阅读说明：本技术 定位装置 (Positioning device ) 是由 宫尾将德 浅井健太郎 森内阳介 于 2018-11-21 设计创作，主要内容包括：进行测定车辆(2)的位置的定位的定位装置(1、31)具备：内部定位部(18),接收从GNSS卫星发送的信号,使用该接收到的信号进行上述定位；信息获取部(16、33),获取与上述车辆相关的信息亦即车辆相关信息；以及选择部(17、34),选择使用基于上述内部定位部的上述定位得到定位结果的第一定位方式、和能代替上述内部定位部的上述定位或者除此之外使用上述车辆相关信息得到精度比通过上述第一定位方式得到的上述定位结果高的定位结果的第二定位方式中任一方,作为上述定位的方式。上述选择部若判断为通过上述第二定位方式得到的上述定位结果的精度比通过上述第一定位方式得到的上述定位结果的精度低,则切换上述定位的方式以选择上述第一定位方式。(A positioning device (1, 31) for performing positioning for measuring the position of a vehicle (2) is provided with: an internal positioning unit (18) that receives a signal transmitted from a GNSS satellite and performs the positioning using the received signal; an information acquisition unit (16, 33) that acquires vehicle-related information that is information related to the vehicle; and a selection unit (17, 34) that selects, as the positioning method, either a first positioning method that uses a positioning result obtained by the positioning by the internal positioning unit, or a second positioning method that can obtain a positioning result with higher accuracy than the positioning result obtained by the first positioning method, instead of or in addition to the positioning by the internal positioning unit, using the vehicle-related information. If it is determined that the accuracy of the positioning result obtained by the second positioning method is lower than the accuracy of the positioning result obtained by the first positioning method, the selection unit switches the positioning method to select the first positioning method.)

1. A positioning device (1, 31) for positioning a vehicle (2) for measurement, comprising:

an internal positioning unit (18) that receives a signal transmitted from a GNSS satellite and performs the positioning using the received signal;

an information acquisition unit (16, 33) that acquires vehicle-related information that is information related to the vehicle; and

a selection unit (17, 34) that selects either a first positioning method in which a positioning result is obtained using the positioning by the internal positioning unit or a second positioning method in which a positioning result with higher accuracy than the positioning result obtained by the first positioning method can be obtained using the vehicle-related information instead of the positioning by the internal positioning unit or a positioning result with higher accuracy than the positioning result obtained by the first positioning method can be obtained using the vehicle-related information in addition to the positioning by the internal positioning unit, as the positioning method,

if it is determined that the accuracy of the positioning result obtained by the second positioning method is lower than the accuracy of the positioning result obtained by the first positioning method, the selection unit switches the positioning method to select the first positioning method.

2. The positioning device of claim 1,

the vehicle-related information is information indicating a result of the positioning of a device that measures a position of the vehicle and performs correction for improving accuracy of the positioning,

in the second positioning method, the positioning result is obtained using the vehicle-related information.

3. The positioning device of claim 1,

the vehicle-related information is information required for the purpose of performing the estimated positioning,

in the second positioning method, the result of the positioning by the internal positioning unit is corrected by estimated positioning using the vehicle-related information, and the positioning result is obtained.

4. The positioning device of claim 3,

if the selection unit (34) determines that the positioning accuracy is equal to or higher than the predetermined value, the selection unit determines that the accuracy of the positioning result obtained by the second positioning method is lower than the accuracy of the positioning result obtained by the first positioning method.

5. The positioning device according to claim 3 or 4,

if the number of positioning histories is determined to be insufficient, the selection unit (34) determines that the accuracy of the positioning result obtained by the second positioning method is lower than the accuracy of the positioning result obtained by the first positioning method.

6. The positioning device according to any one of claims 2 to 5,

when a service or an application using the positioning result is started to be executed, the selection unit switches the positioning method according to the characteristics of the service or the application.

7. The positioning device according to any one of claims 2 to 6,

the vehicle-related information is information that can be acquired from an external device (4, 6, 7) that can be mounted on the vehicle,

if it is determined that the external device is not mounted on the vehicle, the selection unit determines that the accuracy of the positioning result obtained by the second positioning method is lower than the accuracy of the positioning result obtained by the first positioning method.

8. The positioning device according to any one of claims 2 to 7,

the vehicle-related information is information that can be acquired from an external device (4, 6, 7) that can be mounted on the vehicle,

if the selection unit determines that the external device is in a failure state, the selection unit determines that the accuracy of the positioning result obtained by the second positioning method is lower than the accuracy of the positioning result obtained by the first positioning method.

9. The positioning device according to any one of claims 2 to 8,

the vehicle-related information is information that can be acquired from an external device (4, 6, 7) that can be mounted on the vehicle,

the information acquisition unit is configured to acquire the vehicle-related information by communicating with the external device,

if the communication is not established, the selection unit determines that the accuracy of the positioning result obtained by the second positioning method is lower than the accuracy of the positioning result obtained by the first positioning method.

10. The positioning device according to any one of claims 2 to 9,

if it is determined that the vehicle-related information is not normal, the selection unit determines that the accuracy of the positioning result obtained by the second positioning method is lower than the accuracy of the positioning result obtained by the first positioning method.

11. The positioning device according to any one of claims 2 to 10,

if it is determined that the reliability of the vehicle-related information is lower than a desired level, the selection unit determines that the accuracy of the positioning result obtained by the second positioning method is lower than the accuracy of the positioning result obtained by the first positioning method.

Technical Field

The present invention relates to a positioning device for performing positioning for measuring a position of a vehicle.

Background

Conventionally, there is a positioning apparatus that performs positioning for measuring the position of a mobile body using GNSS and that has a plurality of positioning systems (see, for example, patent document 1). GNSS is a general term for satellite positioning systems such as GPS, GLONASS, Galileo, and quasi-zenith satellites, and is an omission of Global positioning satellite System (Global navigation satellite System). The above-described plurality of positioning methods include UE-Based positioning in which positioning calculation is performed on the positioning apparatus side and UE-Assisted positioning in which positioning calculation is performed on the positioning server side.

UE-Based positioning has an advantage that the frequency of wireless communication with the positioning server can be suppressed to a low level, and thus power consumption in the positioning apparatus can be reduced, compared to UE-Assisted positioning. However, the UE-Based positioning has a disadvantage that a positioning result cannot be obtained in an environment where positioning is difficult, such as an environment where a positioning satellite is difficult to observe, for example, when a mobile object to which a positioning device is attached is located between buildings.

On the other hand, even in an environment where positioning cannot be performed on the positioning apparatus side, if wireless communication with the positioning server is possible, there is an advantage that a base station positioning result, that is, a backup positioning result can be obtained, and therefore, a situation where a positioning result cannot be obtained does not occur. However, the UE-Assisted positioning has a disadvantage that the frequency of wireless communication with the positioning server increases and power consumption in the positioning apparatus increases, compared to the UE-Based positioning.

Therefore, in the configuration described in patent document 1, the positioning method is set to UE-Based positioning in the normal state, so that power consumption in the positioning apparatus is reduced and the positioning result is obtained. In the configuration described in patent document 1, when the number of visible satellites for UE-Based positioning is less than a predetermined threshold, the positioning method is switched to UE-Assisted positioning, thereby avoiding the occurrence of a situation in which a positioning result cannot be obtained.

Patent document 1: japanese laid-open patent publication No. 2015-059905

When the positioning device is used for a vehicle, the following positioning method is also conceivable in addition to the positioning method in which the positioning device performs positioning itself. That is, in some cases, a vehicle is provided with a device having a function for performing positioning, such as a navigation device. The navigation device has map information, and can correct the positioning result by map matching and the like, so that the accuracy of the positioning result is relatively high.

Further, in some cases, a vehicle is provided with a device having a sensor group such as an acceleration sensor, a gyro sensor, a speedometer, a distance meter, and an azimuth meter. By using the information that can be acquired from these sensor groups, it is possible to correct the positioning result obtained by the positioning apparatus itself.

Thus, when the positioning device is used in a vehicle, a positioning method in which a highly accurate positioning result is obtained by acquiring information indicating a positioning result of a navigation device, a positioning method in which a highly accurate positioning result is obtained by performing correction using information acquired from a sensor group, and the like are considered. However, the above-described conventional technology presupposes that the positioning device is used in a mobile terminal, and therefore, it is not assumed that such a positioning method specific to a vehicle is appropriately selected.

Disclosure of Invention

The invention aims to provide a positioning device capable of selecting an appropriate positioning mode in the application of positioning a vehicle.

