, the Vx direction is the left-to-right direction.

[0131] To calculate the speed of the user, first, the coordinates of the observation point are calculated. If the angle θ1 between point P1 and BLE antenna B on BLE antenna A and the angle θ2 between point P2 and BLE antenna B on BLE antenna A are known, the coordinates of the observation point are obtained, and these are first calculated using the following equations (16) and (17).

[0132] Note that D1a is the distance between BLE antenna A and point P1, D1b is the distance between BLE antenna B and point P1, D2a is the distance between BLE antenna A and point P2, D2b is the distance between BLE antenna B and point P2, and Dab is the distance between BLE antenna A and BLE antenna B.

[0133] cosθ1 = (D1a ２ + Dab ２ -D1b ２ ) / (2×D1a×Dab) ・・(16) cosθ2 = (D2a ２ + Dab ２ -D2b ２ ) / (2×D2a×Dab) (17) Then, by taking these inverse trigonometric functions, θ1 and θ2 can be found.

[0134] Next, using the following equations (18) and (19), the angles θ1 and θ2 found are used to find the observation points (i.e., the coordinates of points P1 and P2) observed the first and second times, where θab is the angle between the X-axis direction of BLE antenna A and the direction of BLE antenna B.

[0135] First time: (x1, y1) = (D1a × cos(π-θab-θ1), D1a × sin(π-θab-θ1)) (18) Second time: (x2, y2) = (D2a × cos(π-θab-θ2), D2a × sin(π-θab-θ2)) (19) Based on the observation results, the user’s speed V [m / s] is calculated using the following formula (20).

[0136] V = {(x2-x1) ２ +(y2-y1) ２} １／２ / (T2-T1) (20) Then, the speed component Vx of the vector of the velocity V in the direction of the vehicle 3 (that is, the vehicle direction) is calculated using the following equation (21).

[0137] Vx=V×(|x1-x2|) / {(x2-x1) ２ +(y2-y1) ２} １／２ (21) Then, similarly to the first determination method, if ΔV is not 0, the polling period is corrected as follows.

[0138] The initial value of the polling period of the entry zone ZA is set to T0_entry [ms], and the optimized polling period is set to Topt_entry [ms].

[0139] The distance traveled in the default polling period is set as D, and the following equation (22) is set.

[0140] V0×T0_entry=D (22) Furthermore, to maintain functionality, the following equation (23) is set so as to proceed the same amount as the default.

[0141] Vx×Topt_entry=D (23) Using the above formulas (22) and (23), the optimized polling period Topt_entry is calculated from the following formula (24).

[0142] Topt_entry=(V0 / Vx)×T0_entry (24) The next communication is performed after Topt_entry.

[0143] [1-7. Communication Sequence] Next, a communication sequence for determining a polling cycle in the first embodiment will be described.

[0144] <First Communication Sequence> In the first communication sequence, a case where a polling period is appropriately determined depending on the noise environment will be described. Note that the case where the vehicle 3 enters the welcome zone will be described as an example.

[0145] 11A, when the vehicle 3 enters the welcome zone, the master vehicle 3 (i.e., the BLE transmitter 81 of the in-vehicle device 5) transmits a polling signal to the slave key fob 19 at a predetermined polling period (e.g., 250 ms) set in accordance with the welcome zone. In other words, the polling signal is transmitted at the predetermined polling period via BLE communication.

[0146] Note that PDU is an abbreviation for Protocol Data Unit, which is a well-known unit of data to be transmitted. When transmitted as a polling signal, the PDU contains ID information, encryption information, etc., as is well known.

[0147] Next, the key fob 19 receives the polling signal at the BLE receiving unit 97 and transmits a PDU including a response signal indicating that the polling signal has been received from the BLE transmitting unit 107 to the vehicle 3 .

[0148] Next, the above-described BLE-CS communication is performed between the vehicle 3 and the key FOB 19, and the distance between the vehicle 3 and the key FOB 19 is measured.

[0149] Thereafter, operations such as transmitting a polling signal and receiving a response signal are repeated at the same polling period between the vehicle 3 and the key FOB 19. Note that if the transmission of the polling signal and the reception of the response signal fail, the distance between the vehicle 3 and the key FOB 19 is not measured via BLE-CS communication.

[0150] If the above-mentioned transmission and reception of a signal (for example, reception of a response signal) fails due to noise or the like, the polling period is changed according to the number of failures (for example, according to the number of failures after three transmissions and receptions). In other words, the polling period is shortened as the number of failures increases.

[0151] FIG. 11B shows an example in which the polling period is shortened to 200 ms when one of three transmissions and receptions fails.

[0152] Specifically, as shown in FIG. 11B, if one of three transmissions and receptions fails, the vehicle 3 transmits a polling signal (i.e., PDU) to the key fob 19 at a polling period (e.g., 200 ms) shorter than the polling period shown in FIG. 11A.

[0153] Next, the key fob 19 that has received the polling signal transmits to the vehicle 3 a PDU that includes a response signal indicating that the polling signal has been received.

[0154] Next, the above-described BLE-CS communication is performed between the vehicle 3 and the key FOB 19, and the distance between the vehicle 3 and the key FOB 19 is measured.

[0155] Thereafter, operations such as transmission of polling signals and reception of response signals are repeated between the vehicle 3 and the key fob 19 at the same polling period.

[0156] Furthermore, if two out of three transmissions and receptions fail, the polling period may be shortened to 150 ms, and if three out of three transmissions and receptions fail, the polling period may be shortened to 100 ms. Note that if transmission and reception fail a certain number of times in a row, the communication connection may be cut off.

[0157] <Second Communication Sequence> The second communication sequence describes an example of changing the polling period when the key fob 19 crosses a zone, specifically, an example of changing the polling period immediately, taking the case where the vehicle 3 enters the entry zone from the welcome zone as an example.

[0158] As shown in FIG. 12, when a vehicle 3 is in a welcome zone, the master vehicle 3 transmits a polling signal (i.e., PDU) to the slave key fob 19 at a predetermined polling period (e.g., 250 ms) set in accordance with the welcome zone.

[0159] Next, the key fob 19 that has received the polling signal transmits to the vehicle 3 a PDU that includes a response signal indicating that the polling signal has been received.

[0160] Next, the above-described BLE-CS communication is performed between the vehicle 3 and the key FOB 19 to measure the distance between the vehicle 3 and the key FOB 19. This distance measurement determines which zone the key FOB 19 is in.

[0161] Thereafter, in the same manner, the vehicle 3 transmits a polling signal to the key fob 19 at the polling period (for example, 250 ms), and the key fob 19 receives the polling signal and transmits a PDU including a response signal to the vehicle 3.

[0162] Next, the above-described BLE-CS communication is similarly performed between the vehicle 3 and the key FOB 19 to measure the distance between the vehicle 3 and the key FOB 19.

[0163] If this distance measurement determines that the key fob 19 has approached the vehicle 3 and entered the entry zone from the welcome zone, the vehicle 3 changes its polling period to a predetermined polling period (e.g., 100 ms) set in accordance with the entry zone.

[0164] At the same time, the vehicle 3 requests the key fob 19 to change the period for receiving and replying to polling signals (i.e., the polling reception period) on the key fob 19 side in accordance with the change in the polling period (i.e., the polling interval) of the vehicle 3. Note that the polling reception period is set to the same as the polling period for transmitting polling signals from the vehicle 3, and therefore, hereinafter, the polling reception period may be simply referred to as the polling period.

[0165] In other words, since the key FOB 19 receives and replies according to a polling cycle, the vehicle 3 requests the key FOB 19 to change the cycle at which the key FOB 19 receives and replies (i.e., a polling cycle change request).

[0166] The key fob 19 transmits to the vehicle 3 a response signal (that is, a well-known ACK) indicating that the polling period change request has been received.

[0167] Thereafter, PDUs are transmitted and received between the vehicle 3 and the key fob 19 in the same manner as described above at the updated polling period.

[0168] This second communication sequence has the advantage that if the zone in which the key fob 19 is located is changed, the polling period can be immediately changed to a preferred one.

[0169] The third communication sequence describes an example of changing the polling period when the key fob 19 moves beyond the zone, specifically, a case in which the changed polling period is notified again, where the vehicle 3 moves from the welcome zone to the entry zone.

[0170] As shown in FIG. 13, when a vehicle 3 is in a welcome zone, the master vehicle 3 transmits a polling signal (i.e., PDU) to the slave key fob 19 at a predetermined polling period (e.g., 250 ms) set in accordance with the welcome zone.

[0171] Next, the key fob 19 that has received the polling signal transmits to the vehicle 3 a PDU that includes a response signal indicating that the polling signal has been received.

[0172] Next, the above-described BLE-CS communication is performed between the vehicle 3 and the key FOB 19 to measure the distance between the vehicle 3 and the key FOB 19. This distance measurement determines which zone the key FOB 19 is in.

[0173] If this distance measurement determines that the key fob 19 has approached the vehicle 3 and entered the entry zone from the welcome zone, the vehicle 3 changes its polling period to a predetermined polling period (e.g., 100 ms) set in accordance with the entry zone.

[0174] At the same time, the vehicle 3 transmits a request to the key fob 19 to change the polling period (i.e., the polling reception period) of the key fob 19. In other words, the key fob 19 receives and replies according to the polling period of the vehicle 3, so a polling period change request is sent to the key fob 19.

[0175] The key fob 19 transmits to the vehicle 3 a response signal (i.e., ACK) indicating that the polling period change request has been received.

