JP7549938B2 - Communications processing device and communications processing method - Google Patents

Description

This disclosure relates to a communication processing device and a communication processing method.

In recent years, moving objects such as vehicles are connected to external devices (e.g., servers) via communication networks such as the Internet so that they can communicate with each other. Patent Document 1 discloses a system that transmits communication traffic data related to the vehicle's in-vehicle network to an external device (e.g., a cyber hub) via the communication network.

Patent No. 6382724

However, Patent Document 1 does not disclose any technology related to improving the efficiency of communication data volume when transmitting data to an external device.

Therefore, the present disclosure provides a communications processing device and a communications processing method that can efficiently increase the amount of communication data.

A communication processing device according to one aspect of the present disclosure includes an acquisition unit that acquires mobile body information indicating a state of the mobile body, and a decision unit that decides a communication frequency in communication between the mobile body and an external device based on the mobile body information and decision criteria information indicating decision criteria in communication between the mobile body and an external device of the mobile body.

A communication processing method according to one aspect of the present disclosure acquires mobile body information indicating the state of a mobile body, and determines the communication frequency between the mobile body and an external device based on the mobile body information and decision criteria information indicating decision criteria for communication between the mobile body and an external device of the mobile body.

A communication processing device according to one aspect of the present disclosure can improve the efficiency of communication data volume.

FIG. 1 is a diagram showing a schematic configuration of a communication system according to a first embodiment. FIG. 2 is a block diagram showing a functional configuration of the communication frequency determination device according to the first embodiment. FIG. 3 is a diagram for explaining the idea of determining the communication frequency in the determination unit according to the first embodiment. FIG. 4 is a diagram showing a table for determining the communication frequency in the determination unit according to the first embodiment. FIG. 5 is a flowchart showing the operation of the communication frequency determination device according to the first embodiment. FIG. 6 is a timing chart for explaining the communication frequency determined by the determination unit according to the first embodiment. FIG. 7 is a flowchart showing the operation of the communication frequency determination device according to the first modification of the first embodiment. FIG. 8 is a flowchart showing the operation of the communication frequency determination device according to the second modification of the first embodiment. FIG. 9 is a timing chart for explaining the communication frequency determined by the determination unit according to the second modification of the first embodiment. FIG. 10 is a flowchart showing the operation of the communication frequency determination device according to the third modification of the first embodiment. FIG. 11 is a flowchart showing a first example of the operation of the communication frequency determination device according to the fourth modification of the first embodiment. FIG. 12 is a flowchart showing a second example of the operation of the communication frequency determination device according to the fourth modification of the first embodiment. FIG. 13 is a flowchart showing a third example of the operation of the communication frequency determination device according to the fourth modification of the first embodiment. FIG. 14 is a block diagram illustrating a functional configuration of a communication frequency determination device according to the second embodiment. FIG. 15 is a flowchart showing the operation of the communication frequency determination device according to the second embodiment. FIG. 16 is a flowchart showing the operation of the communication frequency determination device according to the modification of the second embodiment.

(Background to this disclosure)
Before describing the embodiments of the present disclosure, the background to the present disclosure will be described.

In recent years, it has been considered to transmit information such as the status of a mobile object, such as a vehicle, via a communication network to a monitoring system (e.g., a server) that monitors the mobile object. For example, it has been considered to periodically notify (communicate) information indicating that the mobile object is operating normally to a server at predetermined time intervals from the mobile object. This enables the monitoring system to grasp the status of the monitored mobile object. Note that communication between a mobile object and a server at predetermined time intervals is also referred to as periodic communication. Periodic communication is an example of communication between a mobile object and a server.

The periodic communication may be, for example, communication to confirm whether communication between the mobile body and the monitoring system is connected without interruption. For example, periodic data (e.g., a heartbeat signal) is transmitted from the mobile body to the monitoring system at regular time intervals. For example, when communication between the mobile body and the monitoring system is disconnected, the mobile body will no longer transmit periodic data to the monitoring system, and therefore the monitoring system can determine that communication with the mobile body has been disconnected if it does not receive periodic data for a specified period of time (e.g., several tens of seconds).

However, even when a mobile object is operating normally, it may become unable to communicate due to various factors (e.g., being out of communication range, etc.). In such a case, if the mobile object performs regular communication with the monitoring system at a preset communication frequency, for example, depending on the communication timing (transmission timing), it may not be possible to transmit the regular data immediately before communication becomes unavailable. In other words, the mobile object may not be able to transmit the state immediately before communication becomes unavailable to the monitoring system.

Moving objects also place a large load on the communication network because they periodically transmit periodic data. Furthermore, if the contract stipulates that communication fees are determined according to the amount of communication, the periodic transmission of periodic data will increase the amount of communication and the communication costs will also rise. In this way, if moving objects uniformly communicate with the monitoring system periodically at a preset communication frequency, this can result in an increase in the load on the communication network and communication costs.

As described above, there is a problem with the efficiency of communication data volume in conventional periodic communication. Therefore, the inventors of the present application conducted extensive research into improving the efficiency of communication data volume when periodic communication is performed from a mobile object to a monitoring system, and devised the communication processing device etc. shown below.

A communication processing device according to one aspect of the present disclosure includes an acquisition unit that acquires mobile body information indicating a state of the mobile body, and a decision unit that decides a communication frequency in communication between the mobile body and an external device based on the mobile body information and decision criteria information indicating decision criteria in communication between the mobile body and an external device of the mobile body.

As a result, the communication processing device can determine the communication frequency between the mobile device and an external device based on the mobile device information and the decision criteria information. Therefore, the communication processing device can make the amount of communication data more efficient than if the communication frequency was uniform.

Furthermore, for example, the mobile body information may include at least one of information regarding the communication status between the mobile body and the external device, information regarding a cyber attack on the mobile body, and information regarding a malfunction of equipment installed on the mobile body.

As a result, the communications processing device can determine the frequency of communications by acquiring at least one of information regarding the communication status between the mobile body and an external device, information regarding cyber attacks on the mobile body, and information regarding failures of equipment installed in the mobile body.

Also, for example, the determination criteria information may include correspondence information for linking the mobile body information and the communication frequency in the communication, and the determination unit may determine the communication frequency in the communication based on the mobile body information and the correspondence information.

This allows the communications processing device to determine the communication frequency using the correspondence information, thereby reducing the amount of processing required to determine the communication frequency.

Also, for example, the decision criteria information may include a decision model for determining the communication frequency in the communication from the mobile body information, which is generated in advance by machine learning, and the decision unit may determine the communication frequency in the communication based on the mobile body information and the decision model.

This allows the communications processing device to determine the communication frequency even if there is no data for determining the communication frequency, such as correspondence information.

In addition, for example, the information regarding the communication state may include at least one of the speed of the moving body, the position of the moving body, the radio wave strength of the wireless communication with the external device, and the communication state with other moving bodies in the vicinity of the moving body.

As a result, the communications processing device can determine the communication frequency according to the state of the mobile body (the communication state of the mobile body) simply by acquiring at least one of the following: the speed of the mobile body, the position of the mobile body, the radio wave strength of wireless communications with an external device, and the communication state with other mobile bodies in the vicinity of the mobile body.

In addition, for example, the information regarding the cyber attack may include at least one of communication connection information indicating the state of the wireless communication connection of the mobile body and the travel time from the start of the travel of the mobile body.

As a result, the communications processing device can determine the communication frequency according to the state of the mobile body (the state of the mobile body against cyber attacks) simply by acquiring at least one of the communications connection information indicating the state of the mobile body's wireless communication connection and the travel time from the start of the mobile body's travel.

In addition, for example, the information regarding the failure may include at least one of the acceleration of the moving body and the moving time of the moving body.

As a result, the communications processing device can determine the communication frequency according to the state of the mobile body (the state of the equipment mounted on the mobile body in relation to a malfunction) simply by acquiring at least one of the acceleration of the mobile body and the travel time of the mobile body.

Also, for example, the determination unit may determine whether the mobile body will be in a state where communication with the external device is not possible, and if it determines that communication will be not possible, determine the communication frequency to be immediate transmission.

By determining the communication frequency to be immediate transmission, the communication processing device can transmit communication data to an external device before the mobile body is unable to communicate with the external device. Therefore, the communication processing device can efficiently manage the amount of communication data so as to increase the certainty that the external device can obtain the state of the mobile body before it is unable to communicate.

Also, for example, the determination unit may determine the communication frequency in the first period based on a first communication frequency in a second period following the first period determined based on the mobile body information acquired in the first period, and a second communication frequency in the first period determined based on the mobile body information acquired in a third period prior to the first period.

