JP7275606B2 - Vehicle localization system - Google Patents

Description

The present disclosure relates to technology for estimating the relative position of a communication device (hereinafter referred to as a mobile terminal) carried by a user with respect to a vehicle using radio waves.

Conventionally, three or more reference stations with known positions perform wireless communication with mobile terminals such as smartphones to identify the distance from each reference station to the mobile terminal, and estimate the position of the mobile terminal based on the distance information from each reference station. A method for doing so has been proposed (for example, Patent Document 1). As a method of specifying the distance from the reference station to the mobile terminal, a method using the propagation time of radio waves (in other words, flight time), a method using received signal strength (RSS), and the like have been proposed. Positioning methods using the propagation time of radio waves (hereinafter referred to as propagation time methods) include the TOA (Time Of Arrival) method, the TDOA (Time Difference Of Arrival) method, and the like.

By the way, as a technique for estimating the absolute position of a mobile terminal or the like, there is conventionally a technique of a global navigation satellite system (GNSS). The absolute position here is not a position relative to the vehicle, but a specific point of the earth (e.g., center ) as the origin, and refers to position coordinates in a three-dimensional coordinate system that rotates with the earth. Generally, in GNSS, the positioning accuracy improves as the number of positioning satellites acquired by the mobile terminal increases. In particular, when the mobile terminal is in an environment with many objects such as buildings that reflect radio signals (a so-called multipath environment), an increase in the number of acquired satellites can be expected to further improve the positioning accuracy.

JP 2011-80946 A

According to a configuration in which three or more communication devices (hereinafter referred to as in-vehicle communication devices) are installed as the reference stations at different locations in the vehicle, each in-vehicle communication device calculates/measures the distance to the mobile terminal, The relative position of the mobile terminal (hereinafter, terminal position) can be estimated. However, the above method assumes that three or more in-vehicle communication devices can communicate with the mobile terminal. Therefore, if the number of in-vehicle communication devices that can communicate with the mobile terminal is less than three, the terminal position cannot be specified.

For example, if one or a plurality of in-vehicle communication devices fails and the number of in-vehicle communication devices that can operate normally becomes less than three, the terminal position cannot be identified. Further, even if three or more in-vehicle communication devices are normal, the number of in-vehicle communication devices capable of communicating with the mobile terminal may be less than three depending on the position of the mobile terminal. For example, when the mobile terminal is located out of the line of sight of some of the in-vehicle communication devices, an event may occur in which some of the in-vehicle communication devices cannot communicate with the mobile terminal. Even in such a case, the terminal position cannot be specified.

In response to such a problem, increasing the number of in-vehicle communication devices can reduce the possibility of inability to estimate the terminal position. However, increasing the number of in-vehicle communication devices causes an increase in cost. In addition, since the mounting space of a vehicle is limited, there is an upper limit to the number of in-vehicle communication devices that can be installed. For example, depending on the vehicle model, it is conceivable that only three in-vehicle communication devices can be installed.

Further, distance information (for example, propagation time) specified by communication between each in-vehicle communication device and a mobile terminal includes an error. Therefore, even if there are three or more in-vehicle communication devices with which the mobile terminal can communicate, the estimation accuracy is not necessarily high. In particular, there is a high possibility that other vehicles and walls exist around the parked vehicle, creating a multipath environment. When the vehicle is in a multipath environment, the error included in the distance information specified by communication between each on-vehicle communication device and the mobile terminal may increase. With respect to such a problem, according to a concept similar to GNSS, if the number of installed on-vehicle communication devices is increased, it can be expected to reduce the possibility of erroneously estimating the terminal position. However, as described above, increasing the number of in-vehicle communication devices poses problems such as an increase in cost.

The present disclosure has been made based on this situation, and its purpose is to address the possibility of inability to estimate the terminal position and erroneous estimation of the terminal position without adding an in-vehicle communication device as a reference station. To provide a vehicle position estimation system capable of reducing the risk of

A first vehicular position estimation system for achieving the object is such that a plurality of in-vehicle communication devices (12) arranged at different positions in a vehicle wirelessly communicate with a portable terminal carried by a user of the vehicle. A position estimation system for a vehicle that determines the position of a mobile terminal with respect to a vehicle by receiving a signal from the mobile terminal, so that each on-board communication device directly or indirectly determines the distance from the mobile terminal to the on-vehicle communication device by receiving a signal from the mobile terminal. A position estimation unit (F6 ), a person detection unit (F5) that detects the position of a person existing in a predetermined range by analyzing an image captured by a camera that includes a predetermined range outside the vehicle as an imaging range, and a sensor or electronic device mounted on the vehicle a vehicle information acquisition unit (F1) that acquires information indicating the state of the vehicle from the control device and determines whether or not the vehicle is in an empty state based on the information indicating the state of the vehicle; When the vehicle information acquisition unit determines that the vehicle is empty, the estimation unit obtains the distance information generated by each on-board communication device, the installation position of each on-board communication device, and the person detected by the person detection unit. The position of the mobile terminal outside the vehicle is estimated based on the position information of the person , which is the position information of the mobile terminal.
A second vehicular position estimation system for achieving the object is such that a plurality of in-vehicle communication devices (12) arranged at different positions in a vehicle wirelessly communicate with a mobile terminal carried by a user of the vehicle. A position estimation system for a vehicle that determines the position of a mobile terminal with respect to a vehicle by receiving a signal from the mobile terminal, so that each on-board communication device directly or indirectly determines the distance from the mobile terminal to the on-vehicle communication device by receiving a signal from the mobile terminal. A position estimation unit (F6 ) and the output signal of a laser radar, a millimeter wave radar, an ultrasonic sensor, an infrared sensor, or an optical sensor installed in the vehicle so that the detection range includes a predetermined range outside the vehicle. A person detection unit (F5) that detects the position of a person, acquires information indicating the state of the vehicle from a sensor or an electronic control device mounted on the vehicle, and detects the vehicle based on the information indicating the state of the vehicle. and a vehicle information acquisition unit (F1) that determines whether or not the vehicle is in an empty state, and the position estimation unit, when the vehicle information acquisition unit determines that the vehicle is in an empty state, each in-vehicle communication Based on the distance information generated by the device, the installation position of each in-vehicle communication device, and the human position information, which is the position information of the person detected by the person detection unit, the position of the mobile terminal outside the vehicle is estimated. It is configured.

A case where the user exists near an empty vehicle is, for example, a case where the user is about to board a parked vehicle, or a case where the parked vehicle automatically travels to the user. In other words, a scene in which the user is present near an empty vehicle corresponds to a scene in which the user is about to board the vehicle. In this way, in a scene where the user is about to board an empty vehicle, it is expected that the user is carrying the portable terminal. In other words, positional information of people present around the vehicle (hereinafter referred to as human positional information) can function as information suggesting the position of the mobile terminal.

The position estimation unit having the above configuration was created based on such an idea, and provided that the vehicle is parked, distance information from each in-vehicle communication device to the mobile terminal and The position of the mobile terminal is estimated by complementarily using the position information of the person existing in the mobile terminal. In this way, according to the configuration in which human position information is used together with position estimation of the mobile terminal, even if the number of in-vehicle communication devices that can observe the distance to the mobile terminal is relatively small, the terminal position is incorrectly estimated. It is possible to reduce the fear that the terminal position cannot be estimated. In other words, according to the above configuration, it is possible to reduce the possibility that the terminal position cannot be estimated or that the terminal position is erroneously estimated without adding an on-vehicle communication device as a reference station.

It should be noted that the symbols in parentheses described in the claims indicate the corresponding relationship with specific means described in the embodiments described later as one aspect, and limit the technical scope of the present disclosure. isn't it.

It is a figure showing the whole electronic key system composition for vehicles. 2 is a functional block diagram for explaining the configuration of the mobile terminal 2; FIG. 1 is a functional block diagram for explaining the configuration of an in-vehicle system 1; FIG. FIG. 3 is a diagram for explaining an example of mounting positions of a UWB communication device 12 and an external camera; 2 is a block diagram showing the configurations of a smart ECU 11 and a UWB communication device 12; FIG. It is a flowchart about a parking position estimation process. FIG. 4 is a diagram showing the relationship between propagation time and round trip time; It is a figure for demonstrating the position estimation method which uses an external camera together. It is a figure for demonstrating the position estimation method which uses an external camera together. 10 is a flowchart for explaining the operation of a position estimator F6 of modification 1; FIG. 11 is a functional block diagram for explaining the configuration of a smart ECU 11 of Modification 2; FIG. 4 is a diagram for explaining a problem when a vehicle Hv is in a multipath environment; FIG. 11 is a functional block diagram for explaining the configuration of a smart ECU 11 of Modification 3; FIG. 21 is a diagram for explaining the operation of the vehicle electronic key system in Modification 9;

[Embodiment]
Hereinafter, as an example of an embodiment of the vehicle position estimation system of the present disclosure, a vehicle electronic key system to which the vehicle position estimation system is applied will be described with reference to the drawings. A vehicle electronic key system according to the present disclosure includes, as shown in FIG. there is The vehicle Hv on which the in-vehicle system 1 is mounted is hereinafter also referred to as the own vehicle.

<Overview>
The in-vehicle system 1 and the mobile terminal 2 are configured to be able to perform wireless communication (hereinafter referred to as UWB communication) of the UWB-IR (Ultra Wide Band Impulse Radio) system. That is, the in-vehicle system 1 and the mobile terminal 2 are configured to be capable of transmitting and receiving impulse-like radio waves (hereinafter referred to as impulse signals) used in UWB communication. An impulse signal used in UWB communication is a signal having an extremely short pulse width (for example, 2 nanoseconds) and a bandwidth of 500 MHz or more (that is, an ultra-wide bandwidth).

Frequency bands that can be used for UWB communication (hereinafter referred to as UWB band) include 3.2 GHz to 10.6 GHz, 3.4 GHz to 4.8 GHz, 7.25 GHz to 10.6 GHz, and 22 GHz to 29 GHz. Of these various frequency bands, the impulse signal in this embodiment is realized using radio waves in the 3.2 GHz to 10.6 GHz band. The frequency band used for the impulse signal may be appropriately selected according to the country in which the vehicle Hv is used. Note that the impulse signal may have a bandwidth of 500 MHz or more, and may have a bandwidth of 1.5 GHz or more.

As a modulation method for UWB-IR communication, various methods such as a PPM (pulse position modulation) method, which modulates at the pulse generation position, can be adopted. Specifically, on-off modulation (OOK: On Off Keying) method, pulse width modulation (PWM: Pulse Width Modulation), pulse amplitude modulation (PAM: Pulse-Amplitude Modulation) method, pulse code modulation (PCM: Pulse-Code Modulation) etc. can be adopted. The on/off modulation method expresses information (for example, 0 and 1) by the presence/absence of an impulse signal, and the pulse width modulation method expresses information by the pulse width. The pulse amplitude modulation method is a method of expressing information by the amplitude of an impulse signal. The pulse code modulation method is a method of expressing information by combining pulses.