[0176] Next, the vehicle 3 transmits a polling signal (i.e., PDU) to the key fob 19 at the polling period (e.g., 250 ms), but in this case, the changed polling period is transmitted again. In other words, as a fail-safe in case the ACK is noise data, the polling period is transmitted again to the key fob 19.

[0177] Thereafter, the key fob 19 that has received the polling signal transmits a PDU including a response signal to the vehicle 3 .

[0178] Next, the above-described BLE-CS communication is similarly performed between the vehicle 3 and the key FOB 19 to measure the distance between the vehicle 3 and the key FOB 19.

[0179] Thereafter, PDUs are transmitted and received between the vehicle 3 and the key fob 19 in the same manner as described above at the updated polling period.

[0180] In this third communication sequence, the polling period is again notified to the key fob 19, which has the advantage of enabling more reliable communication than the second communication sequence.

[0181] <Fourth Communication Sequence> The fourth communication sequence describes an example of changing the polling period when the key fob 19 crosses a zone, specifically, an example of changing the polling period for the vehicle 3 and the key fob 19. Note that the example is a case where the vehicle 3 enters the entry zone from the welcome zone.

[0182] As shown in FIG. 14, when a vehicle 3 is in a welcome zone, the master vehicle 3 transmits a polling signal (i.e., PDU) to the slave key fob 19 at a predetermined polling period (e.g., 250 ms) set in accordance with the welcome zone.

[0183] Next, the key fob 19 that has received the polling signal transmits to the vehicle 3 a PDU that includes a response signal indicating that the polling signal has been received.

[0184] Next, the above-described BLE-CS communication is performed between the vehicle 3 and the key FOB 19 to measure the distance between the vehicle 3 and the key FOB 19. This distance measurement determines which zone the key FOB 19 is in.

[0185] If this distance measurement determines that the key fob 19 has approached the vehicle 3 and entered the entry zone from the welcome zone, the vehicle 3 changes its polling period (i.e., polling interval) to a predetermined polling period (e.g., 100 ms) set for the entry zone. Meanwhile, the key fob 19 receives and replies according to the polling period, so it changes the reception and reply period. Note that, as described above, the reception and reply period corresponds to the polling period (i.e., is the same as the polling period).

[0186] Thereafter, the same PDUs as described above are transmitted and received between the vehicle 3 and the key FOB 19 at the updated polling period. Also, the above-described BLE-CS communication is performed between the vehicle 3 and the key FOB 19, and the distance between the vehicle 3 and the key FOB 19 is measured in the same manner.

[0187] In this fourth communication sequence, the vehicle 3 and the key FOB 19 can independently change the polling period and reception period, which has the advantage that there is no need to send or receive information regarding the polling period between the vehicle 3 and the key FOB 19.

[0188] <Fifth Communication Sequence> The fifth communication sequence will be described as an example in which the polling period is changed when the key fob 19 crosses a zone. Specifically, another example in which the polling periods of the vehicle 3 and the key fob 19 are changed will be described. Note that the example will be a case in which the vehicle 3 enters the welcome zone from the approach zone.

[0189] As shown in FIG. 15, when a vehicle 3 is in an approach zone, the master vehicle 3 transmits a polling signal (i.e., PDU) to the slave key FOB 19 at a predetermined polling period (e.g., 500 ms) set in accordance with the approach zone.

[0190] Next, the key fob 19 that has received the polling signal transmits to the vehicle 3 a PDU that includes a response signal indicating that the polling signal has been received.

[0191] Next, the above-described BLE-CS communication is performed between the vehicle 3 and the key FOB 19 to measure the distance between the vehicle 3 and the key FOB 19. Here, as is well known, the distance is measured on both the vehicle 3 side and the key FOB 19 side by one-way communication.

[0192] The following describes a case where the measured distances on the vehicle 3 side and the key fob 19 side vary as a result of this measurement.

[0193] For example, vehicle 3 determines that key fob 19 is in the welcome zone because the distance is, for example, 10 m or less. On the other hand, key fob 19 determines that key fob 19 is in the approach zone because the distance is, for example, more than 10 m.

[0194] As a result, the polling period in vehicle 3 is changed to, for example, 250 ms in accordance with the welcome zone. On the other hand, since there is no zone change in key fob 19, the polling period remains at 500 ms.

[0195] Next, the vehicle 3 transmits a polling signal at the end of the previous polling period, and the key fob 19 transmits a response signal to the polling signal.

[0196] Thereafter, BLE-CS communication is performed between the vehicle 3 and the key FOB 19, and the distance between the vehicle 3 and the key FOB 19 is measured.

[0197] Next, the vehicle 3 transmits a polling signal at the changed polling cycle, but the key fob 19 does not recognize the change in the polling cycle and is therefore unable to transmit a response signal.

[0198] Next, since there is no response signal, the vehicle 3 returns the polling period to the original value and transmits a polling period change request to the key fob 19 at the polling period before the change.

[0199] In this fifth communication sequence, the vehicle 3 and the key fob 19 can independently change the polling period and reception period, but if the vehicle 3 does not receive a response signal from the key fob 19, it transmits to the key fob 19, using the old polling period, that the polling period has been changed. This has the advantage that the key fob 19 can reliably recognize the change in the polling period.

[0200] [1-8. Initial Polling Cycle] Next, a method for determining an initial polling cycle when BLE communication is performed will be described.

[0201] <First Initial Polling Period> In the method of determining the first initial polling period (that is, the initial value of the polling period), a case where the key fob 19 leaves the connection area and re-enters the connection area will be described.

[0202] As shown in Fig. 16, the key fob 19 periodically transmits advertisements (i.e., Advertisements), which are advertising signals, and the vehicle 3 periodically scans (i.e., Scans) to receive the advertisements. Note that an advertisement is a transmission of information from one device to another, and in this case, it means that the key fob 19 broadcasts its presence to the surrounding area. Furthermore, scanning means that the key fob 19 enters a receiving state and takes in the advertisements.

[0203] When the key fob 19 enters the reception area from outside, the vehicle 3 receives the advertisement from the key fob 19.

[0204] Next, the vehicle 3 transmits a connection request to the key fob 19 to establish BLE communication with the key fob 19. The polling period at this time is a predetermined time T0 ms.

[0205] Only the first time, the vehicle 3 uses the signal strength of the advertisement (i.e., the communication radio wave strength) to calculate the distance between the vehicle and the key by well-known RSSI measurement. RSSI is an abbreviation for Received Signal Strength Indicator.

[0206] If the distance between the vehicle keys is greater than 30 m, it is determined to be in a connection zone, the polling period is set to 3000 ms, and a request is made to the key fob 19 to change the polling period (i.e., polling interval).

[0207] The key FOB 19 returns an ACK, and thereafter transmits and receives normal PDUs via BLE communication as usual.

[0208] <Second Initial Polling Cycle> In the method of determining the second initial polling cycle, a case where the key fob 19 leaves the connection area and re-enters the connection area will be described.

[0209] In this second method for determining the initial polling period, the distance between the vehicle keys is first calculated using BLE-CS instead of RSSI.

[0210] As shown in FIG. 17, the key fob 19 periodically transmits advertisements, so the vehicle 3 periodically scans and receives the advertisements.

[0211] When the key fob 19 enters the reception area from outside, the vehicle 3 receives the advertisement from the key fob 19.

[0212] Next, the vehicle 3 transmits a connection request to the key fob 19 to establish BLE communication with the key fob 19. The polling period at this time is a predetermined time T0 ms.

[0213] Next, after the time T0 has elapsed, the vehicle 3 obtains the vehicle key distance through BLE-CS communication only for the first time.

[0214] If the distance between the vehicle keys is greater than 30 m, it is determined to be in a connection zone, the polling period is set to 3000 ms, and a request is made to the key fob 19 to change the polling period.

[0215] The key FOB 19 returns an ACK, and thereafter transmits and receives normal PDUs via BLE communication as usual.

[0216] The second method for determining the initial polling period has the advantage of improving the accuracy of measuring the distance between the vehicle keys compared to the first method for determining the initial polling period.

[0217] [1-9. Polling Period During Pairing] Next, a case where a polling period is determined when well-known pairing in BLE communication is performed between the in-vehicle device 5 (e.g., the key integrated ECU 11 and the BLE device 15 controlled by the key integrated ECU 11) and the key FOB 19 will be described.

[0218] As shown in FIG. 18, when pairing, the key integrated ECU 11 and the key FOB 19 generate, share, and verify an encryption key.

[0219] Next, the key integrated ECU 11 requests battery information such as the voltage and capacity of the battery BT from the key fob 19. In response, the key fob 19 returns the battery information to the key integrated ECU 11.

[0220] Next, the key integrated ECU 11 determines the polling period based on the battery capacity (e.g., remaining battery capacity) and other factors. For example, it calculates the polling period for each zone that achieves the target battery life. Note that the relationship between the battery capacity or target battery life and the polling period can be determined in advance through experiments or the like.

[0221] Next, the key integrated ECU 11 instructs the vehicle computer 121 to read the PEPS functions (e.g., welcome function, auto-unlock function, etc.) of the vehicle 3. The welcome function is a function that uses various lights of the vehicle 3 to illuminate the surroundings of the vehicle 3 and the ground near the doors when the occupant gets in. The auto-unlock function is a function that automatically unlocks the doors when the key fob 19 approaches the vehicle 3.

[0222] The vehicle computer 121 instructs each of the zone controllers 123 to 127 to read out the PEPS function that each of the zone controllers 123 to 127 has.