This allows the communications processing device to determine the communication frequency for a first period (current period) based on the state of the mobile body during the first period. In other words, the communications processing device can determine a communication frequency that is more suitable for the state of the mobile body during the first period. Therefore, the communications processing device can streamline the amount of communication data to a level that is more suitable for the first period.

Also, for example, the determination unit may determine the higher communication frequency between the first communication frequency and the second communication frequency as the communication frequency for the first period.

As a result, the communications processing device can more reliably perform communication between the mobile body and an external device even if the vehicle state changes between the third period and the first period. Therefore, the communications processing device can efficiently use the amount of communication data in terms of reliably performing communication between the mobile body and an external device.

For example, the device may further include a storage unit that stores the mobile body information previously acquired, and the determination unit may determine the communication frequency based on the mobile body information previously acquired.

As a result, when the communications processing device determines the communication frequency based on an item in which the state of the mobile body changes depending on the conditions around the mobile body, the communications processing device can determine a communication frequency that is less affected by the conditions around the mobile body. For example, if the mobile body is a vehicle, the speed of the vehicle (an example of the state of the mobile body) may change depending on the presence or absence of traffic lights, etc. In this case, by determining the communication frequency using the past vehicle speed as well, the effect of the presence or absence of traffic lights, etc. on the communication frequency can be reduced.

Also, for example, the communication processing device may be mounted on the mobile object.

This allows the communications processing device to obtain mobile unit information directly from the mobile unit. In other words, the communications processing device can more reliably determine the communication frequency without relying on the communication state outside the mobile unit.

For example, the device may further include a transmission unit that transmits communication data of the communication to the external device based on the communication frequency determined by the determination unit, and the communication data may include at least one of communication frequency information indicating the communication frequency determined by the determination unit and information regarding the next communication.

This allows the communications processing device to notify an external device of the determined communication frequency. The communications processing device can cause the external device to perform processing according to the communication frequency.

In addition, for example, the communication data may further include information indicating at least one of the reasons for determining the communication frequency determined by the determination unit and the reasons for determining the information regarding the next communication.

This allows the communications processing device to notify an external device of the reason for the determined communication frequency. The communications processing device can further cause the external device to perform processing according to the reason for the determination.

Also, for example, the reason for determining the communication frequency may include information indicating that the mobile body is in a state where it cannot communicate with the external device, or that the mobile body has recovered from a state where it cannot communicate.

This allows the communications processing device to notify the external device that it is no longer able to communicate with the external device, or that the mobile object has recovered from a state in which it is no longer able to communicate. The communications processing device can further cause the external device to perform processing in response to the notification.

Also, for example, the communication processing device may be mounted on the external device.

This allows the communications processing device to reduce the amount of processing in the mobile device. In addition, since the communication frequency determination process can be performed by an external device with abundant computational resources, the communication frequency determination process can be performed more quickly.

In addition, a communication processing method according to one aspect of the present disclosure acquires mobile body information indicating the state of the mobile body, and determines the communication frequency in communication between the mobile body and an external device based on the mobile body information and decision criteria information indicating decision criteria in communication between the mobile body and an external device of the mobile body.

This provides the same effect as the above-mentioned communications processing device.

These general or specific aspects may be realized by a system, a method, an integrated circuit, a computer program, or a non-transitory recording medium such as a computer-readable CD-ROM, or by any combination of the system, method, integrated circuit, computer program, or recording medium. The program may be pre-stored in the recording medium, or may be supplied to the recording medium via a wide area communication network including the Internet.

The following describes the embodiment in detail with reference to the drawings.

The embodiments described below are all comprehensive or specific examples. The numerical values, components, the arrangement and connection of the components, steps, and the order of steps shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, among the components in the following embodiments, components that are not described in an independent claim are described as optional components. Furthermore, each figure is a schematic diagram and is not necessarily a precise illustration. Furthermore, the same components are given the same reference numerals in each figure.

In addition, in this specification, terms that indicate relationships between elements, such as "match" and "same," and numerical values are not expressions that express only a strict meaning, but are expressions that include a range that is substantially equivalent, for example, a difference of about a few percent.

(Embodiment 1)
Hereinafter, a communication system according to the present embodiment will be described with reference to the drawings.

[1-1. Configuration of communication system]
First, the configuration of a communication system 1 according to the present embodiment will be described with reference to Fig. 1 and Fig. 2. Fig. 1 is a diagram showing a schematic configuration of the communication system 1 according to the present embodiment. Fig. 2 is a block diagram showing a functional configuration of a communication frequency determination device 40 according to the present embodiment.

As shown in FIG. 1, the communication system 1 includes a vehicle 10, a base station 20, and a server 30. The communication system 1 is a system for transmitting periodic data (communication data) from the vehicle 10 to the server 30 via the base station 20. Note that while one vehicle 10 is shown in FIG. 1, there may be two or more vehicles 10, and the number of vehicles 10 is not particularly limited as long as there is one or more vehicles 10. In this embodiment, a communication frequency determination device 40 is mounted on the vehicle 10. The communication frequency determination device 40 is an example of a communication processing device that performs processing in communication.

The vehicle 10 is, for example, an automobile capable of wireless communication. The vehicle 10 has various sensors (not shown) that detect the state of the vehicle 10 (vehicle state). The various sensors detect, for example, at least one of first information regarding the communication state between the vehicle 10 and the server 30, second information regarding a cyber attack on the vehicle 10, and third information regarding a failure of equipment mounted on the vehicle 10. Details will be described later, but the first information includes, for example, at least one of the speed, position, etc. of the vehicle 10. In this case, the sensor includes a speed sensor that detects the speed of the vehicle 10, a GPS sensor that detects the current position of the vehicle 10, etc. In addition, the second information includes, for example, at least one of communication connection information indicating the state of the wireless communication connection of the vehicle 10, the running time of the vehicle 10, etc. In this case, the sensor includes a sensor that measures the radio wave strength of a wireless signal received by a wireless communication unit such as the communication unit 43, a sensor that measures the running time, etc. In addition, the third information includes, for example, the acceleration of the vehicle 10. In this case, the sensor includes an acceleration sensor that detects the acceleration of the vehicle 10. Note that the vehicle 10 is an example of a moving body, and the vehicle state is an example of moving body information.

The vehicle 10 may or may not have the functionality to perform autonomous driving or driving assistance.

The base station 20 is a wireless base station (so-called access point) used in a mobile communication system such as a third generation mobile communication system (3G), a fourth generation mobile communication system (4G), or LTE (registered trademark). The base station 20 can establish a communication link with the vehicle 10 over a specified communication channel using a wireless interface to perform wireless communication. The base station 20 can also establish a communication link with the server 30 over a specified communication channel using a wireless interface to perform wireless communication. The base station 20 transfers data exchanged between the vehicle 10 and the server 30. The base station 20 and the server 30 may also communicate with each other via wired communication.

The server 30 is a monitoring system that monitors the vehicle 10. The server 30 can also be said to be an information processing device that performs processing for monitoring the vehicle 10. The server 30 is configured to include, for example, an information processing unit that performs processing for monitoring, and an output unit (e.g., a monitor device) that outputs the processing results of the information processing unit, but is not limited to this. The server 30 wirelessly communicates with the vehicle 10. The server 30 is an example of a device external to the vehicle 10.

The communication network through which the vehicle 10 and the server 30 communicate is, for example, the Internet, but is not limited to this and may be a wide area communication network using a mobile phone network, a satellite communication network, Wi-Fi (registered trademark), etc.

As shown in FIG. 2, the communication frequency determination device 40 has an acquisition unit 41, a determination unit 42, and a communication unit 43.

The acquisition unit 41 is a processing unit that acquires the vehicle state indicating the state of the vehicle 10 from various sensors mounted on the vehicle 10. The acquisition unit 41 acquires the vehicle state, for example, via the in-vehicle network of the vehicle 10. The acquisition unit 41 acquires, for example, the current vehicle state. The vehicle state indicates, for example, various states of the vehicle 10 after the engine of the vehicle 10 has started, that is, various states of the vehicle 10 while it is running.

The acquisition unit 41 may, for example, acquire the vehicle state periodically, or may acquire the vehicle state at a frequency according to the communication frequency determined by the determination unit 42. The acquisition unit 41 may also store the acquired vehicle state in a storage unit (not shown).

The determination unit 42 determines the communication frequency in the periodic communication between the vehicle 10 and the server 30 based on the vehicle state and the determination criteria information indicating the determination criteria in the communication between the vehicle 10 and the server 30. It can also be said that the determination unit 42 changes the communication frequency in the periodic communication from the preset communication frequency based on the vehicle state and the determination criteria information. The determination unit 42 determines the communication frequency based on, for example, the vehicle state of the vehicle 10 at the current time and the determination criteria information, but is not limited to this. The communication frequency is, for example, information indicating the frequency at which communication data is transmitted to the server 30, and may be, for example, information indicating the next transmission timing or information indicating the time interval for transmission. The determination of the communication frequency in the determination unit 42 will be described later.

