Data sharing system

Abstract

The disclosed data sharing system comprises a plurality of vehicles (2) existing within a network (3) and a server (1) that defines a role for each of the vehicles (2), the data sharing system making data sharing between the vehicles (2) possible. The server (1) defines the role of a first vehicle for one of the vehicles (2) and defines the role of second vehicles for the other vehicles (2). The first vehicle stores a database obtained by collecting data generated by the second vehicles, and provides the data contained in the database to the second vehicles in response to a request from the second vehicles.

Description

Data sharing system

[0001] This case relates to a data sharing system that enables data sharing between vehicles.

[0002] Conventionally, a data sharing system that uses vehicle-to-vehicle communication to share information with vehicles in the vicinity of a vehicle is known (see Patent Document 1). This type of system allows vehicle steering information and acceleration / deceleration information to be shared with surrounding vehicles in real time, thereby improving the accuracy of predicting the behavior of each vehicle. Meanwhile, data sharing systems have also been proposed that allow not only information about the behavior of surrounding vehicles but also information about the driving environment and roads to be shared via a server (see Patent Documents 2 and 3). This type of system allows information about road construction and traffic accidents that other vehicles have previously discovered to be easily shared.

[0003] International Publication No. 2019 / 150460 JP 2022-106017 A JP 2019-061478 A

[0004] Server-based data sharing systems offer the advantage of allowing server administrators (e.g., automobile manufacturers) to centrally manage data and easily maintain data quality. However, they face the challenge of achieving both reduced server maintenance costs and improved communication quality. For example, building a global data sharing system may require installing a server in each country (or region), which can increase costs. Furthermore, the greater the physical distance between the server and each vehicle, the more likely communication problems (e.g., communication delays and interruptions) are to occur, potentially reducing convenience for vehicle users. Therefore, it is desirable to install more servers to address communication quality concerns, which can further increase costs.

[0005] One of the objectives of this case was devised in light of the above-mentioned problems, and is to provide a data sharing system that can achieve both reduced server maintenance costs and improved communication quality. In addition to this objective, another objective of this case is to achieve effects derived from the various components shown in the "Mode for Carrying Out the Invention" below, which are not obtainable with conventional technology.

[0006] The disclosed data sharing system can be realized as the following disclosed aspects (application examples) and solves at least part of the above-mentioned problems. Each of the aspects from aspect 2 onwards is an aspect that can be selected as an additional aspect, and each of the aspects can be omitted. None of the aspects from aspect 2 onwards discloses an aspect or configuration that is essential to the present invention.

[0007] Aspect 1. The disclosed data sharing system includes a plurality of vehicles existing within a network and a server that assigns roles to each of the vehicles, and realizes data sharing among the vehicles. The server assigns the role of a first vehicle to one of the vehicles and assigns the role of a second vehicle to the other vehicles. The first vehicle also stores a database that collects data generated by the second vehicles, and provides the data contained in the database to the second vehicle in response to a request from the second vehicle.

[0008] Aspect 2. In the above aspect 1, it is preferable that the server assigns a role to at least one of the vehicles as a third vehicle that is neither the first vehicle nor the second vehicle. It is also preferable that the third vehicle stores a copy of the database stored in the first vehicle.

[0009] Aspect 3. In the above aspect 2, it is preferable that the server changes the role of the first vehicle to the second vehicle and changes the role of the third vehicle to the first vehicle when any of the following conditions 1 to 3 is met: Condition 1. A first assignment period has elapsed since the role of the first vehicle was set. Condition 2. The communication blackout time of the first vehicle has become equal to or longer than a first blackout time. Condition 3. Based on the area in which the role of the first vehicle is set, the first vehicle has moved away from the area by equal to or longer than a first exit distance.

[0010] Aspect 4. In an aspect including Aspect 2 above, it is preferable that the server changes the role of at least one of the second vehicles to the third vehicle when any of the following conditions 4 to 7 is met: Condition 4. A second assignment period has elapsed since the role of the third vehicle was set. Condition 5. The communication blackout time of the third vehicle is equal to or longer than a second blackout time. Condition 6. Based on the area in which the role of the third vehicle is set, the third vehicle has moved away from the area by a second exit distance or more. Condition 7. The role of the third vehicle has been changed to the first vehicle.

[0011] Aspect 5. In an aspect including the above-mentioned Aspect 1, it is preferable that, when selecting the vehicle to be assigned the role of the first vehicle, the server calculates a first cumulative time that the vehicle has been connected to the network and a second cumulative time that the vehicle has played the role of the first vehicle, and selects the vehicle based on a value obtained by dividing the second cumulative time by the first cumulative time. Aspect 6. In an aspect including the above-mentioned Aspect 1, it is preferable that the server determines the vehicle to be assigned the role of the first vehicle based on the deterioration state and communication stability of the vehicle.

[0012] Aspect 7. In an aspect including the above-mentioned Aspect 2, it is preferable that, when selecting the vehicle to be assigned the role of the third vehicle, the server calculates a first cumulative time that the vehicle has been connected to the network and a third cumulative time that the vehicle has played the role of the first vehicle or the third vehicle, and selects the vehicle based on a value obtained by dividing the third cumulative time by the first cumulative time. Aspect 8. In an aspect including the above-mentioned Aspect 2, it is preferable that the server determines the vehicle to be assigned the role of the third vehicle based on the deterioration state and communication stability of the vehicle.

