Electronic key systems, lock control devices

Abstract

To provide an electronic key system and a lock control device capable of suppressing a practical cost.SOLUTION: A smart ECU is connected to a handle embedded device being a UWB transmitter embedded in a door handle. The UWB transmitter as the handle embedded device generates a measured distance value showing a distance to the portable device by transmitting / receiving an impulse signal, and reports it to the smart ECU together with reception strength. The smart ECU unlocks a door by assuming that a user grasps the door handle based on a fact that the reception strength is lowered to a predetermined value or less in a state that the measured distance value with the handle embedded device is stable at the predetermined value or less.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present disclosure relates to an electronic key system and a lock control device that can unlock a door lock mechanism based on the results of communication with a pre-linked mobile device without the user having to operate the mobile device. [Background technology]

[0002] Patent Document 1 discloses a system that unlocks a vehicle door on the condition that it is confirmed that a pre-registered mobile device is present in the locking / unlocking area and that a touch sensor provided on the door of the vehicle is touched by the user. The locking / unlocking area here is an area where an in-vehicle system locks / unlocks the door based on the results of communication with the mobile device, and is an area outside the vehicle cabin that is within a predetermined distance (for example, 1 meter) from the door.

[0003] In this type of technology, radio waves in the LF (Low Frequency) band are often used to determine whether a portable device is within the locking / unlocking area (hereinafter referred to as location determination). Radio waves in the LF band are used because it is easy to limit the reach of wireless signals to the vicinity of the door. Meanwhile, in recent years, configurations for determining location using UWB (Ultra Wide Band) communication have also been proposed (for example, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5477218 [Patent Document 2] Japanese Patent Publication No. 2020-122727 Summary of the Invention [Problem to be solved by the invention]

[0005] In conventional electronic key systems such as those disclosed in Patent Document 1, a device separate from the communication device used for position determination is used to detect a user's unlocking operation. For example, a communication device that transmits an LF signal is used for position determination, while a touch sensor, push button, or infrared sensor is used to detect user operations such as unlocking. As such, conventional configurations require an action sensor, such as a touch sensor or door button, to detect user operations for locking or unlocking the door in addition to hardware for position determination, which can increase the cost of the entire system.

[0006] The present disclosure has been made based on the above considerations and viewpoints, and one of its objectives is to provide an electronic key system and a lock control device that can reduce implementation costs. [Means for solving the problem]

[0007] The electronic key system for achieving the above-mentioned object is an electronic key system that controls a door locking mechanism by wirelessly communicating with a pre-registered portable device, and includes: an antenna (51) for wirelessly communicating with the portable device, which is positioned inside the door handle (11) or within a certain distance from the door handle; a ToF-related value acquisition unit (F22) that acquires a ToF-related value, which is a parameter indicating the time of flight (ToF) of radio waves from the antenna to the portable device, based on the communication results with the portable device using the antenna; an intensity acquisition unit (F21) that acquires the reception strength of the signal from the portable device at the antenna; and a control unit (F4) that controls the state of the locking mechanism based on the fluctuation pattern of the reception strength when the ToF-related value is below a predetermined value.

[0008] In the above configuration, the control unit considers a drop in reception strength when a mobile device is located within a predetermined distance from a predetermined antenna as corresponding to a user operation to lock / unlock the door, and controls the state of the locking mechanism (e.g., unlocking). This configuration makes it possible to detect user operations using the antenna for determining the position of the mobile device, eliminating the need for an action sensor such as a touch sensor. This also reduces implementation costs.

[0009] The lock control device for achieving the object is a lock control device that is used in connection with an antenna (51) placed inside the door handle (11) or within a certain distance from the door handle, and includes: a ToF-related value acquisition unit (F22) that acquires a ToF-related value, which is a parameter indicating the time of flight (ToF: Time of Flight) of radio waves from the antenna to the portable device, based on the results of communication with a pre-registered portable device using the antenna; an intensity acquisition unit (F21) that acquires the reception strength of the signal from the portable device at the antenna; and a control unit (F4) that controls the state of the lock mechanism of the door on which the door handle is provided, based on the fluctuation pattern of the reception strength when the ToF-related value is equal to or less than a predetermined value.

[0010] The lock control device is a device that includes the ToF-related value acquisition unit, intensity acquisition unit, and control unit in the electronic key system described above, and by having these configurations, it functions in the same way as the electronic key system and achieves the same effects.

[0011] Note that the reference numerals in parentheses in the claims indicate correspondence with specific means described in the embodiments below as one aspect, and do not limit the technical scope of the present disclosure. Furthermore, the present disclosure considers an action sensor as an optional element, and does not prohibit the installation of an action sensor. The present disclosure can also be applied to vehicles, buildings, etc. that have action sensors installed around doors. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a diagram illustrating an overall view of a vehicle electronic key system. [Figure 2] FIG. 1 is a diagram illustrating an example of an installation position of a UWB communication device. [Figure 3] FIG. 10 is a diagram showing an exterior door handle with a built-in UWB communicator. [Figure 4] FIG. 2 is a block diagram illustrating the configuration of a UWB communication device. [Figure 5] FIG. 10 is a diagram illustrating a round trip time. [Figure 6] 10 is a flowchart illustrating a search process. [Figure 7] FIG. 2 is a functional block diagram of a smart ECU. [Figure 8] 10 is a flowchart illustrating unlocking-related processing. [Figure 9] FIG. 10 is a diagram for explaining a drop point of the reception intensity. [Figure 10] 10A and 10B are diagrams conceptually illustrating transitions in reception strength for each antenna when a swipe operation is performed. [Figure 11] FIG. 10 is a diagram illustrating an example of control content according to a fluctuation pattern of reception strength. [Figure 12] 10A and 10B are diagrams illustrating an example of control contents for each fluctuation pattern of reception strength. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In the following description, the front-rear, left-right, and up-down directions are defined based on the vehicle Hv unless otherwise noted. The following description can be modified as needed to comply with the laws, regulations, and customs of the region in which the vehicle Hv is used.

[0014] <Preface> Fig. 1 is a diagram showing an example of the schematic configuration of a vehicle electronic key system. As shown in Fig. 1, the vehicle electronic key system includes an in-vehicle system 1 and a portable device 2. The in-vehicle system 1 is a system installed in the vehicle Hv. The portable device 2 is a device carried by the user of the vehicle Hv, and device information such as a device ID is registered in the vehicle Hv.

[0015] A plurality of portable devices 2 can be registered in the in-vehicle system 1. In the following example, it is assumed that a plurality of portable devices 2 are registered in the in-vehicle system 1. Of course, only one portable device 2 may be linked to the in-vehicle system 1. The device ID is a number used by the in-vehicle system 1 to identify the portable device 2. The device ID may be a device address or a universally unique identifier (UUID). The device ID may also be a code assigned by the in-vehicle system 1 (a so-called key ID).

[0016] The in-vehicle system 1 and the portable device 2 are configured to perform bidirectional wireless communication using radio waves in a predetermined frequency band. Here, as an example, the in-vehicle system 1 and the portable device 2 are configured to perform UWB communication, which is wireless communication using the UWB-IR (Ultra Wide Band - Impulse Radio) method. That is, the in-vehicle system 1 and the portable device 2 are configured to be able to transmit and receive impulse-shaped radio waves (hereinafter, impulse signals) used in UWB communication. The impulse signal used in UWB communication is a signal with an extremely short pulse width (e.g., 2 ns) and a bandwidth of 500 MHz or more (i.e., ultra-wide bandwidth).