The decision criteria information may include, for example, a table showing the decision criteria (for example, the table shown in FIG. 4 described later), or may include a machine learning model (an example of a decision model) that is generated in advance by machine learning and is used to determine the communication frequency in the communication between the vehicle 10 and the server 30 from the vehicle state. The decision criteria information may be stored in advance in a storage unit (not shown), and the decision unit 42 may obtain the decision criteria information by reading it out from the storage unit.

The communication unit 43 transmits communication data for periodic communication to the server 30 based on the communication frequency determined by the determination unit 42. For example, when a timer that measures time detects that the time determined by the determination unit 42 has elapsed (times out), the communication unit 43 transmits communication data for periodic communication to the server 30. The communication unit 43 is configured to include a communication interface such as a communication adapter for communicating with the server 30. The communication unit 43 is an example of a transmission unit. Note that the determination unit 42 may determine whether the time determined by the determination unit 42 has elapsed. In other words, the determination unit 42 may have a function of detecting that the time determined by the determination unit 42 has elapsed.

In this embodiment, an example is described in which the communication frequency determination device 40 is mounted on the vehicle 10, but this is not limited thereto, and at least some of the functions of the communication frequency determination device 40 may be possessed by the server 30. For example, the communication frequency determination device 40 may be mounted on the server 30. In this case, the server 30 transmits communication frequency information indicating the communication frequency determined by the communication frequency determination device 40 to the vehicle 10. Then, the vehicle 10 transmits communication data of the regular communication to the server 30 based on the communication frequency information received from the server 30.

[1-2. Concept of determining communication frequency in the determination unit]
Next, the concept of determining the communication frequency in the determination unit 42 will be described with reference to Fig. 3. Fig. 3 is a diagram for explaining the concept of determining the communication frequency in the determination unit 42 according to this embodiment. Specifically, Fig. 3 shows a table in which vehicle state information, a condition for shifting to low frequency, and a reason are associated with each other. The vehicle state information indicates each item of the state of the vehicle 10. The condition for shifting to low frequency is a condition for the state of the vehicle 10 required to shift the communication frequency to low frequency. The reason indicates the reason why it is acceptable to shift to low frequency. Note that low frequency means, for example, a communication frequency lower than a communication frequency preset between the vehicle 10 and the server 30, that is, reducing the number of communications.

As shown in FIG. 3, vehicle status information includes speed, acceleration, Internet connection information, location information, radio wave strength, communication availability with surrounding moving objects (e.g., surrounding vehicles), and travel time.

The speed indicates the current speed of the vehicle 10. When the speed is low (e.g., below a preset speed), the communication frequency can be shifted to a frequency lower than the preset frequency. When the speed is low, the movement amount of the vehicle 10 is small, so the change in radio wave strength per unit time is also small. Therefore, the vehicle 10 is unlikely to be out of communication range (measures to prevent being out of range are taken), so the communication frequency can be set to a low frequency.

The acceleration indicates the current acceleration of the vehicle 10. When the acceleration is low (e.g., below a preset acceleration), the communication frequency can be shifted to a frequency lower than the preset frequency. When the acceleration is low, the impact on the equipment mounted on the vehicle 10 (e.g., the communication frequency determination device 40 or each sensor) is small. Therefore, since the equipment is less likely to break down due to the impact (measures against breakdowns are taken), it is possible to set the communication frequency to a low frequency.

The Internet connection information includes the amount of communication in the wireless communication of the vehicle 10. When the amount of communication in the Internet connection information is low (for example, equal to or less than a preset amount of communication), the communication frequency can be shifted to a lower frequency than the preset frequency. When the vehicle 10 is under a cyber attack or infected with malware, the amount of communication may increase due to the download of unauthorized software, etc. On the other hand, when the amount of communication is low, the risk that the vehicle 10 is under a cyber attack or infected with malware is low. Therefore, it is possible to lower the communication frequency. Note that hereinafter, being under a cyber attack or being infected with malware will also be referred to simply as being under a cyber attack. The Internet connection information is also an example of communication connection information that indicates the state of the wireless communication connection.

The location information indicates the current location (e.g., three-dimensional position) of the vehicle 10. If the location information indicates that the vehicle 10 is traveling outside a specified area (e.g., outside a mountainous region), the communication frequency can be shifted to a lower frequency than the preset frequency. When the vehicle 10 is traveling outside a mountainous region, the communication success rate between the vehicle 10 and the server 30 is high (measures are taken to prevent being out of range), so the communication frequency can be reduced. Note that the specified area may be an area with a low communication success rate, and is not limited to a mountainous region.

Radio wave strength indicates the strength of radio waves received by the vehicle 10. When the radio wave strength is high (e.g., equal to or greater than a preset strength), the communication frequency can be reduced to a frequency lower than the preset frequency. When the radio wave strength is high, the success rate of communication between the vehicle 10 and the server 30 is high (measures are taken to prevent being out of range), so the communication frequency can be reduced.

The communication availability of the surrounding mobile objects indicates information on the communication state between the vehicle 10 and mobile objects (e.g., other vehicles) around the vehicle 10. The communication availability of the surrounding mobile objects may be, for example, the number of mobile objects that can communicate with the vehicle 10. The communication availability of the surrounding mobile objects may also be, for example, the number of mobile objects that can communicate with the vehicle 10 and the server 30. When the communication availability of the surrounding mobile objects indicates that communication is possible with a predetermined number or more (e.g., all) of mobile objects around the vehicle 10, the communication frequency can be shifted to a frequency lower than a preset frequency. When communication with the surrounding mobile objects is possible, the vehicle 10 can communicate with the server 30 through the surrounding mobile objects even if the vehicle 10 and the server 30 are in a state where communication is not possible between the vehicle 10 and the server 30. In other words, when communication with the surrounding mobile objects is possible, the communication success rate between the vehicle 10 and the server 30 is high (measures against out-of-range communication are taken), so the communication frequency can be reduced. Note that the mobile objects here may be mobile objects other than vehicles as long as they can communicate with the vehicle 10.

Travel time indicates the time that the vehicle 10 is moving (running). Travel time indicates, for example, the time that has elapsed since the vehicle 10 started running. Travel time can also be said to indicate, for example, the time that has elapsed since the driving force of the vehicle 10 was started. If the travel time indicates a long period of driving (for example, driving for a predetermined time or longer), the communication frequency can be shifted to a frequency lower than the predetermined frequency. In the case of a long period of driving, the risk of equipment failure and cyber-attack at the current time is considered to be lower than when the engine is started, so the communication frequency can be set to a low frequency (for example, lower than when the engine is started).

The speed, location information, radio wave strength, and communication availability with surrounding mobile objects are examples of the first information. Note that the first information may include at least one of the speed, location information, radio wave strength, and communication availability with surrounding mobile objects.

The internet connection information and travel time are examples of the second information. Note that the second information may include at least one of the internet connection information and travel time.

The acceleration and travel time are examples of the third information. Note that the third information may include at least one of the acceleration and travel time.

Note that the conditions for transitioning to low frequency are not limited to those shown in Figure 3.

Note that while FIG. 3 describes a case where the communication frequency is low, the opposite is true for a case where the communication frequency is high. Taking Internet connection information as an example, if the Internet connection information has a high communication volume (e.g., a communication volume equal to or greater than a preset communication volume), the communication frequency may be made higher than the preset frequency. If the communication volume is high, there is a high risk that the vehicle 10 is under a cyber attack or infected with malware, so the communication frequency is made high.

The same applies to other items of vehicle condition information.

The determination unit 42 may increase the communication frequency in the periodic communication based on FIG. 3 when, for example, at least one of the following is satisfied: the communication state is worse than the first state based on the first information, the risk of a cyber attack is higher than the first risk based on the second information, and the risk of equipment failure is higher than the second risk based on the third information. This allows the communication frequency determination device 40 to increase the communication frequency, i.e., shorten the transmission interval, when the risk to the vehicle 10 is high. In other words, the communication frequency determination device 40 can ensure that periodic communication between the vehicle 10 and the server 30 is performed more reliably. Therefore, the communication frequency determination device 40 can make the amount of communication data more efficient from the viewpoint of ensuring that periodic communication between the vehicle 10 and the server 30 is performed.

Furthermore, based on FIG. 3, the determination unit 42 may reduce the communication frequency in the periodic communication when, for example, at least one of the following is satisfied: the communication state is better than the second state based on the first information, the risk of a cyber attack is lower than the third risk, and the risk of equipment failure is lower than the fourth risk. As a result, the communication frequency determination device 40 can reduce the communication frequency, i.e., lengthen the transmission interval, when the risk to the vehicle 10 is low. In other words, the communication frequency determination device 40 can effectively reduce the amount of communication data. Therefore, the communication frequency determination device 40 can make the amount of communication data more efficient in terms of reducing the amount of communication data.