[0013] In the disclosed data sharing system, the server assigns the roles of first and second vehicles to each vehicle, and the first vehicle stores the database and provides data to the second vehicle. By moving some of the server's functions to the first vehicle in this way, server maintenance costs can be reduced. Furthermore, because the role of the first vehicle is assigned to one of the vehicles in the network, communication failures between the first and second vehicles are less likely to occur, improving communication quality.

[0014] 1 is a schematic diagram showing an overview of a data sharing system; FIG. 2 is a schematic diagram for explaining an area corresponding to a network; FIG. 3 is a block diagram for explaining the configuration of a data sharing system; FIG. 4 is a table showing the roles of servers and vehicles (master vehicle, replica vehicle, client vehicle) related to the data sharing system; (A) to (C) are examples of tables stored on the server; and (D) are examples of databases stored in the master vehicle. FIG. 5 is a flowchart illustrating a procedure for setting a role; and FIG. 6 is a flowchart illustrating a procedure for changing a role.

[0015] A data sharing system according to an embodiment of the present invention will now be described. This data sharing system enables data sharing between vehicles and includes multiple vehicles in a network and a server connectable to each vehicle. In this embodiment, multiple vehicles exist within a single network, and each vehicle in the network can connect to a single server. The shared data is data related to location (geographical elements) (location-related data). This data includes, for example, road information for route planning, congestion information (vehicle density information, average dwell time information), obstacle information, road construction information, road surface unevenness information, information on faded white lines and road markings, traffic regulation information, traffic enforcement information, and road flooding information.

[0016] The network according to this embodiment refers to a network (local network, localized network) established for each region or district, and refers to a communication network formed to correspond to each area obtained by dividing the earth's surface into predetermined areas. Each area may be, for example, an area divided into a mesh pattern, an area divided according to administrative districts, or an area divided based on the location of wireless communication facilities (for example, base stations and antennas).

[0017] The vehicle according to this embodiment has at least a positioning function and a communication function, and includes an engine vehicle that runs using an engine (internal combustion engine) as a drive source, a motor vehicle that runs using a motor (electric motor) as a drive source, a hybrid vehicle (HEV, Hybrid Electric Vehicle) that runs using an engine and a motor as drive sources, and a plug-in hybrid electric vehicle (PHEV, Plug-in Hybrid Electric Vehicle) that can be externally charged or externally powered.

[0018] A plug-in hybrid vehicle is a hybrid vehicle equipped with an engine and motor as drive sources, a generator as a power generation device, and a battery as a power storage device, and which allows the battery to be externally charged or externally supplied with power from the battery. The former plug-in hybrid vehicle is equipped with a charging port (inlet) for inserting a charging cable that supplies power from an external charging facility, a wireless power receiving device, etc. The latter plug-in hybrid vehicle is equipped with an outlet (receptacle) for external power supply, a wireless power supply device, etc. It is possible for the above charging port and outlet to be installed together on a single plug-in hybrid vehicle.

[0019] [1. Device Configuration] Fig. 1 is a schematic diagram showing an overview of a data sharing system according to an embodiment. This data sharing system includes a plurality of vehicles 2 present within a network 3 and a server 1 that assigns a predetermined role to each of the vehicles 2. The vehicles 2 are connected cars that have the function of communicating with the server 1 via the network 3. The vehicles 2 are capable of communicating with at least other vehicles 2 via the network 3, and may also be capable of vehicle-to-vehicle communication (direct communication with other vehicles 2). An information provision service for the vehicles 2 using the network 3 is also called a CCS (connected car service).

[0020] The server 1 is a computer capable of providing information to each vehicle 2 via the network 3. Unlike server devices according to the prior art, the server 1 of this embodiment does not have the function of providing information about the driving environment and roads to each vehicle 2. The server 1 has both the function of having any vehicle 2 present in the network 3 take over this role and the function of providing each vehicle 2 with identification information for identifying that vehicle 2. A plurality of such networks 3 may be provided. One server 1 may be connectable to a plurality of networks 3 via, for example, the Internet. It is sufficient that one or more servers 1 are provided worldwide; it is not necessary to provide one server 1 for each network 3.

[0021] FIG. 2 is a schematic diagram for explaining an area corresponding to a network 3. The network 3 is formed to correspond to a regional mesh 4, which is a seamless mesh of the earth's surface, based on latitude and longitude, for example. One regional mesh 4 is, for example, several square kilometers to several tens of square kilometers in size. One network 3 may correspond to an individual regional mesh 4, or one network 3 may correspond to multiple adjacent regional meshes 4. In this embodiment, a mobile phone network corresponding to approximately one regional mesh 4 is associated with one network 3. The expected number of vehicles 2 present in one network 3 is, for example, several hundred to several thousand.

[0022] 3 is a block diagram showing the device configuration of the server 1 and vehicle 2 included in the data sharing system. The server 1 is provided with a calculation means 10 (role setting means) having a processor 11 and memory 12, a communication means 13, and a storage means 14. The calculation means 10 is a device that is the main device for performing calculation processing on the server 1, and the communication means 13 is a device for sending and receiving information to and from the vehicle 2 and other computers via the network 3.

[0023] The storage means 14 is a device that stores the contents of the arithmetic processing executed by the server 1 as a processing program, and also stores the results of the arithmetic processing. The contents of the processing program are read into the processor 11 and memory 12 as appropriate and executed. The storage means 14 may be provided separately from the server 1. Furthermore, the server 1 may be one of multiple virtual servers included in a single physical server, or multiple physical servers may function as a single virtual server.