In a first aspect of the present invention, a positioning device performs positioning for measuring a position of a vehicle, and includes an internal positioning unit, an information acquisition unit, and a selection unit. The internal positioning unit receives a signal transmitted from a GNSS satellite, and performs positioning using the received signal. The information acquisition unit acquires vehicle-related information that is information related to a vehicle. The selection unit selects either one of the first positioning method and the second positioning method as a positioning method. The first positioning method is a method of obtaining a positioning result by using positioning by an internal positioning unit, and corresponds to positioning by the positioning device itself.

The second positioning method can obtain a positioning result with higher accuracy than the positioning result obtained by the first positioning method using the vehicle-related information instead of the positioning by the internal positioning portion, or can obtain a positioning result with higher accuracy than the positioning result obtained by the first positioning method using the vehicle-related information in addition to the positioning by the internal positioning portion. As the second positioning method, the above-described positioning method, that is, the positioning method in which the high-accuracy positioning result is obtained by acquiring the information indicating the positioning result of the navigation device, the positioning method in which the high-accuracy positioning result is obtained by performing the correction using the information acquired from the sensor group, and the like are assumed.

In such a configuration, if it is determined that the accuracy of the positioning result obtained by the second positioning method is lower than the accuracy of the positioning result obtained by the first positioning method, the selection unit switches the positioning method to select the first positioning method. In other words, the selection unit selects the positioning method so that a highly accurate positioning result is always obtained. In this way, according to the above configuration, since an appropriate positioning method is selected from the viewpoint of improving the accuracy of the positioning result, it is possible to obtain an effect that an appropriate positioning method can be selected for use in positioning of the vehicle.

Drawings

The above object and other objects, features and advantages of the present invention will become more apparent from the following detailed description with reference to the accompanying drawings. The attached figures are such that,

FIG. 1 is a diagram schematically showing the configuration of a car-mounted device and a navigation device according to a first embodiment,

FIG. 2 is a diagram schematically showing the contents of the periodic processing of the first embodiment,

fig. 3 is a diagram schematically showing the contents of the first information acquisition process of the first embodiment,

fig. 4 is a diagram schematically showing the contents of the second information acquisition process of the first embodiment,

FIG. 5 is a diagram schematically showing the contents of the selection processing of the first embodiment,

FIG. 6 is a view schematically showing the configuration of a vehicle-mounted device according to a second embodiment,

FIG. 7 is a diagram schematically showing the contents of the periodic processing in the second embodiment,

fig. 8 is a diagram schematically showing the contents of the second information acquisition process of the second embodiment,

FIG. 9 is a diagram schematically showing the content of the correction selection processing of the second embodiment,

fig. 10 is a diagram for explaining a specific example of selection of a positioning method in the correction selection processing according to the second embodiment.

Detailed Description

Hereinafter, a plurality of embodiments will be described with reference to the drawings. In each embodiment, the same reference numerals are given to the actually same components, and the description thereof is omitted.

(first embodiment)

The first embodiment will be described below with reference to fig. 1 to 5.

The in-vehicle device 1 shown in fig. 1 is used for positioning for measuring the position of the vehicle 2, and corresponds to a positioning device. The in-vehicle device 1 is configured as a Data Communication Module (Data Communication Module), that is, a wireless Communication ECU called DCM, for example. Further, the ECU is an electronic control device. In this case, the in-vehicle device 1 can perform services such as an emergency notification and stolen vehicle tracking.

The in-vehicle device 1 can communicate with a navigation device 4 as an external device that can be mounted on the same vehicle 2 via a communication line 3. The in-vehicle device 1 may communicate with the navigation device 4 via a communication network 5, which is an in-vehicle LAN such as CAN. The in-vehicle device 1 can communicate with other in-vehicle devices 6 and 7, a factory tool 8, and the like as external devices that can be mounted on the same vehicle 2 via the communication network 5.

The in-vehicle device 6 is an instrument ECU including a speedometer, a travel distance meter, and the like, and has vehicle speed information indicating a speed of the vehicle 2, that is, a vehicle speed, travel distance information indicating a travel distance of the vehicle 2, various failure diagnosis information, and the like. The in-vehicle device 7 is an ECU including an acceleration sensor, an angular velocity sensor, and an azimuth meter, and has acceleration information indicating the acceleration of the vehicle 2, angular velocity information indicating the angular velocity of the vehicle 2, azimuth information indicating the azimuth, which is the traveling direction of the vehicle 2, failure diagnosis information of the sensors, and the like.

The factory tool 8 performs failure diagnosis and the like of various devices mounted on the vehicle 2 in a factory or the like. In this case, at the time of factory shipment, the in-vehicle device installation information indicating the information of the installed device at the time of factory shipment is set by the factory tool 8, and the in-vehicle device installation information is transmitted to the in-vehicle device 1.

The in-vehicle device 1 operates by receiving power supply from a vehicle battery 9 mounted on the vehicle 2. The vehicle battery 9 also supplies power to other in-vehicle devices in the same manner. The in-vehicle device 1 includes a power supply circuit 10, a backup battery 11, a GNSS receiver 12, a controller 13, and the like. The power supply circuit 10 controls the electric power supplied from the vehicle battery 9 and supplies the electric power to the respective components of the in-vehicle device 1. A backup battery 11 is connected to the power supply circuit 10. When the power supply from the vehicle battery 9 is cut off, the power supply circuit 10 controls the power supplied from the backup battery 11 and supplies the power to the respective components of the in-vehicle device 1.

The GNSS receiver 12 includes a GNSS antenna 14, and receives signals periodically transmitted from GNSS satellites via the GNSS antenna 14. The GNSS antenna 14 is configured as an in-vehicle antenna mounted on the vehicle 2. The GNSS receiver 12 outputs GNSS positioning information indicated by the received signal to the controller 13.

The control unit 13 controls the overall operation of the in-vehicle device 1, and is mainly configured by a microcomputer including a CPU (central processing unit), a ROM (read only memory), a RAM (random access memory), and the like. The control unit 13 includes a positioning calculation unit 15, a communication processing unit 16, and a selection unit 17. The positioning operation unit 15, the communication processing unit 16, and the selection unit 17 are realized by the CPU of the control unit 13 executing programs stored in the ROM or the like, in other words, realized by software.

The positioning calculation unit 15 performs positioning calculation using GNSS positioning information given from the GNSS reception unit 12. In the present embodiment, the internal positioning unit 18 is configured by the GNSS reception unit 12 and the positioning calculation unit 15. The positioning calculation unit 15 outputs self-positioning position information Da, which is position information of the vehicle 2 obtained by performing the positioning calculation, to the selection unit 17. Hereinafter, the self-positioning position information Da is also referred to as first position information Da.

The communication processing unit 16 communicates with the navigation device 4 to acquire the accuracy correction position information Db, which is the position information of the vehicle 2 output from the navigation device 4. Although described in detail later, the navigation device 4 performs positioning for measuring the position of the vehicle 2 and performs correction for improving the accuracy of the positioning. Therefore, the accuracy correction position information Db is position information having higher accuracy than the self-positioning position information Da. Hereinafter, the precision correction position information Db is also referred to as second position information Db.

In the present embodiment, the communication processing unit 16 corresponds to an information acquisition unit. The second position information Db indicating the result of the positioning by the navigation device 4 corresponds to vehicle-related information that is information related to the vehicle 2. When the communication processing unit 16 acquires the second position information Db, it outputs the second position information Db to the selection unit 17.

The vehicle-mounted device 1 configured as described above has, as the positioning system, two systems, that is, a first positioning system in which the positioning result is obtained by the positioning by the internal positioning unit 18 and a second positioning system in which the positioning result is obtained by the second position information Db output from the navigation device 4 instead of the positioning by the internal positioning unit 18. The in-vehicle device 1 further includes a selection unit 17 as a configuration for selectively performing the positioning operation of the two modes.

The selection unit 17 selects either one of the first positioning method and the second positioning method. When the first positioning method is selected, the selection unit 17 uses the first position information Da given from the positioning calculation unit 15 as the result of positioning the vehicle 2. When the second positioning method is selected, the selection unit 17 uses the second position information Db given from the communication processing unit 16 as the result of positioning the vehicle 2. The selection unit 17 communicates with the in-vehicle devices 6 and 7 and the plant tool 8 via the communication network 5, and acquires various information that can be obtained from the in-vehicle devices 6 and 7 and the plant tool 8.