The determination unit 42 may perform at least one of the following processes: increasing the communication frequency and decreasing the communication cost frequency.

The first state and the second state may be the same communication state, or the second state may be a state in which the communication state is better than the first state. The first risk and the third risk may be the same risk, or the third risk may be a lower risk than the first risk. The second risk and the fourth risk may be the same risk, or the fourth risk may be a lower risk than the second risk.

In this embodiment, the determination unit 42 determines the communication frequency based on the vehicle state and a preset table. FIG. 4 is a diagram showing a table for determining the communication frequency in the determination unit 42 according to this embodiment. The table may be stored in, for example, a storage unit (not shown) provided in the vehicle 10. The table is an example of correspondence information for linking the vehicle state with the communication frequency in communication.

As shown in FIG. 4, the table is a table in which a set of vehicle status information, such as speed, acceleration, Internet connection, location information, radio wave strength, whether communication with surrounding mobile bodies is possible, and travel time, is associated with the communication frequency at that time. Note that the table may be any table in which at least one of the items of vehicle status information is associated with the communication frequency. The communication frequency is, for example, a discrete value such as very low, low, or high, but is not limited to this.

For example, the determination unit 42 extracts a set of states that match the currently acquired vehicle state, and determines the communication frequency corresponding to the set as the communication frequency for periodic communication. For example, when the determination unit 42 acquires a vehicle state indicating that the vehicle speed, acceleration, and Internet connection are "low," the location information is "non-mountainous area," the radio wave strength is "high," the communication availability of surrounding mobile objects is "100% possible," and the travel time is "one hour or more," the determination unit 42 determines the communication frequency to be the communication frequency indicated by "very low." Also, when the determination unit 42 acquires a vehicle state indicating that the vehicle speed, acceleration, and Internet connection are "high," the location information is "mountainous area," the radio wave strength is "low," the communication availability of surrounding mobile objects is "10% possible," and the travel time is "less than one hour," the determination unit 42 determines the communication frequency to be immediate transmission, which is the communication frequency indicated by "high."

In the above, the determination unit 42 has been described as determining the communication frequency using a table, but the present invention is not limited to this, and the communication frequency may be determined by fuzzy inference. For example, the determination unit 42 may determine the communication frequency by fuzzy inference using the vehicle state as input information. The determination unit 42 may also determine the communication frequency using a machine learning model (one example of a determination model) such as a neural network. For example, the determination unit 42 may acquire the vehicle state and the machine learning model, and determine the communication frequency in the communication between the vehicle 10 and the server 30 based on the acquired vehicle state and the machine learning model. The acquisition of the machine learning model means, for example, reading information such as network parameters and a calculation algorithm (machine learning algorithm) in the machine learning model from the storage unit. The machine learning model is learned by machine learning using at least one of the items of the vehicle state information shown in FIG. 4 as input information and the communication frequency corresponding to the input information as teacher data. The determination unit 42 acquires the output obtained by inputting the current vehicle state into the learned machine learning model as the determined communication frequency. Note that the machine learning model is not limited to a neural network and may be, for example, a random forest, a decision tree, etc.

In the above description, the communication frequency is a discrete value (e.g., very low, low, high) classified according to the vehicle state, but it may be a continuous value (e.g., 10 seconds, 11 seconds, 12 seconds, etc.) calculated using a regression equation that shows the relationship between the vehicle state and the communication frequency.

[1-3. Operation of communication frequency determination device]
Next, the operation of the communication frequency determination device 40 will be described with reference to Figures 5 and 6. Figure 5 is a flowchart showing the operation of the communication frequency determination device 40 according to the present embodiment.

As shown in FIG. 5, the acquisition unit 41 of the communication frequency determination device 40 acquires the current vehicle state from various sensors mounted on the vehicle 10 (S101). The acquisition unit 41 outputs the acquired vehicle state to the determination unit 42.

Next, the determination unit 42 determines the communication frequency for a period after the current time based on the current vehicle state (S102). The determination unit 42 determines the communication frequency for a period after the current period including the current time based on, for example, the current vehicle state and the table shown in FIG. 4. The determination unit 42 outputs the determined communication frequency to the communication unit 43.

Here, the communication frequency determined by the determination unit 42 will be described with reference to FIG. 6. FIG. 6 is a timing chart for explaining the communication frequency determined by the determination unit 42 according to this embodiment. FIG. 6(a) shows a timing chart in the prior art, and FIG. 6(b) shows a timing chart in the determination unit 42 according to this embodiment. Note that FIG. 6 shows the communication frequency relative to the risk of being out of communication range as an example of risk. It is shown that the risk of being out of communication range increases from "low risk" to "high risk", and "out of range" indicates being out of communication range. Note that the risk includes at least one of the risks of being out of communication range, being under a cyber attack, and the risk of equipment failure.

In FIG. 6(a), t0 to t9 indicate the timings for transmitting communication data in the conventional technology, and p0 to p8 indicate the periods (time intervals) between each transmission timing in the conventional technology. In the conventional technology, the communication frequency remains constant and does not change even if the risk to the vehicle 10 changes over time, so the periods p0 to p8 are the same. In this case, for example, the vehicle 10 is out of communication range at transmission timing t9, so communication data cannot be transmitted at transmission timing t9. In other words, in the conventional technology, it may happen that the state immediately before going out of communication range cannot be transmitted to the server 30.

T10 to t17 shown in FIG. 6(b) indicate the timings of transmitting communication data at the communication frequency determined by the determination unit 42 according to this embodiment, and p10 to p15 indicate the periods (time intervals) between each transmission timing according to this embodiment. In this embodiment, the communication frequency changes according to the change over time in the risk in the vehicle 10 (change over time in the vehicle state), so at least one of the periods p10 to p15 can become another period. Note that the period p0 shown in FIG. 6(a) and the period p10 shown in FIG. 6(b) are the same period, and are preset periods. Also, the transmission timings t0 and t10, and the transmission timings t1 and t11 are the same.

The determination unit 42 determines the communication frequency for the period p11, which is the period following the period p10, based on, for example, the vehicle state and the determination criterion information acquired during the period p10 shown in FIG. 6B. The determination unit 42 determines, for example, the length of the period p11 or the time of the transmission timing t12 as the communication frequency. Since the risk is low during the period p10 (for example, the risk is equal to or less than a predetermined value), the determination unit 42 determines the period p11 following the period p10 to be longer than the period p10. In other words, the determination unit 42 delays the transmission timing t12 of the period p11. It can also be said that the determination unit 42 reduces the communication frequency. In this way, when the risk is low, the determination unit 42 can reduce communication costs while suppressing communication failure by reducing the communication frequency. In this case, the period p10 is an example of a first period, and the period p11 is an example of a second period.

Next, because the risk remains low during period p11, the decision unit 42 sets the communication frequency for period p12, which is the period following period p11, to be even lower than the communication frequency for period p11. As the communication frequency for period p12, the decision unit 42 sets the length of period p12 to be shorter than period p11. In other words, the decision unit 42 further delays the transmission timing t13. In this way, the decision unit 42 may gradually lower the communication frequency if the risk continues to be low. In this case, period p11 is an example of a first period, and period p12 is an example of a second period. Note that periods p11 and p12 may be periods of the same length.

Next, because the risk is transitioning from low to medium in period p12 (risk is shifting higher), the decision unit 42 sets the communication frequency for period p13, which is the period following period p12, higher than the communication frequency for period p12. As the communication frequency for period p13, the decision unit 42 sets the length of period p13 to be shorter than period p12. In other words, the decision unit 42 advances the transmission timing t14. In this case, period p12 is an example of a first period, and period p13 is an example of a second period.

Next, because the risk remains medium during period p13, the decision unit 42 sets the communication frequency for period p14, which is the period following period p13, to be even lower than the communication frequency for period p13. As the communication frequency for period p14, the decision unit 42 sets the length of period p14 to be shorter than period p13. In other words, the decision unit 42 further advances the transmission timing t15. In this way, the decision unit 42 may gradually increase the communication frequency if the medium risk state continues. In this case, period p13 is an example of a first period, and period p14 is an example of a second period. Note that periods p13 and p14 may be periods of the same length.