[0024] The vehicle 2 is provided with a calculation means 20 having a processor 21 and a memory 22, a positioning means 23, a detection means 24, a communication means 25, and a storage means 26. The calculation means 20 is a device that is the main device for performing calculation processing in the vehicle 2. The positioning means 23 is a device (e.g., a car navigation device) that acquires position information of the vehicle 2 based on detection information from a GNSS (Global Navigation Satellite System) device, a vehicle speed sensor, a steering angle sensor, a yaw rate sensor, a radio signal strength sensor, etc. (not shown).

[0025] The detection means 24 detects information about the road and driving environment of the vehicle 2. Specific examples of the detection means 24 include a radar device, an ultrasonic sensor device, a video camera device, an infrared camera device, etc. that detect objects (other vehicles, obstacles, police vehicles, etc.) that exist around the vehicle 2 or on the road surface. The information acquired by the detection means 24 is linked to the position information acquired by the positioning means 23 to become position-related data.

[0026] The communication means 25 is a device that allows the vehicle 2 to exchange information with the server 1 and other vehicles 2. The storage means 26 is a device that stores the contents of the arithmetic processing executed in the vehicle 2 as a processing program, and also stores the results of the arithmetic processing. The contents of the processing program are read into the processor 21 and memory 22 as appropriate and executed. The processing program and the results of the arithmetic processing stored in the storage means 26 correspond to the role of each vehicle 2, which will be explained below.

[0027] 4 is a table showing the functions and roles of the server 1 and the vehicles 2. The server 1 in this embodiment has the function of assigning and setting one of three types of roles to each of the multiple vehicles 2 present in the network 3. The roles are the role of master vehicle (first vehicle), the role of client vehicle (second vehicle), and the role of replica vehicle (third vehicle). These roles are not fixedly assigned to specific vehicles 2, but are dynamically assigned to all vehicles 2 within the network 3.

[0028] The master vehicle is a vehicle that collects location-related data generated by the vehicle itself and other vehicles 2, creates a database, and stores and manages this database in the storage means 26. One of the vehicles 2 present in the network 3 is designated as the master vehicle by the server 1 on a rotating basis. The location-related data contained in the database is provided to the vehicle itself and other vehicles 2 in response to a request from the vehicle itself or other vehicles 2. The generation of location-related data may be performed by all vehicles 2 including the master vehicle, or may be performed only by the client vehicles described below.

[0029] Only one vehicle 2 is set to the role of master vehicle at any one time within one network 3. The period during which the role of master vehicle is set (appointed) (term of office of master vehicle) is basically set to a maximum of the first assignment period (several weeks to several months). After that period has elapsed, the role of that vehicle 2 is changed to client vehicle, and the role of master vehicle is handed over to one of the vehicles 2 currently holding the role of replica vehicle. When the role of master vehicle is cancelled (dismissed), the database information that had been stored in the storage means 26 up to that point is erased. Note that the setting conditions for the master vehicle (appointment conditions and dismissal conditions) may be changed, and specific examples of this will be described later.

[0030] A replica vehicle is a vehicle that stores and manages a copy (replica) of the database stored in the master vehicle in the storage means 26. Of the vehicles 2 present in the network 3, one to several vehicles are designated as replica vehicles by the server 1 on a rotating basis. The contents of the replica stored in the replica vehicle may be updated, for example, every time a change is made to the master vehicle's database, or may be updated at a predetermined interval. For example, it may be updated at predetermined time intervals, or every time the database is changed a predetermined number of times. If database replication is not necessary, the replica vehicle may be omitted.

[0031] The role of replica vehicle is preferably set to one or more vehicles within one network 3. The period for which the role of replica vehicle is set (the term of the replica vehicle) is basically set to a maximum of the second assignment period (for example, a period longer than the first assignment period). After that period has elapsed, the role of the vehicle 2 is changed to client vehicle, and the role of replica vehicle is handed over to one of the vehicles 2 currently holding the role of client vehicle. When the role of replica vehicle is dismissed, the replica information in the database that had been stored in the storage means 26 up to that point is erased. Note that the above-mentioned replica vehicle setting conditions (appointment conditions and dismissal conditions) may be changed, and specific examples of this will be described later.

[0032] If a vehicle 2 that was the master vehicle at that time is released from the role of replica vehicle before the second assignment period has elapsed since the role of replica vehicle was assigned, one of the vehicles 2 that was currently serving as a replica vehicle will be appointed as the master vehicle. In this case, the copy of the database stored in the storage means 26 will be used as the master vehicle database. Also, since the number of replica vehicles will decrease when a replica vehicle is promoted to a master vehicle, the role of replica vehicle will be newly assigned to one of the vehicles 2 that was currently serving as a client vehicle.

[0033] A client vehicle is a vehicle 2 that generates location-related information that associates the information acquired by the detection means 24 with the location information acquired by the positioning means 23, and transmits the location-related information to the master vehicle. The IP address and port number of the master vehicle to which the location-related information is to be sent are appropriately obtained by querying the server 1. Each piece of location-related information generated by a client vehicle is added to and stored in the database of the master vehicle. The role of client vehicle is set to all remaining vehicles 2 that are neither master vehicles nor replica vehicles among the vehicles 2 present in the network 3.