In addition, the in-vehicle system 1 and the mobile terminal 2 of the present embodiment are configured to be able to perform wireless communication (hereinafter referred to as BLE communication) conforming to the Bluetooth Low Energy (Bluetooth is a registered trademark) standard as a second communication method. there is Note that the first communication method refers to the aforementioned UWB communication. As the second communication method, in addition to Bluetooth Low Energy, various short-range wireless communication methods such as Wi-Fi (registered trademark) and ZigBee (registered trademark) that can set the communication distance to about 10 meters are adopted. It is possible. The second communication method may provide a communication distance of, for example, several meters to several tens of meters. Hereinafter, in order to distinguish between impulse signals in UWB communication and radio signals in BLE communication, radio signals conforming to the BLE standard are also referred to as BLE signals. Specific configurations of the in-vehicle system 1 and the mobile terminal 2 will be described in order below.

<Regarding the configuration of the mobile terminal 2>
First, the configuration and operation of the mobile terminal 2 will be described. The mobile terminal 2 is associated with the in-vehicle system 1 and is a device that functions as an electronic key for the vehicle Hv. The mobile terminal 2 can be realized by using a communication terminal used for various purposes. For example, the mobile terminal 2 is a smart phone. The mobile terminal 2 may be an information processing terminal such as a tablet terminal. The mobile terminal 2 may also be a rectangular, oval (fob-type) or card-shaped small device conventionally known as a smart key. In addition, the mobile terminal 2 may be configured as a wearable device that is worn on a user's finger, arm, or the like.

The mobile terminal 2 includes a UWB communication unit 21, a BLE communication unit 22, and a mobile-side control unit 23, as shown in FIG. The mobile-side control unit 23 is connected to each of the UWB communication unit 21 and the BLE communication unit 22 so as to be mutually communicable.

The UWB communication unit 21 is a communication module for transmitting and receiving UWB impulse signals. The UWB communication unit 21 generates a modulated signal while electrically processing, such as modulating the baseband signal input from the mobile-side control unit 23, and transmits this modulated signal by UWB communication. A modulated signal is a signal obtained by modulating transmission data with a predetermined modulation method (for example, PCM modulation method). A modulated signal is a signal sequence (hereinafter referred to as a pulse sequence signal) in which a plurality of impulse signals are arranged at time intervals corresponding to transmission data. When the UWB communication unit 21 receives a series of modulated signals (that is, pulse sequence signals) composed of a plurality of impulse signals transmitted from the in-vehicle system 1, the UWB communication unit 21 demodulates the received signals to restore data before modulation. Then, it outputs the received data to the mobile-side control section 23 .

Also, the UWB communication unit 21 has a reflection response mode and a normal mode as operation modes. Upon receiving an impulse signal, the UWB communication unit 21 in reflection response mode returns the impulse signal reflectively (in other words, immediately/as quickly as possible). Whether or not to operate in the reflection response mode is switched by the mobile-side control unit 23 based on an instruction signal from the in-vehicle system 1, for example. It takes a predetermined time (hereinafter referred to as response processing time Tb) from when the mobile terminal 2 receives the impulse signal from the in-vehicle system 1 to when it transmits the impulse signal as a response signal. The response processing time Tb is determined according to the hardware configuration of the mobile terminal 2 . An assumed value of the response processing time Tb can be specified in advance by testing or the like.

The normal mode is a mode in which a series of pulse sequence signals from the preamble to the end is received and then a response signal corresponding to the content of the received data is returned. Even in the reflection response mode, the portable terminal 2 reflectively returns a series of impulse signals similar to the pulse series signal transmitted from the in-vehicle system 1, and then generates a response signal having contents corresponding to the received data. It may be configured to return the

The BLE communication unit 22 is a communication module for implementing BLE communication. The BLE communication unit 22 is connected to the mobile-side control unit 23 so as to be able to communicate with each other. The BLE communication unit 22 receives a BLE signal transmitted from the vehicle Hv and provides it to the mobile-side control unit 23, modulates data input from the mobile-side control unit 23, and transmits the modulated data to the vehicle Hv.

The mobile-side control unit 23 is configured to control operations of the UWB communication unit 21 and the BLE communication unit 22 . The mobile-side control unit 23 is implemented using a computer including, for example, a CPU, a RAM, and a ROM.

The mobile-side control unit 23 causes the BLE communication unit 22 to wirelessly transmit a wireless signal including source information at predetermined transmission intervals. This notifies (that is, advertises) the presence of itself to the in-vehicle system 1 and the like. Hereinafter, for the sake of convenience, a radio signal that is periodically transmitted for the purpose of advertising will be referred to as an advertising signal. The source information is, for example, unique identification information assigned to the mobile terminal 2 (hereinafter referred to as terminal ID). The terminal ID functions as information for identifying the mobile terminal 2 from other communication terminals. By receiving this advertising signal, the in-vehicle system 1 recognizes that the mobile terminal 2 exists within the BLE communication range of the vehicle Hv. As another aspect, the mobile terminal 2 may transmit an advertisement signal based on a request from the in-vehicle system 1 . In addition, when reception data is input from the BLE communication unit 22, the mobile-side control unit 23 generates a baseband signal corresponding to a response signal corresponding to the reception data, and transmits the baseband signal to the BLE communication unit 22. Output.

Further, when reception data is input from the UWB communication unit 21, the mobile-side control unit 23 generates a baseband signal corresponding to a response signal corresponding to the reception data, and transmits the baseband signal to the UWB communication unit 21. Output. The baseband signal output from the mobile-side control unit 23 to the UWB communication unit 21 is modulated by the UWB communication unit 21 and transmitted as a radio signal.

<About in-vehicle system 1>
Next, the functions and configuration of the in-vehicle system 1 will be described. The in-vehicle system 1 is configured to implement a passive entry passive start system (hereinafter referred to as a PEPS system) by performing wireless communication with the mobile terminal 2 using radio waves in a predetermined frequency band. For example, when the in-vehicle system 1 can confirm that the portable terminal 2 exists within the operation area preset for the vehicle Hv, the door is opened based on the user's operation of the door button 14, which will be described later. Execute control such as locking and unlocking.

The operation area is an area for the in-vehicle system 1 to execute predetermined vehicle control such as locking and unlocking the doors based on the presence of the mobile terminal 2 in the area. For example, the vicinity of the driver's seat door, the vicinity of the front passenger seat door, and the vicinity of the trunk door are set as operation areas. The vicinity of the door refers to a range within a predetermined working distance from the outer door handle. The outer door handle refers to a gripping member provided on the outer surface of the door for opening and closing the door. A working distance that defines the size of the working area is, for example, 0.7 m. Of course, the working distance may be 1 m or 1.5 m. The working distance is preferably set to be smaller than 2 m from the viewpoint of security.

The in-vehicle system 1 includes a smart ECU 11, a plurality of UWB communication devices 12, a BLE communication device 13, a door button 14, a start button 15, a body ECU 16, a side camera 17, and a rear camera 18, as shown in FIG. The in-vehicle system 1 also includes a body system actuator 161, an in-vehicle sensor 162, and the like. Note that the ECU in the member name is an abbreviation for Electronic Control Unit, meaning an electronic control unit.

The smart ECU 11 is an ECU that locks and unlocks the door by performing wireless communication with the mobile terminal 2 via the UWB communication device 12 or the BLE communication device 13 . The smart ECU 11 is connected to the body ECU 16, the side camera 17, and the rear camera 18 so as to be able to communicate with each other via a communication network built in the vehicle. The smart ECU 11 is also electrically connected to the UWB communication device 12 , the BLE communication device 13 , the door button 14 and the start button 15 . The smart ECU 11 is implemented using a computer, for example. That is, the smart ECU 11 includes a CPU 111, a flash memory 112, a RAM 113, an I/O 114, and a bus line connecting these components.

A terminal ID assigned to the mobile terminal 2 owned by the user is registered in the flash memory 112 . The flash memory 112 also stores a program (hereinafter referred to as a position estimation program) and the like for causing the computer to function as the smart ECU 11 . The position estimation program described above may be stored in a non-transitory tangible storage medium. Execution of the position estimation program by CPU 111 corresponds to execution of a method corresponding to the position estimation program. Details of the smart ECU 11 will be described separately later.

The UWB communication device 12 is a communication module for performing UWB communication with the mobile terminal 2 . Each of the plurality of UWB communication devices 12 is configured to be able to perform UWB communication with other UWB communication devices 12 mounted on the vehicle Hv. That is, each UWB communication device 12 is configured to be able to wirelessly communicate with the mobile terminal 2 and other UWB communication devices 12 . For convenience, a UWB communicator 12 for another UWB communicator 12 is also referred to as the other device. The UWB communication device 12 corresponds to an in-vehicle communication device.

Each UWB communication device 12 is connected to the smart ECU 11 via a dedicated communication line or an in-vehicle network so as to be able to communicate with each other. The operation of each UWB communication device 12 is controlled by the smart ECU 11 . Each UWB communication device 12 is assigned a unique communication device number. A communication device number functions as information for identifying a plurality of UWB communication devices 12 . The mounting positions and electrical configuration of the plurality of UWB communication devices 12 will be described separately later.

The BLE communication device 13 is a communication module for implementing BLE communication. The BLE communication device 13 is connected to the smart ECU 11 so as to be able to communicate with each other. The BLE communication device 13 receives the BLE signal transmitted from the mobile terminal 2 and provides it to the smart ECU 11 . The BLE communication device 13 also modulates data input from the smart ECU 11 and wirelessly transmits the data to the mobile terminal 2 . The BLE communication device 13 is attached to an arbitrary position of the vehicle Hv. For example, the BLE communication device 13 is attached to an instrument panel, an upper end portion of a windshield, a C-pillar (in other words, a rear pillar), a rocker portion, and the like. One or more BLE communication devices 13 may be provided. The BLE communication device 13 corresponds to a different system communication device.

The door button 14 is a button for the user to unlock and lock the door of the vehicle Hv. The door button 14 is provided, for example, on each door handle of the vehicle Hv. When the user presses the door button 14 , the door button 14 outputs an electric signal indicating that fact to the smart ECU 11 . The door button 14 corresponds to a configuration for the smart ECU 11 to receive a user's unlocking instruction and locking instruction. A touch sensor may be employed as a configuration for receiving at least one of the user's unlocking instruction and locking instruction. A touch sensor is a device that detects that a user is touching the door handle.