[0223] The PEPS functions read from each of the zone controllers 123 to 127 are returned to the key integrated ECU 11 via the vehicle computer 121 .

[0224] The key integrated ECU 11 corrects the polling period according to the received PEPS function. For example, if an auto-unlock function is available, the polling period may be shortened. Thereafter, as necessary (for example, in the case of the fourth or fifth communication sequence shown in FIG. 14 or FIG. 15 ), the key integrated ECU 11 requests the key fob 19 to register the polling period for each zone, and the key fob 19 notifies the key integrated ECU 11 of the completion of the registration.

[0225] Note that pairing may be performed using NFC instead of BLE communication.

[0226] [1-10. Control Processing] Next, the control processing in the first embodiment will be described.

[0227] <First Control Process (Key FOB Side)> The first control process is a process performed in the key fob 19 when changing the polling period in accordance with the vehicle key distance.

[0228] 19 , when the key fob 19 is in the standby state in step (hereinafter, S) 100, it is determined in S110 whether the key fob 19 has moved based on a signal from the acceleration sensor 93. If the determination here is affirmative, the process proceeds to S120, whereas if the determination here is negative, the process returns to S100. Note that when the key fob 19 is in the standby state, the integrated circuit (i.e., the BLE IC) that controls the operation of the BLE device 15 is in the OFF state, in which power is not supplied from the battery BT.

[0229] In S120, the BLE IC is started up.

[0230] In the next step S130, advertisements are periodically transmitted.

[0231] In the next step S140, it is determined whether or not a reply has been received from the vehicle 3 that received the advertisement. If the determination here is affirmative, the process proceeds to step S180, whereas if the determination here is negative, the process proceeds to step S150.

[0232] In S150, it is determined whether or not the key fob 19 has stopped based on the signal from the acceleration sensor 93. If the determination here is affirmative, the process proceeds to S160, whereas if the determination here is negative, the process returns to S130.

[0233] In S160, the key fob 19 is set to the standby state (i.e., the BLE IC is turned off), and this process is temporarily terminated.

[0234] On the other hand, in S180, which is reached when a positive determination is made in S140, the connection process is started. That is, a process is performed to establish communication between the in-vehicle device 5 of the vehicle 3 (i.e., the BLE device 15) and the key fob 19. During this process, an initial polling period is handshake. That is, a process is performed to exchange the communication method, setting values, and the like when communicating between the vehicle 3 and the key fob 19.

[0235] In the next step S190, it is determined whether communication has been established between the vehicle 3 and the key fob 19 (i.e., whether the communication connection has been completed). If the determination here is affirmative, the process proceeds to step S200; if the determination here is negative, the process proceeds to step S210.

[0236] In S210, it is determined whether or not the connection has failed multiple times (for example, N times), and if the determination here is affirmative, the process returns to S130, whereas if the determination here is negative, the process returns to S180.

[0237] On the other hand, in S200, which is performed after the connection is completed, the distance between the vehicle keys is measured by BLE-CS communication. Note that, as will be described later in connection with the control on the vehicle 3 side, the polling period can be determined according to the distance between the vehicle keys.

[0238] In the next S210, it is determined whether or not a request to change the polling period has been received from the vehicle 3. If the determination here is affirmative, the process proceeds to S230, whereas if the determination here is negative, the process proceeds to S250.

[0239] In S230, the polling period is changed, that is, the period for receiving data is changed to match the changed polling period.

[0240] In the next step 240, an ACK is returned to the vehicle 3 indicating that the request to change the polling period has been received.

[0241] In the next step S250, it is determined whether or not a message has been received from the vehicle 3. If the determination is affirmative, the process proceeds to step S270, whereas if the determination is negative, the process proceeds to step S260. The message may include, for example, information about the polling period set in the vehicle 3.

[0242] In S260, it is determined whether or not message reception has failed N times. If the determination here is affirmative, the process returns to S130, whereas if the determination here is negative, the process returns to S270.

[0243] On the other hand, in S270, a message is sent back to the vehicle 3, and the process returns to S200. The returned message may be a message whose content corresponds to the message received from the vehicle 3.

[0244] <Second Control Process (Vehicle Side)> The second control process is a process that is performed in the vehicle 3 when changing the polling period in accordance with the vehicle key distance.

[0245] As shown in FIG. 20, in S300, regular scanning is performed to receive advertisements.

[0246] In the next S310, it is determined whether or not an advertisement has been received from the key fob 19. If the determination here is affirmative, the process proceeds to S320, whereas if the determination here is negative, the process returns to S300.

[0247] In S320, the connection process is started, that is, a process is performed to establish communication between the vehicle 3 and the key fob 19. During this process, an initial polling period is handshake.

[0248] In the next step S330, it is determined whether communication has been established between the vehicle 3 and the key fob 19 (i.e., whether the communication connection has been completed). If the determination here is affirmative, the process proceeds to step S350; if the determination here is negative, the process proceeds to step S340.

[0249] In S340, it is determined whether or not connection has failed N times. If the determination here is affirmative, the process returns to S300, whereas if the determination here is negative, the process returns to S320.

[0250] On the other hand, in S350, which is proceeded to after the connection is completed, the distance between the vehicle 3 and the key fob 19 is measured by BLE-CS communication.

[0251] In the next step S355, the polling period is determined according to the distance between the vehicle keys. That is, since each zone is set according to the distance between the vehicle keys and the polling period is set according to each zone, the polling period can be determined according to the distance between the vehicle keys.

[0252] In the next step S360, it is determined whether or not to change the polling period in accordance with the change in zone. If the determination here is affirmative, the process proceeds to step S330, whereas if the determination here is negative, the process proceeds to step S400.

[0253] In S330, the polling period of the vehicle 3 is changed in accordance with the change in zone, so a request to change the polling period is sent to the key fob 19.

[0254] In the next S340, it is determined whether or not an ACK signal indicating that the polling period change request has been received has been received from the key fob 19. If the determination here is affirmative, the process proceeds to S390, whereas if the determination here is negative, the process proceeds to S400.

[0255] In S390, the polling period is changed.

[0256] In the next step S400, a message is sent to the key fob 19. This message may include, for example, information about the polling period set in the vehicle 3.

[0257] In the next S410, it is determined whether or not a reply to the message has been received from the key fob 19. If the determination here is affirmative, the process returns to S350, whereas if the determination here is negative, the process proceeds to S410.

[0258] In S410, it is determined whether or not the reception of a reply to the message has failed N times. If the determination here is affirmative, the process returns to S430, whereas if the determination here is negative, the process returns to S400.

[0259] In S430, the communication connection is terminated and the process is temporarily ended. When the connection is terminated, the process returns to the initial periodic scan.

[0260] [1-11. Other Control Processes] Next, other control processes in the first embodiment will be described.

[0261] 21 and 22, a description will be given of the overall control process for changing the polling period based on the functionality of the vehicle 3. This control process is performed on the vehicle 3 side (i.e., the key integrated ECU 11).

[0262] As shown in FIG. 21, in S500, the PEPS function of the vehicle 3 is read out according to the procedure shown in FIG.

[0263] Next, in S510, it is determined whether the entry function has been activated by the unlock switch. If the determination here is affirmative, the process proceeds to S530, whereas if the determination here is negative, the process proceeds to S520. The entry function is a function that is activated when entering the vehicle. The unlock switch is a switch provided on the operating unit 45 of the key fob 19, and is a switch that commands the operation of manually unlocking the doors.

[0264] In S520, the entry zone boundary and polling period are corrected according to the function, and the process proceeds to S550.

[0265] On the other hand, in S530, the entry zone is deleted. Since the unlock switch initiates BLE communication after the user presses the unlock switch, there is no requirement for responsiveness of the polling cycle, and it is sufficient that only the BLE communication connection is established. Therefore, the entry zone is deleted. Note that if the welcome function is present, the entry zone is deleted, and the welcome zone starts from 0 m.

[0266] In the next step S540, a flag is set, i.e., no_entry_zone = 1. The initial value of no_entry_zone is 0.

[0267] In the next step S550, it is determined whether or not the welcome function is present. If the determination is affirmative, the process proceeds to step S620, whereas if the determination is negative, the process proceeds to step S560.

[0268] In S560, it is determined whether or not no_entry_zone is 0. If the determination here is affirmative, the process proceeds to S580, whereas if the determination here is negative, the process proceeds to S570.

[0269] In S570, when the distance from vehicle 3 is in the range of 0 m to 40 m, the polling period is set to 4000 ms, and the process is terminated (see FIG. 22). In other words, when there is no welcome function and the entry function is activated by the unlock switch, there is no requirement for responsiveness of the polling period in any zone, so the polling period is set to 4000 ms regardless of the distance.

[0270] On the other hand, in S580, the polling period of the welcome zone is set to the default value.

[0271] In the next step S590, the welcome zone is set to a range of 3 m.

[0272] In the next step S600, the polling period of the approach zone is set to a default value.

[0273] In the next step S610, the approach zone is set to 10 m, and the process proceeds to step S650.

[0274] The processing of steps 580 to 610 is performed to ensure that a reply from the key fob 19 is received in the entry zone when the welcome function is not present.

[0275] If the answer to S550 is YES, the process proceeds to S620, where it is determined whether the welcome function requires polling at a distance greater than 10 m. If the answer to S620 is YES, the process proceeds to S630, whereas if the answer to S620 is NO, the process proceeds to S640.

[0276] In S630, the middle zone is deleted because the range from the approach zone to the connection zone is narrowed by the welcome zone, and if there are multiple zones with slow polling cycles, cycle switching processing is required frequently when crossing between zones, so the middle zone is deleted.