[0034] The server 1 assigns the above-mentioned roles to each vehicle 2. The server 1 stores information for identifying the location and role of each vehicle 2 within the network 3. However, unlike the server device according to the prior art, the server 1 of this embodiment does not store the individual location-related information generated by the client vehicles or the database that is a compilation of such information. In other words, in this embodiment, the functions previously handled by the server device according to the prior art are transferred to the master vehicle, thereby reducing the load on the server 1.

[0035] 5A to 5C are examples of tables stored in the storage means 14 of the server 1. The address management table shown in FIG. 5A is a table in which unique information for identifying each vehicle 2 is stored. The address management table records the vehicle identification number (VIN, Vehicle Identification Number) of each vehicle 2 and the IP address and port number related to communication with each vehicle 2. Each vehicle 2 periodically communicates with the server 1 to notify the server 1 of its own IP address and port number, and to obtain the IP address and port number of the master vehicle.

[0036] The area management table shown in Figure 5 (B) is a table that stores unique information for identifying the network 3 (or the regional mesh 4 corresponding to that network 3) to which each vehicle 2 is connected. The area management table records the vehicle identification number of each vehicle 2 and the area identification number (area ID) of the network 3 (or the regional mesh 4 in which that vehicle 2 is located) to which each vehicle 2 is connected.

[0037] The role management table shown in Fig. 5(C) is a table that stores the role of each vehicle 2. The role management table records the vehicle identification number of each vehicle 2 and the role of each vehicle 2. For the master vehicle and replica vehicle, information such as the date and time when the role was set and the cumulative time for which the role of the master vehicle or replica vehicle has been set may be added.

[0038] 6 shows an example of a database stored in the storage means 26 of the master vehicle. This database stores location-related information generated by the client vehicle. The location-related information includes information about the details detected by the detection means 24 of the client vehicle (e.g., obstacles, road bumps / depressions, traffic enforcement, etc.) and the detected location (latitude and longitude). Information about the date and time when the location-related information was generated, an area identification number, etc. may also be added to the information.

[0039] The information in the database managed by the master vehicle is available to all vehicles 2 in the network 3 in which the master vehicle is located. For example, vehicles 2 other than the master vehicle periodically transmit their own vehicle's position information to the master vehicle and request nearby position-related information. Upon receiving this request, the master vehicle searches the database based on the received position information and returns position-related information present in the vicinity of the vehicle 2. The returned position-related information is displayed, for example, on a map image in a car navigation device. Similar control is also performed in the master vehicle. The master vehicle periodically searches the database based on its own vehicle's position information to obtain position-related information present in the vicinity of the vehicle. The obtained position-related information is displayed, for example, on a map image in a car navigation device.

[0040] [3. Example of Role Setting Conditions] The role of master vehicle is set to any vehicle 2 in the network 3 when there is no master vehicle in the network 3 or when the current master vehicle is dismissed. The conditions (appointment conditions) for selecting a vehicle 2 suitable as the master vehicle may be selected from the conditions shown below. In addition, the role of master vehicle may be dismissed when any of the dismissal conditions shown below is met. Furthermore, the assignment and dismissal of the role of master vehicle may be determined by combining multiple assignment conditions and dismissal conditions.

[0041] [Appointment Conditions] Condition M1. The current master vehicle was a replica vehicle when it was released. Condition M2. The connection time to the network 3 is within a predetermined time range. Condition M3. The deterioration degree of the vehicle 2 or the storage means 26 is within a predetermined deterioration range. Condition M4. The communication stability is high (the communication quality is good). Condition M5. The first cumulative time T connected to the network 3 １ The second cumulative time T ２ The ratio (T ２ / T １ ) is equal to or less than a predetermined value (or within a predetermined ratio range). Condition M6. The above ratio (T ２ / T １ ) is the smallest.

[0042] [Dismissal conditions] Condition M7. The first assignment period has elapsed since the role of master vehicle was assigned. Condition M8. The communication blackout time of the master vehicle is equal to or longer than the first blackout time. Condition M9. Based on the area where the role of the master vehicle is assigned (the area corresponding to one network 3), the master vehicle has moved away from that area by more than the first withdrawal distance. Condition M10. The first withdrawal time has elapsed since the master vehicle left that area.

[0043] The above condition M1 states that when a master vehicle is dismissed, a successor should be preferentially selected from among the replica vehicles. The connection time in the above condition M2 means the elapsed time from the date and time when communication with the server 1 was first established within the network 3. Condition M2 states that a vehicle 2 that is neither too new nor too old is suitable to be the master vehicle.

[0044] The degree of deterioration in the above condition M3 refers to the deterioration of the vehicle 2 over time and the deterioration of the storage read / write performance. Condition M3 also states that a vehicle 2 that is not new and has not significantly deteriorated is suitable to be the master vehicle. The above condition M4 states that the master vehicle should be selected taking into consideration the stability of communication between the vehicles 2. The above conditions M5 and M6 are examples of methods for achieving fair master vehicle role selection on a rotational basis.

[0045] The first responsibility period of the above condition M7 is, for example, several weeks to several months. The communication blackout time of the above condition M8 refers to the time during which communication with the master vehicle cannot be established within the network 3. The communication blackout time may be determined, for example, by the server 1 periodically checking whether communication with the master vehicle can be established. Alternatively, it may be determined by having the server 1 notify the absence of the master vehicle when vehicles other than the master vehicle cannot establish communication with the master vehicle. The above conditions M9 and M10 are examples of conditions that are determined when the master vehicle moves to a location with a different area identification number.