Next, because the risk has shifted from medium to high in period p14 (the risk is becoming even higher), the decision unit 42 sets the communication frequency for period p15, which is the period following period p14, to be higher than the communication frequency for period p14. As the communication frequency for period p15, the decision unit 42 sets the length of period p15 to be shorter than period p14. In other words, the decision unit 42 further advances the transmission timing t16. In this way, when the risk is high, the decision unit 42 can prevent communication failure by increasing the communication frequency and increasing the number of communications between the vehicle 10 and the server 30. In this case, period p14 is an example of a first period, and period p15 is an example of a second period.

Next, in the period p15, when the risk becomes even higher (for example, when the state becomes No. N shown in FIG. 4), such as when it is predicted that the vehicle 10 will be out of communication range in the future, the decision unit 42 sets the communication frequency to immediate transmission. For example, the decision unit 42 determines whether the vehicle 10 will be in a state where communication with the server 30 is impossible, and when it is determined that communication will be impossible, decides the communication frequency to immediate transmission. In this way, the decision unit 42 updates the transmission timing t16, which is before the transmission timing t17 of the period p15 determined in the period p14, to the transmission timing of the period p15. It is possible to determine whether the vehicle 10 will be in a state where communication with the server 30 is impossible based on the current position or driving route of the vehicle 10. For example, when the vehicle 10 is driving in a mountainous area, is about to drive in a mountainous area, or the vehicle 10 has a function of performing automatic driving, it is possible to determine based on the driving route of the automatic driving, etc.

The determination unit 42 may, for example, calculate the communication frequency multiple times in each period. Then, the determination unit 42 may determine the communication frequency for the next period based on the multiple communication frequencies. The determination unit 42 may, for example, determine the communication frequency based on a statistical value (average value, median value, mode, etc.) of the multiple communication frequencies, or may determine the lowest or highest communication frequency of the multiple communication frequencies as the communication frequency for the next period.

Referring again to FIG. 5, next, the determination unit 42 determines whether the current time is the determined transmission timing (S103). If it is the transmission timing (Yes in S103), the determination unit 42 generates communication data including communication frequency information indicating the communication frequency for the next period (S104). The determination unit 42 outputs the generated communication data to the communication unit 43.

Next, the communication unit 43 transmits the communication data acquired from the determination unit 42 to the server 30 (S105). For example, at the transmission timing t11 shown in FIG. 6B, the communication unit 43 transmits communication data including communication frequency information indicating the transmission timing t12 or the length of the period p11 to the server 30.

Next, after step S105, or if it is not time to transmit (No in S103), the communication frequency determination device 40 returns to step S101 and continues processing.

When the communication frequency is determined to be instantaneous transmission, the determination unit 42 judges Yes in step S103. When the communication frequency is determined to be instantaneous transmission, the determination unit 42 may generate communication data including a preset specified value or the previous communication frequency as communication frequency information. The specified value may be, for example, a preset communication frequency for periodic communication (for example, period p10 shown in (b) of FIG. 6), or a communication frequency that is set specifically as the communication frequency for instantaneous transmission.

In the above, the communication unit 43 has been described as an example in which the communication data includes the communication frequency information and is transmitted, but the present invention is not limited to this. The communication unit 43 may transmit the communication data including at least one of the communication frequency information and the information regarding the next communication. The information regarding the next communication may include at least one of information indicating how many minutes after the next communication, information indicating the time of the time transmission, information indicating a period (or time zone) during which the next communication may be impossible, and information indicating the conditions for the next communication. The information indicating the period during which the next communication may be impossible may include, for example, information indicating that the communication may be impossible for the next 10 minutes. The information indicating the conditions for the next communication may include, for example, information indicating that the next communication will be performed when a specific condition is met. The communication unit 43 may also transmit communication data to the server 30 that does not include the communication frequency information. In this case, the communication data includes the vehicle state, and the server 30 has the function of the determination unit 42 that determines the communication frequency from the vehicle state included in the communication data. In other words, the communication frequency may be determined by both the vehicle 10 and the server 30.

(First Modification of First Embodiment)
The communication system according to this modification will be described below with reference to Fig. 7. Fig. 7 is a flowchart showing the operation of the communication frequency determination device according to this modification. Note that the configuration of the communication system according to each modification of embodiment 1, including this modification, may be similar to the configuration of the communication system 1 according to embodiment 1, and the following description will use the reference numerals of each component in the communication system 1 of embodiment 1. Also, in Fig. 7, operations that are the same as or similar to those in Fig. 5 are given the same reference numerals as in Fig. 5, and description will be omitted or simplified.

As shown in FIG. 7, the determination unit 42 acquires the vehicle state (S101) and then determines whether the vehicle 10 has recovered from a communication-disabled state based on the vehicle state (S201). The determination unit 42 may perform the determination in step S201 based on the radio wave strength acquired by the acquisition unit 41, for example. If the radio wave strength is equal to or greater than a predetermined strength, the determination unit 42 determines that the vehicle 10 has recovered from a communication-disabled state to a communication-enabled state.

Next, if the determination unit 42 determines that communication was not possible before step S201 and that the communication has returned from the non-communicable state in step S201 (Yes in S201), the determination unit 42 generates communication data including communication reason information indicating that the communication has returned from the non-communicable state (S202) and outputs the generated communication data to the communication unit 43.

Next, the communication unit 43 transmits the communication data acquired from the determination unit 42 to the server 30 (S203). This allows the server 30 to recognize that the vehicle 10 has recovered from the communication disabled state.

In addition, if the determination unit 42 determines in step S201 that the vehicle has not recovered from a state in which communication is not possible (No in S201), for example, if the vehicle was in a state in which communication was possible before step S201, the determination unit 42 determines the communication frequency (S102) based on the vehicle state acquired in step S101.

Next, after determining the communication frequency, the determination unit 42 determines whether the vehicle 10 will be in a state where communication is not possible (S204). The determination unit 42 determines whether the vehicle 10 is scheduled to travel in an area that will be out of communication range in the future. The determination unit 42 determines whether the vehicle 10 will be in a state where communication is not possible in the period p15 shown in FIG. 6(b). When the determination unit 42 determines that the vehicle 10 will be in a state where communication is not possible in the period p15 for which the communication frequency has been determined (Yes in S204), it changes (updates) the communication frequency in the period p15 to immediate transmission (S205).

Next, the decision unit 42 generates communication data including communication frequency information and communication reason information (S206). The communication reason information is information indicating the reason why immediate transmission was determined. The communication reason information may be information indicating, for example, that there is a possibility that the vehicle 10 is out of communication range, or that the vehicle state has become such that immediate transmission is determined as shown in the table of FIG. 4. Note that the communication reason information does not need to be included in the communication data.

Next, the communication unit 43 transmits the communication data acquired from the determination unit 42 to the server 30 (S207). For example, the communication unit 43 transmits the communication data including the communication frequency information and the communication reason information to the server 30 at the transmission timing t16 of the period p15 shown in FIG. 6B.

The vehicle 10 is assumed to be out of communication range after transmitting communication data to the server 30 at transmission timing t16. The server 30 can recognize that the vehicle 10 is out of range based on the communication reason information, and therefore can suppress the server 30 from immediately determining that communication with the vehicle 10 has been cut off even if it does not receive regular communication data from the vehicle 10 for a specified period of time.

If the decision unit 42 determines that the vehicle 10 will not be in a communication-disabled state (No in S204), it executes the processing of steps S103 to S105. Steps S103 to S105 are the same as steps S103 to S105 in FIG. 5, and therefore a description thereof will be omitted.

Next, after steps S105, S203, and S207, or if it is not time to transmit (No in S103), the communication frequency determination device 40 returns to step S101 and continues processing.

If communication was not possible before step S201 and it is determined in step S201 that the communication has not returned from the non-communicable state (No in S201), the communication frequency determination device 40 returns to step S101 and continues the process, for example.

As described above, the decision unit 42 according to this modified example generates communication data including information indicating the reason for the determined communication frequency (communication reason information). When changing the communication frequency, the decision unit 42 can also be said to transmit communication reason information indicating the reason for the change to the server 30. The decision reason may also include information indicating that the vehicle 10 is unable to communicate with the server 30, or that the vehicle 10 has recovered from an inability to communicate state.

Note that, in the above, an example has been described in which the communication unit 43 transmits communication data including communication frequency information and communication reason information, but this is not limiting. When the communication data includes at least one of communication frequency information indicating the communication frequency determined by the determination unit 42 and information regarding the next communication, the communication unit 43 may further transmit communication data including information indicating at least one of the reasons for determining the communication frequency determined by the determination unit 42 and the reasons for determining the information regarding the next communication. For example, when the communication data includes information regarding the next communication, the communication unit 43 may transmit communication data including information indicating the reason for determining the information regarding the next communication. The reason for determining the information regarding the next communication may include, for example, information indicating the reason for determining that communication may not be possible (for example, the vehicle is scheduled to travel outside of communication range in the future).