[0277] In the next step 640, the welcome zone boundary and polling period are corrected according to the function, and the process proceeds to step S650.

[0278] In S650 of Fig. 22, it is determined whether the zone interval is less than 3 m. If the determination here is affirmative, the process proceeds to S660, whereas if the determination here is negative, the process proceeds to S670.

[0279] In S660, the zone interval is corrected to 3 m.

[0280] In the next S670, it is determined whether the range of the zones excluding the connection zone is less than 30 m. If the answer is affirmative, the process proceeds to S680; if the answer is negative, the process proceeds to S690. Note that the middle zone may be omitted depending on the conditions, so the "range of the zones excluding the connection zone" is the entry zone to the middle zone if there is a middle zone, or the entry zone to the approach zone if there is no middle zone.

[0281] In S680, the range of the connection zone is corrected to a range of 10 m to (40 m - range of zones excluding the connection zone) m.

[0282] In the next step S690, it is determined whether the battery life is satisfied as a result of correcting the entry zone and welcome zone. If the determination is affirmative, the process proceeds to step S710, whereas if the determination is negative, the process proceeds to step S700.

[0283] In S700, the polling period from the approach zone to the connection zone is corrected so as to satisfy the battery life, and the process ends. The relationship between the polling period and the battery life can be determined in advance by experiment, etc.

[0284] On the other hand, in S710, the polling period from the approach zone to the connection zone is shortened within a range that satisfies the battery life, and this process is temporarily terminated.

[0285] <Fourth Control Process> Next, the control process for changing the polling period based on the functionality of the vehicle 3 described above with reference to Figures 21 and 22 will be described in detail with reference to Figures 23 to 27.

[0286] As shown in FIG. 23, in S800, the PEPS function of the vehicle 3 is read out according to the procedure shown in FIG.

[0287] In S810, it is determined whether or not the vehicle has a projection light welcome function. If the determination here is affirmative, the process proceeds to S820, whereas if the determination here is negative, the process proceeds to S930 in Fig. 24. The projection light is a light that illuminates the ground and displays welcome text or other symbols on the ground when the vehicle is boarded.

[0288] In S820, it is determined whether or not the automatic unlock function is available. If the determination here is affirmative, the process proceeds to S830, whereas if the determination here is negative, the process proceeds to S860.

[0289] In S830, the following is determined, taking into account the functionality of the auto-unlock function: the boundary of the entry zone (i.e., the outer boundary; the same applies below) is set to 7 m by multiplying the default value of 5 m by a weighting factor of 1.4, and the polling period is set to 50 ms by multiplying the default value of 100 ms by a weighting factor of 0.5.

[0290] In the next step S840, the following details are determined, taking into account the functionality of the projection light: the welcome zone boundary is set to 15 m by multiplying the default value of 10 m by a weighting factor of 1.5, and the polling period is set to 250 ms by multiplying the default value of 500 ms by a weighting factor of 0.5.

[0291] In the next step S850, the polling period is set to one of the following values ​​depending on the distance between the vehicle and key, and then the process ends. That is, the polling period is set to 50 ms for distances between 0 and 7 m, 250 ms for distances between 7 and 15 m, 1000 ms for distances between 15 and 25 m, and 4000 ms for distances between 25 and 40 m. Note that the auto-unlock function is enabled for distances between 0 and 7 m, and the projection light function is enabled for distances between 7 and 15 m.

[0292] If the determination in S820 is negative, the process proceeds to S860, where it is determined whether or not an unlock sensor is present. If the determination is positive, the process proceeds to S870, whereas if the determination is negative, the process proceeds to S900.

[0293] In S870, the following is determined, taking into consideration the functionality of the unlock sensor: the boundary of the entry zone is set to 5 m by multiplying the default value of 5 m by a weighting factor of 1.0, and the polling period is set to 100 ms by multiplying the default value of 100 ms by a weighting factor of 1.0.

[0294] In the next step S880, the following is determined, taking into consideration the functionality of the projection light: the welcome zone boundary is set to 15 m by multiplying the default value of 10 m by a weighting factor of 1.5, and the polling period is set to 250 ms by multiplying the default value of 500 ms by a weighting factor of 0.5.

[0295] In the next step S890, the polling period is set to one of the following values ​​depending on the distance between the vehicle and key, and then the process ends. That is, the polling period is set to 100 ms for a distance of 0 to 5 m, 250 ms for a distance of 5 to 15 m, 500 ms for a distance of 15 to 25 m, and 3000 ms for a distance of 25 to 40 m. Note that the unlock sensor functions between 0 and 5 m, and the projection light functions between 5 and 15 m.

[0296] On the other hand, in S900, which is reached when a negative determination is made in S860, the entry zone is deleted.

[0297] In the next step 910, the following details are determined, taking into account the functionality of the projection light: the welcome zone boundary is set to 15 m by multiplying the default 10 m by a weighting factor of 1.5, and the polling period is set to 250 ms by multiplying the default 500 ms by a weighting factor of 0.5.

[0298] In S920, the polling period is set to the following value according to the distance between the vehicle and key, and then the process ends: 250 ms for 0 m to 15 m, 500 ms for 15 m to 25 m, and 2000 ms for 25 m to 40 m. Note that the projection light functions between 0 m and 15 m.

[0299] Next, as shown in Fig. 24, in S930, it is determined whether or not the welcome function of the mirror footwell lighting (i.e., lighting that illuminates the footwell of the door mirror) is present. If the determination here is affirmative, the process proceeds to S940, whereas if the determination here is negative, the process proceeds to S1050 in Fig. 25.

[0300] In S940, it is determined whether or not the automatic unlock function is available. If the determination here is affirmative, the process proceeds to S950, whereas if the determination here is negative, the process proceeds to S980.

[0301] In S950, the following is determined, taking into account the functionality of the auto-unlock function: the entry zone boundary is set to 7 m by multiplying the default 5 m by a weighting factor of 1.4, and the polling period is set to 50 ms by multiplying the default 100 ms by a weighting factor of 0.5.

[0302] In the next step S960, the following is determined, taking into account the functionality of the mirror footwell lighting: the welcome zone boundary is set to 10 m by multiplying the default value of 10 m by a weighting factor of 1.0, and the polling period is set to 500 ms by multiplying the default value of 500 ms by a weighting factor of 1.0.

[0303] In the next step S970, the polling period is set to one of the following values ​​depending on the distance between the vehicle and key, and then the process ends. That is, the polling period is set to 50 ms for distances between 0 and 7 m, 500 ms for distances between 7 and 10 m, 600 ms for distances between 10 and 20 m, 1000 ms for distances between 20 and 30 m, and 4000 ms for distances between 30 and 40 m. Note that the auto-unlock function is enabled for distances between 0 and 7 m, and the mirror footwell illumination is enabled for distances between 7 and 10 m.

[0304] If the determination in S940 is negative, the process proceeds to S980, where it is determined whether or not an unlock sensor is present. If the determination is positive, the process proceeds to S990, whereas if the determination is negative, the process proceeds to S1020.

[0305] In S990, the following is determined, taking into consideration the functionality of the unlock sensor: the entry zone boundary is set to 5 m by multiplying the default value of 5 m by a weighting factor of 1.0, and the polling period is set to 100 ms by multiplying the default value of 100 ms by a weighting factor of 1.0.

[0306] In the next step S1000, the following is determined, taking into consideration the functionality of the mirror footwell lighting: the welcome zone boundary is set to 10 m by multiplying the default value of 10 m by a weighting factor of 1.0, and the polling period is set to 500 ms by multiplying the default value of 500 ms by a weighting factor of 1.0.

[0307] In the next step S1010, the polling period is set to one of the following values ​​according to the distance between the vehicle and key, and then the process is terminated. That is, the polling period is set to 100 ms for distances between 0 and 5 m, 500 ms for distances between 5 and 10 m, 600 ms for distances between 10 and 20 m, 1000 ms for distances between 20 and 30 m, and 3000 ms for distances between 30 and 40 m. Note that the unlock sensor functions between 0 and 5 m, and the mirror footwell lights function between 5 and 10 m.

[0308] On the other hand, in S1020, which is reached when a negative determination is made in S980, the entry zone is deleted.

[0309] In the next step 1030, the following details are determined, taking into account the functionality of the mirror footwell lighting: the welcome zone boundary is set to 10 m by multiplying the default value of 10 m by a weighting factor of 1.0, and the polling period is set to 500 ms by multiplying the default value of 500 ms by a weighting factor of 1.0.

[0310] In the next step S1040, the polling period is set to one of the following values ​​depending on the distance between the vehicle and key, and then the process ends. That is, the polling period is set to 500 ms for distances between 0 and 10 m, 600 ms for distances between 10 and 20 m, 1000 ms for distances between 20 and 30 m, and 2000 ms for distances between 30 and 40 m. Note that the mirror footwell lighting functions between 0 and 10 m.

[0311] Next, as shown in Fig. 25, in S1050, it is determined whether or not a welcome function for indoor illumination (i.e., illumination that lights up the room) is present. If the determination here is affirmative, the process proceeds to S1060, whereas if the determination here is negative, the process proceeds to S1180 in Fig. 26.

[0312] In S1060, it is determined whether or not the automatic unlock function is available. If the determination here is affirmative, the process proceeds to S1070, whereas if the determination here is negative, the process proceeds to S1110.