[0017] Note that UWB communication can utilize multiple channels, as disclosed in IEEE802.15.4z. For example, the in-vehicle system 1 communicates with the portable device 2 using the fifth channel of UWB communication. Of course, the in-vehicle system 1 may also be configured to communicate with the portable device 2 using the third or ninth channel. The third channel refers to the frequency band from 4243 MHz to 4742 MHz (center frequency: 4492 MHz). The fifth channel refers to radio waves in the 6489.6 MHz (approximately 6.5 GHz) ±250 MHz band, i.e., the frequency from 6240 MHz to 6739 MHz. The ninth channel refers to the frequency band from 7738 MHz to 8237 MHz (center frequency: 7987.2 MHz). Note that IEEE (registered trademark) is an abbreviation for the Institute of Electrical and Electronics Engineers.

[0018] Furthermore, various modulation methods can be used for UWB-IR communication, including on-off keying (OOK), pulse position modulation (PPM), and pulse width modulation (PWM). On-off keying is a method of expressing information (e.g., 0 and 1) by the presence or absence of an impulse signal. Pulse position modulation is a method of modulating the position at which a pulse occurs. Pulse width modulation is a method of expressing information by the pulse width. Here, as an example, UWB communication between the in-vehicle system 1 and the portable device 2 is performed using the OOK method. Data transmission via UWB communication is achieved using multiple impulse signals. Hereinafter, the data signal exchanged in UWB communication will be referred to as a UWB signal. Because a UWB signal contains multiple impulses, it can also be called a pulse sequence signal.

[0019] Here, as an example, the vehicle Hv is a vehicle equipped with front and rear seats, with the driver's seat located on the right side. Both left and right rear doors, which are doors for the rear seats, are configured as so-called power sliding doors that open and close electrically. Also, here, as an example, the front doors, which are doors for the front seats, are configured to open and close manually. Of course, in other embodiments, the front doors may also be configured to open and close electrically. Furthermore, various doors may be configured as upward-deploying doors that open and close electrically. Here, upward-deploying doors refer to doors that open by deploying approximately perpendicular to the ground, and include gull-wing doors, scissor doors, raptor doors, butterfly doors, canopy doors, and the like. In this disclosure, the right-side rear door will also be referred to as the right rear door, the left-side rear door will also be referred to as the left rear door, the right-side front door will also be referred to as the right front door, and the left-side front door will also be referred to as the left front door.

[0020] <About Mobile Device 2> The mobile device 2 is a portable, general-purpose information processing terminal equipped with UWB communication capabilities. Various communication terminals, such as a smartphone or a wearable device, can be used as the mobile device 2. A wearable device is a device worn on the user's body and can take a variety of shapes, such as a wristband, a watch, a ring, glasses, or earphones.

[0021] The portable device 2 includes a UWB communication unit and a device control unit. The UWB communication unit is a communication module for performing UWB communication. The device control unit is configured as a computer including, for example, a processor, memory, storage, etc. A device ID is stored in the storage. The device ID is different for each portable device 2. The device control unit performs processing related to communication with the in-vehicle system 1. The storage of the portable device 2 may also store a key code used in wireless authentication processing with the in-vehicle system 1. The key code may also be called an encryption key, etc.

[0022] When the portable device 2 of this embodiment receives a UWB signal transmitted from the in-vehicle system 1, it returns a response signal corresponding to the received signal. For example, when the portable device 2 receives a UWB signal as a search signal, it returns a UWB signal including its own device ID as a response signal to the in-vehicle system 1. The search signal is a signal used by the in-vehicle system 1 to search for the portable device 2, and is a type of signal that requests the portable device 2 to return a response signal. The UWB signals transmitted by the portable device 2 and the in-vehicle system 1 may include a code indicating the sender or destination.

[0023] The portable device 2 may be a smart key, which is a dedicated device used as an electronic key for the vehicle Hv. The smart key is a device that is transferred to the owner together with the vehicle Hv when the vehicle Hv is purchased. The smart key can be considered one of the accessories to the vehicle Hv. The smart key can have a variety of shapes, such as a flat rectangular parallelepiped type, a flat ellipsoid type (a so-called fob type), or a card type. The smart key may be called a vehicle portable device, a key fob, a key card, an access key, or the like.

[0024] <Configuration of In-Vehicle System 1> 1, the in-vehicle system 1 includes a smart ECU 4, multiple UWB communication devices 5, multiple door lock motors 6, multiple opening / closing motors 7, a welcome lamp 8, and a power supply ECU 9. The ECU in the component names is an abbreviation for Electronic Control Unit, and refers to an electronic control device.

[0025] The smart ECU 4 is connected to various devices via dedicated signal lines. Some devices may be connected to the smart ECU 4 so that they can communicate with each other via an in-vehicle network Nw. The in-vehicle network Nw is a communication network built within the vehicle Hv. A variety of standards can be adopted for the in-vehicle network Nw. The connection configuration between devices shown in this disclosure is an example, and the specific connection configuration between devices can be changed as appropriate.

[0026] The smart ECU 4 is an ECU that determines the device position relative to the vehicle Hv based on the reception status of signals from the portable device 2 at each of the UWB communication devices 5, and performs vehicle control according to the determination result. The device position refers to the location of the portable device 2. By receiving the UWB signal transmitted from the portable device 2, the smart ECU 4 detects that the portable device 2 is present within a predetermined range outside the vehicle, and executes a sequence related to determining the device position and authenticating it. The smart ECU 4 corresponds to a lock control device. Details of the functions of the smart ECU 4 will be described separately later.

[0027] The smart ECU 4 is implemented using a computer. That is, the smart ECU 4 includes a processor 41, a memory 42, a storage 43, an I / O 44, and bus lines connecting these components. The processor 41 is an arithmetic core such as a CPU (Central Processing Unit). The memory 42 is a volatile memory such as a RAM (Random Access Memory). The processor 41 accesses the memory 42 to execute various processes for implementing the functions of each functional unit described below.

[0028] The storage 43 includes a non-volatile storage medium such as a flash memory. The storage 43 stores control programs executed by the processor 41. The control programs include a location determination program that determines the location of the portable device 2. Execution of the location determination program by the processor 41 corresponds to execution of a location determination method corresponding to the control program. The I / O 44 is a circuit module for communicating with other devices.

[0029] The storage 43 stores a device ID for each portable device 2 in association with a key code. The smart ECU 4 can identify whether the communication partner is a portable device 2 or an unregistered device based on the device ID included in the received signal. The storage 43 also stores communication device setting data indicating the installation position of each UWB communication device 5 in the vehicle Hv. The installation position of each UWB communication device 5 can be expressed as a point on a vehicle coordinate system, which is a two-dimensional coordinate system centered on an arbitrary position on the vehicle Hv and parallel to both the width direction and the front-to-rear direction of the vehicle Hv. The X axis forming the vehicle coordinate system can be set parallel to the vehicle width direction, and the Y axis can be set parallel to the front-to-rear direction of the vehicle. The center of the coordinate system can be any location, such as the center of the vehicle body or the installation position of the smart ECU 4.

[0030] The UWB communication device 5 is a communication module for performing UWB communication. As shown in FIG. 2, the in-vehicle system 1 of this embodiment includes UWB communication devices 5a to 5d and 6p to 6q as the UWB communication devices 5. Each UWB communication device 5 has substantially the same configuration and performance. The UWB communication devices 5a to 5d are UWB communication devices 5 arranged on the outer surface of the vehicle Hv. For example, as shown in FIG. 3, the UWB communication device 5a is built into the outer door handle 11 of the right front door. The UWB communication device 5b is built into the outer door handle 11 of the left front door. The UWB communication device 5c is arranged in the center of the rear bumper, and the UWB communication device 5d is arranged in the center of the front bumper.

[0031] As an example, the UWB communication devices 5a, 5b, and 5c are respectively arranged in the center of a right area ER, a left area EL, and a rear area EB, which are vicinity areas EA described later. In this disclosure, the UWB communication devices 5a, 5b, and 5c built into the exterior door handle 11 are also referred to as handle-mounted devices. The handle-mounted device corresponds to a dual-purpose device, that is, a UWB communication device 5 used for both determining the device position and detecting user operations.