(Second Modification of First Embodiment)
The communication system according to this modification will be described below with reference to Figures 8 and 9. Figure 8 is a flowchart showing the operation of communication frequency determination device 40 according to this modification.

As shown in FIG. 8, the acquisition unit 41 of the communication frequency determination device 40 acquires the vehicle state for a first period (e.g., a period including the current time) from various sensors mounted on the vehicle 10 (S301). Step S301 is similar to step S101 shown in FIG. 5. The acquisition unit 41 outputs the acquired vehicle state to the determination unit 42.

Next, the determination unit 42 determines the communication frequency for a second period following the first period based on the vehicle state during the first period and the determination criteria information (S302). Step S302 is similar to step S102 shown in FIG. 5. The determination unit 42 determines the communication frequency for the second period based on, for example, the vehicle state during the first period and the table shown in FIG. 4 (an example of the determination criteria information). The determination unit 42 outputs the determined communication frequency to the communication unit 43. Note that the first period and the second period are consecutive periods, but are not limited to this.

Next, the determination unit 42 acquires the communication frequency for the first period that was determined in the third period, which is the period before the first period (S303). The determination unit 42 acquires the communication frequency for the first period that was determined in the third period, for example, by reading it from a storage unit (not shown). Note that the first period and the third period are consecutive periods, but are not limited to this.

Next, the determination unit 42 determines whether the communication frequency in the second period is higher than the communication frequency in the first period (S304). The fact that the communication frequency in the second period is higher than the communication frequency in the first period means that the second period is in a higher risk situation (at least one of the risks of being out of service, being under cyber-attack, and being broken down) than the first period. In this case, the communication frequency in the second period is higher than the communication frequency in the first period. Therefore, if the communication frequency in the second period is higher than the communication frequency in the first period (Yes in S304), the determination unit 42 changes the communication frequency in the first period to the communication frequency in the second period determined in step S302 (S305). Also, if the communication frequency in the second period is equal to or lower than the communication frequency in the first period (No in S304), the determination unit 42 keeps the communication frequency in the first period as the communication frequency determined for the third period.

In this manner, the determination unit 42 according to this modified example determines (updates) the communication frequency for the current period based on the communication frequency (one example of the first communication frequency) for a period (e.g., a second period) following the current period determined in the current period (e.g., a first period) and the communication frequency for the current period determined in the period preceding the current period (e.g., a third period). The determination unit 42, for example, determines the higher communication frequency of the first communication frequency and the second communication frequency as the communication frequency for the first period. For example, when the risk for the first period becomes higher than that for the third period, the determination unit 42 updates the communication frequency for the first period to the communication frequency for the second period, which is higher than the communication frequency for the first period. In this manner, when the risk for the first period becomes higher than that for the third period, the determination unit 42 can update the communication frequency for the first period to a communication frequency according to the change in the risk.

The processing after step S305 (S103 to S105) is similar to steps S103 to S105 in FIG. 5, and a description thereof will be omitted.

In the example of FIG. 8, the decision unit 42 updates the communication frequency for the first period to the first communication frequency when step S304 is Yes, but this is not limited to updating to the first communication frequency. When step S304 is Yes, the decision unit 42 may update the communication frequency to a communication frequency higher than the communication frequency for the first period determined in the third period. When the communication frequency is set in stages, the decision unit 42 may update the communication frequency to a communication frequency that is one or more stages higher than the communication frequency determined in the third period when step S304 is Yes.

In the example of FIG. 8, the determination unit 42 increases the communication frequency in the first period when the risk in the first period is higher than that in the third period. However, the determination unit 42 may also decrease the communication frequency in the first period when the risk in the first period is lower than that in the third period. Specifically, if the answer is No in step S304, the determination unit 42 may further determine whether the communication frequency in the second period is lower than the communication frequency in the first period by a predetermined amount or more. If the answer is No in step S304 and the communication frequency in the second period is lower than the communication frequency in the first period by a predetermined amount or more, the determination unit 42 may update the communication frequency in the first period to the communication frequency in the second period that is lower than the communication frequency determined in the third period. In this case, the communication data is not transmitted at the transmission timing of the first period determined in the third period. This can effectively reduce the communication load.

The communication frequency determined by the determination unit 42 will now be described with reference to FIG. 9. FIG. 9 is a timing chart for explaining the communication frequency determined by the determination unit 42 according to this modified example. (a) of FIG. 9 shows a timing chart for the determination unit 42 according to embodiment 1, and (b) of FIG. 9 shows a timing chart for the determination unit 42 according to this modified example. (b) of FIG. 9 is a timing chart after the processing of step S305 in FIG. 8 has been performed during period p22, i.e., after the communication frequency during period p22 has been updated.

In FIG. 9(b), t10-t12 and t23-t29 indicate the timing of communication data transmission in this modified example, and p20-p28 indicate the period between each transmission timing in this modified example. Note that periods p10 and p20, and periods p11 and p21 are the same period.

As shown in FIG. 9(b), the determination unit 42 determines the communication frequency for period p22 (an example of a first period) in period p21 (an example of a third period). Periods p11 and p21 have the same risk. Therefore, the communication frequency for period p22 determined by the determination unit 42 in period p21 is the same as the communication frequency for period p12 determined in period p11 shown in FIG. 9(a). In other words, in period p21, the determination unit 42 determines the transmission timing for period p22 to be the same as t13.

Next, during period p22, the determination unit 42 determines the communication frequency for period p23 (an example of a second period) (corresponding to S302 in FIG. 8).

Next, the determination unit 42 determines whether the communication frequency in period p23 is higher than the communication frequency in period p22 during period p22 (corresponding to S304 in FIG. 8). In the example of FIG. 9, the risk changes from "low" to "medium" during period p22, so the communication frequency in period p23 determined by the determination unit 42 is higher than the communication frequency in period p22 (corresponding to Yes in S304 in FIG. 8).

Next, the decision unit 42 decides to transmit communication data in period p22 without waiting for the transmission timing in the communication frequency decided in period p21 (for example, the same timing as the transmission timing t13 shown in (a) of FIG. 9). It can also be said that the decision unit 42 makes the communication frequency in period p22 higher than the communication frequency decided in period p21. For example, the decision unit 42 decides to transmit communication data at transmission timing t23, which is earlier than transmission timing t13. For example, during period p22, the decision unit 42 updates the communication frequency in period p22 to the communication frequency in period p13, which is a shorter period. Note that, although period p22 and period p13 are the same period in FIG. 9, period p22 may be a period longer than period p13.

(Third Modification of First Embodiment)
The communication system according to this modification will be described below with reference to Fig. 10. Fig. 10 is a flowchart showing the operation of communication frequency determination device 40 according to this modification.

As shown in FIG. 10, the acquisition unit 41 of the communication frequency determination device 40 acquires the vehicle state (S101). The vehicle state includes, for example, information regarding whether communication between the vehicle 10 and the base station 20 is possible. In the following, an example will be described in which the information regarding whether communication between the vehicle 10 and the base station 20 is possible, and includes the current radio wave strength.

Next, the determination unit 42 determines whether the radio wave intensity is less than a threshold value (S401). Step S401 can also be considered as a step of determining whether the vehicle 10 can communicate stably with the base station 20. The threshold value is, for example, a value that can determine whether the vehicle 10 and the base station 20 can communicate stably, and is set in advance and stored in a storage unit (not shown).

Next, when the radio wave intensity is less than the threshold (Yes in S401), the determination unit 42 determines whether or not there is another vehicle (an example of another moving body) with which communication is possible (S402). When communication between the vehicle itself and the base station 20 cannot be performed stably (for example, communication is impossible), the determination unit 42 can also be said to determine whether or not there is a vehicle in the vicinity that can communicate with the base station 20 (or the server 30). For example, the determination unit 42 may determine whether or not there is a vehicle with which communication is possible by V2X (Vehicle-to-Everything) communication via the communication unit 43. When there is a vehicle with which communication is possible (Yes in S402), the determination unit 42 proceeds to step S102.

The processing in steps S102 to S104 is similar to steps S102 to S104 in FIG. 5, and therefore will not be described.

Next, the communication unit 43 transmits the communication data acquired from the determination unit 42 to the server 30 (S403). If the answer is Yes in step S401, the communication unit 43 transmits the communication data to the server 30 via the other vehicle. The communication unit 43 transmits the communication data to the other vehicle by, for example, V2X communication. This makes it possible to transmit the communication data to the server 30 via the other vehicle when the vehicle is unable to communicate with the base station 20. This makes it possible to reduce the occurrence of communication being disabled between the vehicle 10 and the server 30.

If the answer to step S401 is No, the communication unit 43 transmits communication data from the vehicle to the server 30 (S403). In other words, if the answer to step S401 is No, the communication unit 43 transmits communication data to the server 30 without going through another vehicle.