[0046] The role of the replica vehicle is set to any vehicle 2 in the network 3 when there are no predetermined number of replica vehicles in the network 3 or when the current replica vehicle is dismissed. The conditions (appointment conditions) for selecting a vehicle 2 suitable for the replica vehicle may be selected from the conditions shown below. In addition, the role of the replica vehicle may be dismissed when any of the dismissal conditions shown below is met. Furthermore, the assignment and dismissal of the role of the replica vehicle may be determined by combining multiple appointment conditions and dismissal conditions.

[0047] [Appointment Conditions] Condition R1. The current replica vehicle was a client vehicle when it was released. Condition R2. The connection time to the network 3 is within a predetermined time range. Condition R3. The deterioration degree of the vehicle 2 or the storage means 26 is within a predetermined deterioration range. Condition R4. The communication stability is high (the communication quality is good). Condition R5. The first cumulative time T connected to the network 3 １ The third cumulative time T ３ The ratio (T ３ / T １ ) is equal to or less than a predetermined value (or within a predetermined ratio range). Condition R6. The above ratio (T ３ / T １ ) is the smallest.

[0048] [Dismissal conditions] Condition R7. The second assignment period has elapsed since the replica vehicle's role was assigned. Condition R8. The replica vehicle's communication blackout time is equal to or longer than the second blackout time. Condition R9. Based on the area where the replica vehicle's role is assigned (the area corresponding to one network 3), the replica vehicle has moved away from that area by more than the second exit distance. Condition R10. The second exit time has elapsed since the replica vehicle left that area.

[0049] The above condition R1 states that when a replica vehicle is dismissed, a successor will be preferentially selected from among the client vehicles. The above conditions R2 to R4 are similar to the above conditions M2 to M4, and state the conditions for vehicle 2 that are suitable for the replica vehicle. The above conditions R5 and R6 are examples of methods for achieving fair replica vehicle role assignment on a rotational basis.

[0050] The second assignment period under condition R7 above is, for example, a longer period than the first assignment period, ranging from several months to a year. Conditions R8 to R10 above are similar to conditions M8 to M10 above. The role of a replica vehicle imposes a smaller computational load, communication load, and storage load than the role of a master vehicle. Therefore, the terms of service of a replica vehicle may be set relatively long by relaxing the conditions for dismissing a replica vehicle (conditions R7 to R10) more than the conditions for dismissing a master vehicle (conditions M7 to M10).

[0051] 7 is a flowchart illustrating the procedure for the server 1 to set the role of each vehicle 2 when it receives communication from each vehicle 2. The server 1 periodically receives communication from each vehicle 2, checks the IP address and port number of each vehicle 2 based on the address management table, and updates the IP address and port number as necessary. The server 1 also obtains the area identification number of the network 3 to which each vehicle 2 is connected (or the regional mesh 4 in which the vehicle 2 is located) based on the location information of each vehicle 2, and updates the area management table. Next, the server 1 searches for master vehicles and replica vehicles that are present on the same network 3 as the vehicle 2 based on the area management table and role management table.

[0052] In step A1, it is determined whether a master vehicle exists in the same network 3 as the vehicle 2. If the condition in step A1 is not met, the process proceeds to step A2, where the role of the vehicle 2 is set to master vehicle and recorded in the role management table. A specific example of the vehicle 2 that is set to the role of master vehicle in step A2 is the vehicle 2 that first connected to the network 3 (or regional mesh 4).

[0053] If the condition of step A1 is met, the process proceeds to step A3. In step A3, it is determined whether a predetermined number of replica vehicles exist in the same network 3 as the vehicle 2. If the condition of step A3 is not met, the process proceeds to step A4, where the role of the vehicle 2 is set to replica vehicle and recorded in the role management table. A specific example of a vehicle 2 to be set as the replica vehicle in step A4 is the vehicle 2 that is second to be connected to the network 3 (or regional mesh 4). Note that if the condition of step A3 is met, the process proceeds to step A5, where the role of the vehicle 2 is set to client vehicle.

[0054] FIG. 8 is a flowchart illustrating a procedure for changing the role of each vehicle 2. Based on this flowchart, the server 1 periodically manages whether the role of each network 3 (or regional mesh 4) needs to be changed or reset. In step B1, it is determined whether the condition for removing the master vehicle is met. If this condition is met, the process proceeds to steps B2 to B4 for selecting a successor master vehicle; if this condition is not met, the process proceeds to step B5. In step B5, it is determined whether the condition for removing the replica vehicle is met. If this condition is met, the process proceeds to steps B6 to B8 for selecting a successor replica vehicle; if this condition is not met, the control of this flowchart ends.

[0055] In step B2, in order to select a candidate master vehicle from among the replica vehicles, a value for quantitatively evaluating the past experience of the master vehicle is calculated. That is, the first cumulative time T １and the second cumulative time T during which each replica vehicle served as the master vehicle. ２ and the first cumulative time T １ The second cumulative time T ２ Ratio T ２ / T １ (Second cumulative time T ２ The first cumulative time T １ The ratio T ２ / T １ The smaller the value of , the less experience the master vehicle has, and the lower its contribution to the entire network 3 .