[0032] The UWB communication device 5p is a UWB communication device 5 for covering, for example, the front seats in the vehicle interior as a communication area, and is disposed, for example, on the upper edge of the windshield, the instrument panel, or the center console. The UWB communication device 5q is a UWB communication device 5 for covering, for example, the rear seats or the trunk in the vehicle interior as a communication area, and is disposed, for example, on the upper edge of the rear window or in the trunk.

[0033] The X-axis, Y-axis, and Z-axis shown in Figures 2, 3, etc. are elements for explaining the mounting position and mounting posture of the UWB communication device 5 relative to the vehicle Hv. The X-axis is parallel to the vehicle width direction, with the right direction of the vehicle being the positive direction. The Y-axis is parallel to the vehicle front-rear direction, with the front of the vehicle being the positive direction. The Z-axis is parallel to the height direction of the vehicle Hv.

[0034] The operation of each UWB communication device 5 is controlled by the smart ECU 4. While each UWB communication device 5 is operating, it transmits data indicating the reception status of a signal from the portable device 2 to the smart ECU 4. The data indicating the reception status may include the presence or absence of reception, the reception strength, the distance measurement value, etc. The UWB communication device 5 is a communication device used to determine the position of the portable device 2, and is also referred to as an anchor or a reference station. Details of the UWB communication device 5 will be described separately below.

[0035] The door lock motor 6 is a motor for switching the state (locked / unlocked) of the door lock mechanism. The lock mechanism may also be called a latch mechanism. A door lock motor 6 is provided for each door. The door lock motor 6 is driven based on a control signal input from the smart ECU 4, and switches the lock mechanism from an unlocked state to a locked state, or from a locked state to an unlocked state. Note that another ECU, such as a body ECU, may be present between the door lock motor 6 and the smart ECU 4.

[0036] The opening / closing motors 7 are motors for opening and closing doors. The in-vehicle system 1 includes an opening / closing motor 7a for a right rear door, an opening / closing motor 7b for a left rear door, and an opening / closing motor 7c for a trunk door as the opening / closing motors 7. The trunk door is a door provided on the rear portion of the vehicle and may also be called a back door, a back gate, or a rear gate. Each opening / closing motor 7 is driven based on an open instruction signal, which is a control signal instructing the door to open, input from the smart ECU 4, and causes the controlled door to transition from a closed state to an open state. Furthermore, the opening / closing motor 7 is driven based on a close instruction signal, which is a control signal instructing the door to close, input from the smart ECU 4, and causes the controlled door to transition from an open state to a closed state. The open state here includes not only a fully open state but also a state that is not completely closed, such as a half-open state. The extent to which the door is opened by automatic control may be set by the user.

[0037] The welcome lamps 8 are lighting devices that illuminate the road surface near the doors. For example, the welcome lamps 8 are arranged on the side sills or side mirrors. The lighting state of the welcome lamps 8 is switched based on an instruction from the smart ECU 4. The welcome lamps 8 may also be projectors that project images onto the road surface near the doors.

[0038] The power supply ECU 9 is an ECU that controls the on / off state of the traction power supply installed in the vehicle Hv. For example, the power supply ECU 9 switches the traction power supply from off to on based on a request signal from the smart ECU 4. In an engine vehicle, the ignition power supply corresponds to the traction power supply. In an electric vehicle, the system main relay corresponds to the traction power supply.

[0039] In addition to the sensors / switches / ECUs described above, various devices are directly or indirectly connected to the smart ECU 4. For example, output signals such as a courtesy switch and a shift position sensor can be input to the smart ECU 4. The courtesy switch is a switch that outputs a signal indicating the open / closed state of the door. The shift position sensor is a sensor that outputs a signal indicating the current shift position.

[0040] <Configuration of UWB Communication Device> Here, the configuration of each UWB communication device 5 will be described. Each of the plurality of UWB communication devices 5 includes, as shown in FIG. 4, an antenna 51, a transmission unit 52, a reception unit 53, and a controller 54. The antenna 51 is an antenna for transmitting and receiving UWB signals. The UWB communication device 5 of the present embodiment includes a first antenna 51A and a second antenna 51B as the antenna 51. The first antenna 51A is a transmission antenna 51 and is electrically connected to the transmission unit 52. The second antenna 51B is a reception antenna 51 and is electrically connected to the reception unit 53. Note that the first antenna 51A may be configured as a transceiver antenna. In that case, the first antenna 51A may also be connected to the reception unit 53 as shown by the dashed line in FIG. 4.

[0041] The transmission unit 52 is configured to generate a UWB signal corresponding to the baseband signal input from the smart ECU 4 and radiate this UWB signal as radio waves from the first antenna 51A. The UWB signal is a set / series of impulse signals. The transmission unit 52 includes a circuit for electrically processing the baseband signal, such as a modulation circuit 521. The transmission unit 52 outputs an electrical impulse signal corresponding to the transmission data to the first antenna 51A.

[0042] The reception unit 53 is a circuit module that receives the UWB signal transmitted from the mobile device 2 via the second antenna 51B and electrically processes it. The reception unit 53 includes a demodulation circuit 531, a reception intensity detection circuit 532, and the like. The reception intensity detection circuit 532 sequentially outputs a signal indicating the reception intensity to the controller 54.

[0043] The controller 54 is configured to control the operation of the UWB communication device 5. The controller 54 is realized using, for example, an IC (Integrated Circuit). The controller 54 outputs received data to the smart ECU 4 and outputs transmission data input from the smart ECU 4 to the transmitter 52.

[0044] The controller 54 also includes an RTT measurement unit 541 and a reporting unit 542. The RTT measurement unit 541 is a timer that measures the round trip time (RTT), which is the time elapsed from when the transmitter 52 transmits a fast pulse signal until when the receiver 53 receives the fast pulse. The fast pulse is the first impulse signal among multiple impulse signals that make up the transmission / reception data. The transmission timing of the impulse signal may be notified by the transmitter 52, or may be determined by the controller 54 by monitoring the voltage level of the signal line extending from the transmitter 52 to the first antenna 51A. The RTT measurement unit 541 uses the timing at which the reception strength first exceeds a predetermined detection threshold after data transmission by the transmitter 52 as the reception timing of the fast pulse. As another aspect, the RTT measurement unit 541 may measure the time from when the last pulse of the transmission data is transmitted until when the last pulse of the reception data is received as the round trip time. Various methods can be used to measure the round trip time.

[0045] As shown in FIG. 5, the round trip time corresponds to the round trip flight time (Tf×2) plus the length of the search signal (Trq) and the response processing time (Tn) at the portable device 2. Tf in the figure indicates the one-way flight time. Trq in the figure indicates the length of the search signal, and Trs indicates the length of the response signal. The response processing time is the time required to generate and output a response signal corresponding to a received signal. The one-way flight time corresponds to the distance from the UWB communication device 5 to the portable device 2. The RTT measurement unit 541 measures the elapsed time since the transmitter 52 transmitted the impulse signal by counting clock signals input from a clock oscillator (not shown).

[0046] The reporting unit 542 generates a distance measurement value based on the round trip time measured by the RTT measuring unit 541. The distance measurement value is a parameter indicating the distance to the portable device 2. For example, the reporting unit 542 calculates a round trip flight time by subtracting a pre-designed estimated value for response processing time and the length of the search signal from the measured round trip time. Then, the reporting unit 542 multiplies the value obtained by dividing the round trip flight time by 2 by the flight time of the radio wave, and uses this value as the distance measurement value.

[0047] Of course, the formula for converting the round trip time into the measured distance is not limited to the above example. The process of converting the round trip time into the measured distance may include correction processes other than those described above, such as a process for correcting a reaction delay time in the receiving unit 53. In addition, in this embodiment, the measured distance is expressed in the dimension of distance, but in other aspects, the measured distance may be a parameter in the dimension of time. For example, the measured distance may be the time of flight (ToF) for one way or round trip. The measured distance may also be called a ToF-related value. The round trip time itself may also be used as the measured distance.