The start button 15 is a push switch for the user to start the drive source (for example, engine) of the vehicle Hv. When the start button 15 is pushed by the user, it outputs an electrical signal to the smart ECU 11 to indicate that. Here, as an example, the vehicle Hv is a vehicle provided with an engine as a power source, but is not limited to this. The vehicle Hv may be an electric vehicle or a hybrid vehicle. When the vehicle Hv is a vehicle having a motor as a drive source, the start button 15 is a switch for starting the drive motor.

The body ECU 16 is an ECU that controls the body system actuator 161 based on a request from the smart ECU 11 . The body ECU 16 is communicably connected to various body system actuators 161 and various in-vehicle sensors 162 . The body system actuator 161 here is, for example, a door lock motor that constitutes a lock mechanism for each door, a seat actuator for adjusting the seat position, and the like. The in-vehicle sensor 162 here is a courtesy switch or the like arranged for each door. A courtesy switch is a sensor that detects opening and closing of a door. The body ECU 16 locks and unlocks each door by outputting a predetermined control signal to a door lock motor provided for each door of the vehicle Hv based on a request from the smart ECU 11, for example.

The side camera 17 is a camera that images the rear side of the vehicle Hv. One side camera 17 is provided on each of the left and right side surfaces. The side camera 17 is provided, for example, so as to photograph the range reflected in the door mirror seen by the driver sitting in the driver's seat. That is, as shown in FIG. 4, the in-vehicle system 1 includes a right side camera 17A attached to the right side of the vehicle Hv so as to image the right rear of the vehicle Hv, and a left side camera 17A so as to image the left rear of the vehicle Hv. and a left camera 17B attached to the surface. The side camera 17 is, for example, a camera that constitutes an electronic mirror system. The electronic mirror system is a system for displaying an image of the rear side of the vehicle Hv captured by each side camera 17 on a predetermined display. The hatching shown in FIG. 4 conceptually represents the imaging direction/range of each camera.

The right camera 17A is mounted near the lower end of the right A pillar, for example, with its imaging surface directed toward the rear right of the vehicle Hv. The A pillar is the first pillar from the front in the vehicle Hv. The A-pillar is also called the front pillar. For example, the right camera 17A is provided at the mounting position of the right side door mirror instead of the right side door mirror. The operation of the right camera 17A is controlled by the smart ECU 11 or the like. When driven, the right camera 17A captures an image of the range from the right side to the rear of the vehicle Hv at a predetermined frame rate, and provides the image signal to the smart ECU 11 and the like.

The left camera 17B is attached at a position corresponding to (in other words, bilaterally symmetrical to) the right camera 17A on the left side of the vehicle. The operation of the left camera 17B is also controlled by the smart ECU 11 or the like. When driven, the left camera 17B captures an image of the range from the left side to the rear of the vehicle Hv at a predetermined frame rate, and provides the image signal to the smart ECU 11 and the like.

The rear camera 18 is a camera that captures an image behind the vehicle. The rear camera 18 is installed near the rear end of the vehicle or the upper end/lower end of the rear glass. The operation of the rear camera 18 is controlled by the smart ECU 11 or the like. When driven, the rear camera 18 takes an image of the rear of the vehicle Hv at a predetermined frame rate and provides the image signal to the smart ECU 11 and the like. Both the side camera 17 and the rear camera 18 are cameras that capture images of the outside of the vehicle (in other words, the outside world). Therefore, without distinguishing between the side camera 17 and the rear camera 18, a camera that captures an image of the outside of the vehicle is also referred to as an outside camera hereinafter.

<Mounting position and electrical configuration of each UWB communication device 12>
As shown in FIG. 4, the in-vehicle system 1 of this embodiment includes a right side communication device 12A, a left side communication device 12B, a front side communication device 12C, and a rear side communication device 12D as the UWB communication device 12 as shown in FIG. The right side communication device 12A is arranged, for example, in the area above the B pillar (in other words, the center pillar) on the right side of the vehicle. The upper region of the pillar refers to the region that is the upper half of the pillar. The upper region of the pillar also includes the upper end of the pillar. The left side communication device 12B is arranged, for example, in an area above the B pillar on the left side of the vehicle. The front side communication device 12C is arranged near the rearview mirror (in other words, at the upper end of the windshield). The rear side communication device 12D is attached, for example, to the vehicle width direction central portion of the ceiling portion located above the rear seat. In addition, in FIG. 4, the roof portion is transparent in order to clarify the mounting position of the UWB communication device 12. As shown in FIG.

The flash memory 112 stores communication device position data indicating the installation position of each UWB communication device 12 . The installation position of each UWB communication device 12 in the vehicle Hv may be expressed as a point in a three-dimensional orthogonal coordinate system with an arbitrary point on the vehicle as a reference point (in other words, the origin). Here, as an example, it is represented as a point on a three-dimensional coordinate system (hereinafter referred to as a vehicle three-dimensional coordinate system) having mutually orthogonal X, Y, and Z axes with the center of the front wheel axle as the origin. The X-axis forming the vehicle three-dimensional coordinate system is parallel to the vehicle width direction and the positive direction is the right side of the vehicle. The Y-axis is parallel to the front-rear direction of the vehicle, and the forward direction of the vehicle is the positive direction. The Z-axis is parallel to the height direction of the vehicle, and the positive direction is the upper side of the vehicle. The center of the three-dimensional coordinate system can be appropriately changed, for example, the center of the rear wheel axle. Of course, as another aspect, the mounting position of each UWB communication device 12 may be represented by polar coordinates. The installation position of each UWB communication device 12 may be stored in association with the communication device number.

Each of the plurality of UWB communication devices 12 includes a transmitting section 31, a receiving section 32, and a propagation time measuring section 33, as shown in FIG. The transmission unit 31 is configured to generate an impulse signal while electrically processing the baseband signal input from the smart ECU 11, such as modulating it, and radiate the impulse signal as radio waves. The transmitter 31 is implemented using, for example, a modulation circuit 311 and a transmission antenna 312 .

The modulation circuit 311 is a circuit that modulates the baseband signal input from the smart ECU 11 . The modulation circuit 311 generates a modulated signal corresponding to data indicated by the baseband signal input from the smart ECU 11 (hereinafter referred to as transmission data), and transmits the modulated signal toward the transmission antenna 312 . A modulated signal is a signal obtained by modulating transmission data with a predetermined modulation method. The modulated signal in this embodiment corresponds to a signal sequence in which a plurality of impulse signals are arranged at time intervals corresponding to transmission data, as described above. The modulation circuit 311 includes a circuit that generates an electrical impulse signal (hereinafter referred to as a pulse generation circuit) and a circuit that amplifies and shapes the impulse signal.

The transmission antenna 312 is configured to convert the electrical impulse signal output by the modulation circuit 311 into radio waves and radiate them into space. That is, the transmitting antenna 312 radiates a pulsed radio wave having a predetermined bandwidth in the UWB band as an impulse signal. When the modulation circuit 311 outputs an electrical impulse signal to the transmission antenna 312, the modulation circuit 311 simultaneously outputs a signal indicating that the impulse signal has been output (hereinafter referred to as a transmission notification signal) to the propagation time measurement unit 33. do.

The transmitter 31 of this embodiment is configured so that the rise time of the impulse signal is 1 nanosecond. Rise time is the time required for the signal strength to first exceed 10% of its maximum amplitude until it exceeds 90% of its maximum amplitude. The rise time of the impulse signal is determined according to the hardware configuration such as the circuit configuration of the transmitter 31 . The rise time of the impulse signal can be specified by simulation or actual test. Note that the rise time of an impulse signal used for UWB communication is generally about 1 nanosecond.

The receiving unit 32 includes a receiving antenna 321 and a demodulation circuit 322, for example. The receiving antenna 321 is an antenna for receiving impulse signals. The receiving antenna 321 outputs an electrical impulse signal corresponding to the impulse signal transmitted by the mobile terminal 2 to the demodulation circuit 322 .

When the reception antenna 321 receives an impulse signal for UWB communication, the demodulation circuit 322 electrically processes the signal such as demodulation to generate a reception signal, and outputs the reception signal to the smart ECU 11 . The pulse sequence signal acquired by the demodulation circuit 322 is obtained by arranging a plurality of impulse signals input from the receiving antenna 321 in time series at actual reception intervals. The demodulation circuit 322 is configured to demodulate a series of modulated signals (that is, pulse sequence signals) composed of a plurality of impulse signals transmitted from the mobile terminal 2 or another device, and restore data before modulation.

The demodulation circuit 322 includes a frequency conversion circuit that converts the frequency of the impulse signal received by the receiving antenna 321 into a baseband signal and outputs the baseband signal, an amplifier circuit that amplifies the signal level, and the like. In addition, when an impulse signal is input from the receiving antenna 321 , the receiving section 32 outputs a signal indicating that the impulse signal has been received (hereinafter referred to as a reception notification signal) to the propagation time measuring section 33 .

The propagation time measurement unit 33 is a timer that measures the time from the transmission of the impulse signal by the transmission unit 31 to the reception of the impulse signal by the reception unit 32 (hereinafter referred to as round trip time). The timing at which the transmission unit 31 transmits the impulse signal is specified by the input of the transmission notification signal. Also, the timing at which the receiving unit 32 receives the impulse signal is specified by the input of the reception notification signal. That is, the propagation time measurement unit 33 measures the time from when the modulation circuit 311 outputs the transmission notification signal to when the demodulation circuit 322 outputs the reception notification signal. The round-trip time corresponds to the round-trip signal flight time plus the response processing time at the communication partner.

The propagation time measurement unit 33 measures the elapsed time after the transmission unit 31 transmits the impulse signal by counting clock signals input from a clock oscillator (not shown). The counting by the propagation time measurement unit 33 is stopped when a reception notification signal is input or when a predetermined upper limit value is reached, and the count value is output to the smart ECU 11 . In other words, the round trip time is reported to the smart ECU 11 . Note that when the report of the round trip time to the smart ECU 11 is completed, the count value of the propagation time measurement unit 33 returns to 0 (that is, reset).

When the measurement of the round trip time is completed, the propagation time measurement unit 33 calculates the propagation time based on the round trip time and provides it to the smart ECU 11 . The propagation time measuring section 33 corresponds to the propagation time specifying section. The operation of the propagation time measuring unit 33 related to the calculation of the propagation time will be separately described later. The propagation time measurement unit 33 is implemented using an IC, for example. In addition, the UWB communication device 12 has a reflection response mode like the UWB communication section 21 of the mobile terminal 2 . The reflection response mode of the UWB communication device 12 is the same as the reflection response mode of the UWB communication section 21 .