[0056] In the next step B3, the communication stability and the degree of deterioration (the degree of deterioration of the vehicle 2 and the storage means 26) of each replica vehicle are confirmed. Then, in step B4, a successor master vehicle that satisfies the master vehicle appointment conditions is selected from the replica vehicles. For example, the ratio T ２ / T １ The replica vehicle with the smallest value of T will become the next master vehicle. ２ / T １ The replica vehicle with a relatively small value and a deterioration level within the predetermined deterioration range becomes the successor master vehicle. The role of vehicle 2, which had been the master vehicle until then, is changed to client vehicle. Then, proceed to steps B6 to B8 to select a successor to the vacant replica vehicle.

[0057] In step B6, in order to select candidates for replica vehicles from among the client vehicles, a value for quantitatively evaluating the past experiences of the master vehicle and the replica vehicle is calculated. That is, the first cumulative time T １ and a third cumulative time T during which each client vehicle has served as a master vehicle or a replica vehicle. ３ and the first cumulative time T １ The third cumulative time T ３ Ratio T ３ / T １ (Third cumulative time T ３ The first cumulative time T １ The ratio T ３ / T １The smaller the value of , the less experience the master vehicle or replica vehicle has, and the lower the contribution to the entire network 3 .

[0058] In the next step B7, the communication stability and the degree of deterioration (the degree of deterioration of the vehicle 2 and the storage means 26) of each client vehicle are confirmed. Then, in step B8, a successor replica vehicle that satisfies the replica vehicle appointment conditions is determined from among the client vehicles. For example, the ratio T ３ / T １ The client vehicle with the smallest value of T will be the successor replica vehicle. ３ / T １ The client vehicle with a relatively small value and a deterioration degree within a predetermined deterioration range becomes the successor replica vehicle. The role of vehicle 2, which was the replica vehicle until then, is changed to that of a client vehicle, except when it is promoted to a master vehicle.

[0059] [5. Effects] (1) The data sharing system of this embodiment includes a plurality of vehicles 2 present in a network 3 and a server 1 that assigns roles to each vehicle 2, in order to realize data sharing among a plurality of vehicles 2. The server 1 assigns the role of master vehicle (first vehicle) to one of the vehicles 2, and assigns the roles of client vehicles (second vehicles) to the other vehicles 2. The master vehicle stores a database that collects location-related data generated by the client vehicles, and provides the location-related data contained in the database to the client vehicles in response to requests from the client vehicles.

[0060] In this way, by assigning the roles of master vehicle and client vehicle to vehicles 2 in network 3 and having the master vehicle centrally manage the database of location-related data, the computational load on server 1 and the capacity of storage means 14 can be significantly reduced compared to when the database is managed by server 1, and the costs associated with maintaining and managing server 1 can be reduced.

[0061] Furthermore, in the data sharing system of this embodiment, a master vehicle in the network 3 provides location-related data to client vehicles in the same network 3. In other words, communication is completed within an area where the physical distance is relatively short. This reduces the probability of communication failures (e.g., communication delays or communication interruptions) occurring between the master vehicle and the client vehicle when transferring location-related data, thereby improving communication quality. Therefore, it is possible to achieve both reduced costs for maintaining and managing the server 1 and improved communication quality within the network 3.

[0062] In the data sharing system of this embodiment, there is only one master vehicle in each network 3 that centrally manages the database. Alternatively, it is also possible to configure the database to be stored in the storage means 26 of all vehicles 2, with each vehicle 2 managing its own location-related data. However, in this case, each vehicle 2 will retain unnecessary location-related data that is not used by the vehicle itself, raising concerns about pressure on the onboard storage and the progression of its deterioration. According to the configuration of this embodiment, delegating database management to the master vehicle can prevent pressure on the onboard storage of other vehicles 2 and the progression of its deterioration. Furthermore, by having only the master vehicle function as a server, it is possible to encourage cache reuse and improve response times for providing location-related data.

[0063] Furthermore, compared to when each vehicle 2 manages the database individually, the load on the network 3 (degree of communication congestion) can be reduced. For example, if N vehicles 2 in one network 3 generate one piece of position-related data and share it with other vehicles 2, assuming the size of the position-related data is 1 KB, the overall communication volume on the network 3 will be N(N-1) KB. On the other hand, if only the master vehicle manages the database, the position-related data does not need to be shared with all vehicles 2, and each vehicle 2 requests the data from the master vehicle when it needs to use the position-related data. Therefore, assuming that the master vehicle provides each vehicle 2 with position-related data M times in response to each vehicle 2's request for position-related data, the overall communication volume on the network 3 will be (N-1)+M KB. Here, assuming N=1000, the communication volume for the former is 999,000 KB and the communication volume for the latter is 999+M KB, and it is highly likely that the latter will result in a smaller load on the network 3.

[0064] Furthermore, compared to when the database is managed individually by each vehicle 2, it is possible to reduce the incompleteness of data for each network 3 (regional mesh 4). In other words, it takes time for location-related data generated by other vehicles 2 in the network 3 to be transmitted to all vehicles 2, and it is difficult to confirm that the information has been completely disseminated throughout the network 3. On the other hand, when only the master vehicle manages the database, location-related data can be efficiently collected and easily managed.

[0065] (2) In the above data sharing system, the server 1 can assign the role of a replica vehicle (third vehicle) that is neither a master vehicle nor a client vehicle. The replica vehicle is assigned to at least one of the vehicles 2 in the network 3 and stores a copy (replica) of the database stored in the master vehicle. With this configuration, even when the master vehicle is absent (for example, when communication is interrupted, when the master vehicle is moved to a distant location, or when the master vehicle is scrapped), the role of the master vehicle can be quickly taken over by the replica vehicle. Therefore, smooth and reliable data sharing can be achieved.