[0048] The reporting unit 542 is configured to associate the distance measurement value with the reception strength of the response signal and report it to the smart ECU 4. The reception strength reported together with the round trip time may be the peak value of the fast pulse, or the average or median value of the peak values ​​of the multiple impulses that make up the response signal.

[0049] The controller 54 including the above configuration performs a search process based on an instruction from the smart ECU 4. As shown in FIG. 6, the search process includes a step (S11) of transmitting a search signal, a step (S12) of waiting for reception of a response signal, and a step (S13) of reporting the reception result. The report data when the response signal is received includes the above-mentioned measured distance and reception strength. The report data when the response signal is received may also include the device ID of the portable device 2 that returned the response. If a response signal is not received even after a predetermined response waiting time has elapsed since transmitting the search signal, the reporting unit 542 returns a code indicating that the portable device 2 was not found to the smart ECU 4 as report data. The above report data can be rephrased as search result data.

[0050] Note that some or all of the circuits corresponding to the transmitter 52 and the receiver 53 may be built into an IC serving as the controller 54. One UWB communication device 5 may be equipped with only one antenna 51, or may be equipped with three or more antennas 51. The number of antennas 51 may differ for each UWB communication device 5.

[0051] <About the Smart ECU4 functions> The smart ECU 4 executes programs stored in the storage 43 to provide functions corresponding to the various functional blocks shown in Fig. 7. Specifically, the smart ECU 4 includes, as functional units, a vehicle information acquisition unit F1, a communication device control unit F2, a position determination unit F3, and a control unit F4. The smart ECU 4 also includes a search result storage unit M1.

[0052] The search result storage unit M1 is a storage medium for storing search result data for a predetermined period of time for each UWB communication device 5. The search result storage unit M1 is realized using a part of the storage area of ​​the storage 43. Note that the search result storage unit M1 may also be realized using a non-volatile storage medium that is physically independent from the storage 43. The search result storage unit M1 is configured so that the processor 41 can write, read, delete, and so on, data to and from the search result storage unit M1.

[0053] The vehicle information acquisition unit F1 acquires various vehicle information indicating the state of the vehicle Hv and user operations on the vehicle Hv from sensors, ECUs, switches, etc. mounted on the vehicle Hv. The vehicle information includes, for example, the state (on / off) of the driving power source, the open / closed state of each door, the locked / unlocked state of each door, the shift position, etc.

[0054] The communication device control unit F2 controls the operating state of the UWB communication device 5. Based on a request from the position determination unit F3, the communication device control unit F2 transitions the requested UWB communication device 5 from a power-saving state to a normal state or switches the normal state to a power-saving state. The normal state here refers to a state in which communication with the portable device 2 is possible. The power-saving state refers to a state in which power consumption can be reduced compared to the normal state and in which at least some or all functions are stopped. The power-saving state may also be a state in which the power is turned off. For example, the communication device control unit F2 intermittently returns each UWB communication device 5 to the normal state from the power-saving state to perform a search process even while the driving power is off. The communication device control unit F2 may continue to operate each UWB communication device 5 in the normal state while the driving power is on.

[0055] The communication device control unit F2 performs a process of acquiring data indicating the communication status with the portable device 2 and received data from each UWB communication device 5 and storing the data in the memory 42. The data indicating the communication status includes search result data. The data stored in the memory 42 is referenced as appropriate by the position determination unit F3 and the control unit F4. The communication device control unit F2 includes an intensity acquisition unit F21 and a distance measurement value acquisition unit F22 as sub-functional units. The intensity acquisition unit F21 is configured to acquire the reception intensity from each UWB communication device 5 and store it in the search result storage unit M1, and the distance measurement value acquisition unit F22 is configured to acquire the distance measurement value from each UWB communication device 5 and store it in the search result storage unit M1. The distance measurement value acquisition unit F22 corresponds to the ToF-related value acquisition unit.

[0056] The position determination unit F3 is a module that determines the position of the portable device 2 in cooperation with the communication device control unit F2 and each UWB communication device 5. The position determination unit F3 has a function to calculate, as the device position, device position coordinates that are the position coordinates of the portable device 2 in the vehicle coordinate system, and a function to determine a device stay area that is an area (section) in which the portable device 2 is located. The position determination unit F3 causes each UWB communication device 5 to perform a search process in turn while the vehicle Hv is parked. The search period that specifies the execution interval of the search process in one UWB communication device 5 is 100 milliseconds, 200 milliseconds, 500 milliseconds, etc.

[0057] The search process in the parked state can be rephrased as a search process for detecting the approach of a user and / or executing unlocking control. The position determination unit F3 may change the combination of UWB communication devices 5 that execute the search process depending on the state of the vehicle. While the vehicle Hv is parked, the UWB communication device 5q may not be caused to execute the periodic search process. By limiting the number of UWB communication devices 5 that execute the search process periodically while the vehicle Hv is parked, it is possible to reduce power consumption while the vehicle is parked.

[0058] The position determination unit F3 calculates the position coordinates of the target device relative to the vehicle Hv by combining the distance measurements from the multiple UWB communication devices 5 and the mounting positions of each UWB communication device 5 in the vehicle Hv. This calculation process is performed using a method similar to triangular positioning or multi-point positioning in the technical fields of GNSS and position estimation. In this disclosure, the process of calculating the device position coordinates using the distance measurements from multiple anchors, such as triangular positioning, is also referred to as coordinate calculation processing. The device position coordinates can be expressed in a vehicle coordinate system, for example.

[0059] Three-point positioning is conceptually equivalent to calculating the coordinates of the intersection of three ranging circles. A ranging circle is a circle whose center is the installation position of the UWB communication device 5 and whose radius is the observed ranging value. Since the installation positions of the UWB communication devices 5 in the vehicle Hv are known, if the distances from three or more UWB communication devices 5 to the portable device 2 can be obtained, the position coordinates (device position coordinates) of the portable device 2 can be identified by solving simultaneous equations. Note that, because individual ranging values ​​contain errors, three or more ranging circles may not intersect at a single point. The coordinate calculation process, which is the process of calculating the device position coordinates, is conceptually equivalent to the process of calculating the point at which the total distance from multiple ranging circles is the smallest in a local area where multiple ranging circles are densely packed together.

[0060] Furthermore, the position determination unit F3 determines whether the portable device 2 is present in a nearby area EA based on the search results of the multiple UWB communication devices 5. The nearby area EA is an area in which the in-vehicle system 1 executes predetermined vehicle control, such as locking or unlocking the doors, based on the presence of the portable device 2 within the area. For example, the nearby area EA is set to a range within a predetermined operating distance from the exterior door handles 11 provided on the right front door, the left front door, and the trunk door. The nearby area EA can also be called a passive entry area or a locking / unlocking area. The operating distance can be set to 0.75 m, 1 m, 1.5 m, or the like. In this embodiment, the nearby area EA on the right side of the vehicle is also called the right area ER, the nearby area EA on the left side is also called the left area EL, and the nearby area EA on the rear side is also called the rear area EB.

[0061] In this embodiment, since UWB communication device 5a is provided on outer door handle 11 of the right front door, position determination unit F3 determines that the device stay area is right area ER based on the fact that the distance measurement value of UWB communication device 5a is equal to or less than the operating distance. Position determination unit F3 also determines that the device stay area is left area EL based on the fact that the distance measurement value of UWB communication device 5b is equal to or less than the operating distance, and determines that the device stay area is rear area EB based on the fact that the distance measurement value of UWB communication device 5c is equal to or less than the operating distance.

[0062] Depending on the model of the vehicle Hv, it is possible that the UWB communication device 5 is located at a position that is off the center of the neighborhood area EA. In such a case, the location determination unit F3 may use the device location coordinates obtained in the coordinate calculation process to determine whether the staying area corresponds to the neighborhood area EA.