Here, the UWB communication device 12 shows a mode in which a transmitting antenna (that is, the transmitting antenna 312) and a receiving antenna (that is, the receiving antenna 321) are separately provided, but the present invention is not limited to this. do not have. The UWB communicator 12 may be configured using a directional coupler to share a single antenna element for transmission and reception. Also, the modulation circuit 311 and the demodulation circuit 322 may be incorporated in an IC that provides the function of the propagation time measuring section 33 . The UWB communication device 12 may be realized using one antenna and one dedicated IC having various circuit functions.

<Functions of smart ECU 11>
The smart ECU 11 provides functions corresponding to various functional blocks shown in FIG. 5 by executing the position estimation program described above. That is, the smart ECU 11 has functional blocks including a vehicle information acquisition unit F1, a BLE communication processing unit F2, a UWB communication processing unit F3, a communication device diagnosis unit F4, an external world information acquisition unit F5, a position estimation unit F6, and a vehicle control unit F7. It has

The vehicle information acquisition unit F1 acquires various information indicating the state of the vehicle Hv (hereinafter referred to as vehicle information) from sensors, an ECU (for example, the body ECU 16), switches, etc. mounted on the vehicle Hv. Vehicle information includes, for example, the open/closed state of doors, the locked/unlocked state of each door, whether the door button 14 has been pressed, whether the start button 15 has been pressed, and the like. Also, the vehicle information acquisition unit F1 identifies the current state of the vehicle Hv based on the various information described above. For example, the vehicle information acquisition unit F1 determines that the vehicle Hv is parked when the engine is off and all the doors are locked. Of course, the conditions for determining that the vehicle Hv is parked may be appropriately designed, and various determination conditions can be applied. Here, the state in which the vehicle Hv is parked refers to a state in which no one is on board the vehicle Hv (that is, the vehicle is in an empty state) and the vehicle Hv is locked.

Acquiring information indicating the locked/unlocked state of each door corresponds to determining the locked/unlocked state of each door and detecting the locking/unlocking operation of the door by the user. do. Acquiring electrical signals from the door button 14 and the start button 15 corresponds to detecting user operations on these buttons. That is, the vehicle information acquisition unit F1 corresponds to a configuration for detecting user's operations on the vehicle Hv, such as opening and closing the door, pressing the door button 14, pressing the start button 15, and the like. The vehicle information hereinafter also includes the user's operation on the vehicle Hv. In addition, the types of information included in vehicle information are not limited to those described above. The vehicle information also includes a shift position detected by a shift position sensor (not shown), a detection result of a brake sensor that detects whether or not the brake pedal is depressed, and the like. Parking brake activation status can also be included in the vehicle information.

The BLE communication processing unit F2 is configured to cooperate with the BLE communication device 13 to transmit and receive data to and from the mobile terminal 2 . For example, the BLE communication processing unit F2 generates data addressed to the mobile terminal 2 and outputs the data to the BLE communication device 13 . As a result, a signal corresponding to desired data is transmitted as radio waves. In addition, the BLE communication processing unit F2 receives data from the mobile terminal 2 received by the BLE communication device 13 . In this embodiment, wireless communication between the smart ECU 11 and the mobile terminal 2 is encrypted as a more preferable aspect. As the encryption method, various methods such as the method specified by Bluetooth can be used.

In the present embodiment, the smart ECU 11 and the mobile terminal 2 are configured to encrypt data communication for authentication and the like in order to improve security, but the present invention is not limited to this. As another aspect, the smart ECU 11 and the mobile terminal 2 may be configured to perform data communication without encryption.

The BLE communication processing unit F2 cooperates with the BLE communication device 13 to perform a process of confirming (in other words, authenticating) that the communication partner is the mobile terminal 2 of the user. The authentication process itself may be performed using various methods such as a challenge-response method. A detailed description thereof is omitted here. It is assumed that data (for example, an encryption key) required for authentication processing is stored in each of the mobile terminal 2 and the smart ECU 11 . The BLE communication processing unit F2 corresponds to the authentication processing unit. A state in which the mobile terminal 2 has been successfully authenticated corresponds to a state in which communication connection with the mobile terminal 2 has been established.

The BLE communication processing unit F2 recognizes that the user is present around the vehicle Hv based on the fact that the BLE communication with the mobile terminal 2 is established. Also, the BLE communication processing unit F2 acquires the terminal ID of the mobile terminal 2 connected for communication from the BLE communication device 13 . According to such a configuration, even if the vehicle Hv is shared by a plurality of users, the smart ECU 11 detects the surrounding area of the vehicle Hv based on the terminal ID of the mobile terminal 2 to which the BLE communication device 13 is connected for communication. can identify users that exist in

In this embodiment, the mobile terminal 2 is authenticated by BLE communication as an example, but the present invention is not limited to this. The authentication process of the mobile terminal 2 (and thus the user) by the smart ECU 11 may be performed by UWB communication. The smart ECU 11 may be configured to perform authentication processing at predetermined intervals while the BLE communication device 13 and the mobile terminal 2 are connected for communication. Further, the smart ECU 11 may be configured to perform authentication processing by BLE communication/UWB communication triggered by a predetermined user operation on the vehicle Hv, such as when the user presses the start button 15 .

The UWB communication processing unit F3 is configured to cooperate with the UWB communication device 12 to transmit and receive data to and from the mobile terminal 2 . The UWB communication processing unit F3 acquires data from the portable terminal 2 that the UWB communication device 12 has received. Additionally, the UWB communication processing unit F3 generates data addressed to the mobile terminal 2 and outputs the data to the UWB communication device 12 . Thereby, a pulse sequence signal corresponding to desired data is wirelessly transmitted. Further, the UWB communication processing unit F3 causes an arbitrary UWB communication device 12 to transmit an impulse signal based on instructions from the communication device diagnosis unit F4 and the position estimation unit F6. The UWB communication device 12 to transmit the impulse signal is selected by the communication device diagnosis unit F4 and the position estimation unit F6.

The communication device diagnostic unit F4 is configured to determine whether each UWB communication device 12 is operating normally (in other words, whether there is a problem). The communication device diagnostic unit F4 detects a problem/failure of the UWB communication device 12 by causing each UWB communication device 12 to perform wireless communication with other devices in order, for example. Defects here also include states in which operation has stopped due to failure.

For example, the communication device diagnosis unit F4 causes the UWB communication device 12 to be diagnosed (hereinafter referred to as the diagnosis target device) to perform wireless communication with a plurality of other devices, and as a result, the communication failure rate with the other device is a predetermined number. If it is equal to or greater than the threshold, it is determined that the device to be diagnosed is out of order. The machine to be diagnosed may be changed in a predetermined order. When the smart ECU 11 has a plurality of processors, for example, and is configured to be able to execute a plurality of arithmetic processes in parallel, a plurality of UWB communication devices 12 are simultaneously set as diagnosis target devices. The communicators 12 may be diagnosed in parallel.

In addition, the communication device diagnosis unit F4 can detect a failure of the UWB communication device 12 using various methods such as a watchdog timer method and a homework answer method. The watchdog timer method is a method in which it is determined that the UWB communication device 12 is out of order when the watchdog timer provided in the smart ECU 11 is not cleared by the watchdog pulse input from the UWB communication device 12 and expires. be. A watchdog timer may be prepared for each UWB communication device 12 . In the homework answering method, the smart ECU 11 as the communication device diagnosis unit F4 sends a predetermined monitoring signal to the diagnosis target device, and checks whether the answer returned from the diagnosis target device is correct. It is a method of judging whether or not the machine to be diagnosed is normal depending on whether or not it is normal. In the homework answering method, the UWB communication device 12 as a device to be diagnosed generates answer data in response to a monitoring signal input from the smart ECU 11 and returns it to the smart ECU 11 . If the response data from the UWB communication device 12 is different from the correct answer data corresponding to the transmitted monitoring signal, or if the response signal is not returned from the smart ECU 11 within a predetermined time limit, the smart ECU 11 detects the response from the UWB communication device. 12 is not operating normally.

Further, the communication device diagnosis unit F4 causes each UWB communication device 12 to perform two-way wireless communication with each of a predetermined plurality of other devices in a predetermined order, thereby performing inter-communication device communication for each combination of UWB communication devices 12. Measure distance. Here, the inter-communication device distance refers to the distance from a certain UWB communication device 12 to another device. The combination of the UWB communication devices 12 that carry out bi-directional wireless communication may be appropriately designed. For example, the UWB communication devices 12 located within line of sight may be registered in advance as a combination for performing two-way wireless communication for diagnosis.

Then, the communication device diagnosis unit F4 determines that the distance between the communication devices in all combinations including the diagnostic target device as a constituent element is outside the predetermined normal range. is determined to be defective. In other words, if the distance between the communication devices in at least one combination is within the normal range, the communication device diagnosis unit F4 determines that the diagnosis target device is normal.

The normal range of the inter-communication device distance for each combination of UWB communication devices 12 is registered in advance in the flash memory 112 through tests and simulations. The normal range for each combination of UWB communication devices 12 may be set based on the straight-line distance between the UWB communication devices 12 . As another aspect, the normal range for each combination of communication devices may be defined by the propagation time of radio signals (so-called TOF: Time Of Flight) instead of the distance. Various methods can be used to measure the distance between the two communication devices and the propagation time of the radio signal by performing wireless communication between the two communication devices. For example, the UWB communication devices 12 are caused to transmit and receive impulse signals to measure the round trip time. Then, the propagation time can be calculated by further dividing the value obtained by subtracting the response processing time in the UWB communication device 12 on the response side from the measured round trip time by 2.

The defects detected using the distance between the communication devices include, for example, poor contact between signal lines and circuit elements inside the communication device, amplifier failures, and the like. If there is a poor contact in the signal line or the amplifier is not working, the impulse signal reception level (in other words, reception sensitivity) will be lower than normal, and the impulse signal reception power will exceed a predetermined detection threshold. Timing can be delayed on the order of 0.5 ns to 1 ns. According to the above method, it is possible to detect a defect inside the communication device that causes a very small delay of several nanoseconds. Further, according to the diagnostic method described above, in addition to an internal failure of the UWB communication device 12, a state in which the UWB communication device 12 is removed from a predetermined mounting position can also be detected as an abnormal state.

Two-way wireless communication (hereinafter referred to as diagnostic wireless communication) for acquiring the inter-communication device distance for each combination of UWB communication devices 12 may be performed periodically, for example, at a predetermined diagnostic cycle. The diagnostic cycle is, for example, one hour. Of course, diagnostic wireless communication may be executed at predetermined timings such as timing when the vehicle Hv is parked, timing when a predetermined time has passed since the vehicle was parked, and timing when the user's approach to the vehicle Hv is detected. may be configured to It should be noted that diagnostic wireless communication is preferably performed when there are no passengers in the vehicle, such as when the vehicle is parked.

When the smart ECU 11 as the communication device diagnostic unit F4 detects a problem with the UWB communication device 12, it executes predetermined recovery processing such as restarting the IC of the UWB communication device 12. FIG. If the UWB communication device 12 does not return to a normal state even after performing the recovery process, it is determined that the UWB communication device 12 has a problem, and is registered in the flash memory 112 or the like as a problem device. . Whether or not each UWB communication device 12 is defective may be managed using the communication device number. Hereinafter, for the sake of convenience, the UWB communication device 12 determined to be operating normally by the communication device diagnosis unit F4 is also referred to as a healthy device.

The external world information acquisition unit F5 analyzes an image (hereinafter referred to as an external world image) input from an external camera such as the side camera 17 or the rear camera 18, and determines whether or not there is a person in a predetermined range corresponding to the surroundings of the vehicle. judge. If a person exists, the position of the person relative to the vehicle Hv (that is, the location) is specified based on the position of the person in the image and the mounting position and orientation of the camera. The relative position of the person with respect to the vehicle Hv may be expressed in a vehicle three-dimensional coordinate system similar to the coordinate system indicating the position of the communication device. Information indicating the relative position of a person existing around the vehicle is provided to the position estimation unit F6 as the person position information. The imaging data of the external camera corresponds to information representing the position of a person present in the imaging range of the external camera. The external world information acquisition unit F5 corresponds to the person detection unit. The vehicle periphery is, for example, an area within 3 m from the vehicle outside the vehicle compartment. The area regarded as the vehicle periphery, in other words, the human detection range may be appropriately designed.

Note that the smart ECU 11 as the external world information acquisition unit F5 may be configured to activate an external camera and acquire an external world image, for example, when it detects that the user is approaching the vehicle Hv. The proximity of the user to the vehicle Hv may be detected based on, for example, the BLE communication device 13 receiving an advertisement signal from the mobile terminal 2 . Whether or not the mobile terminal 2 exists around the vehicle Hv may be determined based on the communication status between the BLE communication device 13 or the UWB communication device 12 and the mobile terminal 2 . According to this control mode, it is not necessary to keep the external camera active while the vehicle is parked, so it is possible to suppress dark current during parking.

The position estimation unit F6 is configured to execute processing for estimating the position of the mobile terminal 2 . The position estimation unit F6 roughly estimates the distance from each UWB communication device 12 to the mobile terminal 2 by causing each UWB communication device 12 to transmit and receive impulse signals to and from the mobile terminal 2 in a predetermined order. Then, based on distance information from each UWB communication device 12 to the mobile terminal 2, the position of the mobile terminal 2 (hereinafter, terminal position) is estimated.

The position estimating unit F6 estimates the terminal position, for example, in a state where the BLE communication device 13 and the mobile terminal 2 have established a communication connection. Hereinafter, for the sake of convenience, the process for estimating the terminal position when the vehicle Hv is parked will also be referred to as a parked position estimation process. The details of the parking position estimation process will be described separately later.

The parking position estimation process corresponds to the process of estimating the position of the mobile terminal 2 outside the vehicle (mainly around the vehicle). Outside the vehicle, the mobile terminal 2 is likely to be carried by the user. Therefore, estimating the position of the mobile terminal 2 corresponds to estimating the position of the user.

When the authentication of the mobile terminal 2 is successful, the vehicle control unit F7 performs vehicle control according to the position of the mobile terminal 2 (in other words, the user) and the state of the vehicle Hv in cooperation with the body ECU 16 and the like. This is the configuration to run. The state of the vehicle Hv is determined by the vehicle information acquisition unit F1. The position of the mobile terminal 2 is determined by the position estimator F6. For example, in a situation where the vehicle Hv is parked, the mobile terminal 2 exists outside the vehicle, and the user presses the door button 14, the vehicle control unit F7 locks the door in cooperation with the body ECU 16. Unlock the mechanism.

<Parking Position Estimation Processing>
Next, the parking position estimation process performed by the smart ECU 11 will be described with reference to the flowchart shown in FIG. The parking position estimation process is performed, for example, at a predetermined position estimation cycle while the communication connection between the BLE communication device 13 and the mobile terminal 2 is established. The state in which the communication connection between the BLE communication device 13 and the mobile terminal 2 is established corresponds to the state in which the authentication of the mobile terminal 2 is successful. A position estimation cycle is, for example, 200 milliseconds. Of course, the position estimation period may be 100 milliseconds or 300 milliseconds. In this embodiment, as an example, the position estimation process includes steps S101 to S109. Each step is mainly executed by the position estimation unit F6 in cooperation with the UWB communication device 12, the BLE communication device 13, the BLE communication processing unit F2, the UWB communication processing unit F3, and the like.

First, in step S101, in cooperation with the BLE communication processing unit F2, the BLE communication device 13 is caused to transmit a reflected response instruction signal. The reflected response instruction signal is a signal that instructs the mobile terminal 2 to operate in the reflected response mode. As a result, the mobile terminal 2 operates to reflexively return the impulse signal every time it receives the impulse signal transmitted from the in-vehicle system 1 .

Next, in step S102, an arbitrary UWB communication device 12 (that is, a healthy device) whose failure is not detected by the communication device diagnosis unit F4 is set as the host device. The host machine corresponds to the UWB communication device 12 that is responsible for measuring the round trip time among the plurality of UWB communication devices 12 . When the processing in step S102 is completed, step S103 is executed. In step S103, an impulse signal is transmitted from the host device. As a result, the propagation time Ta, which is the time until the mobile terminal 2 receives the radio signal transmitted by the host device in step S104, is acquired. At this time, the UWB communication device 12 other than the host device is controlled so as to stop its operation or not to return the impulse signal as a response signal even if it receives the impulse signal.

In the above steps S103 and S104, the propagation time measuring section 33 of the host machine measures the round trip time Tp as shown in FIG. 7 based on the instruction from the position estimating section F6. Then, the assumed value of the response processing time Tb at the mobile terminal 2 is subtracted from the round trip time Tp. The assumed value of the response processing time Tb may be registered in the flash memory 112 as a parameter for calculation. A value obtained by subtracting the response processing time Tb from the round trip time Tp corresponds to the round trip flight time. Therefore, the value obtained by dividing the value obtained by subtracting the response processing time Tb from the round trip time Tp by 2 corresponds to the one-way flight time of the radio signal. The propagation time measurement unit 33 provides the smart ECU 11 with a value obtained by dividing the value obtained by subtracting the response processing time Tb from the round trip time Tp by 2 as the propagation time Ta.

Note that the propagation time measurement unit 33 determines that the propagation time Ta is unknown when the impulse signal as the response signal is not received even after a predetermined response waiting time has elapsed since the impulse signal was transmitted. The data shown may be provided to the smart ECU 11 . The response waiting time may be set to a value, such as 33 nanoseconds, assuming that the user is sufficiently (eg, 10 m or longer) away from the vehicle Hv. Hereinafter, the UWB communication device 12 that can receive the impulse signal as the response signal from the mobile terminal 2 and, as a result, succeeds in measuring the propagation time Ta will also be referred to as a successful ranging device. This is because the propagation time Ta functions as information indicating the distance to the mobile terminal 2 .

In step S105, it is determined whether or not all healthy machines have measured the propagation time Ta. If all sound machines are caused to measure the propagation time Ta, an affirmative decision is made in step S105 and step S107 is executed. On the other hand, if there are still healthy machines that have not yet measured the propagation time Ta, a negative decision is made in step S105 and step S106 is executed.

In step S106, an arbitrary healthy machine whose propagation time Ta has not yet been measured is set as the host machine, and step S103 is executed. The order of operating as a host machine (in other words, the order of transmitting impulse signals) may be appropriately designed. For example, when all the UWB communication devices 12 are sound devices, the position estimation unit F6 sets the right side communication device 12A→left side communication device 12B→front side communication device 12C→rear side communication device 12D in this order as host devices. The propagation time Ta measured by each UWB communication device 12 indirectly indicates the distance to the mobile terminal 2 . That is, the propagation time Ta corresponds to distance information. Therefore, a series of processing from step S103 to step S106 corresponds to processing for collecting distance information from each UWB communication device 12 to the mobile terminal 2 by causing each UWB communication device 12 to transmit an impulse signal.

In step S107, it is determined whether or not three or more UWB communication devices 12 have acquired the propagation time as a result of the processing in steps S103 to S106. In other words, it is determined whether or not there are three or more devices that have succeeded in ranging. The case where three or more UWB communication devices 12 can acquire the propagation time means that the three or more UWB communication devices 12 are in a positional relationship that enables wireless communication with the mobile terminal 2 . It should be noted that cases in which the propagation time cannot be acquired in a certain UWB communication device 12 include cases in which communication with the portable terminal 2 accidentally fails, or cases in which the UWB communication device 12 is out of order. Also, the UWB communication device 12 that has been able to acquire the propagation time corresponds to the UWB communication device 12 that has been able to receive an impulse signal as a response from the mobile terminal 2, for example.

If the propagation time has been acquired by three or more UWB communication devices 12, an affirmative decision is made in step S107, and step S108 is executed. On the other hand, if the number of UWB communication devices 12 whose propagation times have been acquired is less than three, a negative determination is made in step S107 and step S109 is executed.

In step S108, the position of the mobile terminal 2 is calculated based on the installation position of each UWB communication device 12 whose propagation time can be acquired and distance information from each UWB communication device 12 to the mobile terminal 2. FIG. Communication device position data stored in the flash memory 112 may be used for the installation position of each UWB communication device 12 . The distance from each UWB communication device 12 to the mobile terminal 2 may be a value obtained by multiplying the propagation time Ta at each UWB communication device 12 by the speed of light. The position estimation based on the installation position of each UWB communication device 12 and the distance information from each UWB communication device 12 to the mobile terminal 2 can be performed using the principle of triangulation. As the position estimation method using the installation position of each UWB communication device 12 and the distance information to the mobile terminal 2, the least squares method, the Newton-Raphson method, the minimum mean square estimate (MMSE), etc. A variety of algorithms can be employed. Hereinafter, a positioning method for estimating the terminal position using the installation position of each UWB communication device 12 and distance information from each UWB communication device 12 to the mobile terminal 2 will be referred to as a normal method.

