JP2020122726A - Position estimation system for vehicle - Google Patents

Abstract

To provide a position estimation system for a vehicle capable of reducing possibility that the estimation of a terminal position becomes impossible, and achieving improvement in estimation accuracy of the terminal position without additionally providing an on-vehicle communication machine as a reference station.SOLUTION: A smart ECU is connected to: a plurality of UWB communication machines; right and left side cameras; and a rear camera. Each UWB communication machine is configured to transmit/receive an impulse signal to/from a portable terminal to generate distance information to the portable terminal, and to provide it to the smart ECU. The smart ECU is configured to acquire the distance information from each UWB communication machine to the portable terminal, and to analyze a pickup image of an external camera such as a side camera to specify a position of a person existing in the neighborhood of a vehicle. The smart ECU is configured to, when the number of the UWB communication machines which have succeeded in the generation of the distance information to the portable terminal is less than three, estimate the position of the portable terminal by using the distance information from each UWB communication machine to the portable terminal and the position information of the person existing in the neighborhood of the vehicle in a complementary fashion.SELECTED DRAWING: Figure 6

Description

The present disclosure relates to a technique of estimating a relative position of a communication device (hereinafter, a mobile terminal) carried by a user with respect to a vehicle by using radio waves.

Conventionally, three or more base stations whose positions are already known wirelessly communicate with mobile terminals such as smartphones to specify the distance from each base station to the mobile terminal, and estimate the position of the mobile terminal based on the distance information from each base station. A method has been proposed (for example, Patent Document 1). As a method for specifying the distance from the reference station to the mobile terminal, a method using a radio wave propagation time (in other words, a flight time), a method using a received signal strength (RSS), and the like have been proposed. Further, as a positioning method using the propagation time of radio waves (hereinafter, propagation time method), there are TOA (Time Of Arrival) method, 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 relative position with respect to the vehicle, but is a specific point (for example, the center of the earth) such as a geodetic coordinate system using latitude, longitude, and altitude, or an ECEF (Earth Centered, Earth Fixed) coordinate system. ) Is the origin and indicates the position coordinates in a three-dimensional coordinate system that rotates with the earth. Generally, in GNSS, the greater the number of positioning satellites captured by the mobile terminal, the higher the positioning accuracy. In particular, when a mobile terminal exists in an environment where there are many objects such as buildings that reflect wireless signals (a so-called multipath environment), the effect of improving positioning accuracy due to an increase in the number of captured satellites can be further expected.

JP, 2011-80946, A

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

For example, if one or a plurality of vehicle-mounted communication devices breaks down and the number of vehicle-mounted communication devices that can operate normally becomes less than three, the terminal position cannot be specified. Even if three or more in-vehicle communication devices are normal, there may be a situation where there are less than three in-vehicle communication devices that can communicate with the mobile terminal, depending on the position of the mobile terminal. For example, when the mobile terminal is located outside the line-of-sight of some of the vehicle-mounted communication devices, an event may occur in which some of the vehicle-mounted communication devices cannot communicate with the mobile terminal. Even in such a case, the terminal position cannot be specified.

For such a problem, if the number of in-vehicle communication devices is increased, the possibility that the terminal position cannot be estimated can be reduced. However, the addition of in-vehicle communication devices causes an increase in cost. In addition, since the vehicle mounting space is limited, there is an upper limit to the number of in-vehicle communication devices that can be installed. For example, depending on the model of the vehicle, it is possible that only three in-vehicle communication devices can be installed.

Further, the distance information (for example, the propagation time) specified by the communication between each vehicle-mounted communication device and the mobile terminal includes an error. Therefore, the estimation accuracy is not necessarily high even if there are three or more vehicle-mounted communication devices with which the mobile terminal can communicate. In particular, there are other vehicles and walls around the parked vehicle, and there is a high possibility of a multipath environment. When the vehicle is in a multipath environment, the error included in the distance information specified by the communication between each onboard communication device and the mobile terminal may increase. According to the same idea as GNSS with respect to such a problem, it can be expected that the risk of erroneous estimation of the terminal position can be reduced by increasing the number of installed in-vehicle communication devices. However, as described above, there are problems such as an increase in cost when adding onboard communication devices.

The present disclosure has been made based on this situation, and an object thereof is to fear that the terminal position cannot be estimated or to incorrectly estimate the terminal position without adding an in-vehicle communication device as a reference station. An object of the present invention is to provide a vehicle position estimation system that can reduce the risk of the occurrence of

As an example of a vehicle position estimation system for achieving the object, a plurality of vehicle-mounted communication devices (12) arranged at different positions in a vehicle wirelessly communicate with a mobile terminal carried by a user of the vehicle. A vehicle position estimation system for determining the position of a mobile terminal with respect to a vehicle, wherein each in-vehicle communication device directly or indirectly determines the distance from the in-vehicle communication device by receiving a signal from the mobile terminal. The position estimation unit (F6) that is configured to generate the distance information indicated in FIG. 6 and estimates the position of the mobile terminal based on the distance information generated by each in-vehicle communication device and the installation position of each in-vehicle communication device. ) And a person detection unit (F5) for detecting the position of a person existing in a predetermined range by using the detection result of the external sensor that outputs the data indicating the position and type of the object within the predetermined range outside the vehicle. , And the position estimation unit, provided that the vehicle is in an empty state, the distance information generated by each in-vehicle communication device, the installation position of each in-vehicle communication device, the position information of the person detected by the person detection unit It is configured to estimate the position of the mobile terminal outside the vehicle interior based on the person position information.

The case where the user exists in the vicinity of the vehicle in the empty state is, for example, the case where the user is about to board the parked vehicle or the case where the parked vehicle has automatically traveled up to the user. That is, the scene in which the user exists near the vehicle in an empty state corresponds to the scene in which the user is about to board the vehicle. As such, in a scene in which the user is about to board an empty vehicle, the mobile terminal is expected to be carried by the user. That is, the position information of the person existing around the vehicle (hereinafter, the person position information) can function as information indicating the position of the mobile terminal.

The position estimation unit having the above configuration is created based on such an idea, and on condition that the vehicle is parked, the distance information from each in-vehicle communication device to the mobile terminal and the vehicle surroundings. The position of the mobile terminal is estimated by complementarily using the position information of the person present in the. According to the configuration in which the person position information is also used for the position estimation of the mobile terminal, the terminal position is erroneously estimated even when the number of in-vehicle communication devices that can observe the distance to the mobile terminal is relatively small. It is possible to reduce the possibility that the terminal position cannot be estimated. That is, according to the above configuration, it is possible to reduce the possibility that the terminal position cannot be estimated or the terminal position is erroneously estimated without adding an in-vehicle communication device as a reference station.

It should be noted that the reference numerals in parentheses in the claims indicate the correspondence with the specific means described in the embodiments described later as one aspect, and limit the technical scope of the present disclosure. is not.

It is a figure showing the whole electronic key system composition for vehicles. 3 is a functional block diagram for explaining the configuration of the mobile terminal 2. FIG. It is a functional block diagram for explaining the composition of vehicle-mounted system 1. It is a figure for demonstrating an example of the attachment position of UWB communication machine 12 and an external camera. 3 is a block diagram showing configurations of a smart ECU 11 and a UWB communication device 12. FIG. It is a flowchart about a parking position estimation process. It is a figure which shows the relationship between propagation time and round trip time. It is a figure for demonstrating the position estimation method which used the external camera together. It is a figure for demonstrating the position estimation method which used the external camera together. 9 is a flowchart for explaining the operation of the position estimation unit F6 of Modification 1. FIG. 11 is a functional block diagram for explaining a configuration of a smart ECU 11 of Modification 2. It is a figure for demonstrating the subject when the vehicle Hv exists in a multipath environment. FIG. 11 is a functional block diagram for explaining a configuration of a smart ECU 11 of Modification 3; FIG. 13 is a diagram for explaining the operation of the vehicle electronic key system in Modification 9.