[0066] (3) For example, the server 1 may change the role of the master vehicle to a client vehicle and change the role of the replica vehicle to a master vehicle when any of the following conditions 1 to 3 is met: Condition 1. A first assignment period has elapsed since the role of the master vehicle was set. Condition 2. The communication disruption time of the master vehicle is equal to or longer than the first disruption time. Condition 3. Based on the area in which the role of the master vehicle is set, the master vehicle has moved away from that area by more than a first exit distance.

[0067] This configuration allows the master vehicle's period of service and absence to be accurately grasped, and the replica vehicle can be promoted to the master vehicle, realizing smooth data sharing. For example, it is possible to avoid a situation in which only one vehicle 2 is forced to play the role of master vehicle for an extended period of time, thereby improving the fairness of rotation. Furthermore, if the master vehicle moves outside the area (regional mesh 4) corresponding to the network 3, the role of the master vehicle can be quickly handed over to the replica vehicle.

[0068] (4) For example, the server 1 may change the role of at least one of the client vehicles to a replica vehicle when any of the following conditions 4 to 7 is met: Condition 4: A second assignment period has elapsed since the role of the replica vehicle was set. Condition 5: The replica vehicle's communication outage time has exceeded the second outage time. Condition 6: Based on the area in which the role of the replica vehicle is set, the replica vehicle has moved away from that area by more than the second exit distance. Condition 7: The role of the replica vehicle has been changed to a master vehicle.

[0069] This configuration allows for accurate understanding of the replica vehicle's period of service and absence, allowing client vehicles to be promoted to replica vehicles, thereby achieving smooth data sharing. For example, it is possible to avoid a situation in which a specific vehicle 2 is forced to play the role of replica vehicle for an extended period of time, thereby improving the fairness of rotation. Furthermore, when a replica vehicle is promoted to a master vehicle or when the replica vehicle moves outside the area (regional mesh 4) corresponding to the network 3, the role of the replica vehicle can be quickly handed over to a client vehicle.

[0070] (5) When selecting a master vehicle, the server 1 determines the first cumulative time T １ and the second cumulative time T ２ In addition, the second cumulative time T ２ The first cumulative time T １ The value T divided by ２ / T １ (Ratio T ２ / T １ ) to select a vehicle 2 to be set as the master vehicle. This allows the role of master vehicle to be shared more fairly among the vehicles 2 in the network 3, and makes it possible to make the contribution of each vehicle 2 to the entire network 3 approximately equal.

[0071] (6) Furthermore, when selecting a master vehicle, by taking into consideration the deterioration state and communication stability of each vehicle 2, it is possible to reduce the management costs of the vehicles 2 and improve the communication quality within the network 3. For example, it is possible to ask a vehicle 2 with good communication quality to serve as the master vehicle, as long as it does not place an excessive burden on a specific vehicle 2.

[0072] (7) When selecting a replica vehicle, the server 1 determines the first cumulative time T １ and the third cumulative time T ３ In addition, the third cumulative time T ３ The first cumulative time T １ The value T divided by ３ / T １(Ratio T ３ / T １ ) to select a vehicle 2 to be set as a replica vehicle based on the vehicle 2's role. This allows the role of replica vehicle to be shared more fairly among the vehicles 2 in the network 3, and makes it possible to make the contribution of each vehicle 2 to the network 3 approximately equal.

[0073] (8) Furthermore, when selecting a replica vehicle, by taking into consideration the deterioration state and communication stability of each vehicle 2, it is possible to reduce the management costs of the vehicles 2 while improving the communication quality within the network 3. For example, it is possible to ask a vehicle 2 with good communication quality to serve as a replica vehicle, as long as it does not place an excessive burden on a specific vehicle 2.

[0074] [6. Other] The above-described embodiments are merely illustrative and are not intended to exclude various modifications or applications of techniques not explicitly described in the present embodiments. Each configuration of the present embodiments can be modified in various ways without departing from the spirit of the present embodiments. Furthermore, each configuration of the present embodiments can be selected or combined as needed.

[0075] In the above embodiment, the server 1 assigns one of three roles (master vehicle, replica vehicle, client vehicle) to each vehicle 2, but the replica vehicle setting can be omitted. By setting the role of master vehicle to at least one vehicle 2 in the network 3 and setting the role of client vehicle to the other vehicles 2, it is possible to realize a data sharing system that achieves the same effects as the above embodiment.

[0076] Furthermore, it is not necessary to set the role of client vehicle to all vehicles 2 other than the master vehicle. For example, a vehicle 2 that does not have a positioning means 23 or a detection means 24 (a vehicle 2 that cannot generate location-related data) may be exempt from the role of client vehicle, and may be a vehicle 2 that simply receives location-related data provided by the master vehicle. Note that the positioning means 23 is not limited to an in-vehicle navigation device, and the detection means 24 is not limited to an in-vehicle radar device, an in-vehicle video camera device, or the like. For example, a smartphone or a wearable device carried by the user of the vehicle 2 may be used as the positioning means 23 or the detection means 24.

[0077] This invention is applicable to service businesses that provide data sharing systems, and to vehicle manufacturing businesses that apply data sharing systems.