Next, after step S403, if there is no vehicle with which communication is possible (No in S402) or if it is not the timing for transmission (No in S103), the communication frequency determination device 40 returns to step S101 and continues processing.

(Fourth Modification of the First Embodiment)
A communication system according to this modification will be described below with reference to Figs. 11 to 13. In the above-mentioned first embodiment and each modification, the communication frequency is determined each time communication data is transmitted, but the communication frequency is not limited to being determined each time transmission occurs. Each modification regarding the timing of updating the communication frequency will be described below. Fig. 11 is a flowchart showing a first example of the operation of the communication frequency determination device 40 according to this modification. Fig. 11 shows an example in which the communication frequency is updated at predetermined intervals.

As shown in FIG. 11, the determination unit 42 of the communication frequency determination device 40 determines whether a predetermined time has elapsed since the previous communication frequency was updated (S501) in order to determine whether to determine a new communication frequency. If the predetermined time has elapsed (Yes in S501), the determination unit 42 performs the processes of steps S101 and S102. That is, if the predetermined time has elapsed, the determination unit 42 determines a new communication frequency for the next period. If the predetermined time has not elapsed (No in S501), the determination unit 42 proceeds to step S103. That is, if the predetermined time has not elapsed, the determination unit 42 determines the communication frequency for the next period to be the communication frequency determined in the past (e.g., the previous communication frequency).

As a result, processing to change the communication frequency is performed every time a predetermined time has elapsed, thereby reducing the processing burden of determining the communication frequency on the determination unit 42.

In addition, communication data is transmitted at regular intervals for a specified period of time.

Note that, in FIG. 11, an example has been described in which the decision unit 42 re-determines the communication frequency when a predetermined time has elapsed in step S501, but the present embodiment is not limited to this. The decision unit 42 may make the judgment in step S501, for example, based on information indicating whether or not the current state is one in which a risk to the vehicle 10 (at least one of the risks of being out of range, being subject to a cyber attack, and being broken down) may change since the previous communication frequency was determined. The decision unit 42 may re-determine the communication frequency, for example, if the distance traveled by the vehicle 10 since the previous communication frequency was determined is equal to or greater than a predetermined distance.

Figure 12 is a flowchart showing a second example of the operation of the communication frequency determination device 40 according to this modified example. Figure 12 shows another example in which the communication frequency is updated at predetermined intervals.

As shown in FIG. 12, when it is transmission timing (Yes in S103), the determination unit 42 determines whether a predetermined time has passed since the last time the communication frequency was updated (S601). When the predetermined time has passed (Yes in S601), the determination unit 42 generates communication data including communication frequency information indicating the communication frequency determined in step S102 (S104). In this case, the communication frequency will be changed from the next period.

If the predetermined time has not elapsed (No in S601), the determination unit 42 proceeds to step S105. In other words, if the predetermined time has not elapsed, the communication frequency information indicating the communication frequency determined in step S102 is not included in the communication data transmitted in step S105. In this case, communication data is also transmitted in the next period using the communication frequency of the current period.

This allows the communication frequency to be changed every time a specified time elapses, reducing the processing burden of communication data generation on the determination unit 42.

The predetermined times shown in FIG. 11 and FIG. 12 are set in advance and stored in a storage unit (not shown). The predetermined time is, for example, a time that is long enough to include multiple transmission timings. The predetermined time may be, for example, several minutes or several tens of minutes. The predetermined time may also be set, for example, for each region.

Figure 13 is a flowchart showing a third example of the operation of the communication frequency determination device 40 according to this modified example. Figure 13 shows an example in which the communication frequency is updated when the amount of change in the communication frequency is large.

As shown in FIG. 13, when it is transmission timing (Yes in S103), the determination unit 42 determines whether the amount of change in communication frequency is equal to or greater than a threshold (S701). The determination unit 42 performs the determination in step S701, for example, based on whether the amount of change in communication frequency determined in step S102 relative to the communication frequency in the current period (the communication frequency determined in the period before the current period) is equal to or greater than a threshold.

If the amount of change is equal to or greater than the threshold (Yes in S701), the determination unit 42 generates communication data including communication frequency information indicating the communication frequency determined in step S102 (S104). In this case, the communication frequency is changed from the next period. If the amount of change is less than the threshold (No in S701), the determination unit 42 proceeds to step S105. In other words, if the amount of change is less than the threshold, the communication frequency information indicating the communication frequency determined in step S102 is not included in the communication data transmitted in step S105. In this case, communication data is transmitted in the next period using the communication frequency of the current period as well.

This allows changes in communication frequency to be limited to only when the change in communication frequency is equal to or greater than a threshold, thereby reducing the processing burden of communication data generation on the decision unit 42.

(Embodiment 2)
Hereinafter, a communication system according to the present embodiment will be described with reference to the drawings.

[2-1. Configuration of communication system]
First, the configuration of the communication system according to the present embodiment will be described with reference to Fig. 14. Fig. 14 is a block diagram showing the functional configuration of a communication frequency determination device 40a according to the present embodiment. Note that the following description will focus on the differences from the communication frequency determination device 40 according to embodiment 1, and the same reference numerals will be used to designate configurations that are the same as or similar to the communication frequency determination device 40 according to embodiment 1, and descriptions thereof will be omitted or simplified. Note that the configuration of the communication system is the same as that of embodiment 1, and descriptions thereof will be omitted.

As shown in FIG. 14, the communication frequency determination device 40a includes a memory unit 44 in addition to the communication frequency determination device 40 according to embodiment 1.

The memory unit 44 stores the vehicle states acquired in the past. The memory unit 44 stores, for example, the vehicle states at multiple points in time in the past. The memory unit 44 may store, for example, multiple vehicle states acquired within a predetermined time from the present time, or may store a predetermined number of vehicle states. The memory unit 44 may be realized by a semiconductor memory or the like, but is not limited to this.

The determination unit 42 determines the communication frequency for the next period based on the vehicle state acquired in the current period, the vehicle state acquired in the past, and the determination criterion information. For example, the determination unit 42 calculates a first communication frequency based on the vehicle state for the current period based on the vehicle state for the current period and a table (for example, the table shown in FIG. 4, which is an example of the determination criterion information), and calculates a second communication frequency based on the past vehicle state based on the past vehicle state and a table (for example, the table shown in FIG. 4, which is an example of the determination criterion information). Then, the determination unit 42 determines the communication frequency for the next period based on the first communication frequency and the second communication frequency. For example, the determination unit 42 may determine the communication frequency for the next period by performing a predetermined calculation using the first communication frequency and the second communication frequency. For example, the determination unit 42 may determine the average value of the first communication frequency and the second communication frequency as the communication frequency for the next period. The average value may be calculated by, for example, taking a weighted average of the first communication frequency and the second communication frequency.

The past vehicle state may include the vehicle state at each of multiple past points in time. In other words, the second communication frequency may include the communication frequency at each of multiple past points in time.

The determination of the communication frequency is not limited to the above, and the determination unit 42 may, for example, determine the communication frequency for the next period using a table in which the vehicle state for the current period and past vehicle states are associated with the communication frequency, or may determine the communication frequency for the next period to be the output (communication frequency) obtained by inputting the vehicle state for the current period and past vehicle states into a learned machine learning model (an example of decision criteria information).

[2-2. Operation of the communication frequency determination device]
Next, the operation of the communication frequency determination device 40a will be described with reference to Fig. 15. Fig. 15 is a flowchart showing the operation of the communication frequency determination device 40a according to the present embodiment.

As shown in FIG. 15, the acquisition unit 41 of the communication frequency determination device 40a acquires the current vehicle state from various sensors mounted on the vehicle 10 (S101). The acquisition unit 41 outputs the acquired vehicle state to the determination unit 42. Note that step S101 is the same process as step S101 in FIG. 5, but to clarify the difference with step S801, it is written as "acquire current vehicle state" in FIG. 15.

Next, the determination unit 42 acquires the past vehicle state (S801). The determination unit 42 acquires the past vehicle state by reading it from the memory unit 44.

Next, the determination unit 42 determines the communication frequency for the period after the current time based on the current vehicle state and the past vehicle state (S802). The determination unit 42 determines the communication frequency for the next period, for example, as the average value of the communication frequency based on the current vehicle state and the communication frequency based on the past vehicle state.

As a result, when the determination unit 42 determines the communication frequency based on the vehicle state, which may change depending on road conditions such as the speed of the vehicle 10 (presence or absence of traffic lights and congestion, etc.), the determination unit 42 also takes into account the past vehicle state when determining the communication frequency, thereby making it possible to determine a more appropriate communication frequency.

Note that the processing in steps S103 to S105 is similar to steps S103 to S105 in FIG. 5, and so a description thereof will be omitted.