[Embodiment]
Hereinafter, as an example of the 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. As shown in FIG. 1, an electronic key system for a vehicle according to the present disclosure includes an in-vehicle system 1 mounted on a vehicle Hv and a mobile terminal 2 which is a communication terminal carried by a user of the vehicle Hv. There is. The vehicle Hv equipped with the in-vehicle system 1 will be also referred to as a host vehicle hereinafter.

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

In addition, as a frequency band (hereinafter, UWB band) that can be used for UWB communication, there are 3.2 GHz to 10.6 GHz, 3.4 GHz to 4.8 GHz, 7.25 GHz to 10.6 GHz, 22 GHz to 29 GHz and the like. Of these various frequency bands, the impulse signal in this embodiment is realized by 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. The bandwidth of the impulse signal may be 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 for modulating at a pulse generation position can be adopted. Specifically, on-off keying (OOK) method, pulse width modulation (PWM), pulse amplitude modulation (PAM) method, pulse code modulation (PCM). Modulation) etc. can be adopted. The on/off modulation method is a method of expressing information (for example, 0 and 1) by the presence/absence of an impulse signal, and the pulse width modulation method is a method of expressing information by a 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 capable of performing wireless communication (hereinafter, BLE communication) based on 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 above-mentioned UWB communication. As the second communication method, in addition to Bluetooth Low Energy, various short-distance 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 be, for example, one that can provide a communication distance of several meters to several tens of meters. Hereinafter, in order to distinguish an impulse signal in UWB communication from a wireless signal in BLE communication, a wireless signal complying with the BLE standard is also referred to as a BLE signal. Hereinafter, specific configurations of the vehicle-mounted system 1 and the mobile terminal 2 will be sequentially described.

<About 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 a device that is associated with the in-vehicle system 1 and functions as an electronic key of 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 smartphone. The mobile terminal 2 may be an information processing terminal such as a tablet terminal. Further, the mobile terminal 2 may be a rectangular, elliptical (fob-type), or card-type small device conventionally known as a smart key. In addition, the mobile terminal 2 may be configured as a wearable device worn on the user's finger, arm, or the like.

As shown in FIG. 2, the mobile terminal 2 includes a UWB communication unit 21, a BLE communication unit 22, and a mobile-side control unit 23. The mobile-side control unit 23 is connected to the UWB communication unit 21 and the BLE communication unit 22 so that they can communicate with each other.

The UWB communication unit 21 is a communication module for transmitting and receiving UWB impulse signals. The UWB communication unit 21 generates a modulation signal while electrically processing, such as modulating the baseband signal input from the mobile-side control unit 23, and transmits the modulation signal by UWB communication. The modulation signal is a signal obtained by modulating transmission data by a predetermined modulation method (for example, PCM modulation method). The modulated signal is a signal sequence (hereinafter, 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 vehicle-mounted system 1, the UWB communication unit 21 demodulates the received signals and restores the data before modulation. Then, the received data is output to the mobile-side control unit 23.

Further, the UWB communication section 21 has a reflection response mode and a normal mode as operation modes. When the UWB communication unit 21 in the reflection response mode receives the impulse signal, the UWB communication unit 21 returns the impulse signal reflexively (in other words, immediately/quickly). Whether to operate in the reflection response mode is switched by the mobile-side controller 23 based on, for example, an instruction signal from the in-vehicle system 1. It should be noted that it takes a predetermined time (hereinafter, response processing time Tb) from the reception of the impulse signal from the vehicle-mounted system 1 to the transmission of the impulse signal as the response signal by the mobile terminal 2. The response processing time Tb is determined according to the hardware configuration of the mobile terminal 2. The expected value of the response processing time Tb can be specified in advance by a test or the like.

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

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 that they can communicate with each other. The BLE communication unit 22 receives the BLE signal transmitted from the vehicle Hv and provides the BLE signal to the mobile-side control unit 23, modulates the 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 the operations of the UWB communication unit 21 and the BLE communication unit 22. The mobile-side control unit 23 is realized by using a computer including, for example, a CPU, a RAM, a ROM, and the like.

The mobile-side control unit 23 causes the BLE communication unit 22 to wirelessly transmit a wireless signal including transmission source information at a predetermined transmission interval. As a result, the presence of itself is notified (that is, advertised) to the in-vehicle system 1 and the like. Hereinafter, for convenience, a radio signal that is periodically transmitted for the purpose of advertising is referred to as an advertisement signal. The transmission source information is, for example, unique identification information (hereinafter referred to as a terminal ID) assigned to the mobile terminal 2. The terminal ID functions as information for identifying the other communication terminal and the mobile terminal 2. The in-vehicle system 1 recognizes that the mobile terminal 2 exists within the BLE communication range of the vehicle Hv by receiving this advertisement signal. Note that, as another aspect, the mobile terminal 2 may be configured to transmit an advertisement signal based on a request from the in-vehicle system 1. Further, when the 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 the baseband signal is transmitted to the BLE communication unit 22. Output.

Further, when the 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 the baseband signal is transmitted 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 wireless signal.

<About in-vehicle system 1>
Next, the function and configuration of the in-vehicle system 1 will be described. The in-vehicle system 1 is configured to realize a passive entry/passive start system (hereinafter, 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 mobile terminal 2 is present in the operation area preset for the vehicle Hv, the on-vehicle system 1 operates the door button 14 based on a user operation to be described later. Control such as locking and unlocking is executed.

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

As shown in FIG. 3, the vehicle-mounted 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. The in-vehicle system 1 also includes a body system actuator 161, an in-vehicle sensor 162, and the like. The ECU in the member names is an abbreviation for Electronic Control Unit and means an electronic control unit.

The smart ECU 11 is an ECU that locks and unlocks a door by wirelessly communicating with the mobile terminal 2 via the UWB communication device 12 and 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 realized by using, for example, a computer. That is, the smart ECU 11 includes a CPU 111, a flash memory 112, a RAM 113, an I/O 114, a bus line connecting these components, and the like.

In the flash memory 112, the terminal ID assigned to the mobile terminal 2 owned by the user is registered. Further, the flash memory 112 stores a program (hereinafter, position estimation program) for causing a computer to function as the smart ECU 11, and the like. The position estimation program described above may be stored in a non-transitory tangible storage medium. The execution of the position estimation program by the CPU 111 corresponds to the execution of the method corresponding to the position estimation program. Details of the smart ECU 11 will be described 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 the other UWB communication devices 12 mounted on the vehicle Hv. That is, each UWB communication device 12 is configured to be capable of wireless communication with the mobile terminal 2 and another UWB communication device 12. For convenience, another UWB communication device 12 for a certain UWB communication device 12 is also referred to as another 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 in-vehicle network so as to be capable of mutual communication. The operation of each UWB communication device 12 is controlled by the smart ECU 11. A unique communication device number is set for each UWB communication device 12. The communication device number functions as information for identifying the plurality of UWB communication devices 12. The mounting positions and electrical configurations of the plurality of UWB communication devices 12 will be described later.