[0078] REFERENCE SIGNS LIST 1 Server 2 Vehicle 3 Network 4 Regional mesh 10 Calculation means 11 Processor 12 Memory 13 Communication means 14 Storage means 20 Calculation means 21 Processor 22 Memory 23 Positioning means 24 Detection means 25 Communication means 26 Storage means

Claims

1. A data sharing system that includes a plurality of vehicles present in a network and a server that sets a role for each of the vehicles, and realizes data sharing among the vehicles, the server assigns a role of a first vehicle to one of the vehicles and assigns a role of a second vehicle to the other of the vehicles; The first vehicle collects data generated by the second vehicle, stores and manages a database created by the collection, and provides the data contained in the database to the second vehicle in response to a request from the second vehicle. A data sharing system comprising:

2. the server sets a role of a third vehicle that is neither the first vehicle nor the second vehicle to at least one of the vehicles; The third vehicle stores a copy of the database stored in the first vehicle.

2. The data sharing system according to claim 1.

3. When any one of the following conditions is met: Condition 1 that a first assignment period has elapsed since the role of the first vehicle was set; Condition 2 that a communication interruption time of the first vehicle is equal to or longer than a first interruption time; and Condition 3 that, based on an area in which the role of the first vehicle is set, the first vehicle moves away from the area by a first exit distance or more, the server changes the role of the first vehicle to the second vehicle and changes the role of the third vehicle to the first vehicle.

3. The data sharing system according to claim 2.

4. The server changes the role of at least one of the second vehicles to the third vehicle when any of the following conditions is met: condition 4 that a second assignment period has elapsed since the role of the third vehicle was set; condition 5 that the communication interruption time of the third vehicle is equal to or longer than a second interruption time; condition 6 that the third vehicle moves away from the area in which the role of the third vehicle is set by a reference distance equal to or longer than a second exit distance; and condition 7 that the role of the third vehicle is changed to the first vehicle.

3. The data sharing system according to claim 2.

5. When selecting the vehicle to be assigned the role of the first vehicle, the server calculates a first cumulative time during which the vehicle is connected to the network and a second cumulative time during which the vehicle has assumed the role of the first vehicle, and selects the vehicle based on a value obtained by dividing the second cumulative time by the first cumulative time.

2. The data sharing system according to claim 1.

6. The server determines a target to which the role of the first vehicle is assigned based on the deterioration state and communication stability of the vehicle.

2. The data sharing system according to claim 1.

7. When selecting the vehicle to be assigned the role of the third vehicle, the server calculates a first cumulative time during which the vehicle was connected to the network and a third cumulative time during which the vehicle played the role of the first vehicle or the third vehicle, and selects the vehicle based on a value obtained by dividing the third cumulative time by the first cumulative time.

3. The data sharing system according to claim 2.

8. The server determines a target to which the role of the third vehicle is assigned based on the deterioration state and communication stability of the vehicle.

3. The data sharing system according to claim 2.

9. A data sharing system that includes a plurality of vehicles present in a network and a server that sets a role for each of the vehicles, and realizes data sharing among the vehicles, the server sets one of the vehicles to a role of a first vehicle, sets another of the vehicles to a role of a second vehicle, and sets at least one of the vehicles to a role of a third vehicle that is neither the first vehicle nor the second vehicle; the first vehicle stores a database that collects data generated by the second vehicle, and provides the data contained in the database to the second vehicle in response to a request from the second vehicle; The third vehicle stores a copy of the database stored in the first vehicle. A data sharing system comprising:

10. When any one of the following conditions is met: Condition 1 that a first assignment period has elapsed since the role of the first vehicle was set; Condition 2 that a communication interruption time of the first vehicle is equal to or longer than a first interruption time; and Condition 3 that, based on an area in which the role of the first vehicle is set, the first vehicle moves away from the area by a first exit distance or more, the server changes the role of the first vehicle to the second vehicle and changes the role of the third vehicle to the first vehicle.

10. The data sharing system according to claim 9.

11. The server changes the role of at least one of the second vehicles to the third vehicle when any of the following conditions is met: condition 4 that a second assignment period has elapsed since the role of the third vehicle was set; condition 5 that the communication interruption time of the third vehicle is equal to or longer than a second interruption time; condition 6 that the third vehicle moves away from the area in which the role of the third vehicle is set by a reference distance equal to or longer than a second exit distance; and condition 7 that the role of the third vehicle is changed to the first vehicle.

10. The data sharing system according to claim 9.

12. When selecting the vehicle to be assigned the role of the third vehicle, the server calculates a first cumulative time during which the vehicle was connected to the network and a third cumulative time during which the vehicle played the role of the first vehicle or the third vehicle, and selects the vehicle based on a value obtained by dividing the third cumulative time by the first cumulative time.

10. The data sharing system according to claim 9.

13. The server determines a target to which the role of the third vehicle is assigned based on the deterioration state and communication stability of the vehicle.

10. The data sharing system according to claim 9.

14. A data sharing system that includes a plurality of vehicles present in a network and a server that sets a role for each of the vehicles, and realizes data sharing among the vehicles, the server assigns a role of a first vehicle to one of the vehicles and assigns a role of a second vehicle to the other of the vehicles; the first vehicle stores a database that collects data generated by the second vehicle, and provides the data contained in the database to the second vehicle in response to a request from the second vehicle; When selecting the vehicle to be assigned the role of the first vehicle, the server calculates a first cumulative time during which the vehicle is connected to the network and a second cumulative time during which the vehicle has assumed the role of the first vehicle, and selects the vehicle based on a value obtained by dividing the second cumulative time by the first cumulative time. A data sharing system comprising: