Mobile terminal, positioning method, positioning program, and recording medium

Abstract

To provide a portable-type autonomous navigation device, and a positioning method and positioning program for the autonomous navigation device, with which it is possible to determine a reference position and a reference azimuth of autonomous navigation at low cost, even while on the go.SOLUTION: A portable terminal according to the present invention is a portable-type autonomous navigation device, comprising: a vehicle information acquisition part for acquiring vehicle information that indicates a position and a direction of a vehicle; a relative information acquisition part for acquiring relative information that indicates a relative position and a relative attitude of the autonomous navigation device to the vehicle, when the autonomous navigation device is located on the outside of the vehicle; a reference information acquisition part for calculating a reference position and a reference attitude of the autonomous navigation device, on the basis of the vehicle information and the relative information; and an autonomous navigation processing part for executing autonomous navigation positioning using the reference position and the reference attitude as initial information of autonomous navigation.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an autonomous navigation device, a positioning method and a positioning program for an autonomous navigation device. [Background technology]

[0002] In recent years, for example, in mobile terminals such as smartphones, an autonomous navigation (DR: Dead Reckoning, also called inertial navigation) technology has been developed that is equipped with an inertial measurement unit (IMU) including an acceleration sensor and a gyro sensor and estimates the position and orientation of the mobile terminal in areas where a Global Positioning System (GPS) signal or geomagnetism cannot be obtained. However, in order to perform autonomous navigation, it is necessary to determine a reference position and a reference orientation at the start of autonomous navigation.

[0003] For example, Patent Document 1 discloses a technology for determining the initial position and initial orientation when performing inertial navigation of a mobile terminal, in which an NFC (Near Field Communication) tag is placed at any position indoors in a home or office, the NFC tag communicates with the mobile terminal, and the mobile terminal photographs the NFC tag, thereby obtaining the initial position and initial orientation of the mobile terminal. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-42246 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the mobile terminal of Patent Document 1 requires the installation of a dedicated NFC tag, and for example, there is a possibility that the NFC tag is not installed in the facility where the user is visiting. Also, for example, it is costly to install NFC tags in public facilities such as subway stations and large commercial facilities.

[0006] The present invention has been made in consideration of the above points, and aims to provide a portable autonomous navigation device that is inexpensive and can determine a reference position and reference orientation for autonomous navigation even when away from the office, as well as a positioning method and positioning program for the autonomous navigation device. [Means for solving the problem]

[0007] The invention described in claim 1 is a portable autonomous navigation device comprising: a vehicle information acquisition unit that acquires vehicle information indicating a position and direction of a vehicle; a relative information acquisition unit that acquires relative information indicating a relative position and relative attitude of the autonomous navigation device with respect to the vehicle when the autonomous navigation device is located outside the vehicle; a reference information acquisition unit that calculates a reference position and reference attitude of the autonomous navigation device based on the vehicle information and the relative information; and an autonomous navigation processing unit that performs autonomous navigation positioning using the reference position and the reference attitude as initial information for autonomous navigation.

[0008] The invention described in claim 8 is a positioning method executed in a portable autonomous navigation device, comprising: a vehicle information acquisition step of acquiring vehicle information indicating a position and direction of the vehicle; a relative information acquisition step of acquiring relative information indicating a relative position and relative attitude of the autonomous navigation device with respect to the vehicle when the autonomous navigation device is located outside the vehicle; a reference information acquisition step of calculating a reference position and reference attitude of the autonomous navigation device based on the vehicle information and the relative information; and an autonomous navigation processing step of performing autonomous navigation positioning using the reference position and the reference attitude as initial information for autonomous navigation.

[0009] The invention described in claim 13 is a positioning program which causes a computer mounted on a portable autonomous navigation device to execute the following steps: a vehicle information acquisition step of acquiring vehicle information indicating the position and direction of the vehicle; a relative information acquisition step of acquiring relative information indicating the relative position and relative attitude of the autonomous navigation device with respect to the vehicle when the autonomous navigation device is located outside the vehicle; a reference information acquisition step of calculating a reference position and reference attitude of the autonomous navigation device based on the vehicle information and the relative information; and an autonomous navigation processing step of performing autonomous navigation positioning using the reference position and the reference attitude as initial information for autonomous navigation.

[0010] The invention described in claim 14 is a computer-readable recording medium, characterized in that it stores a positioning program that causes a computer mounted on a portable autonomous navigation device to execute the following: a vehicle information acquisition step of acquiring vehicle information indicating the position and direction of the vehicle; a relative information acquisition step of acquiring relative information indicating the relative position and relative attitude of the autonomous navigation device with respect to the vehicle when the autonomous navigation device is located outside the vehicle; a reference information acquisition step of calculating a reference position and reference attitude of the autonomous navigation device based on the vehicle information and the relative information; and an autonomous navigation processing step of performing autonomous navigation positioning using the reference position and the reference attitude as initial information for autonomous navigation. [Brief description of the drawings]

[0011] [Figure 1] 1 is a diagram illustrating a configuration of an autonomous navigation system according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a functional block diagram of a mobile terminal according to a first embodiment of the present invention. [Diagram 3] FIG. 4 is a diagram illustrating a method for calculating relative information of a mobile terminal according to the first embodiment of the present invention. [Figure 4] FIG. 3 is a diagram showing an operation routine of the vehicle positioning device according to the first embodiment of the present invention. [Diagram 5] FIG. 4 is a diagram showing an operation routine of the mobile terminal according to the first embodiment of the present invention. [Figure 6]FIG. 11 is a diagram illustrating a configuration of an autonomous navigation system according to a second embodiment of the present invention. [Figure 7] FIG. 11 is a functional block diagram of a mobile terminal according to a second embodiment of the present invention. [Figure 8] FIG. 11 is a diagram illustrating a method for calculating relative information of a mobile terminal according to a second embodiment of the present invention. [Figure 9] FIG. 11 is a diagram showing an operation routine of the vehicle positioning device according to the second embodiment of the present invention. [Figure 10] FIG. 11 is a diagram showing an operation routine of a mobile terminal according to a second embodiment of the present invention.

[0012] In the following, preferred embodiments of the present invention will be described. In the following description and the accompanying drawings, the same reference numerals are used to designate substantially the same or equivalent parts. Example 1

[0013] Hereinafter, an autonomous navigation system 100 including a mobile terminal 10 as an autonomous navigation device according to a first embodiment of the present invention will be described with reference to the accompanying drawings.

[0014] 1 is a diagram showing an example of a configuration of an autonomous navigation system 100 according to a first embodiment of the present invention. The autonomous navigation system 100 includes a mobile terminal 10, which is a mobile autonomous navigation device, and a vehicle positioning device 20 mounted on an automobile M.

[0015] The mobile terminal 10 is a mobile autonomous navigation device carried by a passenger CR of the automobile M. The mobile terminal 10 is, for example, a mobile terminal such as a smartphone having an inertial measurement unit (IMU) including an acceleration sensor and a gyro sensor. FIG. 1 shows a state in which the passenger CR gets out of the automobile M.

[0016] The vehicle positioning device 20 is a positioning device mounted on the automobile M, which measures the position and orientation of the automobile M. The vehicle positioning device 20 is, for example, a car navigation system including a positioning unit 21, a GPS receiver 23, an IMU 25, and a vehicle speed information acquisition unit 27. By these components working together, the vehicle positioning device 20 is capable of measuring the position of the automobile M, which is indicated by latitude, longitude, and altitude in a geographic coordinate system, and the orientation indicating the forward direction of the automobile M.

[0017] The GPS receiver 23 is mounted on the automobile M, and is a device that receives signals (GPS signals) from GPS (Global Positioning System) satellites. The GPS receiver 23 is communicably connected to the positioning unit 21, and is capable of transmitting the received GPS signals to the positioning unit 21. The GPS receiver 23 is disposed, for example, on the dashboard of the automobile M. The GPS receiver 23 may be disposed anywhere as long as it can receive GPS signals.

[0018] The IMU 25 is an inertial measurement device including an acceleration sensor and a gyro sensor mounted on the automobile M. The IMU 25 acquires inertial information of the acceleration, deceleration, or angular velocity of the automobile M. The IMU 25 is communicably connected to the positioning unit 21 and can transmit the acquired inertial information to the positioning unit 21. The IMU 25 is disposed, for example, in the dashboard. The IMU 25 may be disposed anywhere as long as it can acquire inertial information of the automobile M.

[0019] The vehicle speed information acquisition unit 27 is a device mounted on the automobile M and acquires the traveling speed of the automobile M. The vehicle speed information acquisition unit 27 acquires speed information of the automobile M, for example, from a vehicle speed pulse obtainable from the automobile M or a wheel speed measured by a wheel speed sensor. The vehicle speed information acquisition unit 27 is communicably connected to the positioning unit 21 and is capable of transmitting the acquired speed information to the positioning unit 21. In addition, the vehicle speed information acquisition unit 27 is disposed, for example, in the dashboard. Note that the vehicle speed information acquisition unit 27 may be disposed anywhere as long as it is possible to acquire the speed information of the automobile M.

[0020] The positioning unit 21 cooperates with the IMU 25 and the vehicle speed information acquisition unit 27 to perform autonomous navigation positioning based on inertial information and speed information.

[0021] The vehicle positioning device 20 is capable of measuring the position and orientation of the automobile M in the geographic coordinate system based on the information acquired by the GPS receiver 23, the IMU 25, and the vehicle speed information acquisition unit 27. Specifically, when the GPS receiver 23 is in an area where a GPS signal can be received while the automobile M is traveling, the positioning unit 21 determines the position and orientation in the geographic coordinate system indicated by the GPS signal as the position and orientation of the automobile M. Furthermore, when the GPS receiver 23 enters an area where a GPS signal cannot be received while the automobile M is traveling, the positioning unit 21 identifies the position and orientation of the automobile M in the geographic coordinate system by performing positioning using autonomous navigation based on the position and orientation of the automobile M where the GPS signal was last received.

[0022] The positioning unit 21 performs speed correction of the received inertial information at any time by comparing the inertial information acquired by the IMU 25 with the speed information acquired by the vehicle speed information acquisition unit 27. Furthermore, the positioning unit 21 has a map matching function for correcting the derived position by matching the position derived by autonomous navigation positioning with map information, for example. This enables the vehicle positioning device 20 to perform accurate autonomous navigation positioning.

[0023] That is, the automobile M has a vehicle positioning device 20, which is an on-board navigation device capable of acquiring vehicle information indicating the position and forward direction of the automobile M in a geographic coordinate system by a hybrid navigation system that combines satellite navigation and autonomous navigation.

[0024] Moreover, the vehicle positioning device 20 and the mobile terminal 10 further include a wireless communication function conforming to, for example, the Bluetooth (registered trademark) standard, and are connected by the wireless communication. For example, the vehicle positioning device 20 transmits to the mobile terminal 10 vehicle information indicating the position and direction of the automobile M measured by the positioning unit 21 when the automobile M is stopped (for example, the ignition is off) or when a request is made from the mobile terminal 10. Note that the connection between the vehicle positioning device 20 and the mobile terminal 10 is not limited to this. For example, the vehicle positioning device 20 and the mobile terminal 10 may be connected by wire such as Universal Serial Bus (USB) or may be connected by wireless communication conforming to another standard. Any form may be used as long as the vehicle information can be transmitted from the vehicle positioning device 20 to the mobile terminal 10.

[0025] Furthermore, the vehicle positioning device 20 may have a wireless LAN (Local Area Network) function conforming to the IEEE802.11 communication standard and may be connectable to an Internet connection network. For example, the vehicle positioning device 20 may transmit vehicle information indicating the position and direction of the automobile M measured by the positioning unit 21 when the automobile M is stopped to a server (not shown) that stores the vehicle information via the Internet connection network, and the mobile terminal 10 may connect to the server via the Internet network. That is, the vehicle positioning device 20 and the mobile terminal 10 may be connected to each other via an external server device.

[0026] The mobile terminal 10, for example, acquires the position and orientation of the automobile M measured by the vehicle positioning device 20 of the automobile M, sets them as the reference position and reference orientation for its own autonomous navigation, and executes autonomous navigation positioning.

[0027] 2 is a diagram showing a functional block diagram of the mobile terminal 10. The mobile terminal 10 includes a storage unit 12, a control unit 13, a communication unit 14, an output unit 15, and an IMU 16. The mobile terminal 10 is a device in which the respective functional blocks cooperate with each other via a system bus 11.

[0028] The storage unit 12 is configured with, for example, a hard disk device, a solid state drive (SSD), a flash memory, etc., and stores various programs such as an operating system and terminal software, etc. The storage unit 12 also stores outdoor map information showing outdoor road and facility information, indoor map information showing internal map information of the facility at the destination, etc.

[0029] The various programs, global map information, and local map information may be acquired, for example, from another server device or the like via a network, or may be recorded on a recording medium and read via various drive devices. That is, the various programs stored in the storage unit 12 (including a program for executing a process for acquiring initial information for autonomous navigation, which will be described later) can be transmitted via a network, and can be recorded on a computer-readable recording medium and transferred.

[0030] The control unit 13 is configured with a CPU (Central Processing Unit) 13A, a ROM (Read Only Memory) 13B, a RAM (Random Access Memory) 13C, etc., and functions as a computer. The CPU 13A reads out and executes various programs stored in the ROM 13B and the storage unit 12 to realize various functions.

[0031] The communication unit 14 is a communication device mounted on the mobile terminal 10 and capable of wireless communication according to, for example, the Bluetooth (registered trademark) standard. The communication unit 14 is capable of communicating with the vehicle positioning device 20 of the automobile M, transmits a transmission request for vehicle information to the vehicle positioning device 20, and receives signal information including the vehicle information from the vehicle positioning device 20. The communication unit 14 also transmits the received signal information to the control unit 13. The control unit 13 acquires the vehicle information from the signal information received from the communication unit 14. At this time, the control unit 13 functions as a vehicle information acquisition unit that acquires the vehicle information. In other words, the mobile terminal 10 includes the control unit 13 as a vehicle information acquisition unit that acquires vehicle information indicating the position and direction of the automobile M.

[0032] When the vehicle positioning device 20 transmits vehicle information to a server via an Internet connection network, the communication unit 14 may be a communication device capable of communicating according to the IEEE802.11 communication standard. In this case, the communication unit 14 may connect to the Internet connection network via a surrounding access point and acquire vehicle information from the server. The communication unit 14 may also be a communication device capable of connecting to the Internet connection network via a Wide Area Network (WAN) provided by a telecommunications carrier.

[0033] The output unit 15 is an information output device such as a display 15A and a speaker 15B mounted on the mobile terminal 10. Based on a signal output from the control unit 13, the output unit 15 can cause the display 15A to display an image and the speaker 15B to output a sound.

[0034] The control unit 13 has a navigation function that, for example, associates its own position estimated by autonomous navigation with outdoor map information and internal map information of the facility recorded in the memory unit 12, and outputs video or audio to the display 15A and speaker 15B to guide the occupant CR of the automobile M to the destination.

[0035] The IMU 16 is an inertial measurement device mounted on the mobile terminal 10 and includes an acceleration sensor and a gyro sensor. The IMU 16 acquires inertial information such as movement or rotation of the mobile terminal 10. The IMU 16 transmits the acquired inertial information to the control unit 13. The control unit 13 calculates the moving distance and moving direction of the mobile terminal 10 based on the inertial information received from the IMU 16. The control unit 13 also realizes autonomous navigation positioning based on initial information, which is the reference position and reference attitude of the autonomous navigation, and the moving distance and moving direction of the mobile terminal 10 calculated from the inertial information.

[0036] The imaging unit 17 as an image acquisition unit is, for example, an imaging device such as a camera mounted on the mobile terminal 10. In this embodiment, when determining a reference position for autonomous navigation of the mobile terminal 10, the occupant CR gets off the automobile M and then uses the imaging unit 17 to capture a vehicle image including the automobile M from outside the automobile M. The imaging unit 17 transmits the captured vehicle image to the control unit 13. The control unit 13 acquires the vehicle image from the imaging unit 17. At this time, the control unit 13 functions as an image acquisition unit that acquires the vehicle image. In other words, the mobile terminal 10 includes the control unit 13 as an image acquisition unit that acquires a vehicle image captured of the automobile M from outside the automobile M.

[0037] The control unit 13 analyzes the vehicle image received from the imaging unit 17, and calculates from which position the mobile terminal 10 captured the image of the automobile M based on the characteristic points of the automobile M included in the vehicle image. That is, the control unit 13 analyzes the vehicle image and calculates relative information indicating the relative position and relative attitude of the mobile terminal 10 with respect to the automobile M. At this time, the control unit 13 functions as a relative information acquisition unit that acquires relative information indicating the relative position and relative attitude of the mobile terminal 10 with respect to the automobile M. In other words, the mobile terminal 10 includes the control unit 13 as a relative information acquisition unit that acquires relative information indicating the relative position and relative attitude of the mobile terminal 10 with respect to the automobile M when the mobile terminal 10 is located outside the automobile M.

[0038] The control unit 13 calculates the position and attitude of the mobile terminal 10 in the geographic coordinate system at the time of capturing the vehicle image, based on the vehicle information indicating the position and direction of the automobile M in the geographic coordinate system received from the communication unit 14, and the relative information indicating the relative position and relative attitude calculated by analyzing the vehicle image. The control unit 13 also sets the calculated position and attitude of the mobile terminal 10 in the geographic coordinate system as initial information indicating the reference position and reference attitude of the autonomous navigation. At this time, the control unit 13 functions as a reference information acquisition unit that calculates the reference position and reference attitude of the mobile terminal 10. In other words, the mobile terminal 10 includes the control unit 13 as a reference information acquisition unit that calculates the reference position and reference attitude of the mobile terminal 10 based on the vehicle information and the relative information.

[0039] Furthermore, the control unit 13 executes autonomous navigation positioning starting from the initial information based on the initial information and the inertial information received from the IMU 16. At this time, the control unit 13 functions as an autonomous navigation processing unit that executes the autonomous navigation positioning. In other words, the mobile terminal 10 includes the control unit 13 as an autonomous navigation processing unit that executes autonomous navigation positioning using the reference position and the reference attitude as initial information for autonomous navigation.

[0040] The procedure by which the mobile terminal 10 calculates the initial information will be described in detail with reference to FIG.

[0041] FIG. 3 is a diagram illustrating a method of calculating the initial information of the mobile terminal 10 according to the first embodiment of the present invention.

[0042] A passenger CR who is the owner of the mobile terminal 10 stops the automobile M and gets out of the automobile M. After that, the passenger CR captures an image of the area including the automobile M using the imaging unit 17 provided in the mobile terminal 10 from outside the automobile M to obtain a vehicle image. The control unit 13 detects features of the automobile M from the captured vehicle image. The feature points of the automobile M are structures that are located at predetermined positions on the exterior of the automobile M, such as the headlights HL, the front grille FG, the side mirrors SM, the tires TR, or the taillights TL.

[0043] Further, a plurality of reference images of the automobile M captured from a plurality of relative positions and relative attitudes known in advance are stored in the storage unit 12 of the mobile terminal 10. Note that the feature points of the automobile M are recorded in the storage unit 12 of the mobile terminal 10 so that the relative position and arrangement with respect to the vehicle positioning device 20 are known.

[0044] The control unit 13 compares the vehicle image with each of the reference images, detects a reference image having feature points similar to those of the vehicle image, and estimates an approximate relative position and relative attitude of the mobile terminal 10. The control unit 13 also compares the arrangement and size ratio of the feature points of the vehicle image with the arrangement and size ratio of the feature points of the reference image, and calculates the amount of deviation from the relative position and relative attitude of the reference image. The control unit 13 also corrects the calculated amount of deviation to the relative position and relative attitude of the reference image, thereby acquiring relative information indicating the accurate relative position and relative attitude of the mobile terminal 10 with respect to the automobile M. In other words, the control unit 13 as a relative information acquisition unit acquires a vehicle image from the imaging unit 17, and calculates relative information indicating the relative position and relative attitude of the mobile terminal 10 with respect to the automobile M based on the positions of the feature points of the automobile M in the vehicle image.

[0045] Furthermore, the control unit 13 acquires vehicle information via the communication unit 14. For example, after capturing an image of a vehicle or calculating relative information of the mobile terminal 10, the control unit 13 transmits a request signal to the vehicle positioning device 20 via the communication unit 14 by Bluetooth or the like to request transmission of vehicle information. In response to receiving the request signal, the vehicle positioning device 20 transmits vehicle information at the time of receiving the request signal to the mobile terminal 10 by Bluetooth or the like. In other words, the control unit 13 as a vehicle information acquisition unit acquires a vehicle image from the imaging unit 17 and acquires vehicle information at the time of acquiring the vehicle image.

[0046] The control unit 13 calculates a reference position and reference attitude indicating the position and attitude of the mobile terminal 10 in the geographic coordinate system based on vehicle information indicating the position and attitude of the automobile M in the geographic coordinate system and relative information indicating the relative position and relative attitude with respect to the automobile M.

[0047] The control unit 13 sets the calculated reference position and reference attitude as initial information for the autonomous navigation, and executes autonomous navigation positioning from the initial information.

[0048] The method of acquiring the vehicle information is not limited to the above method. For example, when the vehicle positioning device 20 detects that the automobile M has been stopped, the vehicle information indicating the position and direction of the automobile M in the geographic coordinate system at the time of stopping may be transmitted to the mobile terminal 10. Furthermore, when the vehicle positioning device 20 detects that the automobile M has been stopped, the vehicle information may be transmitted to a server that stores the vehicle information by connecting to an Internet connection network. In this case, for example, the mobile terminal 10 may connect to the Internet connection network when capturing an image of the vehicle, and acquire the vehicle information of the automobile M from the server. Furthermore, the vehicle information may be acquired either before or after capturing an image of the vehicle.

[0049] In the first embodiment, the case has been described where the feature points of the automobile M are various parts provided on the automobile M. However, the feature points of the automobile M may be provided separately on the exterior of the automobile M as markers MK capable of image recognition. The markers MK have, for example, a pattern that allows a part or location of the automobile M to be identified. By providing the markers MK, the control unit 13 can, for example, detect a plurality of identifiable markers MK in the vehicle image and calculate relative information with respect to the automobile M from the pattern, inclination, size, etc. of each of the markers MK. This makes it possible to calculate the relative information of the mobile terminal 10 more accurately.

[0050] Also, for example, a vehicle image may be captured by irradiating the automobile M with a grid-shaped or multiple line-shaped laser light from the mobile terminal 10, and a distance measurement image may be generated from the shape of the reflected light of the laser light.

[0051] In the first embodiment, the imaging unit 17 is composed of a camera, and the relative information of the mobile terminal 10 with respect to the automobile M is calculated by analyzing the vehicle image of the automobile M captured by the imaging unit 17. However, the imaging unit 17 may be, for example, a three-dimensional image sensor. The three-dimensional image sensor is, for example, an image sensor such as LiDAR (Light Detection And Ranging) using a pulsed laser. The imaging unit 17 acquires a distance measurement image of the automobile M using a ToF (Time of Flight) method or the like. The control unit 13 acquires the distance measurement image from the imaging unit 17. At this time, the control unit 13 functions as an image acquisition unit that acquires the distance measurement image. In other words, the mobile terminal 10 includes the control unit 13 as an image acquisition unit that acquires a vehicle image including a three-dimensional image of an area including the automobile M from outside the automobile M captured by the imaging unit 17. Also, three-dimensional scan data of the automobile M is recorded in advance in the storage unit 12 of the mobile terminal 10.