The BLE communication device 13 is a communication module for performing BLE communication. The BLE communication device 13 is connected to the smart ECU 11 so that they can 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. Further, the BLE communication device 13 modulates the 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. There may be one BLE communication device 13 or a plurality of BLE communication devices 13. The BLE communication device 13 corresponds to a different type 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 on each door handle of the vehicle Hv, for example. When the user presses the door button 14, the door button 14 outputs an electric signal to that effect to the smart ECU 11. The door button 14 corresponds to a configuration for the smart ECU 11 to receive an unlocking instruction and a locking instruction from the user. A touch sensor may be used as a configuration for receiving at least one of an unlocking instruction and a locking instruction from the user. The touch sensor is a device that detects that the user is touching the door handle.

The start button 15 is a push switch for the user to start a drive source (for example, an engine) of the vehicle Hv. When the start button 15 is pushed by the user, the start button 15 outputs an electric signal to that effect to the smart ECU 11. Here, as an example, the vehicle Hv is a vehicle including 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 equipped with 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 communicatively connected to various body 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 of each door, a seat actuator for adjusting a seat position, or the like. The on-vehicle sensor 162 here is a courtesy switch or the like arranged for each door. The courtesy switch is a sensor that detects opening and closing of the door. The body ECU 16 locks or unlocks each door based on a request from the smart ECU 11, for example, by outputting a predetermined control signal to a door lock motor provided in each door of the vehicle Hv.

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 capture an image of a range reflected in a door mirror viewed from a driver sitting in a driver's seat. That is, as shown in FIG. 4, the in-vehicle system 1 includes the right camera 17A attached to the right side surface of the vehicle Hv so as to image the right rear of the vehicle Hv and the left side of the vehicle Hv so as to image the left rear of the vehicle Hv. The left camera 17B attached to the surface portion. The side camera 17 is, for example, a camera that constitutes an electronic mirror system. The electronic mirror system is a system that displays a rear side image 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 attached near the lower end portion of the right A pillar, for example, in a posture in which the image pickup surface faces the right rear of the vehicle Hv. The A pillar is the first pillar from the front in the vehicle Hv. The A pillar is also called a front pillar. For example, the right camera 17A is provided at the mounting position of the right side door mirror in place of the right side door mirror. The operation of the right camera 17A is controlled by the smart ECU 11 and the like. The right camera 17A captures an image of the area from the right side to the rear of the vehicle Hv at a predetermined frame rate during driving, and provides the video signal to the smart ECU 11 and the like.

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

The rear camera 18 is a camera that images the rear of the vehicle. The rear camera 18 is installed at the rear end of the vehicle or near the upper end/lower end of the rear glass. The operation of the rear camera 18 is controlled by the smart ECU 11 and the like. When driving, the rear camera 18 captures an image of the rear of the vehicle Hv at a predetermined frame rate and provides the video signal to the smart ECU 11 and the like. Each of the side camera 17 and the rear camera 18 is a camera for capturing an image outside the vehicle compartment (in other words, the outside world). Therefore, the side camera 17 and the rear camera 18 are not distinguished from each other, and a camera that captures an image of the outside of the vehicle compartment is also referred to as an external camera hereinafter.

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

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 represented as a point in a three-dimensional orthogonal coordinate system with an arbitrary point of 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, vehicle three-dimensional coordinate system) having the center of the front wheel axle as an origin and having X, Y, and Z axes orthogonal to each other. The X-axis forming the vehicle three-dimensional coordinate system is parallel to the vehicle width direction, and the vehicle right side is the positive direction. The Y-axis is an axis that is parallel to the vehicle front-rear direction and has the forward direction of the vehicle as the positive direction. The Z-axis is an axis that is parallel to the vehicle height direction and has the vehicle upper direction as the positive direction. The center of the three-dimensional coordinate system can be changed as appropriate, 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.

As shown in FIG. 5, each of the plurality of UWB communication devices 12 includes a transmission unit 31, a reception unit 32, and a propagation time measurement unit 33. The transmission unit 31 is configured to generate an impulse signal while electrically processing, such as modulating the baseband signal input from the smart ECU 11, and radiate the impulse signal as a radio wave. The transmission unit 31 is realized using, for example, the modulation circuit 311 and the 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 modulation signal corresponding to the data (hereinafter, transmission data) indicated by the baseband signal input from the smart ECU 11, and transmits the modulation signal to the transmission antenna 312. The modulation signal is a signal obtained by modulating transmission data by a predetermined modulation method. As described above, 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. 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 or shapes the impulse signal.

The transmission antenna 312 is configured to convert the electric impulse signal output from the modulation circuit 311 into a radio wave and radiate it 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. Further, when the modulation circuit 311 outputs an electrical impulse signal to the transmission antenna 312, at the same time, it outputs a signal indicating that the impulse signal is output (hereinafter, a transmission notification signal) to the propagation time measurement unit 33. To do.

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

The reception unit 32 includes, for example, a reception antenna 321 and a demodulation circuit 322. The reception antenna 321 is an antenna for receiving an impulse signal. The reception 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 used for UWB communication, the demodulation circuit 322 generates a reception signal while electrically processing, such as demodulating the signal, and outputs the reception signal to the smart ECU 11. The pulse sequence signal acquired by the demodulation circuit 322 is a plurality of impulse signals input from the reception antenna 321 arranged 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 reception antenna 321 into a signal in the baseband band and outputs the signal, an amplifier circuit that amplifies the signal level, and the like. In addition, when the impulse signal is input from the receiving antenna 321, the receiving unit 32 outputs a signal indicating reception of the impulse signal (hereinafter, a reception notification signal) to the propagation time measuring unit 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, round trip time). The timing at which the transmitter 31 transmits the impulse signal is specified by the input of the transmission notification signal. 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 measuring 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 signal flight time for the round trip and the response processing time at the communication partner.

The propagation time measuring unit 33 measures the elapsed time since the transmitting unit 31 transmitted the impulse signal by counting the clock signals input from the clock oscillator (not shown). The counting by the propagation time measuring 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. That is, the round trip time is reported to the smart ECU 11. When the round trip time is reported to the smart ECU 11, the count value of the propagation time measuring unit 33 returns to 0 (that is, is reset).

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

Note that here, the UWB communication device 12 shows a mode in which the transmitting antenna (that is, the transmitting antenna 312) and the receiving antenna (that is, the receiving antenna 321) are separately provided, but the present invention is not limited to this. Absent. The UWB communication device 12 may be configured to share one antenna element for transmission and reception by using a directional coupler. Further, the modulation circuit 311 and the demodulation circuit 322 may be incorporated in an IC that provides a function as the propagation time measurement unit 33. The UWB communication device 12 may be realized by using one antenna and one dedicated IC having various circuit functions.

<About the function of the smart ECU 11>
By executing the position estimation program described above, the smart ECU 11 provides functions corresponding to various functional blocks shown in FIG. That is, the smart ECU 11 has, as functional blocks, 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. Equipped with.

The vehicle information acquisition unit F1 acquires various information (hereinafter, vehicle information) indicating the state of the vehicle Hv from a sensor, an ECU (for example, the body ECU 16) mounted on the vehicle Hv, a switch, or the like. The vehicle information includes, for example, the opened/closed state of the door, the locked/unlocked state of each door, the presence/absence of depression of the door button 14, the presence/absence of depression of the start button 15, and the like. In addition, 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 condition for determining that the vehicle Hv is parked may be appropriately designed, and various determination conditions can be applied. The state in which the vehicle Hv is parked here means a state in which no one is in the vehicle Hv (that is, an empty state) and the vehicle Hv is locked.