[0313] In S1070, the following is determined, taking into consideration the functionality of the auto-unlock function: the entry zone boundary is set to 7 m by multiplying the default 5 m by a weighting factor of 1.4, and the polling period is set to 50 ms by multiplying the default 100 ms by a weighting factor of 0.5.

[0314] In the next step S1080, the following details are determined, taking into consideration the functionality of the interior illumination: the welcome zone boundary is set to 8 m by multiplying the default 10 m by a weighting factor of 0.8, and the polling period is set to 500 ms by multiplying the default 500 ms by a weighting factor of 1.0.

[0315] In the next step S1090, since the distance between the 7 m boundary of the entry zone and the 8 m boundary of the welcome zone is less than 3 m, the welcome zone boundary is corrected to 10 m.

[0316] In the next step S1100, the polling interval is set to one of the following values ​​depending on the distance between the vehicle and key, and then the process ends. That is, the interval is set to 50 ms for distances between 0 and 7 m, 500 ms for distances between 7 and 10 m, 600 ms for distances between 10 and 20 m, 1000 ms for distances between 20 and 30 m, and 4000 ms for distances between 30 and 40 m. Note that the auto-unlock function is enabled for distances between 0 and 7 m, and the interior illumination is enabled for distances between 7 and 10 m.

[0317] If the determination in S1060 is negative, the flow proceeds to S1110, where it is determined whether or not an unlock sensor is present. If the determination is positive, the flow proceeds to S1120, whereas if the determination is negative, the flow proceeds to S1150.

[0318] In S1120, the following is determined taking into consideration the functionality of the unlock sensor: the entry zone boundary is set to 5 m by multiplying the default value of 5 m by a weighting factor of 1.0, and the polling period is set to 100 ms by multiplying the default value of 100 ms by a weighting factor of 1.0.

[0319] In the next step S1130, the following details are determined, taking into account the functionality of the interior illumination: the welcome zone boundary is set to 8 m by multiplying the default 10 m by a weighting factor of 0.8, and the polling period is set to 500 ms by multiplying the default 500 ms by a weighting factor of 1.0.

[0320] In the next step S1140, the polling period is set to one of the following values ​​depending on the distance between the vehicle and key, and then the process ends. That is, the polling period is set to 100 ms for distances between 0 m and 5 m, 500 ms for distances between 5 m and 8 m, 600 ms for distances between 8 m and 18 m, 1000 ms for distances between 18 m and 28 m, and 3000 ms for distances between 28 m and 40 m. Note that the unlock sensor functions between 0 m and 5 m, and the interior illumination functions between 5 m and 8 m.

[0321] On the other hand, in S1150, which is reached when a negative determination is made in S1110, the entry zone is deleted.

[0322] In the next step 1160, the following details are determined, taking into consideration the functionality of the indoor illumination: the welcome zone boundary is set to 8 m by multiplying the default 10 m by a weighting factor of 0.8, and the polling period is set to 500 ms by multiplying the default 500 ms by a weighting factor of 1.0.

[0323] In the next step S1170, the polling period is set to one of the following values ​​depending on the distance between the vehicle and key, and then the process ends. That is, the polling period is set to 500 ms for distances between 0 and 8 m, 600 ms for distances between 8 and 18 m, 1000 ms for distances between 18 and 28 m, and 2000 ms for distances between 28 and 40 m. Note that the interior illumination functions when the distance is between 0 and 8 m.

[0324] Next, as shown in Fig. 26, in S1180, it is determined whether or not an auto-unlock function is available. If the determination here is affirmative, the process proceeds to S1190, whereas if the determination here is negative, the process proceeds to S1210.

[0325] In S1190, the following is determined, taking into consideration the functionality of the auto-unlock function: the entry zone boundary is set to 7 m by multiplying the default 5 m by a weighting factor of 1.4, and the polling period is set to 50 ms by multiplying the default 100 ms by a weighting factor of 0.5.

[0326] In S1200, the polling period is set to the following value according to the distance between the vehicle and key, and then the process ends. That is, the polling period is set to 50 ms for distances between 0 and 7 m, 500 ms for distances between 7 and 10 m, 600 ms for distances between 10 and 20 m, 1000 ms for distances between 20 and 30 m, and 4000 ms for distances between 30 and 40 m. Note that auto-unlock functions for distances between 0 and 7 m.

[0327] If the determination in S1180 is negative, the process proceeds to S1210, where it is determined whether or not an unlock sensor is present. If the determination is positive, the process proceeds to S1220, whereas if the determination is negative, the process proceeds to S1240.

[0328] In S1220, the following is determined taking into consideration the functionality of the unlock sensor: the boundary of the entry zone is set to 5 m by multiplying the default value of 5 m by a weighting factor of 1.0, and the polling period is set to 100 ms by multiplying the default value of 100 ms by a weighting factor of 1.0.

[0329] In the next step S1230, the polling period is set to one of the following values ​​depending on the distance between the vehicle and key, and then the process ends. That is, the polling period is set to 100 ms for distances between 0 and 5 m, 500 ms for distances between 5 and 8 m, 600 ms for distances between 8 and 18 m, 1000 ms for distances between 18 and 28 m, and 3000 ms for distances between 28 and 40 m. Note that the unlock sensor functions between 0 and 5 m.

[0330] On the other hand, in S1240, which is reached when a negative determination is made in S1210, the polling period is set to the following value, and the process is temporarily terminated: That is, for 0 m to 40 m, it is set to 4000 ms.

[0331] Here, the relationship between each zone, function, zone boundary (i.e., outer boundary), and polling period in FIG. 27 will be explained collectively.

[0332] As shown in Figure 27, the polling cycles for the entry zone and welcome zone are determined by the function. Furthermore, the boundaries of each zone are adjusted to 3m for combinations where the distance between zones is less than 3m. Furthermore, the range from the approach zone to the connection zone and the polling cycle vary depending on the entry function and welcome function.

[0333] In Figure 27, "pre-verification" refers to referring to a polling signal in advance when performing an operation such as auto-unlocking, and "event verification" refers to using a signal from an unlock switch or the like without referring to a polling signal when performing an operation such as unlocking the door.

[0334] 28 and 29, an example of changing the polling period depending on the speed of a person (i.e., the speed of the key fob 19) will be described. Here, the process performed on the vehicle 3 side while connected to the key fob 19 will be described.

[0335] As shown in FIG. 29, in S1300, communication for connection with the key fob 19 (i.e., connection communication) is performed.

[0336] In the next step S1310, communication for measuring the distance with the key fob 19 (i.e., distance measurement communication) is performed. That is, the distance between the vehicle and the key is measured by BLE-CS communication. In this case, timestamp information is transmitted and received.

[0337] In the next S1320, it is determined whether communication has been successful M times (i.e., a specified number of times in the specifications). If the determination is affirmative, the process proceeds to S1330, whereas if the determination is negative, the process proceeds to S1510 in FIG.

[0338] In S1330, the speed V of the person (i.e., the key fob 19) is calculated from the measured vehicle key distance and the time stamp.

[0339] In the next step S1340, the difference (V-V0) between the calculated speed V of the person and the speed V0 of an average person is calculated.

[0340] In the next step S1350, it is determined whether or not |V-V0| exceeds 0.1 m / s. If the determination here is affirmative, the process proceeds to step S1360, whereas if the determination here is negative, the process proceeds to step S1510. Note that a difference of 0.1 m / s or less is considered to be within the error range.

[0341] In S1360, it is determined whether V is equal to or greater than 0. If the determination here is affirmative, the process proceeds to S1360, whereas if the determination here is negative, the process proceeds to S1510. Note that if a person leaves the vehicle 3 (i.e., if V<0), the polling period is maintained.

[0342] In S1370, it is determined whether V0 / V exceeds 0.3. If the determination here is affirmative, the process proceeds to S1380, whereas if the determination here is negative, the process proceeds to S1460 in FIG.

[0343] In S1380, it is determined whether V0 / V is less than 2. If the determination here is affirmative, the process proceeds to S1450 in Fig. 29, while if the determination here is negative, the process proceeds to S1390.

[0344] In S1390, the original polling period T0 is multiplied by the correction value 2 to calculate the polling period update value T. This is to prevent a decrease in functionality when a person approaches at high speed after the polling period is set too long.

[0345] In the next S1400, it is determined whether V0 / V is less than 10. If the determination here is affirmative, the process proceeds to S1470 in Fig. 29, whereas if the determination here is negative, the process proceeds to S1410 in Fig. 29.

[0346] 29, in S1410, the calculation "Tsum = Tsum + 2 × T0" is performed. T0 is the original polling period (i.e., the initial value). Here, each time the condition (i.e., the judgment condition in S1400) is met, the calculated time value Tsum is increased by 2T0.

[0347] In the next step S1420, it is determined whether Tsum is less than 600 [s]. If the determination here is affirmative, the process proceeds to step S1470, whereas if the determination here is negative, the process proceeds to step S1430.

[0348] In S1430, the communication connection with the key fob 19 is disconnected. That is, if a state in which a person is stopped continues for 10 minutes as viewed from the vehicle 3, the communication connection is cut off.

[0349] In the next step S1440, a regular scan is started, and the process ends for the time being.

[0350] On the other hand, in S1450, which is reached when a positive determination is made in S1380, the original polling period T0 is multiplied by the correction value V0 / V to calculate a polling period update value T.

[0351] In the next step S1470, a request to change the polling period is sent to the key fob 19.

[0352] In the next S1480, it is determined whether or not an ACK response to the request to change the polling period has been received from the key fob 19. If the determination is affirmative, the process proceeds to S1490, whereas if the determination is negative, the process proceeds to S1510.

[0353] In S1490, the polling period is updated to the polling period update value T.

[0354] In the next step S1500, if the polling period update value T has elapsed since the distance measurement communication, the process ends.

[0355] On the other hand, in S1460, which is reached when a negative determination is made at S1370 in FIG. 28, in order to achieve the desired battery life of the key fob 19, the original polling period T0 is multiplied by a correction value of 0.3 to calculate a polling period update value T, and then the process proceeds to S1470 and subsequent steps.

[0356] In addition, in S1510, which is reached after a negative determination in S1320, S1350, or S1360 in FIG. 28, if the original polling period T0 has elapsed since the distance measurement communication, the process is temporarily terminated.

[0357] <Sixth Control Process> Here, with reference to FIG. 30, a process performed on the key fob 19 side during connection with the vehicle 3 when the polling period is changed according to the speed of the person as described above will be described.

[0358] As shown in FIG. 30, in S1600, connection communication with vehicle 3 is performed.

[0359] In the next step S1610, distance measurement communication is performed with the vehicle 3. That is, the distance between the vehicle and the key is measured by BLE-CS communication. In this case, time stamp information is transmitted and received.

[0360] In the next step S1620, it is determined whether or not the communication has been successful M times. If the determination here is affirmative, the process proceeds to step S1630, whereas if the determination here is negative, the process proceeds to step S1670.

[0361] In S1630, it is determined whether or not a request to change the polling period to T has been received from vehicle 3. If the determination here is affirmative, the process proceeds to S1640, whereas if the determination here is negative, the process proceeds to S1670.

[0362] In S1640, the polling period is updated to T.

[0363] In the next step S1650, an ACK is returned to the vehicle 3.

[0364] In the next step S1660, after the polling period T has elapsed since the distance measurement communication, the process is temporarily terminated.

[0365] On the other hand, in S1670, after the original polling period T0 has elapsed since the distance measurement communication, this process is temporarily terminated. Note that the process flow of S1660 and S1670 returns to the process of the initial connection communication.

[0366] [1-12. Effects] According to the first embodiment, the following effects can be obtained.

[0367] (1a) In the first embodiment, when a polling signal is transmitted from the in-vehicle device 5 (i.e., the BLE device 15) to the key FOB 19, if a response signal to the polling signal is received from the key FOB 19, distance measurement communication is performed, which is communication for measuring the distance between the BLE device 15 and the key FOB 19. When this distance measurement communication is performed, the distance between the BLE device 15 and the key FOB 19 (i.e., the vehicle-key distance) is calculated based on the phase difference of the signals communicated between the BLE device 15 and the key FOB 19. Then, a polling period, which is the period for transmitting the polling signal, is determined based on the vehicle-key distance.

[0368] With this configuration, the first embodiment can accurately detect the distance between the in-vehicle device 5 (i.e., the vehicle 3) and the key fob 19 and set an appropriate polling period, thereby extending the battery life of the key fob 19 without compromising functionality.

[0369] That is, in the first embodiment, the vehicle key distance can be calculated with high accuracy based on the phase difference (for example, based on BLE-CS communication) of the signals communicated between the vehicle 3 and the key fob 19. Therefore, the polling period can be set appropriately (for example, with high accuracy according to the vehicle key distance) based on the vehicle key distance calculated in this manner, thereby extending the battery life of the key fob 19 without impairing functionality.

[0370] (1b) In the first embodiment, a polling cycle is associated with each zone determined based on the vehicle key distance. The zone in which the key fob 19 is located is determined based on the vehicle key distance, and the polling cycle is determined based on the determined zone. This reduces the power consumption of the battery BT of the key fob 19 while maintaining user convenience.

[0371] (1c) In the first embodiment, the polling period can be determined each time the vehicle-key distance is calculated. This makes it possible to track the user's movements and determine the polling period in real time.

[0372] (1d) In the first embodiment, the distance measurement communication is configured to be capable of channel sounding communication using Bluetooth Low Energy (i.e., BLE-CS communication). This allows the user's position to be detected with high accuracy, making it possible to appropriately determine the polling period. Furthermore, since BLE communication allows for longer-distance communication than UWB communication, it is possible to appropriately set the polling period even when the user's position is far from the vehicle 3. This also makes it possible to handle welcome actions and the like that need to be performed at a location far from the vehicle 3.

[0373] (1e) In the first embodiment, the zone boundary or the polling period can be set based on the zone boundary indicating the outer boundary of the default zone or the default polling period and information about the functions of the vehicle 3. In other words, the optimal zone boundary and polling period can be set for each vehicle 3.

[0374] (1f) In the first embodiment, the zone boundaries or the polling period can be set based on the default zone boundaries or the default polling period and a correction coefficient determined based on the type of PEPS function possessed by the vehicle 3. In other words, the zone boundaries and the polling period can be set according to the PEPS function of the vehicle 3, thereby improving user convenience.

[0375] (1g) In the first embodiment, if the difference between the zone boundaries for each of the plurality of zones is smaller than a predetermined threshold value, the zone boundaries can be set so that the difference between the zone boundaries for each of the plurality of zones is larger than the threshold value. This allows the zone boundaries to be set appropriately.

[0376] (1h) In the first embodiment, the polling period can be set based on the default polling period and the remaining battery power of the key fob 19. This reduces the power consumption of the battery BT of the key fob 19, thereby extending the battery life.

[0377] (1i) In the first embodiment, the speed of the key fob 19 is calculated based on the timestamp associated with the vehicle-key distance, and the polling period can be determined based on that speed as well. This allows the polling period to be set appropriately in accordance with the user's movements.

[0378] (1j) In the first embodiment, the speed of the key fob 19 can be calculated by taking an exponential moving average based on multiple sets of timestamps linked to the vehicle-key distance. This allows the polling period to be set appropriately according to the user's movement.

[0379] (1k) In the first embodiment, two BLE antennas mounted at different positions on the vehicle 3 are used, and the speed of the key FOB 19 relative to the vehicle direction (i.e., the direction toward the vehicle) can be detected based on the distance between the key FOB 19 and one BLE antenna and the distance between the key FOB 19 and the other BLE antenna. This allows the polling period to be set appropriately in accordance with the user's movement.

[0380] (11) In the first embodiment, a correction coefficient (e.g., V / V) is calculated based on the calculated velocity (e.g., V) of the key fob 19 and a preset reference velocity (e.g., V), and the polling period is determined based on the correction coefficient. This allows the polling period to be set appropriately according to the user's movement.

[0381] (1m) In the first embodiment, if the correction coefficient is within a predetermined range, the polling period is determined based on the correction coefficient, and if the correction coefficient is outside the predetermined range, the polling period is determined based on a preset correction coefficient. This allows the polling period to be set within an appropriate range.

[0382] (1n) In the first embodiment, the polling period can be determined based on the number of times a response signal is successfully received in response to a predetermined number of transmitted polling signals. This allows the polling period to be set appropriately according to the noise environment, thereby improving user convenience.

[0383] (1o) In the first embodiment, if the determined polling period differs from the current polling period, a polling period change request to change the polling period is sent to the key fob 19, and the polling period can be changed from the transmission of a polling signal immediately thereafter. This allows the polling period to be immediately changed to the optimal polling period.

[0384] (1p) In the first embodiment, if the determined polling period differs from the current polling period, a polling period change request to change the polling period is sent to the key fob 19, and information on the change in the polling period is also sent when a polling signal is sent immediately afterwards, so that the polling period can be changed from the next polling signal transmission. This ensures that the polling period can be changed reliably.

[0385] (1q) In the first embodiment, the distance between the vehicle keys is estimated based on information on the radio wave intensity of the advertising signal from the key fob 19, and if the estimated distance between the vehicle keys is greater than a predetermined threshold, transmission of a polling signal can be started at a predetermined cycle. For example, even if distance data cannot be obtained by BLE-CS communication, the distance between the vehicle keys can be estimated based on RSSI and the polling cycle can be determined.

[0386] [1-13. Correspondence] Next, the relationship between the present disclosure and the first embodiment will be described.

[0387] The vehicle control system corresponds to vehicle control system 1, the vehicle corresponds to vehicle 3, the portable device corresponds to key FOB 19, the in-vehicle device corresponds to in-vehicle device 5, the communication control unit corresponds to the processing of S350, the distance calculation unit corresponds to the distance measurement unit 87, the polling period determination unit corresponds to the processing of S355, and the polling period memory unit corresponds to the memory unit 23.

[0388] [2. Second Embodiment] The second embodiment has the same basic configuration as the first embodiment, and therefore the following mainly describes the differences from the first embodiment. Note that the same reference numerals as those in the first embodiment indicate the same configuration, and reference is made to the preceding description.

[0389] [2-1. Principle] In the second embodiment, an example will be described in which the BLE output of the key fob 19 is optimized in addition to the optimization of the polling period.

[0390] As shown in FIGS. 31A and 31B, in the second embodiment, similarly to the first embodiment, the polling period is set to be shorter for zones closer to the vehicle 3.

[0391] 31C, the BLE output of the key fob 19 is set to be smaller as the distance between the vehicle 3 and the key fob 19 decreases (i.e., the closer the zone is to the vehicle 3). As is well known, a power unit of 0 dBm corresponds to a power of 1 mW.

[0392] Next, the principle of operation of the second embodiment will be described in detail with reference to FIG.

[0393] 32A, when the BLE output of the key FOB 19 is constant (for example, a default value), the received power of the BLE radio waves at the BLE device 15 of the vehicle 3 (i.e., the BLE received power) decreases as the key FOB 19 is farther from the vehicle 3 (i.e., the BLE antenna of the BLE device 15). Note that Figures 32A and 32B show the relationship between the distance from the BLE antenna (i.e., the distance calculated by BLE-CS) and the BLE received power, with the solid line indicating the theoretical value and the dashed line indicating the actually measured value.

[0394] Therefore, it is understood that the BLE output of the key FOB 19 only needs to have a BLE reception power sufficient to enable the vehicle 3 to measure the distance between the vehicle keys via BLE-CS communication. In other words, when the key FOB 19 is in a zone close to the vehicle 3, the BLE output of the key FOB 19 may be smaller than the default value. More specifically, it is understood that the BLE output of the key FOB 19 may be gradually reduced as the key FOB 19 approaches the vehicle 3 (i.e., distance measurement via BLE-CS communication is possible) as long as the vehicle 3 can ensure a BLE reception power sufficient to enable distance measurement via BLE-CS communication.

[0395] Therefore, in this second embodiment, as shown in FIG. 32C, the smaller the distance between the vehicle 3 and the key FOB 19 (i.e., the closer the zone is to the vehicle 3), the smaller the BLE output of the key FOB 19 is set.

[0396] 32C, the BLE output may be corrected to ensure reliable distance measurement, i.e., the degree of reduction in the BLE output may be suppressed.

[0397] [2-2. Control Processing] <Vehicle Side> First, the control processing performed on the vehicle 3 side in the second embodiment will be described.

[0398] As shown in FIG. 33, in S1700, a PDU is transmitted from the vehicle 3 to the key fob 19.

[0399] In the next step S1710, a PDU including the RSSI value of the signal transmitted from the vehicle 3 is received from the key fob 19. This process is for obtaining its own signal output in order to estimate the influence of the noise environment.

[0400] In the next step S1720, the RSSI of the signal received from the key fob 19 is measured.

[0401] In the next step S1730, distance measurement communication is performed with the key fob 19. That is, the distance between the vehicle and the key is measured by BLE-CS communication.

[0402] In the next step S1740, it is determined whether or not there is a change in the polling period depending on the zone. If the determination here is affirmative, the process proceeds to step S1750, whereas if the determination here is negative, the process is temporarily terminated.

[0403] In S1750, the BLE output of the key fob 19 is determined based on the physical relationship between the RSSI associated with the BLE received power and the distance between the vehicle and the key (e.g., a theoretical value or an actual measurement value). For example, the BLE output of the key fob 19 is determined based on the data shown in Figures 32A and 32C.

[0404] In the next S1760, it is determined whether there is a change in the output of the key fob 19. If the determination here is affirmative, the process proceeds to S1770, whereas if the determination here is negative, the process is temporarily terminated.

[0405] In S1770, a request is made to the key fob 19 to change the BLE output.

[0406] In the next S1780, it is determined whether or not a response has been received from the key fob 19. If the determination here is affirmative, the process proceeds to S1790, whereas if the determination here is negative, the process proceeds to S1795.

[0407] In S1790, the updated output value of the BLE output of the key fob 19 is stored, and the process ends for the time being.

[0408] On the other hand, in S1795, it is stored that the BLE output of the key fob 19 is maintained, and this process is temporarily terminated.

[0409] <Key FOB Side> Next, a control process performed on the key fob 19 side in the second embodiment will be described.

[0410] As shown in FIG. 34, in S1800, the key fob 19 receives a PDU from the vehicle.

[0411] In the next step S1810, the RSSI of the signal received from the vehicle 3 is measured.

[0412] In the next step S1820, a PDU including the RSSI value measured in step S1810 is transmitted to the vehicle 3.

[0413] In the next step S1830, distance measurement communication is performed with the vehicle 3. That is, the distance between the vehicle and the key is measured by BLE-CS communication.

[0414] In the next step S1840, it is determined whether or not there is a request from the vehicle 3 to change the BLE output of the key fob 19. If the determination here is affirmative, the process proceeds to step S1850, whereas if the determination here is negative, the process is temporarily terminated.

[0415] In S1850, an updated value of the BLE output of the key fob 19 is set and updated based on a request for a change in the BLE output from the vehicle 3 and the product requirements of the key fob 19.

[0416] In the next step S1860, the updated output value of the BLE output of the key fob 19 is returned to the vehicle 3, and the process ends.

[0417] [2-3. Effects] The second embodiment has the same effects as the first embodiment. In addition, the second embodiment optimizes the polling period and the BLE output of the key fob 19, which has the significant effect of further extending the battery life of the key fob 19.

[0418] Although the BLE output of the key fob 19 is optimized in accordance with the radio wave intensity here, the BLE output of the in-vehicle device 5 may also be optimized in a similar manner. That is, the BLE output of the BLE device 15 may be reduced as the distance between the vehicle keys decreases. Alternatively, only the BLE output of the BLE device 15 may be optimized.

[0419] 3. Other Embodiments Although the embodiments of the present disclosure have been described above, it goes without saying that the present disclosure is not limited to the above-described embodiments and can take on various forms.

[0420] (3a) In this disclosure, a key fob is used as an example of a portable device that measures distance using BLE-CS communication, but the portable device may also be a portable device such as a smartphone (i.e., an information terminal).

[0421] (3b) In this disclosure, communication between an in-vehicle device and a portable device has been described primarily using Bluetooth Low Energy (i.e., BLE), an extended specification of Bluetooth. However, Bluetooth may also be used for communication between an in-vehicle device and a portable device. Therefore, Bluetooth channel sounding may be used to measure the distance between the in-vehicle device and the portable device, instead of Bluetooth Low Energy channel sounding.

[0422] (3c) The operation of the in-vehicle device or vehicle control system described in this disclosure may be realized by a special-purpose computer provided by configuring a processor and memory programmed to perform one or more functions embodied in a computer program.

[0423] Alternatively, the operation of the in-vehicle device or vehicle control system described in the present disclosure may be realized by a special-purpose computer provided by configuring a processor with one or more dedicated hardware logic circuits.

[0424] Alternatively, the operation of the in-vehicle device or vehicle control system described in this disclosure may be realized by one or more dedicated computers configured by combining a processor and memory programmed to perform one or more functions with a processor configured by one or more hardware logic circuits.

[0425] The computer program may be stored as instructions to be executed by a computer on a computer-readable non-transitory storage medium. The method for realizing the functions of the in-vehicle device or vehicle control system does not necessarily have to include software, and all of the functions may be realized using one or more pieces of hardware.

[0426] (3d) In addition to the above-described in-vehicle device and vehicle control system, the present disclosure can also be realized in various forms, such as a configuration including the in-vehicle device or vehicle control system as a component, a program for causing the computer of the in-vehicle device or vehicle control system to function, a non-transient tangible recording medium such as a semiconductor memory on which this program is recorded, and a vehicle control method.

[0427] (3e) Multiple functions possessed by one component in each of the above embodiments may be realized by multiple components, or one function possessed by one component may be realized by multiple components. Furthermore, multiple functions possessed by multiple components may be realized by one component, or one function realized by multiple components may be realized by one component. Furthermore, part of the configuration of each of the above embodiments may be omitted. Furthermore, at least part of the configuration of each of the above embodiments may be added to or substituted for the configuration of another embodiment. [Technical Ideas Disclosed in the Specification] [Item 1] An in-vehicle device (5) mounted on a vehicle (3) and capable of wireless communication with a portable device (19) carried by a user, comprising: a communication control unit (S350) configured to, when transmitting a polling signal from the in-vehicle device to the portable device, perform ranging communication, which is communication for measuring the distance between the in-vehicle device and the portable device, upon receiving a response signal to the polling signal from the portable device; a distance calculation unit (87) configured, when performing the ranging communication, to calculate the distance between the in-vehicle device and the portable device based on a phase difference of signals communicated between the in-vehicle device and the portable device; and a polling period determination unit (S355) configured to determine a polling period, which is a transmission period of the polling signal, based on the distance calculated by the distance calculation unit.

[0428] [Item 2] The in-vehicle device according to Item 1, further comprising: a polling cycle memory unit (23) configured to store, for each zone determined based on a distance between the in-vehicle device and the portable device, a polling cycle associated with the zone; and the polling cycle determination unit is configured to determine the zone in which the portable device is located based on the distance calculated by the distance calculation unit, and to determine the polling cycle based on the determined zone.

[0429] [Item 3] The in-vehicle device according to item 1 or 2, wherein the polling period determination unit is configured to determine the polling period every time the distance calculation unit calculates the distance between the in-vehicle device and the portable device.

[0430] [Item 4] The in-vehicle device according to any one of items 1 to 3, wherein the communication control unit is configured to be able to perform BLE-CS communication, which indicates channel sounding communication using Bluetooth Low Energy (registered trademark), as the ranging communication.

[0431] [Item 5] The in-vehicle device according to item 2, configured to set the zone boundary or the polling period based on a zone boundary indicating an outer boundary of the default zone or the default polling period, and information related to the vehicle's functions.

[0432] [Item 6] The on-board device according to Item 2, configured to set the zone boundary or the polling period based on a zone boundary indicating an outer boundary of the default zone or the default polling period, and a correction coefficient determined based on a type of PEPS function indicating passive entry and passive start possessed by the vehicle.

[0433] [Item 7] The in-vehicle device according to item 5 or 6, wherein, when a difference between the zone boundaries for each of a plurality of zones is smaller than a predetermined threshold value, the in-vehicle device is configured to set the zone boundaries so that the difference between the zone boundaries for each of the plurality of zones is larger than the threshold value.