In step S109, in addition to the installation position of each UWB communication device 12 whose propagation time can be acquired and the propagation time observed by the UWB communication device 12, the human position information acquired by the external world information acquisition unit F5 to estimate the terminal position. For example, if the propagation time can be measured only by the front side communication device 12C and the rear side communication device 12D, depending on the size of the propagation time, as shown in FIG. (Hereafter, candidate regions) Ar1 and Ar2 can occur. Candidate areas Ar1 and Ar2 refer to areas within a predetermined ranging error from a point where the distance from the front communication device 12C is the front observation distance and the distance from the rear communication device 12D is the rear observation distance. . The front observation distance refers to the distance from the front communication device 12C to the mobile terminal 2, which is determined based on the propagation time observed by the front communication device 12C. The rear observation distance refers to the distance from the rear communication device 12D to the mobile terminal 2, which is determined based on the propagation time observed by the rear communication device 12D. A dashed line in FIG. 8 indicates a point that is the front observation distance from the front communication device 12C, and a two-dot chain line indicates a point that is the rear observation distance from the rear communication device 12D. The distance measurement error may be set to, for example, 15 cm, 30 cm, or 50 cm.

In such a case, when it is confirmed by the external world information acquisition unit F5 that the person Pd exists near the candidate area Ar1 on the right side of the vehicle and no one is present in the candidate area Ar2 on the left side of the vehicle, the mobile terminal 2 is determined to exist in the candidate area Ar1 on the right side of the vehicle. Whether or not the person Pd exists on the right side of the vehicle is specified by analyzing the captured image of the right camera 17A. Whether or not the person Pd exists on the left side of the vehicle is specified by analyzing the image captured by the left camera 17B. An asterisk “☆” in FIG. 8 conceptually indicates the estimated position of the mobile terminal 2 .

A set of points within a predetermined distance from the front side communication device 12C and the rear side communication device 12D can form a three-dimensional ring substantially parallel to the YZ plane. However, it can be expected that the range in which the mobile terminal 2 can exist in the height direction is within 2 m from the ground. At least in normal vehicle use, the possibility that the mobile terminal 2 exists on the roof or under the vehicle body can be ignored. Therefore, in the above example, the candidate area can be divided into two parts, one for the left side and the other for the right side of the vehicle.

As another example, when the propagation time is successfully measured only by the rear side communication device 12D, the point where a person is present in the area that is the rear observation distance from the rear side communication device 12D outside the vehicle is determined by the terminal. adopted as a position. For example, as shown in FIG. 9, based on the image captured by the side camera 17, it is detected that there is no one on the left and right sides of the vehicle at the rear observation distance from the rear communication device 12D, and the image captured by the rear camera 18 is detected. When the presence of a person is detected at a point within the rear observation distance from the rear communication device 12D based on the image, the position of the person captured by the rear camera 18 is adopted as the terminal position. When the position of a person is expressed as a three-dimensional model, the coordinates corresponding to the center/center of gravity of the model may be used as the position coordinates of the person. Hereinafter, a positioning method for estimating the terminal position by using human position information in addition to the installation position of the UWB communication device 12 and the distance information from the UWB communication device 12 to the mobile terminal 2 will be referred to as a combined human position method. . The human position combined method corresponds to a method of specifying the terminal position by complementarily using the distance information from each UWB communication device 12 to the portable terminal 2 and the human position information.

The terminal position calculated as described above is referred to by the vehicle control unit F7 and the like. For example, it is determined whether or not the terminal position calculated in step S107 corresponds to the operating area or the vehicle interior. If the terminal position falls within the operating area, the vehicle control unit F7 unlocks or locks the door based on the determination result.

<Effects of this embodiment>
Here, a comparative configuration will be introduced to explain the effects of this embodiment. In the comparison configuration, the terminal position is determined using only the propagation time of the radio signal to the mobile terminal 2 observed by the plurality of UWB communication devices 12 and the installation position of each UWB communication device 12 without using the captured image of the external camera. is a configuration for estimating In such a comparison configuration, if the number of UWB communication devices 12 that can communicate with the mobile terminal 2 is less than three, the position of the mobile terminal 2 becomes indefinite (cannot be specified). When the terminal position becomes indefinite, it cannot be determined whether or not the portable terminal 2 is present in the operation area, and the doors of the vehicle Hv are not unlocked. In other words, the user cannot use the functions of the PEPS system, which reduces convenience.

In contrast, according to the above-described embodiment, when the number of UWB communication devices 12 that can communicate with the mobile terminal 2 is less than three, it is assumed that the mobile terminal 2 is carried by the user outside the vehicle. , the terminal position is specified based on the image captured by the external camera. According to such a configuration, even if the number of UWB communication devices 12 that can receive the response signal from the mobile terminal 2 is less than three due to a failure of the UWB communication device 12 or an accidental communication error, the terminal position can be determined. can be estimated. The number of UWB communication devices 12 that can communicate with the mobile terminal 2 corresponds to the number of UWB communication devices 12 that can be used to estimate the position of the mobile terminal 2 . The above configuration corresponds to switching between whether or not to use the human location information in the process of estimating the location of the portable terminal 2 outside the vehicle, depending on the number of devices that have succeeded in ranging.

In addition, in this embodiment, each UWB communication device 12 is mounted in a place with good visibility both inside and outside the vehicle, such as the ceiling or the upper area of a pillar. In general, radio waves of 1 GHz or higher (hereinafter referred to as high-frequency radio waves), such as impulse signals used in UWB communication, are likely to be reflected by metal. Also, high-frequency radio waves are easily absorbed by the human body. Therefore, if there is an object that reflects/absorbs radio waves, such as a metal object or a human body (hereinafter referred to as a shield) in the direction of propagation of high-frequency radio waves, the radio wave propagates around (that is, diffracts) around the shield, or is shielded. reflected by objects.

When the mobile terminal 2 and the UWB communication device 12 communicate by diffraction or reflection (that is, indirectly), an error may occur in the estimated distance from the UWB communication device 12 to the mobile terminal 2 . In particular, when the mobile terminal 2 is out of the line of sight of the UWB communication device 12 and the UWB communication device 12 and the mobile terminal 2 communicate with each other by reflection from a structure such as another vehicle. may contain even more errors.

In order to solve such a problem, in this embodiment, each UWB communication device 12 is mounted in a place with good visibility both inside and outside the vehicle. According to such a mounting mode, it is possible to reduce the possibility that the mode of communication with the mobile terminal 2 will be indirect communication. In other words, it is possible to reduce the possibility that the distance from each UWB communication device 12 to the mobile terminal 2 includes an error due to diffraction or reflection of radio signals. As a result, it becomes possible to estimate the terminal position with higher accuracy.

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 in the technical scope of the present disclosure. Various modifications can be made without departing from the scope of the present invention. For example, the various modified examples below can be implemented in combination as appropriate within a range that does not cause technical contradiction. It should be noted that members having the same functions as those of the members described in the above-described embodiments are denoted by the same reference numerals, and description thereof will be omitted. Also, when only part of the configuration is mentioned, the configuration of the previously described embodiments can be applied to the other portions.

[Modification 1]
In the above-described embodiment, a mode of estimating the terminal position by using human position information together when the number of successful ranging devices is less than 3 has been disclosed. is not limited to For example, the position estimating unit F6 may be configured to estimate the terminal position by using the human position information together even when the number of devices that have succeeded in ranging is three or more. An operation example of the position estimating unit F6 based on the technical concept will be described below as a modified example 1 with reference to FIG.

The flowchart shown in FIG. 10 is an alternative process of step S108. The position estimating unit F6 of this modified example, when the number of successful distance measurement devices is three or more, determines the installation position of each UWB communication device 12 that can acquire the propagation time, The position of the mobile terminal 2 is calculated based on the distance information to the terminal 2 (step S201).

Next, the human position information is acquired from the external world information acquisition unit F5, and it is determined whether or not a person exists at the terminal position estimated in step S201 (hereinafter referred to as the estimated position) (step S202). If a person exists at the estimated position (step S202 YES), the estimated position is adopted as the terminal (step S203). On the other hand, if there is no person at the estimated position (step S202 NO), based on the person position information provided from the external world information acquisition unit F5, it is determined whether or not there is a person within a predetermined correction allowable distance from the estimated position. (step S204). The correction permissible distance is a parameter that functions as a threshold value for performing processing for correcting the terminal position to the position of a person existing near the estimated position in step S205, which will be described later. The correction allowable distance is set to a value corresponding to the allowable value of the positioning error of the normal positioning method. The allowable correction distance may be set to, for example, 30 cm or 50 cm.

If a person exists within the correction allowable distance from the estimated position (step S204 YES), the position of that person (a person existing within the correction allowable distance from the estimated position) is adopted as the terminal position (step S205). That is, after correcting the estimated position to the human position, it is adopted as the terminal position. On the other hand, if there is no person within the correction allowable distance from the estimated position (step S204 NO), the terminal position is determined to be indefinite (step S206).

According to the above control mode, even if the propagation distance observed by some of the UWB communication devices 12 includes an error due to the influence of reflection or the like, and an error of about several tens of centimeters occurs in the positioning result, The terminal position can be corrected to the correct position. That is, it is possible to improve the estimation accuracy of the terminal position.

[Modification 2]
The smart ECU 11 daily learns the appearance features of the user from the captured images acquired by the external/vehicle interior cameras, and uses the appearance features to detect a person (hereinafter referred to as a person to be detected) imaged by the external camera. It may be configured to identify whether or not. A person to be detected corresponds to a person existing around the vehicle Hv. A detected person who is not a user is, for example, a passerby.

As the appearance features of the user, images of shoes, clothes, bags, watches, accessories, etc. that the user has worn, facial images, standing (degree of opening of the legs), height, physique, etc. can be adopted. The appearance features of the user may be collected using a camera mounted on the vehicle when the vehicle is entered or when the engine is started. A storage device (hereinafter referred to as appearance feature storage unit M1) that stores data indicating appearance features of the user is implemented using the flash memory 112 of the smart ECU 11 . Note that the appearance feature storage unit M1 may be provided in an external server.

When detecting the presence of a person around the vehicle Hv based on the captured image of the external world camera, the external world information acquisition unit F5 of this modification detects that the detected person It is determined whether or not. For example, when a detected person wears shoes that are highly similar to shoes worn by the user before, the detected person is determined to be a person having the appearance characteristics of the user. A person that includes the user's appearance characteristics corresponds to a possible person of the user. The external world information acquiring unit F5 provides the position estimating unit F6 with human position information including whether the detected person has the appearance characteristics of the user. For the sake of convenience, the function of the external world information acquisition unit F5 that determines whether or not the detected person has the appearance characteristics of the user will be referred to as a user likelihood determination unit F51. The user likelihood determination unit F51 corresponds to a configuration that evaluates the possibility that the person to be detected is the user. FIG. 11 is a functional block diagram schematically showing the configuration of the external world information acquisition section F5 in this modified example.