Obtaining the information indicating the locked/unlocked state of each door is equivalent to determining the locked/unlocked state of each door and detecting the locking/unlocking operation of the door by the user. To do. Further, acquiring the electric signals from the door button 14 and the start button 15 is equivalent to detecting a user operation on these buttons. That is, the vehicle information acquisition unit F1 corresponds to a configuration that detects a user's operation on the vehicle Hv such as opening/closing the door, pressing the door button 14, pressing the start button 15, and the like. The vehicle information thereafter includes a user operation on the vehicle Hv. In addition, the types of information included in the 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 detecting whether or not the brake pedal is depressed, and the like. The operating state of the parking brake 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 perform data transmission/reception with 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 a radio wave. Further, the BLE communication processing unit F2 receives the data received by the BLE communication device 13 from the mobile terminal 2. In the present embodiment, as a more preferable aspect, the wireless communication between the smart ECU 11 and the mobile terminal 2 is configured to be encrypted and executed. 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 and perform data communication for authentication and the like for improving 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 being encrypted.

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 user's mobile terminal 2. The authentication process itself may be performed using various methods such as a challenge-response method. The detailed description is omitted here. It is assumed that data (for example, an encryption key) required for the authentication process 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. The state where the authentication of the mobile terminal 2 is successful corresponds to the state where the communication connection with the mobile terminal 2 is established.

The BLE communication processing unit F2 recognizes that the user exists near the vehicle Hv based on the establishment of the BLE communication with the mobile terminal 2. Further, the BLE communication processing unit F2 acquires, from the BLE communication device 13, the terminal ID of the mobile terminal 2 that is communicatively connected. With such a configuration, even if the vehicle Hv is a vehicle shared by a plurality of users, the smart ECU 11 determines the vicinity of the vehicle Hv based on the terminal ID of the portable terminal 2 with which the BLE communication device 13 is communicatively connected. It is possible to specify users existing in the.

In the present 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 executed by UWB communication. The smart ECU 11 may be configured to perform the authentication process at a predetermined cycle 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 an authentication process 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/receive data to/from the mobile terminal 2. The UWB communication processing unit F3 acquires data received by the UWB communication device 12 from the mobile terminal 2. In addition, the UWB communication processing unit F3 generates data addressed to the mobile terminal 2 and outputs it to the UWB communication device 12. As a result, a pulse series 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 an instruction from the communication device diagnosis unit F4 or the position estimation unit F6. The UWB communication device 12 that transmits the impulse signal is selected by the communication device diagnosis unit F4 and the position estimation unit F6.

The communication device diagnosis unit F4 is configured to determine whether or not each UWB communication device 12 is operating normally (in other words, whether or not a malfunction has occurred). The communication device diagnostic unit F4 detects a malfunction/fault of the UWB communication device 12 by causing each UWB communication device 12 to sequentially perform wireless communication with another device, for example. The malfunction here includes a state in which the operation is stopped due to a failure.

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

In addition, the communication device diagnosis unit F4 can detect the 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 of determining that the UWB communication device 12 is out of order when the watchdog timer provided in the smart ECU 11 expires without being cleared by the watchdog pulse input from the UWB communication device 12. is there. The watchdog timer may be prepared for each UWB communication device 12. Further, the homework answering method means that the smart ECU 11 as the communication device diagnosis unit F4 sends a predetermined monitoring signal to the diagnosis target device and whether the answer returned from the diagnosis target device is correct. This is a method of determining whether or not the diagnosis target machine is normal depending on whether or not it is. In the homework answering method, the UWB communication device 12 as a device to be diagnosed generates reply data for the monitoring signal input from the smart ECU 11 and returns the reply data to the smart ECU 11. The smart ECU 11 determines whether the response data of the UWB communication device 12 is different from the correct answer data corresponding to the transmitted monitoring signal, or when the response signal is not returned from the smart ECU 11 within the predetermined time limit. 12 determines that it is not operating normally.

Further, the communication device diagnostic 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 allowing communication between communication devices for each combination of the UWB communication devices 12. Measure the 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 for bidirectionally performing wireless communication may be appropriately designed. For example, the UWB communication devices 12 located in the 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, when the inter-communication device distances of all the combinations having the diagnosis target device as a constituent element are values outside the predetermined normal range for the diagnosis target device. It is determined that there is a problem with. In other words, if the inter-communication device distance in at least one combination of all the combinations having the diagnosis target device as a component is a value within the normal range, the communication device diagnosis unit F4 determines the diagnosis target device. Is determined to be normal.

The normal range of the inter-communication device distance for each combination of the UWB communication devices 12 is registered in the flash memory 112 in advance by a test or a simulation. The normal range for each combination of the UWB communication devices 12 may be set based on the linear distance between the UWB communication devices 12. As another aspect, the normal range for each combination of communication devices may be defined not by the distance but by the propagation time of a radio signal (so-called TOF: Time Of Flight). As a method for measuring the distance between the communication devices and the propagation time of the wireless signal by the two communication devices performing wireless communication, various methods can be applied. 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 may 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.

It should be noted that the defects detected by using the inter-communication device distance include, for example, a contact failure between the signal line and the circuit element inside the communication device and a failure of the amplifier. When the signal line is poorly contacted or the amplifier is not operating, the reception level of the impulse signal (in other words, reception sensitivity) is lower than normal, and the reception power of the impulse signal exceeds the predetermined detection threshold. The timing may be delayed by about 0.5 nanosecond to 1 nanosecond. According to the above method, it is possible to detect a defect inside the communication device that causes a minute delay of about several nanoseconds. Further, according to the above-described diagnosis method, in addition to the internal failure of the UWB communication device 12, a state in which the UWB communication device 12 is removed from the predetermined mounting position can be detected as an abnormal state.

The two-way wireless communication (hereinafter, diagnostic wireless communication) for acquiring the inter-communication device distance for each combination of the UWB communication devices 12 may be periodically performed at a predetermined diagnosis cycle, for example. The diagnostic cycle is, for example, 1 hour. Of course, in addition to this, the diagnostic wireless communication may be executed at a predetermined timing such as a timing when the vehicle Hv is parked, a timing when a predetermined time has passed after the parking, a timing when the approach of the user to the vehicle Hv is detected, or the like. May be configured. The diagnostic wireless communication is preferably executed when there is no passenger in the passenger compartment, such as when the vehicle is parked.

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

The outside world information acquisition unit F5 analyzes whether an image is input from an outside camera such as the side camera 17 or the rear camera 18 (hereinafter, an outside world image) to determine whether or not a person exists in a predetermined range corresponding to the periphery of the vehicle. judge. When a person exists, the relative position (that is, whereabouts) of the person with respect to the vehicle Hv is specified based on the position of the person in the image, the mounting position of the camera, and the mounting posture. The relative position of the person with respect to the vehicle Hv may be represented by a vehicle three-dimensional coordinate system similar to the coordinate system indicating the communication device position. The information indicating the relative position of the person existing around the host vehicle is provided to the position estimation unit F6 as the person position information. The imaged data of the external camera corresponds to information indicating the position of a person existing in the imaged range of the external camera. The outside world information acquisition unit F5 corresponds to a person detection unit. The area around the vehicle is, for example, an area outside the vehicle and within 3 m from the vehicle. The area regarded as the vicinity of the vehicle, in other words, the detection range of a person may be designed as appropriate.

Note that the smart ECU 11 as the outside world information acquisition unit F5 may be configured to activate the outside world camera and acquire an outside world image when the approach of the user to the vehicle Hv is detected, for example. The approach of the user to the vehicle Hv may be detected based on, for example, that the BLE communication device 13 receives the 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, since it is not necessary to always activate the external camera during parking, 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. Then, the position of the mobile terminal 2 (hereinafter, terminal position) is estimated based on the distance information from each UWB communication device 12 to the mobile terminal 2.

The position estimation unit F6 performs the estimation of the terminal position, for example, when the BLE communication device 13 has established a communication connection with the mobile terminal 2. Hereinafter, for convenience, the process for estimating the terminal position when the vehicle Hv is parked is also referred to as the in-park position estimation process. Details of the parking position estimation process will be described later.

The parking position estimation process corresponds to a process of estimating the position of the mobile terminal 2 outside the vehicle (mainly around the vehicle). It is highly possible that the mobile terminal 2 is carried by the user outside the vehicle. Therefore, estimating the position of the mobile terminal 2 is equivalent to estimating the position of the user.

When the authentication of the mobile terminal 2 is successful, the vehicle control unit F7 cooperates with the body ECU 16 and the like to perform vehicle control according to the position of the mobile terminal 2 (in other words, the user) and the state of the vehicle Hv. It is a configuration to be executed. 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 estimation unit F6. For example, when the vehicle Hv is parked and the mobile terminal 2 is outside the vehicle compartment 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 processing executed by the smart ECU 11 will be described with reference to the flowchart shown in FIG. The parking position estimation process is performed in a predetermined position estimation cycle, for example, in a state where 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. The position estimation cycle is, for example, 200 milliseconds. Of course, the position estimation cycle may be 100 milliseconds or 300 milliseconds. In the present 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, the BLE communication device 13 is caused to transmit a reflection response instruction signal in cooperation with the BLE communication processing unit F2. The reflection response instruction signal is a signal that instructs the mobile terminal 2 to operate in the reflection response mode. As a result, the mobile terminal 2 operates so that each time it receives the impulse signal transmitted from the in-vehicle system 1, the mobile terminal 2 reflexively returns the impulse signal.

Next, in step S102, an arbitrary UWB communication device 12 (that is, a sound device) for which no malfunction has been detected by the communication device diagnosis unit F4 is set as the host device. The host machine corresponds to the UWB communication machine 12 that plays a role of measuring the round trip time among the plurality of UWB communication machines 12. When the processing in step S102 is completed, step S103 is executed. In step S103, the host machine transmits an impulse signal. As a result, the propagation time Ta, which is the time until the wireless signal transmitted by the host machine is received by the mobile terminal 2 in step S104, is acquired. At that time, the UWB communication device 12 other than the host device is controlled so as to stop the operation or not return the impulse signal as the response signal even if the impulse signal is received.

In steps S103 to S104 described above, the propagation time measuring unit 33 of the host machine measures the round trip time Tp as shown in FIG. 7 based on the instruction from the position estimating unit F6. Then, the expected value of the response processing time Tb in the mobile terminal 2 is subtracted from the round trip time Tp. The estimated value of the response processing time Tb may be registered in the flash memory 112 as a parameter for calculation. The value obtained by subtracting the response processing time Tb from the round trip time Tp corresponds to the flight time for a round trip. 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 wireless signal. The propagation time measuring 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.

The propagation time measuring unit 33 determines that the propagation time Ta is unknown if 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 indicated data may be provided to the smart ECU 11. The response waiting time may be set to a value, such as 33 nanoseconds, which assumes a state in which the user is sufficiently (eg, 10 m or more) 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 succeeds in measuring the propagation time Ta will be also referred to as a distance measuring success 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 sound machines have measured the propagation time Ta. When all the sound machines are made to measure the propagation time Ta, the affirmative decision is made in step S105 and the step S107 is executed. On the other hand, when there remains a sound machine for which the propagation time Ta has not been measured, a negative determination is made in step S105 and step S106 is executed.

In step S106, an arbitrary sound machine whose propagation time Ta has not yet been measured is set as the host machine, and step S103 is executed. The order in which the host machine operates (in other words, the order in which impulse signals are transmitted) may be appropriately designed. For example, when all the UWB communication devices 12 are sound devices, the position estimating unit F6 sets the host device in the order of the right communication device 12A→the left communication device 12B→the front communication device 12C→the rear communication device 12D. 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, the series of processes from step S103 to step S106 corresponds to the process of collecting the distance information from each UWB communication device 12 to the mobile terminal 2 by transmitting the impulse signal from each UWB communication device 12.

In step S107, as a result of the processing in steps S103 to S106, it is determined whether or not the propagation time has been acquired by three or more UWB communication devices 12. That is, it is determined whether or not the number of successful distance measuring machines is three or more. The case where the propagation time can be acquired by three or more UWB communication devices 12 means that the three or more UWB communication devices 12 are in a positional relationship capable of wireless communication with the mobile terminal 2. The case where the propagation time cannot be acquired in a certain UWB communication device 12 is, for example, a case where the communication with the mobile terminal 2 fails accidentally or a case where the UWB communication device 12 is out of order. The UWB communication device 12 that has acquired the propagation time corresponds to, for example, the UWB communication device 12 that has received the impulse signal as a response from the mobile terminal 2.

When 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, when the number of UWB communication devices 12 that have acquired the propagation time is less than 3, the 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 that has acquired the propagation time and the distance information from each UWB communication device 12 to the mobile terminal 2. For the installation position of each UWB communication device 12, communication device position data stored in the flash memory 112 may be used. The distance from each UWB communication device 12 to the mobile terminal 2 may be a value obtained by multiplying the propagation time Ta in each UWB communication device 12 by the speed of light. The installation position of each UWB communication device 12 and the position estimation based on the distance information from each UWB communication device 12 to the mobile terminal 2 can be implemented using the principle of triangulation. As a position estimation method using the installation position of each UWB communication device 12 and the distance information to the mobile terminal 2, a least square method, a Newton-Raphson method, a least mean square estimation method (MMSE: Minimum Mean Square Estimate), or the like, Various algorithms can be adopted. Hereinafter, the positioning method for estimating the terminal position using the installation position of each UWB communication device 12 and the distance information from each UWB communication device 12 to the mobile terminal 2 is referred to as a normal method.

In step S109, in addition to the installation position of each UWB communication device 12 that has acquired the propagation time and the propagation time observed by the UWB communication device 12, the human position information acquired by the external information acquisition unit F5 Is used together to estimate the terminal position. For example, when 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. 8, a region where the mobile terminal 2 can exist on the right side and the left side of the vehicle. (Hereinafter, candidate regions) Ar1 and Ar2 may occur. The candidate areas Ar1 and Ar2 are areas in which 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 within a predetermined distance measurement error. .. The front side observation distance refers to the distance from the front side communication device 12C to the mobile terminal 2, which is determined based on the propagation time observed by the front side communication device 12C. The rear side observation distance refers to the distance from the rear side communication device 12D to the mobile terminal 2, which is determined based on the propagation time observed by the rear side communication device 12D. A one-dot chain line in FIG. 8 indicates a point which is a front observation distance from the front communication device 12C, and a two-dot chain line indicates a point which is a 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 that there is no person 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 captured image of the left camera 17B. The star "*" in FIG. 8 conceptually indicates the estimated position of the mobile terminal 2.

The set of points within a predetermined distance from the front-side communication device 12C and the rear-side communication device 12D can be a three-dimensional circular ring that is 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 use of the vehicle, 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, the left side and the right side of the vehicle.

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

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

<Effects of this embodiment>
Here, the effect of the present embodiment will be described by introducing a comparison configuration. The comparison configuration uses 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 image captured by the external camera. Is a configuration for estimating. In such a comparison configuration, when the number of UWB communication devices 12 that can communicate with the mobile terminal 2 is less than 3, the position of the mobile terminal 2 becomes indefinite (unspecified). When the terminal position becomes indefinite, it is not possible to identify whether or not the mobile terminal 2 is present in the operation area, and the door of the vehicle Hv is not unlocked. That is, the user cannot use the function of the PEPS system, and the convenience is reduced.

On the other hand, 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 3, 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 3 due to a failure of the UWB communication device 12 or an accidental communication error, etc. 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-described configuration corresponds to a configuration in which whether or not to use the person position information is switched to the process of estimating the position of the mobile terminal 2 outside the vehicle cabin, depending on the number of successful distance measurement aircraft.

In addition, in the present embodiment, each UWB communication device 12 is mounted in a place with good visibility both inside and outside the vehicle compartment, such as the ceiling and the upper region of the pillar. Generally, radio waves of 1 GHz or higher (hereinafter, high frequency radio waves) such as impulse signals used in UWB communication are easily reflected by metal. Further, high frequency radio waves are easily absorbed by the human body. Therefore, when there is an object (hereinafter referred to as a shield) that reflects/absorbs a radio wave, such as a metal body or a human body, in the traveling direction of the high-frequency radio wave, it propagates or goes around the shield (that is, diffracted). It is reflected by things.

When the mobile terminal 2 and the UWB communication device 12 communicate with each other 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, the UWB communication device 12 and the mobile terminal 2 communicate with each other by reflection from a structure such as another vehicle. May include even more error.

In order to deal with such a problem, in the present embodiment, each UWB communication device 12 is mounted in a place with good visibility both inside and outside the vehicle compartment. According to such a mounting mode, it is possible to reduce the possibility that the communication mode with the mobile terminal 2 is indirect communication. In other words, it is possible to reduce the risk that the distance from each UWB communication device 12 to the mobile terminal 2 may include an error due to diffraction or reflection of a radio signal. As a result, it becomes possible to more accurately estimate the terminal position.

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. Also, various modifications can be implemented without departing from the scope. For example, the following various modified examples can be appropriately combined and implemented within a range in which technical contradiction does not occur. It should be noted that members having the same functions as the members described in the above-described embodiment are designated by the same reference numerals, and the description thereof will be omitted. Further, when only a part of the configuration is mentioned, the configurations of the above-described embodiments can be applied to the other parts.

[Modification 1]
In the above-described embodiment, the mode in which the person position information is used together to estimate the terminal position when the number of successful distance measuring machines is less than three is disclosed. Not limited to. For example, the position estimation unit F6 may be configured to estimate the terminal position by using the person position information in combination even when the number of successful distance measurement devices is three or more. Hereinafter, an operation example of the position estimation unit F6 based on the technical idea will be described as a first modification with reference to FIG.

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

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

When a person exists within the correction allowable distance from the estimated position (YES in step S204), the position of the person (the person existing within the correction allowable distance from the estimated position) is adopted as the terminal position (step S205). That is, the estimated position is corrected to the human position and then used as the terminal position. On the other hand, if there is no person within the correction allowable distance from the estimated position (NO in step S204), the terminal position is determined to be indefinite (step S206).

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

[Modification 2]
The smart ECU 11 learns the appearance features of the user daily from the captured images acquired by the outside/in-vehicle camera, and the person (hereinafter, the person to be detected) who is imaged by the outside camera using the appearance features is the user. It may be configured to identify whether or not. The detected person corresponds to a person existing around the vehicle Hv. The detected person who is not the user is, for example, a passerby or the like.

As the appearance feature of the user, it is possible to employ shoes that the user has worn, images of clothes, bags, watches, accessories and the like, facial images, standing (opening degree of legs), height, physique, and the like. The appearance characteristics of the user may be collected using a camera mounted on the vehicle at the time of vehicle entry or engine start. The storage device (hereinafter, appearance feature storage unit M1) that stores data indicating the appearance feature of the user is realized by using the flash memory 112 of the smart ECU 11. The external characteristic storage unit M1 may be included in an external server.

When the presence of a person is detected around the vehicle Hv based on the image captured by the outside camera, the outside world information acquisition unit F5 of the present modification, the detected person includes a person including the appearance characteristics of the user that can be acquired by then. Or not. For example, when the detected person wears shoes having a high degree of similarity with the shoes worn by the user before, the detected person is determined to be a person having the appearance feature of the user. The person including the appearance feature of the user corresponds to a person who may be the user. The outside world information acquisition unit F5 provides the position estimation unit F6 with the person position information including whether the detected person has the appearance feature of the user. For convenience, the function of the outside world information acquisition unit F5 to determine whether or not the detected person has the appearance feature of the user is 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 detected person is a user. FIG. 11 is a functional block diagram schematically showing the configuration of the outside world information acquisition unit F5 in this modification.

The position estimation unit F6 of the present modification example determines that the external environment information acquisition unit F5 has the appearance feature of the user when estimating the terminal position by using the person position information together, such as Step S109 and Step S205. Only the position information of the person in use is used. The user likelihood determination unit F51 may be configured to output the possibility that the detected person is a user (hereinafter, user likelihood) as a score using a plurality of types of appearance features. In that case, the position estimation unit F6 is configured to use only the position information of the person whose user likelihood is above a certain threshold when estimating the terminal position using the person position information together. Is preferred.

According to the above configuration, it is possible to reduce the risk of estimating the terminal position by using the position information of a person who is not the user such as a passerby. That is, it is possible to further reduce the risk of erroneously determining the terminal position. Further, even when there are a plurality of persons around the vehicle Hv, it is possible to narrow down the persons to be used for estimating the terminal position, and it is possible to reduce the risk of the terminal position becoming indefinite.

[Modification 3]
In a multipath environment, the estimated distance from the UWB communication device 12 to the mobile terminal 2 is likely to include an error. 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 present at the position where the signal is received by the reflection from the reflector 4 such as the adjacent vehicle/wall. The propagation time may be delayed by several nanoseconds. As a result, an error occurs in the estimated distance from the UWB communication device 12 to the mobile terminal 2, and the estimation accuracy of the terminal position deteriorates.

In view of such circumstances, it is preferable that the position estimating unit F6 is configured to estimate the terminal position by using the person position information together when the area around the vehicle Hv is in a multipath environment. .. Hereinafter, an example of the configuration of the smart ECU 11 based on the technical idea will be disclosed as Modification 3. The multi-path environment here means 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 outside 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 the surroundings of the own vehicle are in a multipath environment by analyzing the captured image of 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 another vehicle or a reflector 4 such as a wall or a pillar exists within 1 m from the vehicle Hv. To judge. Then, when the reflector 4 exists within 1 m from the vehicle Hv, it is determined that the periphery of the vehicle Hv is in a multipath environment. Whether the surroundings of the vehicle are in a multipath environment is determined at the time when the vehicle Hv is parked or at the timing when the approach of the user is detected (in other words, when the communication connection with the mobile terminal 2 is established). I hope it is done.

When the communication environment determination unit F52 determines that the own vehicle is in a multipath environment, the position estimation unit F6 of the present modified example determines that the UWB communication device 12 determines whether the vehicle is in the multipath environment. In addition to the distance information to the mobile terminal 2, the person position information is also used to determine the terminal position. With such a configuration, even when the parking position of the vehicle Hv is in a multipath environment, it is possible to reduce the risk of erroneously determining the terminal position.

The method of determining whether or not the area around the vehicle is a multipath environment can be changed as appropriate. For example, the communication environment determination unit F52 may determine whether or not the multipath environment is present, based on the reception status of the signal 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 value, it may be determined that the surroundings of the own vehicle are in a multipath environment. The communication environment determination unit F52 may be configured to determine whether or not the host 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 area around the vehicle is a multipath environment.

[Modification 4]
The position estimation unit F6 uses the person position information in addition to the installation position of each UWB communication device 12 and the distance information to the mobile terminal 2 on condition that the UWB communication device 12 in which the malfunction occurs exists. It may be configured to determine the terminal location. With such a configuration, it is possible to reduce the possibility that the positioning accuracy is deteriorated or the terminal position cannot be estimated due to the presence of the defective device. Whether or not there is a UWB communication device 12 in which a malfunction has occurred may be determined by the communication device diagnosis unit F4. According to the number of UWB communication devices 12 determined to be defective by the communication device diagnostic unit F4, the above configuration determines whether or not the person position information is used for the terminal position estimation processing outside the vehicle interior. This corresponds to the switching configuration.

Further, as another aspect, the position estimation unit F6 uses the person position as the installation position of each UWB communication device 12 and the distance information to the mobile terminal 2 on the condition that the number of sound devices is less than three. It may be configured to use the information together to determine the terminal position. The conditions for the position estimation unit F6 to use the person position information to estimate the terminal position can be combined as appropriate. For example, in consideration of a plurality of factors such as the number of sound planes, the number of successful distance measurement planes, the surrounding environment of the vehicle Hv, it is configured to switch whether or not to use the person position information for estimating the terminal position. It may be. Further, the position estimating unit F6 may be configured to always use the person position information together in the parking position estimating process. In addition, when the accuracy of the person position information is deteriorated such as in the rain or at night, the person position information may not be used together. That is, the position estimation unit F6 may be configured to switch whether or not to use the person position information for the position estimation processing of the portable terminal 2 outside the vehicle, depending on the accuracy/reliability of the person position information. good.

[Modification 5]
In the above, the aspect which determines a terminal position using person position information together, when the predetermined conditions are satisfy|filled in parking position estimation processing was disclosed. That is, on the condition that the vehicle is parked, the terminal position outside the passenger compartment 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 person position information. I disclosed the configuration. However, the smart ECU 11 may be configured to estimate the terminal position by using the person position information together even when the vehicle is not parked. It suffices that the smart ECU 11 be configured to estimate the terminal position by using the person position information together, provided that the vehicle is in an empty state.

For example, the smart ECU 11 may be configured to estimate the terminal position by also using the human position information even when the vehicle Hv is automatically traveling unattended to the user existing outside the vehicle. The automatic traveling to the user existing outside the vehicle compartment is performed by using, for example, an ECU that automatically travels the vehicle Hv (so-called automatic driving ECU) using the rough position information of the user specified by GNSS or the like. Good. The rough position information of the user determined by GNSS or the like may be provided to the vehicle Hv from the mobile terminal 2 via the wide area wireless communication network. After the vehicle Hv approaches the vicinity of the user based on the position information of the user determined by GNSS, the smart ECU 11 specifies the detailed position of the user by the same method as the parking position estimation process. The ECU that automatically drives the vehicle Hv (so-called automatic driving ECU) uses the detailed position information of the user identified by the smart ECU 11 to stop so that the passenger seat/driver's seat is located in front of the user's eyes. With such a configuration, the technical idea of the present disclosure can be applied to not only the scene where the user approaches the vehicle Hv but also the scene where the vehicle Hv approaches the user.

[Modification 6]
In the above-described embodiment, the aspect in which the left and right side cameras 17 and the rear camera 18 are used as the external world camera is disclosed, but the configuration that can be adopted as the external world camera is not limited to this. For example, the external camera may be a wide-angle camera mounted on the ceiling of the vehicle interior so that the interior and exterior of the vehicle can be imaged. The external camera is only required to be configured to capture an image of at least a part outside the vehicle interior, and the vehicle interior may be included in the imaging range. It is preferable that the camera mounted in the vehicle interior as the external camera is configured to be capable of capturing 360 degrees. The wide-angle camera here refers to a camera whose imaging field angle is set to 120 degrees or more. The external camera may be realized using a plurality of wide-angle cameras.

Further, although the configuration in which the external camera is adopted as the sensor (hereinafter, external sensor) that outputs the information indicating the position and type of the object around the vehicle Hv has been disclosed above, the device that can be used as the external sensor is not limited to this. Absent. The external sensor may be realized by, for example, a laser radar, a millimeter wave radar, an ultrasonic sensor, an infrared sensor, an optical sensor, or a combination thereof. The external sensor may be any sensor that outputs data indicating the location of a person. Various human sensor can be adopted as the external sensor. When a laser radar, a millimeter wave radar, an ultrasonic sensor or the like is used as the external sensor, whether or not the detected object corresponds to a human is discriminated using a predetermined characteristic amount such as reflection intensity or contour shape. Good. A variety of algorithms can be adopted as an object detection and type identification method using a millimeter wave radar or the like. It should be noted that the detection range of each external sensor may be designed appropriately, but it is preferable that it is configured to include at least the operation area.

[Modification 7]
The installation mode (specifically, the installation position and the number of installations) of the UWB communication device 12 is not limited to the above-described mode. For example, the right-side communication device 12A and the left-side communication device 12B may be arranged on the A pillar, the C pillar, near the front wheels, near the front corners, and in the side mirror. The right communication device 12A and the left communication device 12B may be attached to the side surface of the vehicle Hv. Further, the front communication device 12C may be installed in the vehicle width direction central portion of the instrument panel, the front portion of the driver's seat, the center console, or the like. The rear communication device 12D may be buried in the central 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.

In addition, as a mounting position of the UWB communication device 12, a B pillar (center pillar), an instrument panel, a center console, an overhead console, the vicinity of a rearview mirror, an upper end portion of a rear glass, or the like can be adopted. The UWB communication device 12 may be arranged near the boundary between the side surface portion of the vehicle Hv and the roof portion (hereinafter, the side surface upper end portion). Such a configuration corresponds to a configuration in which the UWB communication device 12 is provided in the frame portion located above the side window.

Further, when the body of the vehicle Hv is realized by using 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 the passenger seat, or the driver's seat. It is also possible to use a side sill near the inner door handle for the passenger seat. The in-vehicle system 1 may include a UWB communication device 12 arranged on the outer surface of the vehicle Hv. The outer surface portion here is a body portion of the vehicle Hv that is in contact with the vehicle exterior space, and includes a side surface portion, a rear surface portion, and a front surface portion of the vehicle Hv. In addition, the in-vehicle system 1 may include the UWB communication device 12 installed inside the trunk and the UWB communication device 12 installed near the trunk door handle.

Further, the number of UWB communication devices 12 connected to the smart ECU 11 may be three, five, six or more. For example, there may be only three UWB communication devices 12 connected to the smart ECU 11, that is, the right communication device 12A, the left communication device 12B, and the rear communication device 12D. The smart ECU 11 may be connected to at least three UWB communication devices 12.

[Modification 8]
In the above-described embodiment, the aspect in which the propagation time for one way is used as the distance information is disclosed, but the distance information may be the round trip time Tp. 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 propagation time from 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 determines 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 when the mobile terminal 2 should have transmitted the impulse signal can be calculated, for example, by predefining the timing at which the mobile terminal 2 transmits the impulse signal.

[Modification 9]
The signal transmitted/received for estimating the propagation time (and thus the distance) may not be a single impulse signal, but may be a pulse sequence signal having a constant length as shown in FIG. The pulse sequence signal preferably includes transmission source information and destination information. When the pulse sequence signal includes the source information and the destination information, it is possible to suppress the UWB communication device 12 other than the host device from transmitting the response signal without limiting the operation of the UWB communication device 12 other than the host device. it can. In this modification, the propagation time Ta may be calculated from the round trip time Tp using an estimated value of the pulse sequence signal length (hereinafter, signal length) Tc. That is, the propagation time Ta may be calculated as Ta=(Tp−Tb−Tc×2)/2.

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

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

Moreover, although the aspect which estimates the distance from a vehicle-mounted communication device 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 vehicle-mounted communication device to the mobile terminal 2 may be configured to be specified based on the reception intensity of the wireless signal. For example, each in-vehicle communication device may be configured to estimate the distance based on the reception intensity of the signal transmitted from the mobile terminal 2. The reception intensity also corresponds to the distance information.

<Additional notes>
The control unit and the method thereof described in the present disclosure may be realized by a dedicated computer that configures a processor programmed to execute one or more functions embodied by a computer program. Further, the device and the method described in the present disclosure may be realized by a dedicated hardware logic circuit. Furthermore, the device and method described in the present disclosure may be implemented by one or more dedicated computers configured by a combination of a processor that executes a computer program and one or more hardware logic circuits. Further, the computer program may be stored in a computer-readable non-transition tangible recording medium as an instruction executed by a computer.

The control unit here is, for example, the smart ECU 11. 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 substantive memory device and a computer that executes the software, only software, only hardware, or a combination thereof. Some or all of the functions of the smart ECU 11 may be implemented as hardware. The mode of realizing a certain function as hardware includes a mode of realizing using one or a plurality of ICs. Although the smart ECU 11 is realized by using the CPU in the above-described embodiment, the configuration of the smart ECU 11 is not limited to this. The smart ECU 11 may be realized by using an MPU (Micro Processor Unit), a GPU (Graphics Processing Unit), or a data flow processor (DFP: Data Flow Processor) instead of the CPU 111. Further, the smart ECU 11 may be realized by combining a plurality of types of processors such as the CPU 111, MPU, GPU, and DFP. Further, some of the functions that the smart ECU 11 should provide may be realized by using an FPGA (Field-Programmable Gate Array), an ASIC (Application Specific Integrated Circuit), or 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 type communication device), 17 side camera (external sensor), 18 rear camera (external environment) 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 information acquisition unit (person detection unit), F6 position estimation unit, F51 user likelihood determination unit, F52 communication environment determination unit

Claims (9)

A vehicle position for determining the position of the mobile terminal with respect to the vehicle by wirelessly communicating with a mobile terminal carried by a user of the vehicle by a plurality of vehicle-mounted communication devices (12) arranged at different positions in the vehicle. An estimation system,
Each of the vehicle-mounted communication device is configured to generate distance information that directly or indirectly indicates a distance from the vehicle-mounted 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 in-vehicle communication device and the installation position of each in-vehicle communication device;
A person detecting unit (F5) for detecting the position of a person existing in the predetermined range by using a detection result of an external sensor that outputs data indicating the position and type of an object in the predetermined range from the vehicle outside the vehicle; Equipped with
The position estimation unit, on condition that the vehicle is empty, the distance information generated by each in-vehicle communication device, the installation position of each in-vehicle communication device, the person detected by the person detection unit A vehicle position estimation system configured to estimate the position of the portable terminal outside the vehicle cabin based on the person position information that is the position information of the vehicle. The vehicle position estimation system according to claim 1, wherein
A communication device diagnostic unit (F4) for determining whether or not a malfunction has occurred in the in-vehicle communication device,
The position estimation unit, in accordance with the number of the vehicle-mounted communication device is determined to have a malfunction by the communication device diagnosis unit, in the estimation process of the position of the portable terminal outside the vehicle, the person position information, A vehicle position estimation system configured to switch between use and non-use. The vehicle position estimation system according to claim 1 or 2, wherein
A communication device diagnostic unit (F4) for determining whether or not a malfunction has occurred in the in-vehicle communication device,
The position estimation unit,
When the number of the onboard communication devices determined to be operating normally by the communication device diagnosis unit is less than 3, the distance information generated by each onboard communication device and each onboard communication device. The position estimation system for a vehicle configured to estimate the position of the portable terminal outside the vehicle compartment by using the person position information in addition to the installation position. The vehicle position estimation system according to any one of claims 1 to 3,
The position estimation unit uses the person position information for estimating the position of the portable terminal outside the vehicle compartment in accordance with the number of successful distance measurement devices that are the vehicle-mounted communication devices that have successfully generated the distance information. A vehicle position estimation system configured to switch between. The vehicle position estimation system according to any one of claims 1 to 4,
The position estimation unit, when the number of successful distance measuring devices that are the on-vehicle communication devices that succeeded to generate the distance information is less than 3, the distance information generated by each on-vehicle communication device and each on-vehicle communication device. A vehicle position estimating system configured to estimate the position of the portable terminal outside the vehicle by using the person position information in addition to the installation position of the machine. The vehicle position estimation system according to claim 5,
When the number of successful distance measuring devices is less than 3, the position estimating unit determines that the mobile terminal is located based on the distance information generated by the successful distance measuring device and the installation position of the successful distance measuring device. Possible candidate areas are calculated,
A vehicle position estimation system configured to estimate the position of the mobile terminal based on the calculated candidate area and the person position information. The vehicle position estimation system according to any one of claims 1 to 6,
A communication environment determining unit (F52) for determining whether the vehicle is in a multipath environment,
The position estimation unit, on condition that the vehicle is in a multipath environment by the communication environment determination unit, the distance information generated by each vehicle-mounted communication device, and each vehicle-mounted communication device. The position estimation system for a vehicle configured to estimate the position of the portable terminal outside the vehicle compartment by using the person position information in addition to the installation position. The vehicle position estimation system according to any one of claims 1 to 7,
The in-vehicle communication device is configured to perform wireless communication with the mobile terminal using an ultra wideband impulse signal,
An inter-system communication device (13) configured to be capable of wireless communication with the mobile terminal by a communication system different from that of the in-vehicle communication device;
An authentication processing unit (F2) for authenticating the mobile terminal by transmitting and receiving predetermined data to and from the mobile terminal via the different type communication device,
The position estimation unit is configured to use the person position information in a process of estimating the position of the mobile terminal outside the vehicle, provided that the authentication of the mobile terminal by the authentication processing unit is successful. Vehicle position estimation system. The vehicle position estimation system according to any one of claims 1 to 8,
The vehicle position estimation system, wherein the external sensor is realized by using at least one of a camera, an ultrasonic sensor, an infrared sensor, and an optical sensor.

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