[0063] The control unit F4 responds to a user operation on the vehicle Hv and executes control / processing in cooperation with other ECUs according to the device position identified by the position determination unit F3. Details of the control unit F4 will be described later. The control unit F4 includes, as a sub-functional unit, an action detection unit F41 that detects a user operation related to opening and closing the door using the reception strength of a device built into the steering wheel as a dual-purpose device. The user operation related to opening and closing the door includes a grip operation and a swipe operation, which will be described later.

[0064] <Unlocking related processes> Next, the unlocking-related process performed by the smart ECU 4 will be described with reference to the flowchart shown in FIG. 8. The unlocking-related process corresponds to a process for controlling the unlocking of the doors. The unlocking-related process is executed periodically while the vehicle Hv is parked. As shown in FIG. 8, the unlocking-related process includes, as an example, steps S21 to S27. Each step can be executed by the processor 41 according to the arrows shown in FIG. 8.

[0065] Step S21 is a step of causing each UWB communication device 5 to execute a search process in turn. Step S22 is a step of acquiring search result data from each UWB communication device 5. Step S23 is a step of determining whether or not the portable device 2 has been found based on the results of steps S21 to S22. Step S23 corresponds to a step of determining whether or not a response signal from the portable device 2 has been received by at least one UWB communication device 5. If the response signal from the portable device 2 has been received by at least any UWB communication device 5 (S23 YES), the smart ECU 4 executes step S24. On the other hand, if the response signal from the portable device 2 has not been received by any UWB communication device 5 (S23 NO), this flow ends.

[0066] Note that step S23 may be a step of determining whether any of the plurality of steering wheel built-in devices has received a response from the portable device 2. In this case, the smart ECU 4 ends this flow if none of the steering wheel built-in devices has received a response signal from the portable device 2.

[0067] Step S24 is a step for determining whether there is a UWB communication device 5 among the steering wheel built-in devices whose distance measurement value is equal to or less than a predetermined proximity determination value. If there is a UWB communication device 5 among the multiple steering wheel built-in devices whose distance measurement value is equal to or less than the proximity determination value, the UWB communication device 5 is set as the nearest communication device and the subsequent processing is executed. If there is no UWB communication device 5 among the steering wheel built-in devices whose distance measurement value is equal to or less than the proximity determination value, this flow is terminated. The proximity determination value here is, for example, 0.6 or 0.8 m. The proximity determination value may be set to the same value as the operating distance. The nearest communication device corresponds to the UWB communication device 5 closest to the portable device 2, in other words, the UWB communication device 5 installed in the door in front of the user.

[0068] Step S25 is a step of analyzing the time series data of the reception strength observed by the nearest communication device, which is stored in the search result storage unit M1. For example, step S25 refers to the time series data of the reception strength observed by the nearest communication device, and determines whether the current reception strength (Pn) is lower than the reference strength (Prf), which is the reception strength observed a predetermined time before the current time, by a predetermined value or more. The predetermined retroactive time here can be set to 0.5 seconds, 1.0 second, 1.5 seconds, etc.

[0069] In this disclosure, a drop in reception strength by a predetermined value or more relative to the reference strength is referred to as a drop in reception strength, and the time at which the drop in reception strength is detected is also referred to as the drop point (Tdp). Figure 9 is a diagram conceptually showing the relationship between various parameters related to a drop in reception strength, where Tn represents the current time, Pn represents the most recent observed value of reception strength, and ΔP represents the amount of fluctuation in the current reception strength relative to the reference strength.

[0070] The decline determination value, which is a threshold for the amount of fluctuation in reception strength required to determine a decline point, is set to 15 dB, 10 dB, or the like. When the control unit F4 detects a decline in reception strength, it measures the duration of the decline state (Tcn), which is the time during which the reception strength is maintained after the decline point. The state in which the reception strength is maintained after the decline means that the reception strength is fluctuating within a range lower than the upper limit of the decline state, which is determined based on the reception strength at the decline point. The upper limit of the decline state can be set to, for example, the reception strength at the decline point plus a predetermined margin of 3 dB or 5 dB.

[0071] The individual reception strength values ​​used by the smart ECU 4 to analyze the fluctuation pattern of reception strength may not be raw observation values, but may be the average of the most recent N observation values. The smart ECU 4 may detect a decline in reception strength when the moving average of reception strength decreases at a slope (speed) equal to or greater than a predetermined value. This configuration reduces the risk of erroneously identifying the point of decline due to instantaneous fluctuation components of reception strength caused by noise or multipath. The above "N" is a natural number and can be set to 3, 5, etc.

[0072] Step S26 is a step of determining whether the fluctuation pattern of the reception strength matches a predetermined unlocking pattern based on the analysis result of step S25. Step S26 corresponds to a step of determining whether the fluctuation pattern of the reception strength satisfies a predetermined unlocking condition. The unlocking pattern / unlocking condition is set, for example, to the existence of a drop point and the duration of the drop state being equal to or longer than a predetermined value.

[0073] In step S27, the control unit F4 performs unlocking control based on the analysis result of the variation pattern. If the fluctuation pattern of the reception strength satisfies the unlocking condition as a result of the above (YES in S26), the control unit F4 determines that the user has performed a grip operation and unlocks the door (S27). If the intensity variation pattern does not satisfy the unlocking condition, it determines that the user has not yet performed a grip operation and ends this flow. In this disclosure, a grip operation refers to the act of gripping the outer door handle 11. The grip operation can also include the act of placing a hand on the outer door handle 11. The grip operation is a user operation for unlocking or locking the door, that is, corresponds to an example of an unlocking operation or a locking operation.

[0074] (supplement) The developers of the present disclosure have verified the degree of influence of the human body on the reception strength when the portable device 2 is placed 0.3 m from the handle-integrated unit, and have found the following: When a person is holding the outer door handle 11, the reception strength observed at the handle-integrated unit is reduced by nearly 25 dB compared to when the person is not holding the outer door handle 11.

[0075] This is because high frequencies above 1 GHz are easily attenuated by the human body, and this tendency becomes more pronounced as the frequency increases. Although channel 9 was used in the test, a similar tendency can be observed for other channels, such as channel 5. Furthermore, a significant decrease in reception strength was observed even when the outer door handle 11 was simply placed on the handle without firmly gripping it.

[0076] The unlocking pattern settings are based on the test results, and as mentioned above, the drop determination value can be set to 15 dB, 10 dB, or the like. The duration threshold, which is a threshold for the duration of the drop state, can be set to, for example, 0.6 seconds or 1.0 seconds. The drop determination value and duration threshold may be adjusted to values ​​that respond not only to gripping operations but also to waving operations. Waving operations refer to the act of bringing a body part, such as a hand or elbow, close to or into contact with the exterior door handle 11, or in other words, the act of covering the UWB communication device 5 with a human body.

[0077] Note that the longer the duration threshold, the more likely it is that malfunctions will be suppressed, but the longer the duration threshold, the slower the system's response to grip operations will be, which may reduce user convenience. The duration threshold can be appropriately designed to achieve both responsiveness to grip operations and malfunction suppression.

[0078] As described above, the present disclosure has been created with a focus on the phenomenon that the reception strength at the outer door handle 11 incorporating the UWB communication device 5 can be significantly reduced when the outer door handle 11 incorporating the UWB communication device 5 is gripped or when the hand, elbow, or waist is covered. The smart ECU 4 corresponds to a configuration that detects a user's unlocking operation from the fluctuation pattern of the reception strength, provided that the distance measurement value at the handle's built-in device is below a certain value. Furthermore, the above configuration corresponds to a configuration that determines that the user has gripped the outer door handle 11 to unlock the door when the reception strength observed at the handle's built-in device drops by more than a predetermined value when the distance measurement value at the handle's built-in device is below a predetermined value.