The various types of information include vehicle travel information Dc, various types of failure diagnosis information Dd, and vehicle-mounted device installation information De, which are information obtained from a sensor group such as a speedometer, a distance meter, an acceleration sensor, an angular velocity sensor, and an azimuth meter installed in the vehicle 2. The selection unit 17 selects a positioning method based on the information and the like, which will be described in detail later.

The navigation device 4 operates by receiving power supply from the vehicle battery 9. The navigation device 4 includes a power supply circuit 21, a display 22, a GNSS receiver 23, a controller 24, and the like. The power supply circuit 21 controls the electric power supplied from the vehicle battery 9 and supplies the electric power to the respective components of the navigation device 4. The display 22 displays a map, characters, and the like.

The GNSS receiver 23 includes a GNSS antenna 25 and has the same function as the GNSS receiver 12 of the in-vehicle device 1. The GNSS antenna 25 is configured as an in-vehicle antenna, similar to the GNSS antenna 14 of the in-vehicle device 1. The GNSS receiver 23 outputs GNSS positioning information indicated by the received signal to the controller 24.

The control unit 24 controls the overall operation of the navigation device 4, and is mainly configured by a microcomputer including a CPU, a ROM, a RAM, and the like. The control unit 24 includes a positioning calculation unit 26, a correction processing unit 27, and a communication processing unit 28. The positioning operation unit 26, the correction processing unit 27, and the communication processing unit 28 are realized by the CPU of the control unit 24 executing programs stored in the ROM or the like, that is, by software.

The positioning calculation unit 26 performs positioning calculation using the GNSS positioning information given from the GNSS reception unit 23. The positioning calculation unit 26 outputs navigation positioning position information Df, which is the position information of the vehicle 2 obtained by performing the positioning calculation, to the correction processing unit 27. The correction processing unit 27 acquires the map information Dg stored in a storage device, not shown, and communicates with the in-vehicle devices 6 and 7 via the communication network 5 to acquire the vehicle travel information Dc from the in-vehicle devices 6 and 7. The correction processing unit 27 performs map matching processing on the navigation positioning position information Df using the map information Dg and the vehicle travel information Dc, thereby improving the accuracy of positioning.

In this way, the correction processing unit 27 performs correction for improving the accuracy of positioning on the navigation positioning position information Df. The correction processing unit 27 outputs the second position information Db obtained by performing the above correction to the communication processing unit 28. The communication processing unit 28 communicates with the in-vehicle device 1, and transmits the second position information Db given from the correction processing unit 27 to the in-vehicle device 1.

The control unit 24 is configured to be able to transmit navigation failure diagnosis information Dh, which is necessary to perform failure diagnosis of the navigation device 4, to the in-vehicle device 1 and the like via the communication network 5. In the above configuration, the vehicle-mounted device 1 has a function of acquiring the navigation failure diagnosis information Dh via the communication network 5 and performing failure diagnosis of the navigation apparatus 4 based on the navigation failure diagnosis information Dh.

Next, the operation of the above-described structure will be described.

[1] Selection method of positioning method

In the normal case, the selection unit 17 selects the second positioning method, but if it is determined that the accuracy of the positioning result obtained by the second positioning method is lower than the accuracy of the positioning result obtained by the first positioning method, the positioning method is switched to select the first positioning method. Specifically, in the case described below, when the selection unit 17 determines that a switching condition that considers that the accuracy of the positioning result obtained by the second positioning method is lower than the accuracy of the positioning result obtained by the first positioning method is satisfied, the positioning method is switched to select the first positioning method.

That is, when the selection unit 17 determines that the navigation device 4 is not mounted on the vehicle 2 based on the information such as the model of the vehicle 2 and the in-vehicle equipment mounting information De, it determines that the switching condition is satisfied and selects the first positioning system. As a specific situation in which the navigation device 4 is not installed in the vehicle 2, the following example is considered.

For example, the in-vehicle device 1 is used as a common device for a plurality of vehicle types regardless of the presence or absence of the navigation device 4, and when the navigation device 4 is not set for the vehicle type of the vehicle 2, the navigation device 4 is not present in the vehicle 2. In addition, when the installation of the navigation device 4 is not selected by the setting, the navigation device 4 is not present in the vehicle 2.

Further, even when it is determined that the navigation apparatus 4 is mounted on the vehicle 2, if it is determined that the navigation apparatus 4 has failed as a result of the failure diagnosis based on the navigation failure diagnosis information Dh, the selection unit 17 determines that the switching condition is satisfied and selects the first positioning method. Further, even when it is determined that the navigation device 4 is mounted on the vehicle 2 and has not failed, the selection unit 17 determines that the switching condition is satisfied and selects the first positioning method if communication with the navigation device 4 is not established.

Specifically, the selection unit 17 determines that the switching condition is satisfied when a regular communication with the navigation device 4 to be performed under a specific condition, such as an ACC-ON condition, is not established or when the regular communication is an abnormal response. The term "regular communication" as used herein includes a case where the period of communication is variable, a case where a response is always made when a specific condition is satisfied although the period is an irregular interval, and the like.

The "regular communication" may be, for example, communication performed based on a criterion other than time, such as communication performed when the travel distance of the vehicle 2 is equal to or longer than a predetermined distance. As a specific example of the periodic communication based on the travel distance as a determination criterion, the following communication can be mentioned.

That is, in this case, it is assumed that both the in-vehicle device 1 and the navigation device 4 receive the travel distance information of the in-vehicle device 6. In this case, it is assumed that the navigation device 4 notifies the in-vehicle device 1 of the position information (second position information Db) every time a constant travel distance is passed. Under such a premise, when the notification of the position information from the navigation device 4 is interrupted, the selection unit 17 determines that the switching condition is satisfied and dynamically switches the positioning method to select the first positioning method.

Further, even when the navigation device 4 is mounted on the vehicle 2 and communication with the navigation device 4 is established, if it is determined that the received position information (second position information Db) is not normal, the selection unit 17 determines that the switching condition is satisfied and selects the first positioning system. Specifically, when the data format of the second position information Db sent from the navigation device 4 is abnormal, the selection unit 17 determines that the switching condition is satisfied, and switches the positioning method to select the first positioning method.

Further, even when the selection unit 17 determines that the received position information (second position information Db) is normal, if it determines that the reliability of the position information is lower than a desired level, it determines that the switching condition is satisfied and selects the first positioning system. Here, "reliability of positional information" refers to positioning accuracy of the positional information. Therefore, the lower reliability of the position information than the desired level means that the positioning error thereof is larger than assumed.

For example, it is assumed that the navigation device 4 notifies the in-vehicle device 1 of the position information every time a constant travel distance is passed. On this premise, the selection unit 17 can determine that the reliability of the position information is lower than desired when the movement amount of the vehicle 2 calculated from the position information received last time and the position information received this time is a value greatly deviated from the constant travel distance.

When execution of a service or application using the positioning result is started, the selection unit 17 switches the positioning method according to the characteristics of the service or application. As the service or application, for example, a stolen vehicle tracking service can be cited. The stolen vehicle tracking service is a service that is started by receiving a request or the like from the owner of the vehicle, and notifies the owner of the current position or the like of the vehicle 2 from the vehicle-mounted device 1 via an information center or the like.

In the case where the vehicle 2 is stolen, it is assumed that the vehicle battery 9 is removed. The navigation device 4 is configured to operate only by receiving power supply from the vehicle battery 9, and therefore cannot operate when the vehicle battery 9 is removed. On the other hand, the in-vehicle device 1 includes the backup battery 11, and can operate by receiving the power supply from the backup battery 11 even when the power supply from the vehicle battery 9 is cut off.

Therefore, in the present embodiment, when the execution of the stolen vehicle tracking service is started, the selection unit 17 switches the positioning method to select the first positioning method. In this case, the selection unit 17 fixedly selects the first positioning system in conjunction with the stolen vehicle tracking service, regardless of other conditions related to the selection of the positioning system.

[2] Concrete processing contents in the in-vehicle device 1

The on-board device 1 periodically repeats the periodic processing of the contents as shown in fig. 2. As shown in fig. 2, first, in step S101, it is determined whether or not the execution timing of positioning by the internal positioning section 18, in other words, the acquisition timing (update timing) of the first position information Da. The acquisition timing of the first position information Da is a timing corresponding to a cycle of signal transmission from the GNSS satellite. The repetition period of the periodic processing is set to a period shorter than the period of transmitting signals from the GNSS satellites.

Here, if it is the acquisition timing of the first position information Da, yes is obtained in step S101, and the process proceeds to step S102. On the other hand, if the timing is not the acquisition timing of the first position information Da, no is performed in step S101, and the process proceeds to step S103. In step S102, a first information acquisition process is implemented. The first information acquisition process will be described in detail later. After step S102, the process proceeds to step S103.

In step S103, it is determined whether or not it is the timing at which the second position information Db is transmitted from the navigation apparatus 4, in other words, whether or not it is the acquisition timing (update timing) of the second position information Db. Here, if it is the acquisition timing of the second position information Db, yes is obtained in step S103, and the process proceeds to step S104. On the other hand, if the timing is not the acquisition timing of the second position information Db, no is performed in step S103, and the process proceeds to step S105.

In step S104, the second information acquisition process is implemented. The second information acquisition process will be described in detail later. After step S104, the process proceeds to step S105. In step S105, it is determined whether or not the timing is the execution timing of the selection process for selecting the positioning method. The timing of execution of the selection process may be set to any timing.

Here, when it is the execution timing of the selection process, yes is performed in step S105, and the process proceeds to step S106. On the other hand, if the timing is not the execution timing of the selection process, no is performed in step S105, and the process proceeds to step S107. In step S106, selection processing is performed. The selection process will be described in detail later. After step S106 is executed, the process proceeds to step S107.

In step S107, the other processing, which is processing other than the processing related to positioning, among the processing executed by the in-vehicle device 1, is executed. After the execution of step S107, the regular processing ends. In this case, for example, after a predetermined time measured by a timer has elapsed, the periodic processing is restarted, that is, the periodic processing is repeatedly performed.

The specific processing content of the first information acquisition processing described above is as shown in fig. 3. As shown in fig. 3, first, in step S201, the GNSS receiver 12 receives signals, that is, signals periodically transmitted from GNSS satellites. Next, in step S202, positioning calculation by the positioning calculation unit 15, in other words, positioning calculation using GNSS positioning information is performed.

After step S202 is executed, the process proceeds to step S203. In step S203, a history of the first position information Da, which is a positioning result obtained by the positioning operation performed in step S202, is stored, that is, a first position history. The first position history is used in the selection process described later. After execution of step S203, the first information acquisition process ends.

The specific contents of the second information acquisition processing described above are as shown in fig. 4. As shown in fig. 4, first, in step S301, the in-vehicle apparatus installation information De is read out. Next, in step S302, it is determined whether or not the navigation device 4 is mounted on the vehicle 2 based on the in-vehicle apparatus mounting information De and the like. In fig. 4, the navigation device 4 is omitted as "navigation".

Here, if the navigation device 4 is not mounted on the vehicle 2, no is performed in step S302, and the process proceeds to step S310. On the other hand, when the navigation device 4 is mounted on the vehicle 2, yes is performed in step S302, and the process proceeds to step S303. In step S303, the navigation failure diagnosis information Dh is read out. Next, in step S304, it is determined whether or not the result of the failure diagnosis based on the navigation failure diagnosis information Dh is a failure of the navigation apparatus 4.

Here, if the navigation device 4 is in a failure state, yes is performed in step S304, and the process proceeds to step S310. On the other hand, if the navigation device 4 is not in a failure state, no is performed in step S304, and the process proceeds to step S305. In step S305, a communication process with the navigation device 4 is performed. Next, in step S306, it is determined whether or not communication with the navigation device 4 is established.

Here, if communication with the navigation device 4 is not established, no is performed in step S306, and the process proceeds to step S310. In this case, when the response from the navigation device 4 is a no response, an abnormal response, or the like, it is determined that the communication is not established. On the other hand, if the communication with the navigation device 4 is established, yes is performed in step S306, and the process proceeds to step S307.

In step S307, the second position information Db is acquired through communication with the navigation apparatus 4. Next, in step S308, it is determined whether or not the data format or the like of the acquired second position information Db is normal. Here, if the acquired second position information Db is abnormal, no is performed in step S308, and the process proceeds to step S310.

On the other hand, if the acquired second position information Db is normal, yes is obtained in step S308, and the process proceeds to step S309. In step S309, the second position history, which is the history of the second position information Db, is stored. In this case, the second position history also records abnormality detection information indicating that a certain abnormality related to the acquisition of the second position information Db is detected. The second position history is used in the selection process described later. After execution of step S309, the second information acquisition process ends.

As described above, when the navigation device 4 is not mounted on the vehicle 2, when the navigation device 4 is in a failure, when communication with the navigation device 4 is not established, or when the acquired second position information Db is abnormal, the process proceeds to step S310. In step S310, it is determined whether or not the abnormality detection information is recorded in the latest second position history.

If the abnormality detection information is not recorded in the latest second position history, no is performed in step S310, and the process proceeds to step S311. In step S311, the second position history is updated by recording the abnormality detection information. After execution of step S311, the second information acquisition process ends.

On the other hand, if the second position history has recorded the abnormality detection information, yes is performed in step S310, and the second information acquisition process is ended without updating the second position history. As described above, in the second information acquisition process of the present embodiment, only when some kind of abnormality related to the acquisition of the second position information Db is first detected, the abnormality detection information is recorded in the second position history.

The specific contents of the selection processing described above are as shown in fig. 5. As shown in fig. 5, first, in step S401, the execution status of the application or service using the positioning result is checked. Next, in step S402, it is determined whether or not the stolen vehicle tracking service is executed.

Here, if the stolen vehicle tracking service is being executed, yes is performed in step S402, and the process proceeds to step S403. In step S403, the first position information Da is used as the positioning result, in other words, the first positioning manner is selected. After execution of step S403, the selection process ends.

On the other hand, if the stolen vehicle tracking service is not being executed, no is performed in step S402, and the flow proceeds to step S404. In step S404, the latest second position history is read. Next, in step S405, it is determined whether or not the abnormality detection information is recorded in the latest second position history.

Here, if the abnormality detection information is recorded in the latest second position history, yes is performed in step S405, and the process proceeds to step S403. On the other hand, if the abnormality detection information is not recorded in the latest second position history, no is performed in step S405, and the process proceeds to step S406. In step S406, it is determined whether or not the second position information Db has been updated since the selection process was executed last time, based on the second position history read in step S404.

Here, if the second position information Db is not updated, no is performed in step S406, and the process proceeds to step S407. In step S407, it is determined whether or not the timing at which the second position information Db should be updated has come, in other words, whether or not the next update timing of the second position information Db has come. As described above, the update timing may be based on time, may be based on the travel distance, or may be a combination thereof. Therefore, in step S407, it is determined whether or not the predetermined time for updating the second position information Db has elapsed, whether or not the predetermined travel distance for updating the second position information Db has elapsed, or the like.

Here, when the timing of the next update of the second position information Db is reached, yes is obtained in step S407, and the process proceeds to step S403. On the other hand, if the timing of the next update of the second position information Db is not reached, no is performed in step S407, and the process proceeds to step S408. In step S408, the movement amount of the vehicle 2 from the time when the second position information Db was updated last, that is, the last update time, that is, the differential travel distance is calculated. Further, the calculation of the differential travel distance can be performed based on the integral of the vehicle speed or the difference of the travel distances. After the execution of step S408, step S409 is proceeded to, and the second position information Db is adopted as the positioning result, in other words, the second positioning manner is selected. After execution of step S409, the selection process ends.

On the other hand, when the second position information Db is updated, yes is obtained in step S406, and the process proceeds to step S410. In step S410, the differential travel distance from the last update time to the time when the second position information Db is updated this time, that is, the current update time, is calculated. This differential travel distance can be also performed based on the integral of the vehicle speed or the difference in the travel distance, as in the differential travel distance in step S408.

After step S410 is executed, the process proceeds to step S411, where the distance between two points corresponding to the movement amount of the vehicle 2 is calculated from the second position information Db at the time of the previous update and the second position information Db at the time of the current update. Next, in step S412, it is determined whether the reliability of the second position information Db reaches a desired level, in other words, whether the positioning accuracy of the second position information Db is adequate. Specifically, in step S412, it is determined whether the difference between the differential travel distance calculated in step S410 and the distance between the two points calculated in step S411 is within a predetermined value, that is, whether the difference is within a predetermined value. The predetermined value may be set as appropriate in accordance with the desired positioning accuracy.

Here, when the difference between the distances is within the predetermined value, yes is performed in step S412, and the process proceeds to step S413. In step S413, the second position information Db is used as the positioning result, in other words, the second positioning manner is selected. On the other hand, if the difference between the distances exceeds the predetermined value, no is performed in step S412, and the process proceeds to step S414. In step S414, the first position information Da is used as the positioning result, in other words, the first positioning manner is selected. After execution of step S413 or S414, the selection processing ends.

Further, as important factors that the difference between the distances exceeds a predetermined value, it is considered that the error of the nearest second position information Db is large, the error of the second position information Db serving as a reference point is large, and the error of information such as the vehicle speed and the travel distance is large. However, the reliability of the second position information Db is highly likely to be lower than a desired level regardless of which of the above-described factors is the factor that causes the difference between the distances to exceed the predetermined value. Therefore, in the present embodiment, when the difference between the distances exceeds a predetermined value, the first positioning system is switched.

As described above, the in-vehicle device 1 according to the present embodiment is configured to have two positioning modes, i.e., the first positioning mode and the second positioning mode, as the positioning modes, and to be able to selectively perform the positioning operations of these respective modes. Here, the first positioning method is a method of obtaining a positioning result by using the positioning of the internal positioning unit 18, and corresponds to a method of positioning the in-vehicle device 1 itself. In the second positioning method, instead of the positioning by the internal positioning unit 18, the second position information Db output from the navigation device 4 can be used to obtain a positioning result with higher accuracy than the positioning result obtained by the first positioning method.

In the above configuration, the selection unit 17 that selects one of the two positioning systems preferentially selects the second positioning system in the normal state, and switches the positioning system to select the first positioning system if it is determined that the accuracy of the positioning result obtained by the second positioning system is lower than the accuracy of the positioning result obtained by the first positioning system. The selection unit 17 selects these positioning methods so that a highly accurate positioning result is always obtained. As described above, according to the present embodiment, since an appropriate positioning method is selected from the viewpoint of improving the accuracy of the positioning result, an effect is obtained in which an appropriate positioning method can be selected for use in positioning the vehicle 2.

When determining that the navigation device 4 is not mounted in the vehicle 2 based on the in-vehicle device mounting information De, the selection unit 17 determines that the switching condition is satisfied and selects the first positioning method. In this way, even when the navigation device 4 is not present in the vehicle 2 at first or when the navigation device 4 is removed from the vehicle 2, the positioning result of the vehicle 2 can be continuously obtained by performing the positioning by the in-vehicle device 1 itself.

If it is determined that the navigation apparatus 4 is malfunctioning as a result of the malfunction diagnosis based on the navigation malfunction diagnosis information Dh, the selection unit 17 determines that the switching condition is satisfied and selects the first positioning system. In this way, even when a failure occurs in the navigation device 4, the in-vehicle device 1 can perform positioning itself to continue obtaining the positioning result of the vehicle 2.

If the communication with the navigation device 4 is not established, the selection unit 17 determines that the switching condition is satisfied and selects the first positioning method. In this way, even when an abnormality occurs in which communication with the navigation device 4 cannot be established, the in-vehicle device 1 can perform positioning itself to continue obtaining the positioning result of the vehicle 2.

If it is determined that the second position information Db acquired from the navigation apparatus 4 is not normal, the selection unit 17 determines that the switching condition is satisfied and selects the first positioning system. In this way, even when the second position information Db transmitted from the navigation device 4 is abnormal, the in-vehicle device 1 can perform positioning by itself, and the result of positioning the vehicle 2 can be continuously obtained.

If the selection unit 17 determines that the reliability of the second position information Db, that is, the positioning accuracy is lower than the desired level, it determines that the switching condition is satisfied and selects the first positioning system. In this way, even when the positioning error of the second position information Db, which should have high positioning accuracy originally, is very large, the in-vehicle device 1 can perform positioning itself to continue obtaining the positioning result of the vehicle 2.

When the execution of the service or application using the positioning result is started, the selection unit 17 switches the positioning method according to the characteristics of the service or application. Specifically, when the execution of the stolen vehicle tracking service is started, the selection unit 17 switches the positioning method to select the first positioning method. In this way, even when the vehicle battery 9 of the stolen vehicle 2 is removed, the vehicle-mounted device 1 itself that can be operated by receiving the power supply from the backup battery 11 can perform positioning to continue obtaining the positioning result of the vehicle 2, and as a result, the stolen vehicle tracking service can be effectively enabled.

(second embodiment)

A second embodiment will be described below with reference to fig. 6 to 10.

The in-vehicle device 31 of the present embodiment shown in fig. 6 performs positioning of the vehicle 2, and corresponds to a positioning device, in the same manner as the in-vehicle device 1 of the first embodiment. The in-vehicle device 31 differs from the in-vehicle device 1 according to the first embodiment in that a control unit 32 is provided instead of the control unit 13. The control unit 32 differs from the control unit 13 in that a correction processing unit 33 and a selection unit 34 are provided instead of the communication processing unit 16 and the selection unit 17. In this case, the positioning calculation unit 15 outputs the self-positioning position information Da, that is, the first position information Da to the correction processing unit 33 and the selection unit 34.

The in-vehicle device 31 of the present embodiment has, as the positioning system, two systems, i.e., a first positioning system that obtains a positioning result using the positioning by the internal positioning unit 18 and a second positioning system that obtains a positioning result using the vehicle travel information Dc in addition to the positioning by the internal positioning unit 18. In this case, in the second positioning method, the first position information Da is corrected by the estimated positioning using the vehicle travel information Dc, and the positioning result is obtained. The positioning according to the second positioning method is performed mainly by the correction processing unit 33.

That is, the correction processing unit 33 communicates with the in-vehicle devices 6 and 7 via the communication network 5, and acquires the vehicle travel information Dc that can be obtained from the in-vehicle devices 6 and 7. As described above, the vehicle travel information Dc is information obtained from a sensor group such as a speedometer, a travel distance meter, an acceleration sensor, an angular velocity sensor, and an azimuth meter mounted on the vehicle 2. The correction processing unit 33 corrects the first position information Da, which is the result of the positioning by the interior positioning unit 18, by the estimated positioning using the vehicle travel information Dc, thereby improving the accuracy of the positioning.

The correction processing unit 33 outputs the accuracy correction position information Di obtained by performing the correction to the selection unit 34. Hereinafter, the precision correction position information Di is also referred to as second position information Di. In the present embodiment, the correction processing unit 33 corresponds to an information acquisition unit. The vehicle travel information Dc corresponds to vehicle-related information that is information related to the vehicle 2, and also corresponds to information necessary for performing the estimated positioning.

The selection unit 34 selects one of the first positioning method and the second positioning method. When the first positioning method is selected, the selection unit 34 uses the first position information Da given from the positioning calculation unit 15 as the result of positioning the vehicle 2. When the second positioning method is selected, the selection unit 34 uses the second position information Di given from the correction processing unit 33 as the result of positioning of the vehicle 2. The selection unit 34 communicates with the in-vehicle devices 6 and 7 and the plant tool 8 via the communication network 5, and acquires various information that can be obtained from the in-vehicle devices 6 and 7 and the plant tool 8. The selection unit 34 selects a positioning method based on the information and the like, which will be described in detail later.

Next, the operation of the above-described structure will be described.

[1] Selection method of positioning method

In a normal state, the selection unit 34 selects the second positioning method, but if it is determined that the accuracy of the positioning result obtained by the second positioning method is lower than the accuracy of the positioning result obtained by the first positioning method, the positioning method is switched to select the first positioning method. Specifically, in the case described below, when the selection unit 34 determines that a switching condition that considers that the accuracy of the positioning result obtained by the second positioning method is lower than the accuracy of the positioning result obtained by the first positioning method is satisfied, the positioning method is switched to select the first positioning method.

That is, the selection unit 34 determines that the switching condition is satisfied and selects the first positioning system when determining that the in-vehicle devices 6 and 7 are not mounted on the vehicle 2 based on the information such as the model number of the vehicle 2 and the in-vehicle device mounting information De. As a specific situation in which the in-vehicle devices 6 and 7 are not installed in the vehicle 2, the same case as the case of the navigation device 4 described in the first embodiment is considered.

Even when it is determined that the in-vehicle devices 6 and 7 are mounted on the vehicle 2, the selection unit 34 determines that the switching condition is satisfied and selects the first positioning method when it is determined that the in-vehicle devices 6 and 7 are out of order based on the various failure diagnosis information Dd. Even if it is determined that the in-vehicle devices 6 and 7 are mounted on the vehicle 2 and have not failed, the selection unit 34 determines that the switching condition is satisfied and selects the first positioning method if communication with the in-vehicle devices 6 and 7 is not established.

Specifically, the selection unit 34 determines that the switching condition is satisfied when, for example, regular communication with the in-vehicle devices 6 and 7 to be performed under a specific condition such as ACC-ON is not established or when the regular communication becomes an abnormal response. Note that the "regular communication" with the in-vehicle devices 6 and 7 is the same as the "regular communication" with the navigation device 4 described in the first embodiment. In this case, as a specific example of the periodic communication using the travel distance as a determination criterion, the following communication can be mentioned.

That is, in this case, it is assumed that both the in-vehicle device 1 and the in-vehicle device 7 receive the travel distance information of the in-vehicle device 6. In this case, it is assumed that the vehicle running information Dc such as acceleration information, angular velocity information, and direction information is notified from the in-vehicle device 7 to the in-vehicle device 1 every time a constant running distance is passed. On the premise as described above, when the notification of the vehicle travel information Dc from the in-vehicle device 7 is interrupted, the selection unit 34 determines that the switching condition is satisfied and switches the positioning method to select the first positioning method.

Even when the in-vehicle devices 6 and 7 are mounted on the vehicle 2 and communication with the in-vehicle devices 6 and 7 is established, if it is determined that the received information is not normal, the selection unit 34 determines that the switching condition is satisfied and selects the first positioning system. Specifically, when the data format of the information transmitted from the in-vehicle devices 6 and 7 is abnormal, the selection unit 34 determines that the switching condition is satisfied, and switches the positioning method to select the first positioning method.

Further, even when the received information is determined to be normal, if the reliability of the information is determined to be lower than a desired level, the selection unit 34 determines that the switching condition is satisfied and selects the first positioning system. Here, "reliability of information" means the accuracy of a measurement value of a sensor indicated by the information. Therefore, the fact that the reliability of the information is lower than a desired level means that the error of the measurement value of the sensor indicated by the information is larger than assumed.

For example, it is assumed that the vehicle speed information and the travel distance information are transmitted to the in-vehicle device 1 at a constant interval from the in-vehicle device 6. On this premise, the selection unit 34 can determine that the reliability of at least one of the received vehicle speed information and the received travel distance information is lower than desired when the vehicle speed integrated based on the vehicle speed information is significantly deviated from the value of the travel distance obtained based on the travel distance information.

When the positioning accuracy of the first position information Da is considered to be at a level that sufficiently satisfies the desired accuracy, the selection unit 34 determines that the switching condition is satisfied and switches the positioning method to select the first positioning method. Specifically, if the selection unit 34 determines that the positioning accuracy of the first position information Da is equal to or higher than a predetermined value, it determines that the switching condition is satisfied and switches the positioning method to select the first positioning method. The predetermined value may be set as appropriate in accordance with the desired positioning accuracy. In addition, for example, the determination of the positioning accuracy can be performed using a long axis error which is an index for determining a degree of degradation of the positioning accuracy in consideration of the influence of reception of reflected waves due to multipath and the like.

If it is determined that the number of positioning histories necessary to realize the estimated positioning is insufficient for the received vehicle travel information Dc, the selection unit 34 determines that the switching condition is satisfied and switches the positioning method to select the first positioning method. For example, immediately after the driver gets into the vehicle 2 while the vehicle is stopped, the driver cannot correct the position information by the estimated positioning without the travel distance information. In such a case, the selection unit 34 determines that the number of positioning histories required to realize the estimated positioning is insufficient, and switches to the first positioning method.

In general, in correction based on estimated positioning, position information estimated from past positioning history by estimated positioning using a travel distance or the like is compared with pure GNSS position information (first position information Da) newly acquired and evaluated at any time, and weighting of correction is performed. Therefore, although the correction operation by the correction processing unit 33 may be continued when it is determined that the number of positioning histories is insufficient, the second position information Di obtained by the correction operation cannot be used as the positioning result.

The selection unit 34 calculates an index indicating the reliability of the first position information Da and an index indicating the reliability of the second position information Di. The selection unit 34 determines that the switching condition is satisfied and switches the positioning system to select the first positioning system when one of the calculated indexes is at a specific level or when a combination of the indexes, specifically, a result of comparing the indexes satisfies a specific determination condition.

The reliability of the first position information Da and the second position information Di is the positioning accuracy of the position information, as in the "reliability of the position information" described in the first embodiment. Therefore, the reliability of the position information being lower than a desired level means that the positioning error is larger than assumed.

In this case, the reliability of the first position information Da can be quantified using, for example, a long axis error. The reliability of the second position information Di can be quantified by using the offset amount between the position indicated by the first position information Da and the position indicated by the second position information Di, or by using the average of the movement of a plurality of offset amounts in succession.

[2] Specific processing contents in the in-vehicle device 31

The regular processing shown in fig. 7 is periodically repeated in the in-vehicle device 31. The periodic processing of the present embodiment shown in fig. 7 differs from the periodic processing of the first embodiment shown in fig. 2 in that steps S123, S124, S125, and S126 are provided instead of steps S103, S104, S105, and S106.

In step S123, it is determined whether or not the timing at which the vehicle travel information Dc is transmitted from the in-vehicle devices 6 and 7, that is, the acquisition timing (update timing) of the vehicle travel information Dc. Here, if it is the acquisition timing of the vehicle travel information Dc, yes is obtained in step S123, and the process proceeds to step S124. On the other hand, if the timing is not the acquisition timing of the vehicle travel information Dc, no in step S123, and the process proceeds to step S125.

In step S124, second information acquisition processing for acquiring the vehicle travel information Dc is performed. The second information acquisition process will be described in detail later. After step S124, the process proceeds to step S125. In step S125, it is determined whether or not the timing to perform the correction selection process is correct. The timing of execution of the correction selection process may be set to any timing.

Here, when it is the timing of execution of the correction selection process, yes is performed in step S125, and the process proceeds to step S126. On the other hand, if the timing is not the timing of execution of the correction selection process, no is performed in step S125, and the process proceeds to step S107. In step S126, correction selection processing is performed. The correction selection processing is processing for performing a correction operation for obtaining the second position information Di and selecting a positioning method, and will be described in detail later. After step S126, the process proceeds to step S107.

In this case, step S125 may be omitted, and the process may proceed to step S107 if step S123 is no, and may proceed to step S126 after step S124 is executed. In this way, when the acquisition timing of the vehicle travel information Dc is reached, both the second information acquisition process and the correction selection process are executed.

The specific processing contents of the second information acquisition processing of the present embodiment are as shown in fig. 8. As shown in fig. 8, first, in step S501, the in-vehicle apparatus installation information De is read out. Next, in step S502, it is determined whether or not all the devices (for example, the in-vehicle devices 6 and 7) from which the vehicle travel information Dc necessary for the estimated positioning is derived are mounted on the vehicle 2 based on the in-vehicle device mounting information De and the like. In the following description and fig. 8, a device from which the information is obtained will be referred to as an "information source device".

Here, if at least one of the information source devices is not installed in the vehicle 2, no is performed in step S502, and the process proceeds to step S510. On the other hand, when all the information source devices are mounted on the vehicle 2, yes is performed in step S502, and the process proceeds to step S503. In step S503, various failure diagnosis information Dd is read out. Next, in step S504, it is determined whether there is failure information of the information source apparatuses, in other words, whether at least one of the information source apparatuses has failed, based on the various failure diagnosis information Dd.

Here, if there is failure information of the information source device, yes is performed in step S504, and the process proceeds to step S510. On the other hand, if there is no failure information of the information source device, no is performed in step S504, and the process proceeds to step S505. In step S505, communication processing with the information source device is performed. Next, in step S506, it is determined whether or not communication with the information source apparatus is established.

Here, if communication with the information source device is not established, no is performed in step S506, and the process proceeds to step S510. In this case, when the response from the information source device is a no response, an abnormal response, or the like, it is determined that the communication is not established. On the other hand, if communication with the information source device is established, yes is performed in step S506, and the process proceeds to step S507.

In step S507, vehicle travel information Dc necessary for the estimated positioning is acquired through communication with the information source device. Next, in step S508, it is determined whether or not the data format or the like of the acquired vehicle travel information Dc is normal. Here, if the acquired vehicle travel information Dc is abnormal, no is performed in step S508, and the process proceeds to step S510.

On the other hand, if the acquired vehicle travel information Dc is normal, yes is performed in step S508, and the process proceeds to step S509. In step S509, the vehicle travel information Dc in the in-vehicle device 31 is updated. At this time, the acquisition state information indicating the acquisition state of the vehicle travel information Dc is stored as "normal". After execution of step S509, the second information acquisition process ends.

As described above, when at least one of the information source devices is not mounted on the vehicle 2, if there is failure information of the information source device, if communication with the information source device is not established or if the acquired vehicle travel information Dc is abnormal, the process proceeds to step S510. In step S510, the vehicle travel information Dc in the in-vehicle device 31 is not updated, and the acquired state information is stored as "abnormal". At this time, the vehicle travel information Dc determined to be abnormal is invalidated. After execution of step S510, the second information acquisition process ends.

The specific processing contents of the correction selection processing according to the present embodiment are as shown in fig. 9. In the following description and fig. 9, the position of the vehicle 2 obtained by the positioning calculation unit 15, that is, the position of the vehicle 2 indicated by the first position information Da is referred to as a self-positioning position. The position of the vehicle 2 obtained by the correction processing unit 33, that is, the position of the vehicle 2 indicated by the second position information Di is referred to as a corrected position. In this case, it is assumed that the execution cycle of the correction process for obtaining the corrected position, that is, the second position information Di is sufficiently shorter than the update cycle of the first position information Da.

As shown in fig. 9, first, in step S601, acquisition state information of the vehicle travel information Dc required for the estimated positioning is read. In the following description and fig. 9, the vehicle travel information Dc required for the estimated positioning is referred to as necessary information. Next, in step S602, it is determined whether or not there is information that the acquisition status information is abnormal among the necessary information.

Here, if the required information includes information that the acquisition state information is abnormal, yes is performed in step S602, and the process proceeds to step S603. In step S603, the first position information Da is used as the positioning result, in other words, the first positioning manner is selected. Next, in step S604, the self-positioning position is used as a starting point for calculating the next correction position, that is, a next calculation starting point. After execution of step S604, the correction selection processing ends.

On the other hand, if the required information includes no information that the acquired state information is abnormal, no is performed in step S602, and the process proceeds to step S605. In step S605, the reliability of the necessary information is confirmed. Next, in step S606, it is determined whether or not the reliability of the necessary information is lower than a desired level.

If the reliability of the necessary information is lower than the desired level, yes is performed in step S606, and the process proceeds to step S603. On the other hand, if the reliability of the necessary information reaches the desired level, no is performed in step S606, and the process proceeds to step S607. In step S607, it is determined whether or not the first position information Da is updated from the time of calculation of the corrected position. Here, when the first position information Da is updated from the time of calculation of the corrected position, yes is obtained in step S607, and the process proceeds to step S608.

In step S608, it is determined whether or not the positioning accuracy of the first position information Da is equal to or higher than a predetermined value. Here, when the positioning accuracy of the first position information Da is equal to or higher than the predetermined value, yes is performed in step S608, and the process proceeds to step S603. On the other hand, if the positioning accuracy of the first position information Da is smaller than the predetermined value, no is performed in step S608, and the process proceeds to step S609. In step S609, the corrected position is calculated. In this case, a new corrected position is calculated from the first position history, the necessary information, and the history of the corrected position calculated up to this point, based on the travel direction (azimuth) and the travel distance obtained from the necessary information, with the self-positioning position or the corrected position as a starting point.

Next, in step S610, an index indicating the reliability of the corrected position is calculated. In this case, the amount of deviation between the self-positioning position and the corresponding corrected position is calculated based on the first position history and the like, and an index indicating the reliability of the corrected position is calculated from the magnitude of the amount of deviation, the trend of change in the amount of deviation, and the like. After the execution of step S610, the process proceeds to step S611.

In step S611, it is determined whether or not the positioning history number of the first position information is equal to or greater than a required number, which is a number required for evaluating the reliability of the corrected position. Here, when the positioning history number is smaller than the required number, no is performed in step S611, and the process proceeds to step S612. In step S612, the first position information Da is used as the positioning result, in other words, the first positioning manner is selected. Next, in step S613, the correction position calculated this time is used as a next calculation start point. After execution of step S613, the correction selection processing ends.

On the other hand, if the number of positioning schedules is equal to or greater than the required number, the routine proceeds to step S614 as yes in step S611. In step S614, the index indicating the reliability of the corrected position (the reliability of the second position information Di) and the index indicating the reliability of the self-positioning position (the reliability of the first position information Da) are compared, and it is determined whether or not the reliability of the corrected position is higher than the reliability of the self-positioning position.

Here, if the reliability of the corrected position is equal to or less than the reliability of the self-positioning position, no is performed in step S614, and the process proceeds to step S612. On the other hand, if the reliability of the corrected position is higher than the reliability of the self-positioning position, yes is performed in step S614, and the process proceeds to step S615. In step S615, the second position information Di is employed as the positioning result, in other words, the second positioning manner is selected. After the execution of step S615, the process proceeds to step S613.

On the other hand, if the first position information Da is not updated from the time of calculation of the corrected position, no is performed in step S607, and the process proceeds to step S616. In step S616, the corrected position is calculated in the same manner as in step S609. Next, in step S617, an index indicating the reliability of the corrected position is calculated in the same manner as in step S610. After the execution of step S617, the flow proceeds to step S618.

In step S618, it is determined whether or not the second position information Di was employed as the positioning result just before. Here, when the second position information Di is used as the previous positioning result, yes is obtained in step S618, and the process proceeds to step S619. In step S619, the second position information Di is employed as the positioning result, in other words, the second positioning manner is selected. After the execution of step S619, the process proceeds to step S613. On the other hand, if the first position information Da is used as the previous positioning result, no is performed in step S618, and the process proceeds to step S620.

In step S620, it is determined whether or not the positioning accuracy of the first position information Da used as the positioning result is equal to or higher than a predetermined value. Here, when the positioning accuracy is equal to or higher than the predetermined value, yes is performed in step S620, and the process proceeds to step S619. On the other hand, if the positioning accuracy is less than the predetermined value, no is performed in step S620, and the process proceeds to step S621. In step S621, the first position information Da is used as the positioning result, in other words, the first positioning manner is selected. However, in this case, the position information is not updated. After the execution of step S621, the process proceeds to step S613.

Next, a specific example of selection of a positioning method by the above-described correction selection process will be described with reference to fig. 10. In this case, the update cycle of the self-positioning position, that is, the first position information Da is five times the execution cycle of the correction process for obtaining the second position information Di, that is, the correction position.

In fig. 10, a black circle represents a self-localization position, and a circle surrounding the black circle represents an estimation error of the self-localization position, that is, a reliability index. The open four corners indicate correction positions when the self-positioning position is not updated, and the black four corners indicate correction positions when the self-positioning position is updated. The arrow pointing in one direction indicates the movement amount of the vehicle 2 calculated from the previous corrected position and the current corrected position, that is, the movement amount based on the vehicle travel information Dc, the arrows pointing in two directions indicate the amount of deviation between the self-positioning position and the corrected position, and the arrow having a shape in which a black dot is added to one end of a straight line indicates the position adopted as the positioning result.

In fig. 10, the estimated errors from the self-positioning positions a10 to a100 are relatively large, and the reliability is low. The estimated errors from the positioning positions a110 to a130 are small, and the reliability is sufficiently high. The number of positioning history of the first position information Da when the self-positioning positions a10 and a20 are obtained is set to be smaller than the required number.

For example, consider the selection when obtaining the self-positioning positions a10, a 20. In this case, since the number of positioning histories of the first position information Da is smaller than the required number, the self-positioning positions a10 and a20 are used as the positioning results. Further, a selection when the corrected position B11 is obtained is considered. In this case, since the reliability of the previously selected self-positioning position a10 is low, the self-positioning position is selected. However, in this case, the position information is not updated.

Next, a selection when the self-positioning position a30 is obtained is considered. Here, the amount of shift between the self-positioning position a30 and the corrected position B30 corresponding thereto is smaller than the estimation error of the self-positioning position a 30. Therefore, when the self-positioning position a30 is obtained, the corrected position B30 is determined to have high reliability, and therefore the corrected position B30 is adopted as the positioning result. In addition, when the self-positioning positions a40, a60, and a70 are obtained, the corrected positions B40, B60, and B70 are also used as the positioning results, as in the case of obtaining the self-positioning position a 30.

Further, a selection when the corrected position B31 is obtained is considered. In this case, since the corrected position B30 was used as the positioning result, the corrected position B31 was used as the positioning result. In addition, when the corrected positions B41, B61, and B71 were obtained, the corrected positions B41, B61, and B71 were used as positioning results in the same manner as when the corrected position B31 was obtained.