[0052] The control unit 13 compares the distance measurement image acquired by the imaging unit 17 with the 3D scan data recorded in the storage unit 12. The control unit 13 calculates the distance and angle of the 3D scan data with which part of the external shape of the automobile M included in the distance measurement image matches, and acquires the distance and angle as relative information indicating the relative distance and relative attitude of the mobile terminal 10. In other words, the control unit 13 as a relative information acquisition unit acquires a 3D image from the imaging unit 17, and calculates relative information indicating the relative position and relative attitude of the mobile terminal 10 with respect to the automobile M based on the 3D shape and attitude of the automobile M in the 3D image.

[0053] By selecting a three-dimensional image sensor for the imaging unit 17, it becomes possible to acquire more accurate relative information of the mobile terminal 10. Note that the three-dimensional image sensor is not limited to a LiDAR using a pulsed laser, and may acquire a distance measurement image using, for example, a millimeter wave radar or the like.

[0054] Next, an example of an operation routine until the mobile terminal 10 of the first embodiment acquires the initial information will be described.

[0055] Fig. 4 is a diagram showing an operation routine R11 of the vehicle positioning device 20 according to the first embodiment of the present application, and Fig. 5 is a diagram showing an operation routine R12 of the mobile terminal 10 according to the first embodiment of the present application.

[0056] First, there will be described an operation routine R11 of the vehicle positioning device 20. The operation routine R11 is performed, for example, after the occupant CR stops the automobile M.

[0057] When the operation routine R11 is started, the vehicle positioning device 20 determines whether or not there is a request to transmit vehicle information (step S101). The request to transmit vehicle information is a request signal for transmitting vehicle information from a mobile terminal 10 described later to the mobile terminal 10. The request signal is made by communication such as Bluetooth, for example.

[0058] If it is determined that a transmission request for vehicle information has not been made (step S101: No), the vehicle positioning device 20 ends and then executes the operation routine R11 again. That is, the vehicle positioning device 20 repeatedly executes the process of step S101 to determine whether a transmission request for vehicle information has been made.

[0059] When it is determined that a transmission request for vehicle information has been received (step S101: Yes), the vehicle positioning device 20 acquires vehicle information of the automobile M at the time the transmission request was received and transmits this to the mobile terminal 10 (step S102). The vehicle information is the position and direction of the automobile M in a geographic coordinate system. When the automobile M is stopped in an area where a GPS signal can be received, the position and direction in the geographic coordinate system based on the GPS signal are transmitted as the vehicle information. When the automobile M is stopped in an area where a GPS signal cannot be received, the position and direction in the geographic coordinate system estimated by autonomous navigation based on the IMU 25 and the vehicle speed information acquisition unit 27 from the position and direction where the GPS signal was last received are transmitted as the vehicle information.

[0060] In the first embodiment, the vehicle information is transmitted to the mobile terminal 10 in response to a transmission request from the mobile terminal 10. However, the vehicle positioning device 20 may transmit the vehicle information without waiting for a transmission request from the mobile terminal 10. For example, when it is determined that the automobile M is parked, the vehicle positioning device 20 may transmit the vehicle information to the mobile terminal 10 using Bluetooth. The determination of whether the automobile M is parked may be determined, for example, by determining that the engine of the automobile M is stopped. The determination of whether the automobile M is parked may be performed based on the speed of the automobile M detected by the vehicle speed pulse or the wheel side sensor, without being limited to the engine being stopped. Specifically, for example, it may be determined that the automobile M is parked or simply stopped by determining that the detected vehicle speed is 0. Also, as described above, the vehicle positioning device 20 may include a wireless device conforming to the IEEE802.11 communication standard, and when it is determined that the engine of the automobile M is stopped, the vehicle information may be transmitted to a server via an Internet connection network.

[0061] Furthermore, when the vehicle positioning device 20 determines that the speed of the automobile M has become 0 and that the automobile M has been stopped, for example, the mobile terminal 10 or the server updates the vehicle information as needed.

[0062] The vehicle positioning device 20 performs the process of the above-mentioned operation routine R11 to transmit to the mobile terminal 10 vehicle information indicating the position and direction of the automobile M in the geographic coordinate system.

[0063] Next, a description will be given of the operation routine R12 of the mobile terminal 10. The operation routine R12 is executed in parallel with the operation routine R11, for example.

[0064] After the operation routine R12 is started, a vehicle imaging step is performed to acquire a vehicle image including the automobile M, which is captured from outside the automobile M by a passenger CR who has exited the automobile M (step S111). The imaging unit 17 transmits the captured vehicle image to the control unit 13.

[0065] Next, the control unit 13 receives a vehicle image from the imaging unit 17, analyzes the received vehicle image, and calculates relative information with respect to the automobile M (step S112). The control unit 13 compares the vehicle image with a plurality of reference images of the automobile M captured from a plurality of previously known relative positions and relative attitudes recorded in the storage unit 12. The control unit 13 also detects a reference image having feature points similar to those of the vehicle image, and compares the arrangement and size ratio of the feature points of the vehicle image with the arrangement and size ratio of the feature points of the reference image to calculate the relative position and relative attitude of the mobile terminal 10 with respect to the automobile M. The control unit 13 also sets the calculated relative position and relative attitude as relative information.

[0066] The processing of steps S111 and S112 functions as a relative information acquisition step of calculating relative information of the mobile terminal 10. In other words, the positioning method executed in the mobile terminal 10 includes a relative information acquisition step of acquiring relative information indicating the relative position and relative attitude of the mobile terminal 10 with respect to the automobile M when the mobile terminal 10 is located outside the automobile M. The relative information acquisition step further includes a vehicle imaging step of imaging the vehicle from outside the automobile M to acquire a vehicle image. The relative information acquisition step calculates relative information indicating the relative position and relative attitude of the mobile terminal 10 with respect to the automobile M based on the positions of the feature points of the automobile M in the vehicle image.

[0067] Furthermore, the control unit 13 performs a vehicle information acquisition step of acquiring vehicle information via the communication unit 14 (step S113). In this step, for example, after the control unit 13 calculates the relative information, it executes a vehicle information transmission request to the automobile M via the communication unit 14. The vehicle positioning device 20 transmits the vehicle information to the mobile terminal 10 in response to the vehicle information transmission request. In other words, the positioning method executed in the mobile terminal 10 includes a vehicle information acquisition step of acquiring vehicle information indicating the position and direction of the automobile M. Furthermore, in the vehicle information acquisition step, vehicle information at the time of capturing the vehicle image is acquired.

[0068] In this embodiment 1, the case where the vehicle information is acquired after the relative information is calculated will be described. However, for example, the control unit 13 may calculate the relative information after acquiring the vehicle information. Specifically, when the vehicle positioning device 20 determines that the engine of the automobile M has been stopped, the relative information may be automatically transmitted to the mobile terminal 10 using Bluetooth. In this case, the operation routine R12 may automatically start processing upon receiving the vehicle information from the vehicle positioning device 20.

[0069] Furthermore, the control unit 13 may connect to a server via an Internet connection network after calculating the relative information, and obtain the vehicle information stored in the server. In this case, as described above, the vehicle positioning device 20 includes a wireless device conforming to the IEEE802.11 communication standard, and transmits the vehicle information to the server via the Internet connection network when it is determined that the engine of the automobile M has stopped.

[0070] Next, the control unit 13 performs a reference information acquisition step of calculating a reference position and a reference attitude of the mobile terminal 10 based on the relative information and the vehicle information (step S114). The control unit 13 calculates a reference position and a reference direction of the mobile terminal 10 in the geographic coordinate system based on the vehicle information indicating the position and direction of the automobile M in the geographic coordinate system and the calculated relative information with respect to the automobile M. The control unit 13 sets the calculated reference position and reference attitude as initial information in the autonomous navigation. In other words, the positioning method executed in the mobile terminal 10 includes a reference information acquisition step of calculating a reference position and a reference attitude of the mobile terminal 10 based on the vehicle information and the relative information.

[0071] By performing the processing of the above-mentioned operation routine R12, the mobile terminal 10 acquires initial information for autonomous navigation. After that, the control unit 13 performs an autonomous navigation processing step of performing autonomous navigation positioning from the initial information. In other words, the positioning method of the mobile terminal 10 includes an autonomous navigation processing step of performing autonomous navigation positioning using the reference position and the reference attitude as the initial information for autonomous navigation.

[0072] As described above, the operation routine R12 is recorded in the storage unit 12 as a software program of the mobile terminal 10, and is read and executed by the CPU 13A, ROM 13B, and RAM 13C as the control unit 13. The program can be recorded in a computer-readable recording medium and transferred. In other words, the operation routine R12 is an autonomous navigation positioning program that causes a computer mounted on the mobile terminal 10 to execute a vehicle information acquisition step of acquiring vehicle information indicating the position and direction of the automobile M, a relative information acquisition step of acquiring relative information indicating the relative position and relative attitude of the mobile terminal 10 with respect to the automobile M when the mobile terminal 10 is located outside the automobile M, a reference information acquisition step of calculating the reference position and reference attitude of the mobile terminal 10 based on the vehicle information and the relative information, and an autonomous navigation processing step of executing autonomous navigation positioning using the reference position and reference attitude as initial information for autonomous navigation. In addition, the operation routine R12 is a computer-readable recording medium that stores an autonomous navigation positioning program that causes a computer mounted on the mobile terminal 10 to execute a vehicle information acquisition step of acquiring vehicle information indicating the position and direction of automobile M, a relative information acquisition step of acquiring relative information indicating the relative position and relative attitude of the mobile terminal 10 with respect to automobile M when the mobile terminal 10 is located outside the automobile M, a reference information acquisition step of calculating a reference position and reference attitude of the mobile terminal 10 based on the vehicle information and the relative information, and an autonomous navigation processing step of performing autonomous navigation positioning using the reference position and reference attitude as initial information for autonomous navigation.

[0073] According to the first embodiment, the mobile terminal 10 acquires vehicle information indicating the position and direction of the automobile M in a geographic coordinate system, the position of which is measured by the vehicle positioning device 20. The mobile terminal 10 also captures a vehicle image of the automobile M from outside the automobile M, and calculates relative information indicating the relative position and relative attitude of the mobile terminal 10 from the vehicle image. The mobile terminal 10 also calculates a reference position and a reference direction of the mobile terminal 10 in the geographic coordinate system, based on the vehicle information and the relative information. The mobile terminal 10 also sets the calculated reference position and reference attitude as initial information for autonomous navigation, and executes autonomous navigation positioning using the initial information.

[0074] By acquiring vehicle information indicating the position and direction of automobile M in the geographic coordinate system of the vehicle positioning device 20 mounted on automobile M, the mobile terminal 10 is able to provide a portable autonomous navigation device that is inexpensive and capable of determining the reference position and reference orientation for autonomous navigation even when away from home, as well as a positioning method and positioning program for the autonomous navigation device. Example 2

[0075] In the first embodiment, in order for the mobile terminal 10 to calculate the relative information, the occupant CR is required to perform an operation of capturing a vehicle image of the automobile M using a camera or a three-dimensional image sensor. However, the mobile terminal 10 may automatically calculate the relative information without requiring an operation by the occupant CR.

[0076] 6 is a diagram illustrating an example of a configuration of an autonomous navigation system 100A according to a second embodiment of the present invention. The autonomous navigation system 100A includes a mobile terminal 10A, which is a mobile autonomous navigation device, and a vehicle positioning device 20A mounted on an automobile M.

[0077] The vehicle positioning device 20A and the mobile terminal 10A of the embodiment 2 are basically configured similarly to the vehicle positioning device 20 and the mobile terminal 10 of the embodiment 1. The embodiment 2 is different in that the vehicle positioning device 20A includes a plurality of beacon transmitters 29A to 29E, and the mobile terminal 10A receives beacon signals from the plurality of beacon transmitters 29A to 29E to calculate relative information of the mobile terminal 10A.

[0078] The vehicle positioning device 20A is a car navigation system capable of measuring the position and direction in a geographic coordinate system of the automobile M, similarly to the first embodiment. The vehicle positioning device 20A also includes a plurality of beacon transmitters 29A to 29E disposed in separate locations within the automobile M.

[0079] The vehicle positioning device 20A includes a GPS receiver 23, an IMU 25, and a vehicle speed information acquisition unit 27, similar to the vehicle positioning device 20 of the first embodiment, but these are omitted in Fig. 6. The vehicle positioning device 20A has the same configuration as the vehicle positioning device 20 except for the multiple beacon transmitters 29A to 29E, and therefore the description thereof will be omitted in the second embodiment.

[0080] Each of the plurality of beacon transmitters 29A to 29E is, for example, a signal transmitter capable of transmitting a radio signal, which is a beacon signal, to the surroundings of each transmitter. Each of the plurality of beacon transmitters 29A to 29E is communicably connected to the positioning unit 21A, and can transmit a beacon signal including the signal received from the positioning unit 21A to the surroundings in response to the signal.

[0081] Each of the multiple beacon transmitters 29A to 29E is arranged, for example, on the roof and on the left and right side surfaces of the front and rear parts of the exterior of the automobile M. Each of the multiple beacon transmitters 29A to 29E is arranged so that, for example, when the mobile terminal 10A is outside the automobile M, it can receive beacon signals from at least three or more beacon transmitters. Also, each of the beacon transmitters 29A to 29E has a different ID from each other, and each generates a signal that includes its own ID information in the signal received from the positioning unit 21A, and transmits the signal to the surroundings as a beacon signal.

[0082] In the second embodiment, the vehicle positioning device 20A will be described as having five beacon transmitters 29A to 29E. However, the number of beacon transmitters provided in the vehicle positioning device 20A is not limited to this, and the vehicle positioning device 20A may have three or four beacon transmitters, or six or more beacon transmitters. For example, two beacon transmitters may be provided on opposite sides of the roof of the automobile M, or six beacon transmitters may be provided at the rear, center, and front of the exterior of the left and right sides of the automobile M. It is preferable that the mobile terminal 10A can receive direct waves of beacon signals from at least three or more beacon transmitters outside the automobile M.

[0083] In addition, in the second embodiment, a case will be described in which multiple beacon transmitters 29A to 29E are arranged on the exterior of the automobile M. However, the beacon transmitters may be arranged inside the passenger compartment of the automobile M. For example, the multiple beacon transmitters may be arranged near the windshield, door glass, and rear glass of the automobile M as long as they do not affect radio wave attenuation of the beacon signals of the multiple beacon transmitters.

[0084] For example, when the positioning unit 21A detects that the automobile M is stopped, such as when the engine of the automobile M is stopped, the positioning unit 21A generates a signal including vehicle information indicating the position and direction in the geographic coordinate system at the time of the stop, and transmits the signal to each of the plurality of beacon transmitters 29A to 29E. Each of the plurality of beacon transmitters 29A to 29E includes its respective ID information in the signal received from the positioning unit 21A, and transmits the signal to the surroundings as a beacon signal. In other words, the beacon signal includes the vehicle information.

[0085] Furthermore, during a predetermined period after detecting that the automobile M has stopped, the positioning unit 21A transmits signals including vehicle information to the plurality of beacon transmitters 29A to 29E at predetermined cycles, causing each of the beacon transmitters to transmit a beacon signal.

[0086] The mobile terminal 10A receives each beacon signal from the multiple beacon transmitters 29A to 29E in a manner that allows them to be distinguished from one another. The mobile terminal 10A is capable of calculating relative information of the mobile terminal 10A with respect to the automobile M based on changes in each beacon signal from the multiple beacon transmitters 29A to 29E. Specifically, the mobile terminal 10A calculates the relative information of the mobile terminal 10A based on changes in reception strength of each beacon signal received multiple times when moving a predetermined distance outside the automobile M and on inertial information of the IMU 16 within the predetermined section.

[0087] Moreover, the mobile terminal 10A extracts vehicle information contained in each of the received beacon signals and acquires the vehicle information.

[0088] 7 is a diagram showing a functional block diagram of the mobile terminal 10A. The functional blocks of the mobile terminal 10A have a basically similar configuration to the mobile terminal 10 of the first embodiment. The mobile terminal 10A is different in that it has a beacon receiver 18 that receives beacon signals from a plurality of beacon transmitters 29A to 29E provided in the vehicle positioning device 20A. Note that the mobile terminal 10A has the same configuration as the mobile terminal 10 except for the beacon receiver 18, and therefore the description thereof will be omitted in the second embodiment.

[0089] The beacon receiver 18 is a beacon receiver that receives each beacon signal transmitted from the multiple beacon transmitters 29A to 29E of the vehicle positioning device 20A in such a manner that the beacon signals can be distinguished from one another and the reception strength of each beacon signal can be detected. The beacon receiver 18 transmits the signal information and reception strength of each of the received beacon signals to the control unit 13.

[0090] The control unit 13 acquires ID information indicating each of the multiple beacon transmitters 29A to 29E from the beacon signal received from the beacon receiver 18, and records the ID information, the reception time, and the reception strength in association with each other in the storage unit 12. At this time, the control unit 13 functions as a beacon signal acquisition unit that acquires each beacon signal received by the beacon receiver 18. In other words, the mobile terminal 10A includes the control unit 13 as a beacon signal acquisition unit that can receive beacon signals from each of the multiple beacon transmitters 29A to 29E provided in the automobile M in a mutually distinguishable manner.

[0091] Furthermore, the control unit 13 records, in the storage unit 12, the ID information and the reception strength of the beacon signal received at a predetermined cycle for a predetermined period after the automobile M is stopped. That is, when the occupant CR carrying the mobile terminal 10A moves outside the automobile M, the control unit 13 records, in the storage unit 12, the ID information and the reception strength of each beacon signal.

[0092] When the occupant CR carrying the mobile terminal 10A moves, the beacon receiver 18 calculates the section in which the mobile terminal 10A has moved relative to the automobile M while the mobile terminal 10A has received the beacon signal multiple times, based on the change in the reception strength of each beacon signal received multiple times from each beacon transmitter. The control unit 13 also calculates the attitude of the mobile terminal 10A in the moving section by aligning the direction of the moving section in which the inertial information of the IMU 16 during the multiple reception of each beacon signal is calculated. The control unit 13 sets the position and attitude with respect to the automobile M at the time of the calculation as relative information indicating the relative position and relative attitude of the mobile terminal 10A. In other words, the control unit 13 as a relative information acquisition unit calculates relative information indicating the relative position and relative attitude of the mobile terminal 10A in the predetermined section with respect to the automobile M, based on the change in the strength of the beacon signal acquired multiple times from the beacon receiver 18 when the mobile terminal 10A moves in the predetermined section and the change in the attitude of the mobile terminal 10A while the beacon signal is received multiple times.

[0093] Furthermore, the control unit 13 acquires vehicle information indicating the position and direction of the automobile M in the geographic coordinate system from each received beacon signal. The control unit 13 calculates a reference position and a reference attitude indicating the position and direction of the mobile terminal 10A in the geographic coordinate system based on the vehicle information and the relative information, and sets the reference position and the reference attitude as initial information for autonomous navigation.

[0094] The procedure by which the mobile terminal 10A calculates the initial information will be described in detail with reference to FIG.

[0095] FIG. 8 is a diagram illustrating a method of calculating the initial information of the mobile terminal 10A according to the second embodiment of the present invention.

[0096] In this second embodiment, a case will be described in which the mobile terminal 10A acquires first beacon signals SG11, SG12, and SG13 at a first position P1 indicated by a broken line, moves to a second position P2 indicated by a solid line, acquires second beacon signals SG21, SG22, and SG23, and calculates relative information. In this second embodiment, a case will be described in which the mobile terminal 10A calculates relative information based on beacon signals received from beacon transmitters 29A and 29B that can be received as direct waves.

[0097] A passenger CR who is the owner of the mobile terminal 10A stops the automobile M and gets out of the automobile M. The vehicle positioning device 20A detects the stopping of the automobile M, such as the engine being stopped. After detecting the stopping of the automobile M, the positioning unit 21A of the vehicle positioning device 20A transmits vehicle information indicating the position and direction of the automobile M in the geographic coordinate system, which is positioned by the positioning unit 21A, to each beacon transmitter. Each beacon transmitter includes its own ID information in the vehicle information received from the positioning unit 21A, and transmits the information as a first beacon signal SG11, SG12, or SG13.

[0098] The portable terminal 10A held by the occupant CR receives, for example, first beacon signals SG11, SG12, and SG13 from the beacon transmitters 29A and 29B, respectively, at a first position P1. The storage unit 12 stores, for example, in advance, the positions of the multiple beacon transmitters 29A to 29E in the automobile M and the relationship between the reception strength and distance of each of the beacon transmitters. The control unit 13 calculates a first position P1, which is the relative position of the portable terminal 10A with respect to the automobile M, based on the reception strength of each of the first beacon signals SG11, SG12, and SG13 received from the beacon transmitters 29A and 29B, respectively.

[0099] Next, the occupant CR moves and receives, for example, second beacon signals SG21, SG22, and SG23 from the beacon transmitters 29A and 29B, respectively, at a second position P2. The control unit 13 calculates a second position P2, which is the relative position of the mobile terminal 10A with respect to the automobile M, based on the reception strengths of the second beacon signals SG21, SG22, and SG23 received from the beacon transmitters 29A and 29B, respectively.

[0100] Furthermore, the control unit 13 calculates a moving route RT within the moving section from the first position P1 to the second position P2 based on the first position P1 and the second position P2 and the inertial information acquired by the IMU 16 within the moving section from the first position P1 to the second position P2. Specifically, the control unit 13 aligns the inertial direction and the rotation direction of the inertial information acquired by the IMU 16 so that the first and second positions P1 and P2 indicating the relative positions with respect to the automobile M calculated from the reception strengths of the first and second beacon signals become the starting point and the ending point. As a result, the control unit 13 calculates the attitude of the mobile terminal 10A within the moving section from the first position P1 to the second position P2.

[0101] The control unit 13 sets, for example, the relative position and relative attitude of the mobile terminal 10A with respect to the automobile M at the calculated first position P1 as relative information.

[0102] Furthermore, the control unit 13 extracts and acquires vehicle information indicating the position and direction of the automobile M in the geographic coordinate system from each of the received beacon signals SG11, SG12, SG13, SG21, SG22, and SG23. In other words, the control unit 13 as a vehicle information acquisition unit acquires vehicle information from the beacon signals and acquires the vehicle information at the time when the multiple beacon transmitters 29A to 29E transmitted the beacon signals.

[0103] The control unit 13 calculates the position and attitude of the mobile terminal 10A in the geographic coordinate system based on the relative information indicating the calculated relative position and relative attitude with respect to the automobile M and the vehicle information acquired from the beacon signal. The control unit 13 also sets the calculated position and attitude of the mobile terminal 10A in the geographic coordinate system as initial information indicating the reference position and reference attitude of the autonomous navigation.

[0104] This enables the mobile terminal 10A to perform autonomous navigation positioning based on the initial information and the inertial information received from the IMU 16.

[0105] In addition, the mobile terminal 10A receives a beacon signal, automatically calculates relative information, and calculates initial information for autonomous navigation based on the vehicle information and the relative information. That is, the mobile terminal 10A can calculate the initial information for autonomous navigation without requiring a specific operation by the occupant CR.

[0106] In the second embodiment, the case where the relative information is calculated based on the beacon signals received from the beacon transmitters 29A and 29B has been described. However, the calculation of the relative information may use the beacon signals of all the beacon transmitters 29A to 29E. Also, it may be determined whether the received beacon signal is a direct wave or an indirect wave based on the reception strength of the received beacon signal, and the beacon signal used for the calculation of the relative information may be automatically selected.

[0107] In addition, in the second embodiment, the case where the relative information is calculated from the first and second beacon signals has been described, but the relative information may be calculated using three or more beacon signals. For example, the mobile terminal 10A may calculate the relative information as needed and update the relative information as long as the vehicle positioning device 20A continues to transmit beacon signals. By increasing the number of calculations of the relative information, particularly by increasing the number of alignments of the inertial direction and the rotational direction of the inertial information acquired by the IMU 16, it is possible to improve the accuracy of the initial information in the autonomous navigation.

[0108] Next, an example of an operation routine until the mobile terminal 10A of the second embodiment acquires the initial information will be described.

[0109] Fig. 9 is a diagram showing an operation routine R21 of the vehicle positioning device 20A according to the second embodiment of the present invention, and Fig. 10 is a diagram showing an operation routine R22 of the mobile terminal 10A according to the second embodiment of the present invention.

[0110] The operation routine R21 of the vehicle positioning device 20A shown in FIG. 9 is repeatedly executed when the vehicle positioning device 20A is powered on.

[0111] First, the operation routine R21 of the vehicle positioning device 20A will be described. The operation routine R21 is performed, for example, during a predetermined period while the occupant CR is driving the automobile M and after the automobile M is stopped. Also, step S201 of the operation routine R21 is similar to step S101 of the operation routine R11 of the first embodiment shown in FIG. 4, and therefore will not be described.

[0112] In step S201, if it is determined that the automobile M has stopped (step S201: Yes), the vehicle positioning device 20A generates beacon signals to be transmitted from the multiple beacon transmitters 29A to 29E (step S202). In this step, first, the positioning unit 21A transmits vehicle information of the automobile M at the time when the automobile M has stopped to the multiple beacon transmitters 29A to 29E. In addition, the multiple beacon transmitters 29A to 29E generate signals in which their respective ID information has been added to the received vehicle information.

[0113] Next, the vehicle positioning device 20A transmits the generated beacon signals from the multiple beacon transmitters 29A to 29E to the surroundings of the automobile M (step S203). In this step, for example, after detecting that the automobile M has stopped, the beacon signals are transmitted at a predetermined cycle for a predetermined period of time. Specifically, this step operates only for a period estimated to be necessary for the mobile terminal 10A to calculate the relative information, for example, one minute after the automobile M has stopped. In addition, this step transmits the beacon signals at a cycle of one second during this period of time.

[0114] The period and cycle for which this step is performed can be set arbitrarily. For example, the mobile terminal 10A and the vehicle positioning device 20A may each include a communication device such as Bluetooth, and when the mobile terminal 10A completes the calculation of the relative information, it may transmit an end signal for ending this step to the vehicle positioning device 20A.

[0115] Next, the operation routine R22 of the mobile terminal 10A will be described. The operation routine R22 is performed, for example, after the automobile M has stopped.

[0116] When the operation routine R12 is started, the control unit 13 of the mobile terminal 10A starts a beacon reception step of acquiring each beacon signal via the beacon receiver 18 (step S211). The operation routine R22 may automatically start processing upon receiving a beacon signal from the vehicle positioning device 20A. The control unit 13 records the reception time, transmitter ID information, and reception strength of each acquired beacon signal in the storage unit 12 in association with each other.

[0117] Next, the control unit 13 starts acquiring inertial information from the IMU 16 (step S212). The IMU 16 transmits the acquired inertial information to the control unit 13. The control unit 13 records the acquired inertial information in the storage unit 12 in association with time information, an inertial direction, and a rotation direction.

[0118] Next, the control unit 13 determines whether the mobile terminal 10A has moved a predetermined distance or more, based on the inertial information of the IMU 16 (step S213).

[0119] When it is not determined that the mobile terminal 10A has moved the predetermined distance or more (step S213: No), the control unit 13 returns to the process of step S211 and continues acquiring the beacon signal and the inertial information.

[0120] If it is determined that the mobile terminal 10A has moved a predetermined distance or more (step S213: Yes), the control unit 13 ends the acquisition of the beacon signal, and ends the beacon reception step (step S214).

[0121] Next, the control unit 13 calculates relative information indicating the relative position and relative attitude with respect to the automobile M based on the reception time, reception strength, and inertial information of each of the acquired beacon signals (step S215). In this step, first, the control unit 13 calculates the relative position of the mobile terminal 10A with respect to the automobile M at each reception time from the reception strength of each of the acquired beacon signals. Next, the control unit 13 aligns the direction of the inertial information so that the movement based on the acquired inertial information matches each of the relative positions of the mobile terminal 10A with respect to the automobile M at the reception time of each beacon signal of the mobile terminal 10A. In addition, the control unit 13 calculates the relative attitude of the mobile terminal 10A with respect to the automobile M based on the aligned inertial information and each of the relative positions with respect to the automobile M at the reception time of each beacon signal. The control unit 13 sets the relative position and relative attitude of the mobile terminal 10A with respect to the automobile M at the position where the first beacon signal was received among the beacon signals received multiple times as the relative information.

[0122] The mobile terminal 10A performs the processes of steps S211 to S215, thereby functioning as a relative information acquisition step that calculates relative information of the mobile terminal 10A. The positioning method executed by the mobile terminal 10A further includes, in the relative information acquisition step, a beacon reception step that receives beacon signals from each of the multiple beacon transmitters 29A to 29E provided on the automobile M in a mutually distinguishable manner. In the relative information acquisition step, the mobile terminal 10A calculates relative information indicating the relative position and relative attitude of the mobile terminal 10A in a predetermined section with respect to the automobile M, based on changes in the strength of the beacon signals received multiple times when the mobile terminal 10A moves through a predetermined section and changes in the attitude of the mobile terminal 10A while receiving the beacon signals multiple times.

[0123] The relative positions with respect to the automobile M at the time of receiving each beacon signal may be calculated simultaneously in step S211. Also, in step S213, it may be determined whether the mobile terminal 10A has moved a predetermined distance or more based on the calculated relative positions with respect to the automobile M.

[0124] Next, the control unit 13 performs a vehicle information acquisition step of acquiring vehicle information contained in the beacon signal from each piece of acquired beacon information (step S216). In this step, the control unit 13 extracts and acquires the vehicle information from the beacon signal acquired via the beacon receiver 18. In other words, in the vehicle information acquisition step, the vehicle information contained in the beacon signal is acquired to acquire the vehicle information at the time when the multiple beacon transmitters 29A to 29E transmitted the beacon signals.

[0125] The vehicle information may be acquired prior to the calculation of the relative information. Specifically, the vehicle information may be acquired when the beacon signal is received in step S211.

[0126] Next, the control unit 13 performs a reference information acquisition step of calculating a reference position and a reference attitude of the mobile terminal 10A based on the relative information and the vehicle information (step S217). The control unit 13 calculates a reference position and a reference direction of the mobile terminal 10A in the geographic coordinate system based on the vehicle information indicating the position and direction of the automobile M in the geographic coordinate system and the calculated relative information with respect to the automobile M. The control unit 13 sets the calculated reference position and reference attitude as initial information in the autonomous navigation.

[0127] By performing the processing of the above-mentioned operation routine R22, the mobile terminal 10A acquires initial information for autonomous navigation. After that, the control unit 13 performs an autonomous navigation processing step for executing autonomous navigation positioning from the initial information.

[0128] According to the second embodiment, the mobile terminal 10A receives beacon signals from each of the multiple beacon transmitters 29A to 29E provided in the vehicle positioning device 20A of the automobile M. From the change in reception strength of each beacon signal received multiple times when the mobile terminal 10A moves over a predetermined distance, the mobile terminal 10A calculates relative information indicating the relative position and relative attitude of the mobile terminal 10A with respect to the automobile M. The mobile terminal 10A also acquires vehicle information indicating the position and direction of the automobile M in a geographic coordinate system, which is included in the received beacon signal. The mobile terminal 10A also calculates a reference position and a reference direction of the mobile terminal 10A in the geographic coordinate system based on the vehicle information and the relative information. The mobile terminal 10A also sets the calculated reference position and reference attitude as initial information for autonomous navigation, and executes autonomous navigation positioning using the initial information.

[0129] In the second embodiment, it has been described that the beacon signals transmitted by the beacon transmitters 29A to 29E include vehicle information, and the mobile terminal 10A acquires the vehicle information from the received beacon signals. However, the vehicle positioning device 20 may acquire the vehicle information via wireless communication with the vehicle positioning device 20A, as in the first embodiment, without including the vehicle information in the beacon signals transmitted by the beacon transmitters 29A to 29E, or may acquire the vehicle information from a server by connecting to an Internet connection network.

[0130] By receiving beacon signals transmitted from each of the multiple beacon transmitters 29A-29E equipped in the vehicle positioning device 20A mounted on the automobile M, the mobile terminal 10A can determine the reference position and reference attitude of the autonomous navigation without requiring a specific operation by the occupant CR. In addition, by receiving beacon signals transmitted from each of the multiple beacon transmitters 29A-29E, the mobile terminal 10A can provide a portable autonomous navigation device that is inexpensive and can determine the reference position and reference orientation of the autonomous navigation even when away from home, as well as a positioning method and positioning program for the autonomous navigation device.

[0131] In the above embodiment, the mobile terminals 10, 10A are described as being owned by the occupant CR of the automobile M, but as long as the mobile terminals 10, 10A are permitted to communicate with the vehicle positioning devices 20, 20A, or are not prohibited from communicating with the vehicle positioning devices 20, 20A, the owner does not have to be the occupant CR of the automobile M. In this case, for example, a mobile terminal owned by a third party who is not an occupant of the automobile M can obtain vehicle information from the automobile M while it is parked, thereby obtaining initial information for autonomous navigation positioning performed by the mobile terminal. [Explanation of symbols]

[0132] 100 Autonomous Navigation System 10 Mobile devices 11 System Bus 12 Storage section 13 Control section 14 Communications Department 15 Output section 16 IMU 17 Imaging section 18 Beacon Receiver 20 Vehicle positioning device 21 Positioning unit 23 GPS receiver 25 IMU 27 Vehicle speed information acquisition section 29 Beacon transmitter

Claims

1. A mobile terminal, a vehicle information acquisition unit that acquires vehicle information indicating a position and a direction of a vehicle; a relative information acquisition unit that acquires relative information indicating a relative position and a relative attitude of the mobile terminal with respect to the vehicle when the mobile terminal is located outside the vehicle; a reference information acquisition unit that calculates a reference position and a reference attitude of the mobile terminal based on the vehicle information and the relative information; an autonomous navigation processing unit that performs autonomous navigation positioning using the reference position and the reference attitude as initial information; A mobile terminal comprising:

2. the mobile terminal includes an image acquisition unit that acquires a vehicle image obtained by capturing an image of the vehicle from outside the vehicle; The mobile terminal according to claim 1, characterized in that the relative information acquisition unit calculates the relative information indicating the relative position and the relative attitude of the mobile terminal with respect to the vehicle based on the positions of feature points of the vehicle in the vehicle image acquired by the image acquisition unit.

3. the mobile terminal includes an image acquisition unit that acquires a vehicle image including a three-dimensional image of an area including the vehicle from outside the vehicle; The mobile terminal according to claim 1, characterized in that the relative information acquisition unit calculates the relative information indicating the relative position and the relative attitude of the mobile terminal with respect to the vehicle based on the three-dimensional shape and the attitude of the vehicle in the three-dimensional image acquired by the image acquisition unit.

4. 4. The mobile terminal according to claim 2, wherein the vehicle information acquisition unit acquires the vehicle information at a time when the vehicle image acquired by the image acquisition unit is captured.

5. the mobile terminal includes a beacon signal acquisition unit capable of receiving beacon signals from a plurality of beacon transmitters provided in the vehicle in a manner that enables the beacon signals to be distinguished from one another; The mobile terminal according to claim 1, characterized in that the relative information acquisition unit calculates the relative information indicating the relative position and the relative attitude of the mobile terminal with respect to the vehicle in the specified section based on a change in strength of the beacon signal received multiple times by the beacon signal acquisition unit when the mobile terminal moves within the specified section and a change in attitude of the mobile terminal between the reception of the beacon signal multiple times.

6. the beacon signal includes the vehicle information; 6. The mobile terminal according to claim 5, wherein the vehicle information acquisition unit acquires the vehicle information from the beacon signal, and acquires the vehicle information at the time when the plurality of beacon transmitters transmitted the beacon signals.

7. A positioning method executed in a mobile terminal, comprising: a vehicle information acquiring step of acquiring vehicle information indicating a position and a direction of the vehicle; a relative information acquisition step of acquiring relative information indicating a relative position and a relative attitude of the mobile terminal with respect to the vehicle when the mobile terminal is located outside the vehicle; a reference information acquisition step of calculating a reference position and a reference attitude of the mobile terminal based on the vehicle information and the relative information; an autonomous navigation processing step of performing autonomous navigation positioning using the reference position and the reference attitude as initial information; A positioning method comprising:

8. The relative information acquiring step further includes a vehicle imaging step of acquiring a vehicle image by imaging the vehicle from outside the vehicle, The positioning method according to claim 7, characterized in that in the relative information acquisition step, the relative information indicating the relative position and the relative attitude of the mobile terminal with respect to the vehicle is calculated based on positions of feature points of the vehicle in the vehicle image.

9. The positioning method according to claim 8 , wherein in the vehicle information acquisition step, the vehicle information at a time when the vehicle image is captured is acquired.

10. The relative information acquisition step further includes a beacon reception step of receiving beacon signals from a plurality of beacon transmitters provided in the vehicle in a manner that the beacon signals can be distinguished from each other, The positioning method according to claim 7, characterized in that, in the relative information acquisition step, the relative information indicating the relative position and the relative attitude of the mobile terminal with respect to the vehicle in the specified section is calculated based on a change in strength of the beacon signal received multiple times when the mobile terminal moves within the specified section and a change in attitude of the mobile terminal while receiving the beacon signal multiple times.

11. 11. The positioning method according to claim 10, wherein in the vehicle information acquisition step, the vehicle information carried in the beacon signal is acquired to obtain the vehicle information at the time when the plurality of beacon transmitters transmitted the beacon signals.

12. The computer installed in the mobile device a vehicle information acquiring step of acquiring vehicle information indicating a position and a direction of the vehicle; a relative information acquisition step of acquiring relative information indicating a relative position and a relative attitude of the mobile terminal with respect to the vehicle when the mobile terminal is located outside the vehicle; a reference information acquisition step of calculating a reference position and a reference attitude of the mobile terminal based on the vehicle information and the relative information; an autonomous navigation processing step of performing autonomous navigation positioning using the reference position and the reference attitude as initial information; A positioning program that causes the program to execute the above steps.

13. The computer installed in the mobile device a vehicle information acquiring step of acquiring vehicle information indicating a position and a direction of the vehicle; a relative information acquisition step of acquiring relative information indicating a relative position and a relative attitude of the mobile terminal with respect to the vehicle when the mobile terminal is located outside the vehicle; a reference information acquisition step of calculating a reference position and a reference attitude of the mobile terminal based on the vehicle information and the relative information; an autonomous navigation processing step of performing autonomous navigation positioning using the reference position and the reference attitude as initial information; A computer-readable recording medium storing a positioning program for executing the above.

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