[0079] <Effects> The smart ECU 4 described above unlocks the door when the reception strength observed by the UWB communication device 5 built into the outer door handle 11 drops by a predetermined value or more when the distance measurement value of the UWB communication device 5 is below a predetermined value. With this configuration, there is no need to provide the outer door handle 11 with a touch sensor or button as hardware for detecting the user's unlocking operation, which reduces the system implementation costs.

[0080] Furthermore, the smart ECU 4 of the above embodiment unlocks the door not only when the reception strength is reduced but also when the distance measurement value is equal to or less than a predetermined value. The smart ECU 4 does not unlock the door if the reception strength is reduced but the distance measurement value is equal to or greater than a predetermined value. A reduction in reception strength can also occur when the portable device 2 moves away from the UWB communication device 5. This configuration reduces the risk of the door being unlocked due to a reduction in reception strength caused by the removal of the portable device 2. Specifically, it reduces the risk of the door being unlocked when the user passes by the outer door handle 11, i.e., when the portable device 2 approaches the outer door handle 11 and then moves away.

[0081] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications described below are also included within the technical scope of the present disclosure. Furthermore, various modifications other than those described below can be implemented without departing from the gist of the present disclosure. For example, the various supplements and modifications described below can be implemented in appropriate combinations as long as no technical contradictions arise. Note that components having the same functions as the components described above are given the same reference numerals, and their description may be omitted. Furthermore, when only a portion of the configuration is mentioned, the above description can be applied to the other portions.

[0082] <Variation (1)> When the smart ECU 4 detects the presence of a steering wheel-mounted device whose distance measurement value is equal to or less than a predetermined value, the smart ECU 4 may change the search process execution interval for that steering wheel-mounted device to a predetermined concentrated observation value shorter than the default value. For example, if the default value is 200 milliseconds, the concentrated observation value may be set to 50 milliseconds or 100 milliseconds. A shorter search process execution interval corresponds to a shorter sampling interval for the distance measurement value and the reception strength. This configuration enables frequent sampling of the behavior of a user in front of the door, thereby increasing the information available for determining whether the user has performed a grip operation. As a result, the accuracy of determining whether the user has performed a grip operation can be improved.

[0083] <Variation (2)> The smart ECU 4 may be configured to determine that the user has performed an unlocking operation not only when the distance measurement value from the nearest communication device is equal to or less than a predetermined value, but also when the distance measurement value is stable at or less than the predetermined value. That is, when a drop in the reception strength of the nearest communication device is observed while the distance measurement value from the nearest communication device is stable at or less than the predetermined value, the smart ECU 4 may determine that a grip operation has been performed and perform unlocking control. Specifically, step S24 may be a step of determining whether the distance measurement value from the nearest communication device is stable at or less than a predetermined value. A state in which the distance measurement value is stable at or less than a predetermined value refers to a state in which the variance or fluctuation range of the distance measurement value within a certain time period (e.g., 0.6 seconds or 1 second) is less than a predetermined value. The fluctuation range corresponds to the difference between the maximum and minimum values.

[0084] The state in which the distance measurement value is stable and less than the predetermined value corresponds to a situation in which the user is standing in front of the outer door handle 11 where the nearest communication device is installed. Fluctuations in the reception strength under such a situation are likely to be caused by the user's grip operation. In other words, the configuration of this modified example can reduce the risk of the vehicle Hv being unlocked due to a malfunction.

[0085] The smart ECU 4 may also determine whether the reception strength has suddenly dropped based on the reception strength when the distance measurement value first reaches a predetermined value or the initial reception strength during a period in which the distance measurement value is stable at the predetermined value. That is, the smart ECU 4 may be configured to use the reception strength when the distance measurement value first reaches the predetermined value or the initial reception strength during a period in which the distance measurement value is stable at the predetermined value as the reference strength. This configuration further reduces the risk of malfunction. <Variation (3)> The smart ECU 4 may detect a grip operation based on the fluctuation pattern of the reception strength, provided that the device position coordinates are within the vicinity area EA, instead of the distance measurement value of the built-in device in the steering wheel being equal to or less than a predetermined value. Specifically, step S24 may be a step of determining whether the device position coordinates calculated in the coordinate calculation process are within the vicinity area EA. The smart ECU 4 may also be configured to determine that a grip operation has been performed when the reception strength drops by a predetermined value or more when the device position coordinates are within the vicinity area EA and the device position coordinates are stable. The stable state of the device position coordinates refers to a state in which the variance of the device position coordinates within a certain period of time is equal to or less than a predetermined value.

[0086] <Variation (4)> The UWB communication device 5 as a dual-purpose device may include multiple antennas 51. When the dual-purpose device includes multiple antennas 51, the device may be configured to detect a swipe operation based on time-series data of the reception strength at the multiple antennas 51. For example, the smart ECU 4 may detect a user's swipe operation based on the sequential observation of a drop in reception strength at multiple antennas 51 arranged in a row. The swipe operation here refers to the act of sliding a hand in the longitudinal direction of the outer door handle 11 while touching the outer door handle 11.

[0087] For example, the smart ECU 4 determines that a swipe operation has been performed when a temporary decrease in reception strength is observed in the order of the first antenna 51A and the second antenna 51B as shown in Fig. 10. The smart ECU 4 may perform operations such as unlocking or automatically opening the trunk door based on the detection of a swipe operation by the user when the distance measurement value at the nearest communication device is equal to or less than a predetermined value.

[0088] 10A shows the transition of the reception strength at the first antenna 51A when a swipe operation is performed, and FIG. 10B shows the transition of the reception strength at the second antenna 51B. Furthermore, Tdr1 indicates the point at which the reception strength at the first antenna 51A drops, and Tdr2 indicates the point at which the reception strength at the second antenna 51B drops. If Tdr1 and Tdr2 are less than a predetermined value (e.g., 500 milliseconds) that can be considered to be substantially simultaneous, the smart ECU 4 may determine that a grip operation has been performed, rather than a swipe operation. In other words, the smart ECU 4 may determine that the performed operation is a swipe operation, rather than a grip operation, based on whether the difference between Tdr1 and Tdr2 is equal to or greater than a predetermined value. The fluctuation patterns of the reception strength for each antenna 51 corresponding to a grip operation or a swipe operation may be learned and registered based on the results of user trials.

[0089] <Variation (5)> The above describes the case where the smart ECU 4 unlocks the doors when a drop in reception strength at the nearest communication device is triggered. However, the control executed by the smart ECU 4 when a drop in reception strength is triggered is not limited to unlocking the doors. The smart ECU 4 may lock the doors when a drop in reception strength at the nearest communication device is triggered. The smart ECU 4 may execute various controls when a drop in reception strength at the nearest communication device is triggered, such as unlocking the doors, opening the rear door / trunk door, turning on the welcome lamp 8, turning on the driving power, and starting the air conditioner. The smart ECU 4 may also automatically execute multiple controls when a drop in reception strength is triggered.

[0090] The smart ECU 4 may be configured to execute different actions depending on the fluctuation pattern of the reception strength observed by the nearest communication device. Different fluctuation patterns of the reception strength correspond to different operations by the user on the outer door handle 11 where the nearest communication device is installed.

[0091] For example, as shown in the first setting example in Figure 11, the smart ECU 4 unlocks the door when the measured duration of the decrease is equal to or greater than a predetermined first threshold and less than a second threshold. On the other hand, if the duration of the decrease is equal to or greater than a predetermined second threshold, the smart ECU 4 may unlock the door and turn on the running power supply. If the duration of the decrease is less than the first threshold, the smart ECU 4 may turn on the welcome lamp 8. In the figure, Tcn indicates the duration of the decrease, Th1 indicates the first threshold, and Th2 indicates the second threshold.