(Modification of the second embodiment)
The communication system according to this modification will be described below with reference to Fig. 16. Fig. 16 is a flowchart showing the operation of the communication frequency determination device 40a according to this modification. Note that the configuration of the communication system according to this modification may be the same as the configuration of the communication system according to the second embodiment, and the following description will be given using the reference numerals of the components in the communication system according to the second embodiment. Also, in Fig. 16, the same operations as those in Fig. 15 are given the same reference numerals, and the description will be omitted or simplified.

As shown in FIG. 16, when it is transmission timing (Yes in S103), the determination unit 42 of the communication frequency determination device 40a generates communication data including communication frequency information and communication reason information (S901).

In this way, even when the determination unit 42 determines the communication frequency using past vehicle conditions, the determination unit 42 may include communication reason information in the communication data.

Other Embodiments
Although the communication system according to one or more aspects has been described based on the embodiment, the present disclosure is not limited to the embodiment. As long as it does not deviate from the spirit of the present disclosure, various modifications conceived by a person skilled in the art to the present embodiment and forms constructed by combining components in different embodiments may also be included in the present disclosure.

For example, in the above embodiment and the like, an example has been described in which the moving body is a vehicle, but this is not limiting. The moving body may be a moving body other than a vehicle as long as it is movable and capable of communicating with the server via wireless communication, and may be, for example, an air vehicle such as a drone, a ship, or a train.

In addition, in the above embodiment, the communication between the vehicle and the server is described as being regular communication, but this is not limited to this, and the communication may be communication whose frequency changes, or communication that is not performed when certain conditions are met, etc.

In addition, in the above embodiment 2, an example was described in which the communication frequency determination device includes a memory unit, but the memory unit may also be included in the vehicle.

The division of functional blocks in the block diagram is one example, and multiple functional blocks may be realized as one functional block, one functional block may be divided into multiple blocks, or some functions may be transferred to other functional blocks. Furthermore, the functions of multiple functional blocks having similar functions may be processed in parallel or in a time-shared manner by a single piece of hardware or software.

The order in which each step in the flowchart is performed is merely an example to specifically explain the present disclosure, and orders other than those described above may also be used. Some of the steps may also be performed simultaneously (in parallel) with other steps.

In addition, some or all of the components of each processing unit of the communication frequency determination device in the above embodiment may be configured from a single system LSI (Large Scale Integration).

A system LSI is an ultra-multifunctional LSI manufactured by integrating multiple processing units on a single chip, and is specifically a computer system that includes a microprocessor, a ROM (Read Only Memory), a RAM (Random Access Memory), etc. Computer programs are stored in the ROM. The system LSI achieves its functions when the microprocessor operates according to the computer program. Note that all or part of the various processes described above may be realized by hardware such as electronic circuits.

An aspect of the present disclosure may be a computer program that causes a computer to execute each of the characteristic steps included in the transmission frequency determination method (an example of a communication processing method) of the transmission frequency determination device.An aspect of the present disclosure may be a computer-readable non-transitory recording medium on which such a program is recorded. For example, such a program may be recorded on a recording medium and distributed or circulated. For example, the distributed program may be installed in a device having another processor and the program may be executed by the processor, thereby causing the device to perform each of the above processes.

This disclosure is useful for mobile objects that communicate periodically with external devices via a communication network.

1 Communication system 10 Vehicle (mobile body)
20 Base station 30 Server (external device)
40, 40a Communication frequency determination device (communication processing device)
41 Acquisition unit 42 Determination unit 43 Communication unit (transmission unit)
44 Memory unit

Claims (16)

An acquisition unit that acquires moving object information indicating a state of the moving object;
a determination unit that determines a communication frequency in communication between the mobile body and an external device based on the mobile body information and determination criterion information indicating a determination criterion in communication between the mobile body and an external device of the mobile body ;
The mobile object information includes at least one of information regarding a cyber attack on the mobile object and information regarding a failure of equipment mounted on the mobile object,
The information regarding the cyber attack includes at least one of communication connection information indicating a state of a wireless communication connection of the mobile body and a travel time from the start of travel of the mobile body.
Communications processing device. An acquisition unit that acquires moving object information indicating a state of the moving object;
a determination unit that determines a communication frequency in communication between the mobile body and an external device based on the mobile body information and determination criterion information indicating a determination criterion in communication between the mobile body and an external device of the mobile body;
The mobile object information includes at least one of information regarding a cyber attack on the mobile object and information regarding a failure of equipment mounted on the mobile object.
Communications processing device. An acquisition unit that acquires moving object information indicating a state of the moving object;
a determination unit that determines a communication frequency in communication between the mobile body and an external device based on the mobile body information and determination criterion information indicating a determination criterion in communication between the mobile body and an external device of the mobile body;
the determination criterion information includes correspondence relationship information for linking the mobile object information with the communication frequency in the communication,
The determination unit determines the communication frequency in the communication based on the mobile object information and the correspondence relationship information ;
The mobile object information includes information regarding a cyber attack on the mobile object,
The information regarding the cyber attack includes at least one of communication connection information indicating a state of a wireless communication connection of the mobile body and a travel time from the start of travel of the mobile body.
Communications processing device. An acquisition unit that acquires moving object information indicating a state of the moving object;
a determination unit that determines a communication frequency in communication between the mobile body and an external device based on the mobile body information and determination criterion information indicating a determination criterion in communication between the mobile body and an external device of the mobile body;
the decision criterion information includes a decision model for determining the communication frequency in the communication from the mobile object information, the decision criterion information having been generated in advance by machine learning;
The determination unit determines the communication frequency of the communication based on the mobile object information and the determination model; and
The mobile object information includes information regarding a cyber attack on the mobile object,
The information regarding the cyber attack includes at least one of communication connection information indicating a state of a wireless communication connection of the mobile body and a travel time from the start of travel of the mobile body.
Communications processing device. The mobile information includes information regarding a communication state,
A communication processing device as claimed in any one of claims 1 to 4, wherein the information regarding the communication status includes at least one of the speed of the moving body, the position of the moving body, the radio wave strength of wireless communication with the external device , and the communication status with other moving bodies in the vicinity of the moving body. An acquisition unit that acquires moving object information indicating a state of the moving object;
a determination unit that determines a communication frequency in communication between the mobile body and an external device based on the mobile body information and determination criterion information indicating a determination criterion in communication between the mobile body and an external device of the mobile body;
the mobile object information includes information regarding a malfunction of equipment mounted on the mobile object,
The information about the failure includes at least one of an acceleration of the moving object and a moving time of the moving object.
Communications processing device. The communication processing device according to any one of claims 1 to 6, wherein the determination unit determines whether the mobile body will be in a state where communication with the external device is not possible, and if it determines that the mobile body will be in a state where communication is not possible, determines the communication frequency to be immediate transmission. The communication processing device according to any one of claims 1 to 7, wherein the determination unit determines the communication frequency in the first period based on a first communication frequency in a second period following the first period determined based on the mobile body information acquired in the first period, and a second communication frequency in the first period determined based on the mobile body information acquired in a third period before the first period. The communication processing device according to claim 8 , wherein the determination unit determines one of the first communication frequency and the second communication frequency, whichever is higher, as the communication frequency for the first period. Further, a storage unit is provided for storing the previously acquired moving body information,
The communication processing device according to claim 1 , wherein the determination unit determines the communication frequency based on the mobile object information acquired in the past. The communication processing device according to claim 1 , wherein the communication processing device is mounted on the moving object. a transmission unit configured to transmit communication data of the communication to the external device based on the communication frequency determined by the determination unit,
The communication processing device according to claim 11 , wherein the communication data includes at least one of communication frequency information indicating the communication frequency determined by the determination unit and information regarding a next communication. The communication processing device according to claim 12 , wherein the communication data further includes information indicating at least one of a reason for determining the communication frequency determined by the determination unit and a reason for determining the information regarding the next communication. The communication processing device according to claim 13 , wherein the reason for determining the communication frequency includes information indicating that the mobile object becomes unable to communicate with the external device, or that the mobile object has recovered from an inability to communicate state. The communication processing device according to claim 1 , wherein the communication processing device is mounted on the external device. Acquire mobile object information indicating a state of the mobile object;
determining a communication frequency in communication between the mobile body and an external device based on the mobile body information and decision criterion information indicating a decision criterion in communication between the mobile body and an external device of the mobile body ;
The mobile object information includes at least one of information regarding a cyber attack on the mobile object and information regarding a failure of equipment mounted on the mobile object,
The information regarding the cyber attack includes at least one of communication connection information indicating a state of a wireless communication connection of the mobile body and a travel time from the start of travel of the mobile body.
Communication processing method.

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