[0434] [Item 8] The in-vehicle device according to any one of items 1 to 7, wherein the polling period determination unit is configured to set the polling period based on a default polling period and a remaining battery level of the portable device.

[0435] [Item 9] The in-vehicle device according to any one of items 1 to 8, further comprising: a speed calculation unit (11) configured to calculate a speed of the portable device based on a timestamp linked to a distance between the in-vehicle device and the portable device; and the polling period determination unit configured to determine the polling period based also on the speed.

[0436] [Item 10] The in-vehicle device according to Item 9, wherein the speed calculation unit is configured to calculate the speed by taking an exponential moving average based on a plurality of sets of timestamps linked to distances between the in-vehicle device and the portable device.

[0437] [Item 11] The in-vehicle device according to any one of items 1 to 10, configured to use a first antenna (A) and a second antenna (B) mounted at different positions on the vehicle, and to detect the speed of the portable device relative to the direction of the vehicle based on a first distance between the portable device and the first antenna and a second distance between the portable device and the second antenna.

[0438] [Item 12] The in-vehicle device according to Item 9, wherein the polling period determination unit is configured to calculate a correction coefficient based on the speed calculated by the speed calculation unit and a preset reference speed, and to determine the polling period based on the correction coefficient.

[0439] [Item 13] The in-vehicle device according to Item 12, wherein the polling period determination unit is configured to determine the polling period based on the correction coefficient when the correction coefficient is within a predetermined range, and to determine the polling period based on a preset correction coefficient when the correction coefficient is outside the predetermined range.

[0440] [Item 14] The in-vehicle device according to any one of items 1 to 13, wherein the polling period determination unit is configured to determine the polling period based on the number of times that the response signal is successfully received in response to a predetermined number of transmissions of the polling signal.

[0441] [Item 15] The in-vehicle device according to any one of items 1 to 14, wherein the polling period determination unit is configured to, when the determined polling period differs from a current polling period, transmit a period change request to the portable device to change the polling period, and change the polling period from the transmission of a polling signal immediately thereafter.

[0442] [Item 16] The in-vehicle device according to any one of items 1 to 15, wherein the polling period determination unit is configured to, when the determined polling period differs from a current polling period, transmit to the portable device a period change request to change the polling period, and also transmit information on the change of the polling period at the time of a polling signal immediately thereafter, so as to change the polling period from the transmission of the next polling signal.

[0443] [Item 17] The in-vehicle device according to any one of items 1 to 16, wherein the distance calculation unit is configured to estimate a distance between the in-vehicle device and the portable device based on information on radio wave intensity of an advertising signal from the portable device, and is configured to start transmitting the polling signal at a predetermined period if the estimated distance is greater than a predetermined threshold.

[0444] [Item 18] The in-vehicle device according to any one of items 1 to 17, wherein the in-vehicle device is configured to determine the polling period and an output value of a signal output by the in-vehicle device or the portable device based on the distance between the in-vehicle device and the portable device calculated by the distance calculation unit.

[0445] [Item 19] The in-vehicle device according to any one of items 1 to 18, wherein the in-vehicle device is configured to receive, from the portable device, information on radio wave intensity received by the portable device, and determine an output value of a signal to be output by the portable device based on the information on radio wave intensity and a distance between the in-vehicle device and the portable device.

[0446] [Item 20] A vehicle control system including the in-vehicle device according to any one of items 1 to 18 and a portable device.

[0447] [Item 21] A vehicle control method capable of wireless communication between an in-vehicle device (5) mounted on a vehicle (3) and a portable device (19) carried by a user, wherein the in-vehicle device transmits a polling signal from the portable device, and when a response signal to the polling signal is received from the portable device, performs ranging communication as communication to measure the distance between the in-vehicle device and the portable device, and when performing the ranging communication, calculates the distance between the in-vehicle device and the portable device based on a phase difference of signals communicated between the in-vehicle device and the portable device, and determines a polling period, which is a transmission period of the polling signal, based on the distance.

Claims

1. An in-vehicle device (5) mounted on a vehicle (3) and capable of wireless communication with a portable device (19) carried by a user, comprising: a communication control unit (S350) configured to, when a polling signal is transmitted from the in-vehicle device to the portable device, perform distance measurement communication, which is communication for measuring the distance between the in-vehicle device and the portable device, upon receiving a response signal to the polling signal from the portable device; a distance calculation unit (87) configured to, when performing the distance measurement communication, calculate the distance between the in-vehicle device and the portable device based on a phase difference of signals communicated between the in-vehicle device and the portable device; and a polling period determination unit (S355) configured to determine a polling period, which is a transmission period of the polling signal, based on the distance calculated by the distance calculation unit.

2. An in-vehicle device as described in claim 1, comprising a polling period memory unit (23) configured to store, for each zone determined based on the distance between the in-vehicle device and the portable device, a polling period associated with the zone, and the polling period determination unit is configured to determine the zone in which the portable device is located based on the distance calculated by the distance calculation unit, and to determine the polling period based on the determined zone.

3. An in-vehicle device according to claim 1, wherein the polling period determination unit is configured to determine the polling period each time the distance calculation unit calculates the distance between the in-vehicle device and the portable device.

4. An in-vehicle device according to claim 1, wherein the communication control unit is configured to be capable of implementing BLE-CS communication, which indicates channel sounding communication using Bluetooth Low Energy (registered trademark), as the ranging communication.

5. An in-vehicle device according to claim 2, configured to set the zone boundary or the polling period based on a zone boundary indicating an outer boundary of the default zone or the default polling period, and information related to the vehicle's functions.

6. An on-board device according to claim 2, configured to set the zone boundary or the polling period based on a zone boundary indicating the outer boundary of the default zone or the default polling period, and a correction coefficient determined based on the type of PEPS function indicating passive entry and passive start possessed by the vehicle.

7. An in-vehicle device according to claim 5 or 6, configured to set the zone boundaries so that, when the difference between the zone boundaries for each of a plurality of zones is smaller than a predetermined threshold value, the difference between the zone boundaries for each of the plurality of zones is larger than the threshold value.

8. An in-vehicle device according to claim 1, wherein the polling period determination unit is configured to set the polling period based on the default polling period and the remaining battery capacity of the portable device.

9. An in-vehicle device according to claim 1, comprising a speed calculation unit (11) configured to calculate the speed of the portable device based on a timestamp linked to the distance between the in-vehicle device and the portable device, and the polling period determination unit configured to determine the polling period based also on the speed.

10. An in-vehicle device according to claim 9, wherein the speed calculation unit is configured to calculate the speed by taking an exponential moving average based on a plurality of sets of timestamps linked to the distance between the in-vehicle device and the portable device.

11. An on-vehicle device according to claim 1, configured to utilize a first antenna (A) and a second antenna (B) mounted at different positions on the vehicle, and to detect the speed of the portable device relative to the direction of the vehicle based on a first distance between the portable device and the first antenna and a second distance between the portable device and the second antenna.

12. An in-vehicle device according to claim 9, wherein the polling period determination unit is configured to calculate a correction coefficient based on the speed calculated by the speed calculation unit and a preset reference speed, and to determine the polling period based on the correction coefficient.

13. An in-vehicle device according to claim 12, wherein the polling period determination unit is configured to determine the polling period based on the correction coefficient when the correction coefficient is within a predetermined range, and to determine the polling period based on a preset correction coefficient when the correction coefficient is outside the predetermined range.

14. An in-vehicle device according to claim 1, wherein the polling period determination unit is configured to determine the polling period based on the number of times that the response signal is successfully received in response to a predetermined number of transmissions of the polling signal.

15. An in-vehicle device according to claim 1, wherein the polling period determination unit is configured to, if the determined polling period differs from the current polling period, transmit a period change request to the portable device to change the polling period, and change the polling period from the transmission of the polling signal immediately thereafter.

16. An in-vehicle device according to claim 1, wherein the polling period determination unit is configured to, if the determined polling period differs from the current polling period, transmit to the portable device a period change request to change the polling period, and also transmit information on the change in the polling period at the time of the immediately following polling signal, so as to change the polling period from the transmission of the next polling signal.

17. An in-vehicle device as described in claim 1, wherein the distance calculation unit is configured to estimate the distance between the in-vehicle device and the portable device based on information on the radio wave strength of an advertising signal from the portable device, and is configured to start transmitting the polling signal at a predetermined period if the estimated distance is greater than a predetermined threshold.

18. An in-vehicle device according to claim 1, configured to determine the polling period and the output value of a signal output by the in-vehicle device or the portable device based on the distance between the in-vehicle device and the portable device calculated by the distance calculation unit.

19. An in-vehicle device according to claim 1, configured to receive from the portable device information on the radio wave strength received by the portable device, and determine the output value of a signal to be output by the portable device based on the information on the radio wave strength and the distance between the in-vehicle device and the portable device.

20. A vehicle control system comprising the in-vehicle device according to claim 1 and a portable device.

21. A vehicle control method capable of wireless communication between an in-vehicle device (5) mounted on a vehicle (3) and a portable device (19) carried by a user, wherein the in-vehicle device transmits a polling signal from the portable device, and when a response signal to the polling signal is received from the portable device, performs distance measurement communication as communication to measure the distance between the in-vehicle device and the portable device, and when performing the distance measurement communication, calculates the distance between the in-vehicle device and the portable device based on a phase difference between signals communicated between the in-vehicle device and the portable device, and determines a polling period, which is a transmission period of the polling signal, based on the distance.

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