[0092] 11, the smart ECU 4 may unlock only the door corresponding to the nearest communication device when the duration of the decrease is equal to or greater than a predetermined first threshold and less than a predetermined second threshold, while unlocking all doors when the duration of the decrease is equal to or greater than a predetermined second threshold. The fluctuation pattern in which the duration of the decrease is equal to or greater than the predetermined first threshold and less than the second threshold corresponds to an example of a first pattern. The fluctuation pattern in which the duration of the decrease is equal to or greater than the second threshold corresponds to an example of a second pattern.

[0093] The smart ECU 4 corresponds to a configuration that executes different controls depending on the length of the grip time corresponding to the duration of the decline. According to the configuration of the present disclosure, it is possible for the user to execute different controls depending on the length of time the user grips the outer door handle 11, thereby improving user convenience.

[0094] The smart ECU 4 may also execute multiple controls in sequence depending on the duration of the drop. For example, the smart ECU 4 to which the first setting example is applied turns on the welcome lamp 8 when the distance measurement value falls below a predetermined value, and unlocks the vehicle Hv when the duration of the drop is equal to or greater than a first threshold. Thereafter, if the user continues to grip the outer door handle 11 and the duration of the drop is equal to or greater than a second threshold, the smart ECU 4 turns on the running power supply.

[0095] The control to be performed when the duration of the decrease reaches or exceeds the second threshold is not limited to turning on the driving power supply, but may also include starting up an air conditioner or opening a door. The door to be automatically opened may be the trunk door or a rear seat door. The control to be performed when the duration of the decrease reaches or exceeds a predetermined value may be configured to be set by the user via a predetermined setting screen.

[0096] The smart ECU 4 may also perform different controls depending on whether the detected user operation is a grip operation or a swipe operation. When a grip operation is received, the smart ECU 4 may unlock the door, whereas when a swipe operation is detected, the smart ECU 4 may automatically open the sliding door. When a grip operation is received, the smart ECU 4 may unlock the door, whereas when a swipe operation is detected, the smart ECU 4 may lock the door. The grip operation may correspond to an example of a first pattern, and the swipe operation may correspond to an example of a second pattern.

[0097] Furthermore, the smart ECU 4 may change the control content to be performed depending on the swipe direction. For example, the smart ECU 4 may open the trunk door when the swipe direction is forward, and open the right or left sliding door when the swipe direction is reverse. Door opening can be achieved by outputting an open instruction signal to the opening / closing motor 7. The forward direction here can be the swipe direction from the first antenna 51A to the second antenna 51B, or the swipe direction from the second antenna 51B to the first antenna 51A. The reverse direction refers to the direction opposite to the forward direction. The first pattern may be a swipe operation in the forward direction. The second pattern may be a swipe operation in the reverse direction.

[0098] <Variation (6)> The UWB communication device 5 as a dual-purpose device may also have a radar function. For example, the UWB communication device 5 transmits a single impulse signal as a probe wave separately from a data signal containing information such as the source of the transmission, and calculates the distance to an object present around the UWB communication device 5 by measuring the time it takes for the probe wave to be reflected by the object and return. Furthermore, if the UWB communication device 5 has multiple antennas 51, the reporting unit 542 may calculate not only the distance but also the direction and moving speed, and report them to the smart ECU 4.

[0099] In order to distinguish the probe wave from a response signal from the portable device 2, it is preferable that the probe wave be set to, for example, a single impulse signal or a pulse sequence signal with a no-response pattern in which the portable device 2 does not respond. A single impulse signal or a pulse signal sequence with a no-response pattern corresponds to a wireless signal with a specific pattern. Note that transmitting a single impulse signal corresponds to not transmitting other impulse signals for a certain period of time before and after the transmission.

[0100] In this disclosure, the process of detecting the distance to an object based on the time between transmitting a search wave and receiving a reflected wave is referred to as radar processing. Note that the search process is a process of calculating the distance to the portable device 2, while the radar processing is a process of calculating the distance to an object that may reflect the search wave, such as a human body or another vehicle. Radar processing and search processing can differ significantly in that they detect different objects.

[0101] If the steering wheel built-in device has a radar function, the smart ECU 4 may include a radar processing unit F23 that periodically causes the nearest communication device to perform radar processing, as shown in Fig. 12. The radar processing unit F23 periodically causes the nearest communication device to perform radar processing, thereby acquiring time-series data on the distance to a reflecting object present around the nearest communication device.

[0102] The control unit F4 may detect a user's movement of bringing their hand closer to the nearest communication device by analyzing time-series data of the radar processing result. The control unit F4 may be configured to execute vehicle control such as unlocking the doors on the condition that the radar function detects a user's movement of bringing their hand closer to the outer door handle 11 when the distance measurement value is equal to or less than a predetermined value. For example, the control unit F4 may unlock the doors when the distance measurement value is equal to or less than a predetermined value, the radar function detects a user's movement of bringing their hand closer to the outer door handle 11, and a decrease in reception strength is observed.

[0103] Considering various use cases, a drop in reception strength may occur not only when the user performs a grip operation, but also when the user puts the mobile device 2 into a bag or trouser pocket in front of the door, or when the user turns around in front of the door. That is, in the above-described embodiment, even if the user does not intend to unlock the door yet, there may be a case where the smart ECU 4 unlocks the door in response to a drop in reception strength.

[0104] To address this issue, a configuration that uses a radar function to unlock the door only when the user's movement of approaching the outer handle is detected makes it possible to prevent the door from being unlocked due to a malfunction.

[0105] <Variation (7)> The combination device may be mounted on a location other than the outer door handle 11. The combination device may be provided on a member that a user grips / touches when attempting to unlock a door, such as the outer door handle 11. The combination device may be attached to a door panel near the outer door handle 11. For example, the combination device may be embedded in a portion (recess) of the outer panel of the door that faces the outer door handle 11. The combination device may also be attached to a side sill or a B-pillar of a door module. The combination device is preferably located within reach of the hands and feet of a user standing in front of the door, for example, within 1 meter or 0.7 meters of the outer door handle 11. Depending on the installation location of the combination device, the grip operation described above may be replaced by holding a foot, waist, or elbow over the installation location of the combination device.

[0106] When the dual-purpose device is located on the vehicle body other than the outer door handle 11 as described above, it is preferable that a pattern (marker) encouraging the user to place their hand or foot on the surface where the dual-purpose device is embedded is provided. This configuration makes it easier for the user to recognize where on the vehicle body they need to place their hand, foot, elbow, etc. to unlock the door.

[0107] In a configuration in which the dual-purpose device is disposed in the outer door handle 11, the metal panel of the vehicle body facing the outer door handle 11 functions as a reflector, and fluctuations in reception strength associated with gripping the door handle can become significant. Therefore, it is preferable to install the dual-purpose device inside the outer door handle 11. If the dual-purpose device is disposed in a location other than the outer door handle 11, it is preferable to provide a metal plate on the back of the dual-purpose device so that it can transmit strong radio waves to the outside of the vehicle.

[0108] <Variation (8)> The arrangement of the UWB communication devices 5 described in the embodiment is merely an example and can be changed as appropriate. For example, the in-vehicle system 1 may also have a UWB communication device 5 built into the outer door handle 11 for the rear seat. Alternatively, the in-vehicle system 1 may have a UWB communication device 5 disposed at each of the left and right corners of the front bumper and the left and right corners of the rear bumper. Although it is preferable that multiple UWB communication devices 5 are installed in the vehicle cabin, only one may be installed.

[0109] <Variation (9)> As a communication standard between the in-vehicle system 1 and the portable device 2, various standards other than UWB-IR, such as Bluetooth (registered trademark), Wi-Fi (registered trademark), and EnOcean (registered trademark), can be adopted. Also, although the above description has been given of a configuration in which a UWB communication device 5 is used as a communication device for determining location (so-called anchor), the anchor does not necessarily have to be a UWB communication device 5. The anchor may also be a plurality of BLE (Bluetooth Low Energy) communication devices or a Wi-Fi communication device. The BLE communication device is a communication module capable of performing wireless communication in accordance with the BLE standard.