Further, selection of the corrected positions B32 to B34 is considered. In this case, since it is determined that the reliability of the corrected position is high, the corrected positions B32 to B34 are adopted as the positioning result. In addition, when corrected positions B42 to B44, B62 to B64, and B72 to B74 are obtained, corrected positions B42 to B44, B62 to B64, and B72 to B74 are also used as positioning results, as in the case of obtaining corrected positions B32 to B34.

Next, a selection when the self-positioning position a50 is obtained is considered. In this case, the offset between the self-positioning position a50 and the corresponding corrected position B50 is larger than the estimation error of the self-positioning position a 50. However, when considered from the moving average of the offset amount, the reliability of the corrected position B50 is considered to be high. Therefore, in this case, the corrected position B50 is adopted as the positioning result. In addition, when the self-positioning position a80 is obtained, the corrected position B80 is adopted as the positioning result, similarly to when the self-positioning position a50 is obtained.

In addition, the selection when the self-positioning position a90 is obtained is considered. Here, the amount of shift between the self-positioning position a90 and the corrected position B90 corresponding thereto is larger than the estimation error of the self-positioning position a 90. Further, since the offset amounts of the corrected positions B80 and B90 continue to be larger than the estimation errors of the self-positioning positions a80 and a90, the moving average of the offset amounts is also large. Therefore, when the self-positioning position a90 is obtained, the reliability of the corrected position B90 is determined to be low, and therefore the self-positioning position a90 is adopted as the positioning result. Note that, when the self-positioning position a100 is obtained, the self-positioning position a100 is also used as the positioning result, similarly to when the self-positioning position a90 is obtained.

Next, the selection when the self-positioning position a110 is obtained is considered. In this case, the self-localization position a110 is selected as the localization result, considering that the reliability of the self-localization position a110 is sufficiently high. In addition, when the self-positioning positions a120 and a130 are obtained, the self-positioning positions a120 and a130 are selected as the positioning result, similarly to when the self-positioning position a110 is obtained.

In addition, the selection when the corrected position B111 is obtained is considered. In this case, the corrected position B111 is adopted as the positioning result, considering that the self-positioning position a110 was adopted as the positioning result before and the reliability of the self-positioning position a110 is sufficiently high. In addition, when the corrected positions B121 and B131 are obtained, the corrected positions B121 and B131 are adopted as the positioning result, as in the case of obtaining the corrected position B111. In addition, when the corrected positions B112 to B114, B122 to B124, and the like are obtained, the corrected positions B112 to B114, B122 to B124, and the like are also used as the positioning results, as in the case of obtaining the corrected positions B32 to B34.

As described above, the in-vehicle device 31 of the present embodiment is configured to have two modes, i.e., the first positioning mode and the second positioning mode, and to be able to selectively perform positioning operations of these respective modes as the positioning modes. Here, the first positioning method is a method of obtaining a positioning result using the positioning of the internal positioning unit 18 and performing the positioning by the in-vehicle device 31 itself. In addition, the second positioning method can obtain a positioning result with higher accuracy than the positioning result obtained by the first positioning method, using the vehicle travel information Dc in addition to the positioning by the internal positioning portion 18.

In the above configuration, the selection unit 34 that selects one of the two positioning systems preferentially selects the second positioning system in the normal state, and switches the positioning system to select the first positioning system if it is determined that the accuracy of the positioning result obtained by the second positioning system is lower than the accuracy of the positioning result obtained by the first positioning system. The selection unit 34 selects these positioning methods so that a highly accurate positioning result is always obtained. As described above, according to the present embodiment, as in the first embodiment, since an appropriate positioning method is selected from the viewpoint of improving the accuracy of the positioning result, an effect is obtained that an appropriate positioning method can be selected for use in positioning the vehicle 2.

When determining that the information source device (the in-vehicle device 6, 7) is mounted on the vehicle 2 based on the in-vehicle device mounting information De, the selection unit 34 determines that the switching condition is satisfied and selects the first positioning system. In this way, even when the information source device is not present in the vehicle 2 at first or when the information source device is removed from the vehicle 2, the positioning result of the vehicle 2 can be continuously obtained by performing the positioning by the in-vehicle device 31 itself.

When the selection unit 34 determines that the information source device is malfunctioning based on the various types of failure diagnosis information Dd, it determines that the switching condition is satisfied and selects the first positioning method. In this way, even when a failure occurs in the information source device, the in-vehicle device 31 can perform positioning itself, and the result of positioning the vehicle 2 can be obtained continuously.

If the communication with the information source device is not established, the selection unit 34 determines that the switching condition is satisfied and selects the first positioning method. In this way, even when an abnormality occurs in which communication with the information source device cannot be established, the in-vehicle device 31 can perform positioning itself, and the positioning result of the vehicle 2 can be obtained continuously.

If it is determined that the vehicle travel information Dc acquired from the information source device is not normal, the selection unit 34 determines that the switching condition is satisfied and selects the first positioning system. In this way, even when the vehicle travel information Dc transmitted from the information source device is abnormal, the positioning result of the vehicle 2 can be continuously obtained by performing the positioning by the in-vehicle device 31 itself.

If it is determined that the reliability of the vehicle travel information Dc, that is, the accuracy of the measurement value of the sensor indicated by the information is lower than a desired level, the selection unit 34 determines that the switching condition is satisfied and selects the first positioning system. In this way, even when the positioning error of the second position information Di, which should have high positioning accuracy originally, is very large, the in-vehicle device 31 can perform positioning itself, and the positioning result of the vehicle 2 can be obtained continuously.

The selection unit 34 determines that the switching condition is satisfied and selects the first positioning system when the positioning accuracy of the first position information Da is considered to be a level that sufficiently satisfies the desired accuracy. This can reliably obtain the effect that a positioning result with high accuracy is always obtained.

If it is determined that the number of positioning histories necessary to realize the estimated positioning of the vehicle travel information Dc is insufficient, the selection unit 34 determines that the switching condition is satisfied and selects the first positioning method. In this way, even when the driver cannot correct the position information by the estimated positioning immediately after riding the vehicle 2 while the vehicle is stopped, for example, the positioning by the in-vehicle device 31 itself can be performed, and the positioning result of the vehicle 2 can be continuously obtained.

The selection unit 34 determines that the switching condition is satisfied and selects the first positioning system when one of the index indicating the reliability of the first position information Da and the index indicating the reliability of the second position information Di is at a specific level or when a result of comparing the indexes satisfies a specific determination condition. Thus, the following effects are obtained. That is, in the estimated positioning, accumulation of positioning errors due to accumulation of a deviation of the travel bearing often becomes a problem.

According to the selection method as described above, if the constant amount of deviation continues in a state where the second position information Di is used as the positioning result, it is determined that the reliability of the first position information Da is higher than that of the second position information Di. As a result, the first position information Da is used as the positioning result, and the position of the vehicle 2 is reset from the erroneous position based on the accumulation of the positioning errors to the position that should be originally located. Therefore, according to the present embodiment, it is possible to eliminate the problem caused by accumulation of positioning errors that are likely to occur in estimated positioning.

(other embodiments)

The present invention is not limited to the embodiments described above and shown in the drawings, and can be arbitrarily modified, combined, or expanded without departing from the scope of the invention.

The numerical values and the like shown in the above embodiments are examples, and are not limited thereto.

The positioning device of the present invention is not limited to the in-vehicle devices 1 and 31, and may be any device as long as it performs positioning of the vehicle 2, and may be, for example, a mobile communication device such as a mobile terminal that the owner of the vehicle 2 or the like takes in the vehicle.

A sensor group capable of obtaining the same information as the information of the in-vehicle devices 6 and 7 may be attached to the in-vehicle devices 1 and 31. In this case, the selection units 17 and 34 and the correction processing unit 33 can acquire the vehicle travel information from the sensor groups mounted on the in-vehicle devices 1 and 31 without passing through the communication network 5.

The accuracy correction position information Db in the first embodiment is not limited to the information output from the navigation device 4, and may be information indicating the result of positioning another external device that performs positioning of the vehicle 2 and correction for improving the accuracy of the positioning. In this case, the in-vehicle device 1 may be configured to acquire the accuracy correction position information Db by communicating with another external device.

The present invention has been described in terms of embodiments, but it should be understood that the present invention is not limited to the embodiments and configurations. The present invention also includes various modifications and equivalent modifications. In addition, various combinations and modes, and other combinations and modes including only one element, more than one element, or less than one element are also within the scope and spirit of the present invention.