The position estimating unit F6 of this modification, for example, when estimating the terminal position by using the human position information together, such as in steps S109 and S205, is determined by the external world information acquiring unit F5 to have the appearance features of the user. Use only the location information of the person who is Note that the user likelihood determination unit F51 may be configured to score the possibility that the detected person is the user (hereinafter referred to as user likelihood) using multiple types of appearance features and output the scores. In that case, the position estimation unit F6 is configured to use only the position information of a person whose user likelihood is above a certain threshold when estimating the terminal position by using the human position information together. is preferred.

According to the above configuration, it is possible to reduce the possibility of estimating the terminal position using the position information of a person other than the user, such as a passerby. In other words, it is possible to further reduce the possibility of erroneously determining the terminal position. In addition, even if there are a plurality of persons around the vehicle Hv, the persons to be used for estimating the terminal position can be narrowed down, and the fear of the terminal position becoming uncertain can be reduced.

[Modification 3]
In a multipath environment, the estimated distance from the UWB communication device 12 to the mobile terminal 2 tends to include errors. For example, as shown in FIG. 12, when the mobile terminal 2 cannot directly receive the signal from the UWB communication device 12 and is located at a position where the signal is received by reflection from a reflecting object 4 such as an adjacent vehicle/wall, , a delay on the order of several nanoseconds can occur as a propagation time. As a result, an error occurs in the estimated distance from the UWB communication device 12 to the mobile terminal 2, degrading the estimation accuracy of the terminal position.

In view of such circumstances, it is preferable that the position estimating unit F6 is configured to estimate the terminal position using the human position information together when the surroundings of the vehicle Hv are in a multipath environment. . An example of the configuration of the smart ECU 11 based on the technical idea will be disclosed as Modified Example 3 below. The multipath environment here refers to an environment in which other vehicles, walls, pillars, and other reflective objects exist within a predetermined distance (for example, 1 m) from the vehicle Hv.

As shown in FIG. 13, the external world information acquisition unit F5 in this modification includes a communication environment determination unit F52 that determines whether or not the vehicle Hv is in a multipath environment. The communication environment determination unit F52 determines whether or not there is a multipath environment around the vehicle by analyzing the image captured by the external camera. More specifically, the communication environment determination unit F52 analyzes the images captured by the side camera 17 and the rear camera 18, and determines whether or not there is another vehicle, wall, pillar, or other reflecting object 4 within 1 m from the vehicle Hv. judge. When the reflecting object 4 exists within 1 m from the vehicle Hv, it is determined that the surroundings of the vehicle Hv are in a multipath environment. The determination of whether or not the vehicle surroundings are in a multipath environment is performed when the vehicle Hv is parked or when the approach of the user is detected (in other words, when the communication connection with the mobile terminal 2 is established). I wish I could.

When the communication environment determination unit F52 determines that the host vehicle is in a multipath environment, the position estimation unit F6 of this modification performs the In addition to the distance information to the portable terminal 2, the terminal position is determined by using the human position information. According to such a configuration, even when the vehicle Hv is parked in a multipath environment, it is possible to reduce the possibility of erroneously determining the terminal position.

It should be noted that the method of determining whether or not the surroundings of the vehicle are in a multipath environment can be changed as appropriate. For example, the communication environment determination unit F52 may determine whether or not the mobile terminal 2 is in a multipath environment based on the signal reception status from the mobile terminal 2 . For example, when the SN ratio of the BLE signal from the mobile terminal 2 is less than a predetermined threshold, it may be determined that the surroundings of the own vehicle are in a multipath environment. Further, the communication environment determination unit F52 may be configured to determine whether or not the own vehicle is in a multipath environment based on the result of the parking position estimation process. For example, when a negative determination is made in step S204, it may be determined that the surroundings of the vehicle are in a multipath environment.

[Modification 4]
The position estimating unit F6 uses human position information together with the installation position of each UWB communication device 12 and the distance information to the mobile terminal 2 on the condition that there is a UWB communication device 12 having a problem. It may be configured to determine the terminal location. According to such a configuration, it is possible to reduce the possibility that the positioning accuracy is degraded or the terminal position cannot be estimated due to the presence of the malfunctioning aircraft. Whether or not there is a UWB communication device 12 having a problem may be determined by the communication device diagnosis unit F4. In the above configuration, whether or not to use the human location information for estimating the terminal position outside the vehicle is determined according to the number of UWB communication devices 12 determined to be defective by the communication device diagnosis unit F4. It corresponds to the switching configuration.

Further, as another aspect, the position estimating unit F6, on the condition that the number of healthy devices is less than 3, adds human position It may be configured to determine the terminal position using the information in combination. In addition, the conditions for the position estimation unit F6 to use the human position information for estimating the terminal position can be implemented by appropriately combining them. For example, it is configured to switch whether or not to use human location information for estimating the terminal position in consideration of a plurality of factors such as the number of healthy devices, the number of successful devices for distance measurement, and the surrounding environment of the vehicle Hv. It's okay to be there. In addition, the position estimating unit F6 may be configured to always use the human position information together in the parking position estimating process. In addition, when the accuracy of the human location information deteriorates, such as during rainy weather or at night, the configuration may be such that the human location information is not used together. That is, even if the position estimation unit F6 is configured to switch whether or not to use the human position information for the process of estimating the position of the mobile terminal 2 outside the vehicle, depending on the accuracy/reliability of the human position information. good.

[Modification 5]
In the above, when the predetermined condition is satisfied in the parking position estimation process, the aspect of determining the terminal position using the human position information together has been disclosed. In other words, on the condition that the vehicle is parked, the terminal position outside the vehicle is estimated based on the distance information generated by each UWB communication device 12, the installation position of each UWB communication device 12, and the human position information. disclosed a configuration for However, the smart ECU 11 may be configured to estimate the terminal position using the human position information together, even when the vehicle is not parked. The smart ECU 11 may be configured to estimate the terminal position by using the human position information together on condition that the vehicle is in an empty state.

For example, the smart ECU 11 may be configured to estimate the terminal position using the human position information also when the vehicle Hv is automatically traveling unmanned to the user outside the vehicle. Automatic driving to a user who is outside the vehicle is performed by an ECU (a so-called automatic driving ECU) that automatically drives the vehicle Hv, for example, using rough location information of the user identified by GNSS or the like. Good luck. The rough location information of the user determined by GNSS or the like may be provided from the mobile terminal 2 to the vehicle Hv via the wide area wireless communication network. After the vehicle Hv approaches the vicinity of the user based on the user's position information determined by GNSS, the smart ECU 11 identifies the detailed position of the user by the same method as the parking position estimation process. An ECU that automatically drives the vehicle Hv (a so-called automatic driving ECU) uses the detailed location information of the user identified by the smart ECU 11 to stop the vehicle so that the front passenger seat/driver seat is positioned in front of the user. According to such a configuration, the technical concept of the present disclosure can be applied not only to scenes in which the user approaches the vehicle Hv, but also to scenes in which the vehicle Hv approaches the user.

[Modification 6]
In the above-described embodiment, a mode in which the left and right side cameras 17 and the rear camera 18 are used as the external camera is disclosed, but the configuration that can be adopted as the external camera is not limited to this. For example, the external camera may be a wide-angle camera attached to the ceiling of the vehicle interior so as to capture images of the interior and exterior of the vehicle. The external camera may be configured to capture at least part of the exterior of the vehicle, and may include the interior of the vehicle in its imaging range. It is preferable that the camera installed inside the vehicle as an external camera is configured to be capable of 360-degree imaging. A wide-angle camera here refers to a camera whose imaging angle of view is set to 120 degrees or more. The external camera may be implemented using multiple wide-angle cameras.

In the above description, a configuration has been disclosed in which an external camera is employed as a sensor (hereinafter referred to as an external sensor) that outputs information indicating the position and type of an object in the vicinity of the vehicle Hv. do not have. The external sensor may be implemented by, for example, a laser radar, a millimeter wave radar, an ultrasonic sensor, an infrared sensor, an optical sensor, or a combination thereof. Any sensor that outputs data indicating the location of a person may be used as the external sensor. Various human sensors can be used as external sensors. When a laser radar, millimeter-wave radar, ultrasonic sensor, or the like is used as an external sensor, whether or not a detected object corresponds to a human is identified using a predetermined feature amount such as reflection intensity or outline shape. Good luck. Various algorithms can be employed as the object detection and type identification method using millimeter wave radar or the like. It should be noted that the detection range of each external sensor may be appropriately designed, but is preferably configured to include at least the operation area.

[Modification 7]
The manner in which the UWB communication devices 12 are installed (specifically, the installation positions and the number of installations) is not limited to the manner described above. For example, the right side communication device 12A and the left side communication device 12B may be arranged in the A pillar, the C pillar, the vicinity of the front wheel, the vicinity of the front corner, and the side mirror. The right side communication device 12A and the left side communication device 12B may be attached to the side portion of the vehicle Hv. Also, the front communication device 12C may be installed in the central portion of the instrument panel in the vehicle width direction, the front portion of the driver's seat, the center console, or the like. The rear side communication device 12D may be embedded in the center portion of the rear seat in the vehicle width direction. The vicinity of a certain member refers to a region within, for example, 30 cm from the member.

Other possible mounting positions for the UWB communication device 12 include the B-pillar (center pillar), the instrument panel, the center console, the overhead console, the vicinity of the rearview mirror, the upper end of the rear glass, and the like. The UWB communication device 12 may be arranged near the boundary between the side surface and the roof of the vehicle Hv (hereinafter referred to as the upper end of the side surface). Such a configuration corresponds to a configuration in which the UWB communication device 12 is provided in the frame portion positioned above the side window.

If the body of the vehicle Hv is made of a material (for example, resin) that transmits radio waves, the mounting position of the UWB communication device 12 may be the outer door handle for the driver's seat and passenger's seat, or the driver's seat. Also, it is possible to adopt the side sill near the inner door handle for the front passenger seat. The in-vehicle system 1 may include a UWB communication device 12 arranged on the outer surface of the vehicle Hv. Here, the outer surface portion is a body portion of the vehicle Hv that is in contact with the vehicle exterior space, and includes the side surface portion, rear surface portion, and front surface portion of the vehicle Hv. In addition, the in-vehicle system 1 may include a UWB communicator 12 mounted inside the trunk or a UWB communicator 12 mounted near the trunk door handle.

Also, the number of UWB communication devices 12 connected to the smart ECU 11 may be three, five, or six or more. For example, the UWB communicators 12 connected to the smart ECU 11 may be only three, the right communicator 12A, the left communicator 12B, and the rear communicator 12D. It is sufficient that the smart ECU 11 is connected to at least three UWB communication devices 12 .