[0110] Distance measurement methods using BLE communication include a method using RTT and a method using a two-frequency phase difference. The two-frequency phase difference is a parameter determined by transmitting and receiving continuous wave (CW) signals between a BLE communication device and a mobile device 2, and is the difference between the transmission and reception phase differences observed at each of the two frequencies. The two-frequency phase difference corresponds to the amount of change in the transmission and reception phase difference due to a change in frequency.

[0111] The transmit / receive phase difference may also be simply referred to as the phase angle. The transmit / receive phase difference can be determined, for example, by having the BLE communication device and the portable device 2 transmit and receive CW signals to each other, detecting the phase difference between the transmitted signal and the received signal, and then averaging the phase differences observed by both devices. Here, the relationship L = C·Δφ / (2πΔf) holds, where Δφ is the two-frequency phase difference, C (3×10^8 m / sec) is the propagation speed of radio waves, Δf is the difference between the two frequencies, and L is the distance to the portable device 2. However, the two-frequency phase difference for one pair of frequencies may contain errors due to multipath and other factors. Furthermore, the degree of multipath influence varies depending on the frequency. For these reasons, it is preferable for the processor 41 to calculate the distance measurement value based on two or more pairs of two-frequency phase differences, i.e., the transmit / receive phase differences at three or more frequencies.

[0112] <Applicability of this disclosure> The present disclosure is applicable to vehicles for a variety of purposes, such as personal cars and shared cars. The present disclosure may also be applied to company cars owned by corporate organizations and official cars owned by public institutions. Hybrid vehicles can be used by multiple users. The present disclosure is also applicable to a variety of vehicles that travel on roads. That is, the present disclosure can be installed in a variety of vehicles that can travel on roads, such as four-wheeled vehicles, two-wheeled vehicles, three-wheeled vehicles, etc. Mopeds can also be included in the category of two-wheeled vehicles. The present disclosure is applicable to a variety of vehicles, such as electric vehicles and engine vehicles. The concept of an electric vehicle includes electric vehicles, hybrid vehicles, and fuel cell vehicles. The present disclosure is also applicable not only to vehicles, but also to electronic key systems for buildings and facilities.

[0113] <Using with Action Sensor> The present disclosure is also applicable to a configuration equipped with an action sensor, which is dedicated hardware for detecting user operations related to opening and closing the vehicle hybrid. In other words, the installation of an action sensor on the vehicle hybrid is not prohibited, and the above configuration and the action sensor can be used together. The action sensor refers to a touch sensor or push button provided on the outer door handle 11, an infrared sensor provided under the door for detecting the user's foot movement, etc. For example, the smart ECU 4 may be configured to use both the action sensor and a signal strength fluctuation pattern of a dual-purpose device to detect a user's gesture and execute vehicle control corresponding to the detected gesture.

[0114] <Additional remarks> The various flowcharts shown in this disclosure are merely examples, and the number of steps constituting the flowcharts and the execution order of the processes can be changed as appropriate. Furthermore, the apparatus, system, and method described in this disclosure may be implemented by a dedicated computer comprising a processor programmed to execute one or more functions embodied in a computer program. The apparatus and method described in this disclosure may be implemented using dedicated hardware logic circuits. The apparatus and method described in this disclosure may be implemented by one or more dedicated computers configured by combining a processor that executes a computer program with one or more hardware logic circuits. The processor 41 may be implemented using a CPU, a graphics processing unit (GPU), a data flow processor (DFP), or the like. Some or all of the functions of the smart ECU 4 may be implemented using a system-on-chip (SoC), an IC, or a field-programmable gate array (FPGA). The concept of an IC also includes an application-specific integrated circuit (ASIC).

[0115] The computer program may be stored as instructions executed by a computer on a computer-readable non-transitory tangible storage medium. Examples of storage media for the program include a hard-disk drive (HDD), a solid-state drive (SSD), and flash memory. The scope of the present disclosure also includes a program for causing a computer to function as the smart ECU 4, and a non-transitory tangible storage medium such as a semiconductor memory on which the program is stored. [Explanation of symbols]

[0116] 1 In-vehicle system, 2 Portable device, 4 Smart ECU, 5 UWB communication device, F2 Communication device control unit, F21 Intensity acquisition unit, F22 Distance measurement value acquisition unit (ToF related value acquisition unit), F23 Radar processing unit, F3 Position determination unit, F4 Control unit, F41 Action detection unit, M1 Search result storage unit

Claims

1. An electronic key system that controls a door lock mechanism by wirelessly communicating with a pre-registered mobile device, an antenna (51) for wirelessly communicating with the mobile device, the antenna (51) being located inside the door handle (11) or within a certain distance from the door handle; a ToF-related value acquisition unit (F22) that acquires a ToF-related value, which is a parameter indicating a time of flight (ToF) of radio waves from the antenna to the mobile device, based on a communication result with the mobile device using the antenna; an intensity acquisition unit (F21) that acquires a reception intensity of a signal from the mobile device at the antenna; and a control unit (F4) that controls the state of the locking mechanism based on a fluctuation pattern of the reception strength when the ToF-related value is equal to or less than a predetermined value.

2. 2. The electronic key system according to claim 1, The control unit is an electronic key system that unlocks or locks the door when the ToF-related value is below a predetermined value and the reception strength drops by more than a predetermined value compared to a reference strength, which is the reception strength observed at a predetermined timing.

3. 3. The electronic key system according to claim 1, The control unit executes different control depending on the fluctuation pattern of the reception strength when the ToF-related value is equal to or less than a predetermined value.

4. 4. The electronic key system of claim 3, which is used in a vehicle having multiple doors, When the fluctuation pattern of the reception strength corresponds to a first pattern, some of the plurality of doors provided in the vehicle are unlocked, When the fluctuation pattern of the reception strength corresponds to a second pattern, the electronic key system unlocks all of the doors of the vehicle.

5. 4. The electronic key system according to claim 3, which is used in a vehicle, When the fluctuation pattern of the reception strength corresponds to a first pattern, the door is unlocked but the driving power source is kept off, When the fluctuation pattern of the reception strength corresponds to a second pattern, the electronic key system unlocks the door and switches the driving power supply from off to on.

6. 3. The electronic key system according to claim 1, a radar processing unit (F23) for acquiring a distance to a reflecting object based on a time period from when a radio signal of a specific pattern is transmitted from the antenna as a search wave until when the antenna receives the signal of the specific pattern; The control unit Detecting that a user has brought their hand close to the antenna based on time-series data of the distance acquired by the radar processing unit; An electronic key system that unlocks or locks the door when the ToF-related value is below a predetermined value, the reception strength drops by more than a predetermined value, and it detects that a hand has been brought close to the antenna.

7. 3. The electronic key system according to claim 1, two or more of said antennas, The plurality of antennas are arranged side by side in the longitudinal direction of the door handle, the intensity acquisition unit acquires the reception intensity at each of the plurality of antennas, The control unit Detecting a swipe operation by a user on the door handle from a fluctuation pattern of the reception strength at each of the plurality of antennas; The control unit is configured to control the opening and closing of the door based on the detection of the swipe operation when the ToF-related value is equal to or less than a predetermined value.

8. A lock control device connected to an antenna (51) disposed inside a door handle (11) or within a certain distance from the door handle, a ToF-related value acquisition unit (F22) that acquires a ToF-related value, which is a parameter indicating a time of flight (ToF) of radio waves from the antenna to the mobile device, based on a result of communication with a pre-registered mobile device using the antenna; an intensity acquisition unit (F21) that acquires a reception intensity of a signal from the mobile device at the antenna; and a control unit (F4) that controls the state of the lock mechanism of the door on which the door handle is installed based on a fluctuation pattern of the reception strength when the ToF-related value is equal to or less than a predetermined value.

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