[Modification 8]
In the above-described embodiment, the mode of using the one-way propagation time as the distance information is disclosed, but the distance information may be the round-trip time Tp. Further, the distance information may be data that directly indicates the distance to the mobile terminal 2 by multiplying the propagation time by the speed of light. In addition, although the aspect which calculates a propagation time from the round-trip time Tp was disclosed in embodiment mentioned above, it is not restricted to this. For example, when each UWB communication device 12 and the mobile terminal 2 are completely synchronized, each UWB communication device 12 can detect the time when the mobile terminal 2 should have transmitted the impulse signal and the impulse signal from the mobile terminal 2. The propagation time may be calculated from the difference from the time when the is received. The time at which the mobile terminal 2 should have transmitted the impulse signal can be calculated, for example, by prescribing the timing at which the mobile terminal 2 transmits the impulse signal.

[Modification 9]
A signal transmitted and received for estimating the propagation time (and thus the distance) may be a pulse sequence signal having a constant length as shown in FIG. 14 instead of a single impulse signal. The pulse sequence signal preferably contains source information and destination information. When the pulse sequence signal includes source information and destination information, the UWB communication device 12 other than the host device is prevented from transmitting a response signal without restricting the operation of the UWB communication device 12 other than the host device. can. In this modified example, the propagation time Ta may be calculated from the round-trip time Tp using an assumed value of the length of the pulse sequence signal (hereinafter referred to as signal length) Tc. That is, the propagation time Ta can be calculated as Ta=(Tp-Tb-Tc×2)/2.

[Modification 10]
The arrangement of functions provided in the smart ECU 11 and the UWB communication device 12 can be changed as appropriate. For example, the UWB communication device 12 may be provided with part of the functions of the smart ECU 11 (for example, the communication device diagnosis unit F4). Also, part of the functions of the UWB communication device 12 (for example, the propagation time measurement unit 33) may be included in the smart ECU 11. FIG. An ECU other than the smart ECU 11 may have the function of generating the human position information.

[Modification 11]
In the above-described embodiment, an impulse signal of UWB communication is used to measure the distance from the UWB communication device 12 as a reference station to the mobile terminal 2, but the present invention is not limited to this. For example, the in-vehicle communication device that estimates the distance to the mobile terminal 2 may be a communication device that performs wireless communication conforming to short-range wireless communication standards such as Bluetooth, Wi-Fi, and ZigBee. That is, the vehicle-mounted communication device as a reference station mounted in the vehicle Hv acquires the distance information to the mobile terminal 2 using a wireless signal conforming to short-range wireless communication standards such as Bluetooth, Wi-Fi, and ZigBee. It may be configured as follows. It is preferable that the in-vehicle communication device and the mobile terminal 2 are configured to measure the distance using a radio signal of 1 GHz or higher.

Moreover, although the aspect which estimates the distance from a vehicle-mounted communication apparatus to the portable terminal 2 using the propagation time of a radio signal was disclosed above, it is not restricted to this. The distance from the in-vehicle communication device to the mobile terminal 2 may be specified based on the received strength of the radio signal. For example, each in-vehicle communication device may be configured to estimate the distance based on the received strength of the signal transmitted from the mobile terminal 2 . The received intensity also corresponds to distance information.

<Additional notes>
The controller and techniques described in this disclosure may be implemented by a special purpose computer comprising a processor programmed to perform one or more functions embodied by a computer program. The apparatus and techniques described in this disclosure may also be implemented by dedicated hardware logic circuitry. Additionally, the apparatus and techniques described in this disclosure may be implemented by one or more special purpose computers configured in combination with a processor executing a computer program and one or more hardware logic circuits. The computer program may also be stored as computer-executable instructions on a computer-readable non-transitional tangible recording medium.

In addition, a control part here is smart ECU11, for example. Further, the mobile-side control unit 23 can also be included in the above control unit. The means and/or functions provided by the smart ECU 11 can be provided by software recorded in a physical memory device and a computer executing it, software only, hardware only, or a combination thereof. Some or all of the functions provided by the smart ECU 11 may be implemented as hardware. Implementation of a function as hardware includes implementation using one or more ICs. Although smart ECU11 shall be implement|achieved using CPU in embodiment mentioned above, the structure of smart ECU11 is not limited to this. The smart ECU 11 may be implemented using an MPU (Micro Processor Unit), a GPU (Graphics Processing Unit), or a data flow processor (DFP) instead of the CPU 111 . Also, the smart ECU 11 may be implemented by combining multiple types of processors such as the CPU 111, MPU, GPU, and DFP. Furthermore, some of the functions to be provided by the smart ECU 11 may be implemented using FPGAs (Field-Programmable Gate Arrays), ASICs (Application Specific Integrated Circuits), and the like. The same applies to the mobile-side control unit 23 .

1 in-vehicle system, 2 mobile terminal, 11 smart ECU, 12/12A-12D UWB communication device (in-vehicle communication device), 13 BLE communication device (different method communication device), 17 side camera (external sensor), 18 rear camera (external sensor), 21 UWB communication unit, 22 BLE communication unit, 23 mobile-side control unit, 31 transmission unit, 32 reception unit, 33 propagation time measurement unit, F1 vehicle information acquisition unit, F2 BLE communication processing unit (authentication processing unit), F3 UWB communication processing unit, F4 communication device diagnosis unit, F5 external world information acquisition unit (person detection unit), F6 position estimation unit, F51 user likelihood determination unit, F52 communication environment determination unit

Claims (8)

A vehicle position determining a position of a mobile terminal carried by a user of the vehicle by wirelessly communicating with a mobile terminal carried by a user of the vehicle by a plurality of in-vehicle communication devices (12) arranged at different positions in the vehicle. An estimation system,
each of the in-vehicle communication devices is configured to generate distance information that directly or indirectly indicates a distance from the in-vehicle communication device to the mobile terminal by receiving a signal from the mobile terminal;
a position estimation unit (F6) for estimating the position of the mobile terminal based on the distance information generated by each vehicle-mounted communication device and the installation position of each vehicle-mounted communication device;
A person detection unit (F5) that detects the position of a person existing in the predetermined range by analyzing the captured image of the camera that includes the predetermined range outside the vehicle as the imaging range;
Vehicle information for obtaining information indicating the state of the vehicle from a sensor or an electronic control device mounted on the vehicle and determining whether the vehicle is in an empty state based on the information indicating the state of the vehicle. an acquisition unit (F1),
The position estimating unit, when the vehicle information acquiring unit determines that the vehicle is in an empty state, the distance information generated by each of the vehicle-mounted communication devices, the installation position of each of the vehicle-mounted communication devices, A position estimation system for a vehicle configured to estimate the position of the portable terminal outside the vehicle on the basis of human position information , which is the position information of the person detected by the person detection unit. A vehicle position determining a position of a mobile terminal carried by a user of the vehicle by wirelessly communicating with a mobile terminal carried by a user of the vehicle by a plurality of in-vehicle communication devices (12) arranged at different positions in the vehicle. An estimation system,
each of the in-vehicle communication devices is configured to generate distance information that directly or indirectly indicates a distance from the in-vehicle communication device to the mobile terminal by receiving a signal from the mobile terminal;
a position estimation unit (F6) for estimating the position of the mobile terminal based on the distance information generated by each vehicle-mounted communication device and the installation position of each vehicle-mounted communication device;
Based on the output signal of a laser radar, a millimeter wave radar, an ultrasonic sensor, an infrared sensor, or an optical sensor installed in the vehicle so that the detection range includes a predetermined range outside the vehicle, a person existing in the predetermined range A person detection unit (F5) that detects the position of
Vehicle information acquisition for acquiring information indicating the state of the vehicle from a sensor or an electronic control device mounted on the vehicle and determining whether the vehicle is in an empty state based on the information indicating the state of the vehicle A part (F1) and
The position estimating unit, when the vehicle information acquiring unit determines that the vehicle is in an empty state, the distance information generated by each of the vehicle-mounted communication devices, the installation position of each of the vehicle-mounted communication devices, A position estimation system for a vehicle configured to estimate the position of the portable terminal outside the vehicle on the basis of human position information , which is the position information of the person detected by the person detection unit. The vehicle position estimation system according to claim 1 or 2 ,
comprising a communication device diagnostic unit (F4) for determining whether or not there is a problem with the in-vehicle communication device,
The position estimating unit incorporates the human position information into the process of estimating the position of the portable terminal outside the vehicle in accordance with the number of the in-vehicle communication devices determined by the communication device diagnosis unit to be malfunctioning. A vehicle position estimation system that is configured to be used or not. The vehicle position estimation system according to any one of claims 1 to 3 ,
comprising a communication device diagnostic unit (F4) for determining whether or not there is a problem with the in-vehicle communication device,
The position estimation unit
When the vehicle information acquisition unit determines that the vehicle is in an empty state and the number of the on-vehicle communication devices determined to be operating normally by the communication device diagnosis unit is less than three , in addition to the distance information generated by each of the vehicle-mounted communication devices and the installation position of each of the vehicle-mounted communication devices, the human location information is also used to estimate the position of the mobile terminal outside the vehicle. A configured vehicle localization system. The vehicle position estimation system according to any one of claims 1 to 4,
When the number of successful distance measurement devices that are the in-vehicle communication devices that have successfully generated the distance information is less than three, the position estimating unit generates the distance information generated by each of the in-vehicle communication devices and each of the in-vehicle communication a position estimation system for a vehicle configured to estimate the position of the portable terminal outside the vehicle by using the installation position of the mobile terminal and the human position information. A vehicle position estimation system according to claim 5,
When the number of successful ranging devices is less than three, the position estimating unit determines the position of the mobile terminal based on the distance information generated by the successful ranging devices and the installation positions of the successful ranging devices. In addition to calculating the possible candidate regions,
A vehicle position estimation system configured to estimate the position of the portable terminal based on the calculated candidate area and the person position information. A vehicle position estimation system according to any one of claims 1 to 6,
A communication environment determination unit (F52) that determines whether the vehicle is in a multipath environment,
The position estimating unit, on the condition that the vehicle is determined to be in a multipath environment by the communication environment determination unit, and an installation position of the vehicle, and the human position information is also used to estimate the position of the portable terminal outside the vehicle. The vehicle position estimation system according to any one of claims 1 to 7,
The in-vehicle communication device performs wireless communication with the mobile terminal in a first communication method using an ultra-wideband impulse signal,
a communication device (13) configured to be capable of wirelessly communicating with the mobile terminal by a second communication method different from the first communication method ;
An authentication processing unit (F2) that authenticates the mobile terminal by transmitting and receiving predetermined data to and from the mobile terminal via the communication device that performs wireless communication in the second communication method ,
When the vehicle information acquisition unit determines that the vehicle is empty and the authentication processing unit has successfully authenticated the mobile terminal, the position estimation unit determines whether the mobile terminal is located outside the vehicle. A vehicle location estimation system configured to use the person location information for location estimation processing.

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